production - Global Aquaculture Alliance

Transcription

january/february 2014
the
It’s Our People...
global aquaculture
The Global Magazine for Farmed Seafood
January/February 2009
DEPARTMENTS
From The President
From The Editor
GAA Activities
Industry News
GAA Calendar
Advocate Advertisers
11 Tilapia Could Enhance Water Conditions,
Help Control EMS In Shrimp Ponds
Loc H. Tran, Ph.D.; Kevin M. Fitzsimmons, Ph.D.;
Donald V. Lightner, Ph.D.
13 Feed Additives Based On Quorum Sensing Disruption
Could Aid Fight Against EMS/AHPN
Peter Coutteau, Ph.D.; Tim Goossens, Ph.D.
Gregory
Outbound Specialist
Perth Amboy, New Jersey
20 Years of Service
15 Hepatopancreas Colors Related To Vibrios Predict
Survival Of Shrimp To EMS
Dr. Chalor Limsuwan, Dr. Niti Churchird,
On the cover:
Although disease problems have greatly reduced shrimp harvests
in some areas, shifts in global production are keeping the popular
crustaceans coming.
Dr. Natthineee Munkong Wongsiri, Dr. Carlos A. Ching
18 What To Do About EMS/AHPN?
Page 13
Stephen G. Newman, Ph.D.
Quorum Sensing
Disruption Via Feed
22 Biofloc Trial Results In Fast Shrimp Growth,
Low FCR, High Survival
Synergistic blends of natural
antimicrobial compounds added
to aquafeed can interrupt bacterial quorum sensing signaling in
shrimp aquaculture pathogens.
Andrew J. Ray, Ph.D.; Jeffrey M. Lotz, Ph.D.
24 Intensive Farm In Bali, Indonesia, Produces Shrimp
In Biofloc System
Nyan Taw, Ph.D.; Surijo Setio
26 The Bottom Line
Hyper-Intensive Nursery Systems Offer
Advantages For Shrimp Culture
Neil Gervais; Thomas R. Zeigler, Ph.D.
30 Inbreeding Cuts Growth, Reproduction In Shrimp
That Defines Our Brand
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global aquaculture
advocate
Claude E. Boyd, Ph.D.
Page 60
New Intensive Fish
Pond Culture
An in-pond raceway system has
been successfully demonstrated
to increase efficiency and yield
greater production at lower perunit cost.
38 More Tilapia, Higher Profit?
Yitzhak Simon
42 Fishmeal-Free Feeds For Hybrid Tilapia
Nathan Gur, Guy Rubinstein
44 Seabass Hatchery Feeds Artemia Substitute
To Increase Production Stability
Eamonn O’Brien
46 Ecuador Sets Legal Framework For Offshore
Fish Farm Development
We Get It Done!
ii
TIRELESS
Brad J. Argue, Ph.D.; Geovanni Tolentino; J. A. Brock, DVM
34 Sustainable Aquaculture Practices
Nitrite Toxicity Affected By Species Susceptibilty,
Environmental Conditions
Our people will accommodate any special request.
Providing peace-of-mind through dependable service on time, every time...
For more information about PFS, please contact:
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One Main Street
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[email protected]
Phone: 973-820-4044
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Xavier Romero, M.S.
48 Hybrid, Channel Catfish Show Similar Immune
Responses To Ich Parasite
De-Hai Xu, Ph.D.; Phillip Klesius, Ph.D.
60 New Intensive Pond Aquaculture Technology
Demonstrated In China
Michael Cremer, Ph.D.; Jesse Chappell, Ph.D.; Zhang Jian;
Zhou Enhua
64 Aquaculturing Engineering
Unit Processes In RAS Systems
Thomas M. Losordo, Ph.D.
68 Advances In Intensive Copepod Production Technology
M. Dean Kline; Chatham K. Callan, Ph.D.; Charles W. Laidley, Ph.D.
72 Automatic Submersible Fish Cage Systems
Counter Weather, Other Surface Problems
Taeho Kim, Ph.D.
50 Seafood and Health
New Year Wishes For Health And Seafood
Roy D. Palmer, FAICD
74 Data-Driven Management Technology
Can Transform Aquaculture
Diogo Thomaz, MBA, Ph.D.; Stella Adamidou, Ph.D.
52 Food Safety And Technology
Lipid Oxidation Results From Heme Catalysis
George J. Flick, Jr., Ph.D.; David D. Kuhn, Ph.D.
76 Simple Soil Solution Removes Egg Adhesive
To Enhance Carp Seed Production
Prof. N. R. Chattopadhyay
56 U.S. Seafood Markets
Paul Brown, Jr.; Janice Brown; Angel Rubio
77 Sustainable Grouper Farming
Huey-Lang Yang, Ph.D.; Han-You Lin, Ph.D.; Chi-Chu Lin
80 PTC Ceramic Chips Improve Safety, Reliability
Of Electric Immersion Heaters
Christine Venaleck, Ed Dulzer
global aquaculture advocate
1
from the president
GLOBAL AQUACULTURE
ALLIANCE
The Global Aquaculture Alliance is an international non-profit, non-governmental
association whose mission is to further envi
ronmentally responsible aquaculture to meet
world food needs. Our members are producers, processors, marketers and retailers of seafood products worldwide. All aquaculturists
in all sectors are welcome in the organization.
OFFICERS
George Chamberlain, President
Bill Herzig, Vice President
Lee Bloom, Secretary
Jim Heerin, Treasurer
Iain Shone, Assistant Treasurer
Jeff Fort, Chief Financial Officer
Wally Stevens, Executive Director
BOARD OF DIRECTORS
Bert Bachmann
Lee Bloom
Rittirong Boonmechote
Rafael Bru
George Chamberlain
Shah Faiez
Jeff Fort
John Galiher
Jim Heerin
Bill Herzig
Ray Jones
Alex Ko
Jordan Mazzetta
Robins McIntosh
Sergio Nates
John Peppel
John Schramm
Jeff Sedacca
Iain Shone
Wally Stevens
RELATIONSHIP MANAGER
Sally Krueger
[email protected]
EDITOR
Darryl Jory
[email protected]
PRODUCTION STAFF
Assistant Editor
David Wolfe
[email protected]
Graphic Designer
Lorraine Jennemann
[email protected]
HOME OFFICE
4111 Telegraph Road, Suite 302
St. Louis, Missouri 63129 USA
Telephone: +1-314-293-5500
FAX: +1-314-293-5525
E-mail: [email protected]
Website: http://www.gaalliance.org
All contents copyright © 2014
Global Aquaculture Alliance.
Global Aquaculture Advocate
is printed in the USA.
ISSN 1540-8906
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from the editor
Building Upon
Our Roots
New Year:
Leadership Needed
About a week before this writing, hundreds of
participants from around the world joined a GAA
webinar on early mortality syndrome in shrimp that
featured research conducted by the Responsible
Aquaculture Foundation (RAF) in collaboration
George
with the World Bank. How did RAF become such
Chamberlain, Ph.D.
a credible voice in support of the industry?
President
The story began in 1997 with the formation of
Global Aquaculture Alliance
[email protected]
GAA during a time of crisis within the aquaculture
industry. Recall the following quote from the trade
press at the time: “The initiative [GAA] comes not
a moment too soon. Under attack by environmental activists, battling epidemic viral
disease, faced with the question of sustainability and increasingly burdened by legislative demands, aquaculture is rapidly reaching a crisis point. The industry is in dire and
urgent need of effective advocacy and united representation.”
During the next few years, GAA’s primary functions were research and education. It
gathered the facts and took science-based positions on critical issues such as mangrove
conservation, fishmeal utilization, antibiotic residues and international trade – see www.
gaalliance.org/newsroom/whitepapers.php. With each issue, best management practices
were gradually identified, and GAA began to evolve toward its future role of developing
the Best Aquaculture Practices standards and certification program.
As the BAP program gained traction, the early emphasis on research and education
receded. A mechanism was needed to reinforce these important pillars of responsible
aquaculture. It was also clear that the efforts should be broad and all-encompassing –
not targeted toward any single organization or certification program. To assure multistakeholder participation and support, an independent non-profit organization, the
Responsible Aquaculture Foundation, was established in 2010.
Given the importance of disease as the primary factor limiting the growth of aquaculture, RAF began by engaging in a collaborative project with the World Bank entitled
Lessons Learned in Aquaculture Disease Management. This involved missions to Chile
in 2011, Vietnam in 2012, and Mozambique and Madagascar in 2013 to investigate outbreaks of infectious salmon anemia, early mortality syndrome in shrimp, and white spot
syndrome in shrimp, respectively. These studies identified common lessons in disease
management that may ultimately lead to improved policies such as zone management.
Now, RAF is embarking on another important initiative in collaboration with the
World Bank’s Global Food Safety Partnership. This will involve establishing an online
education platform in aquaculture food safety beginning in Malaysia in 2014 and
expanding to Vietnam and other countries thereafter. Imagine the potential of an online
program to cost effectively deliver information to aquaculture technicians around the
world! Once the food safety platform is established, the content can be expanded to
include many other facets of aquaculture education and outreach. For example, information on disease management could be made available in logical educational modules.
Perhaps the most encouraging news for the future of RAF is the recent announcement by GAA Executive Director Wally Stevens that he plans to transition his leadership role from GAA to RAF in the coming months to pursue his passion in education
and training. Given his history of strategic leadership of GAA, this move portends
great strides in the further development of RAF for the benefit of sustainable aquaculture research and education.
As we start another year, the Global Aquaculture
Alliance wants to make it the best ever for the Global
Aquaculture Advocate magazine by continuing to
improve on coverage of the dynamic farmed seafood
industry. With the continued support of our adverDarryl E. Jory, Ph.D.
tisers, subscribers and editorial contributors, we shall
Editor, Development Manager
Global Aquaculture Advocate
meet this challenge and thus look forward with [email protected]
mism to another challenging and rewarding year.
The content of our magazine continues to strongly
support GAA’s mission to feed the world through
responsible aquaculture. As GAA’s flagship publication, the Advocate focuses attention on
the Best Aquaculture Practices program and the increasing number of BAP-certified
facilities around the world, on new technologies and developments that improve production efficiency and sustainability, on seafood safety and quality, and on expanded sustainability in the marketplace. GAA believes we have a great story to tell the world about
aquaculture, and the Advocate is a key venue through which to tell that story.
As stated before, GAA’s position is that the sustainable expansion of the aquaculture
industry faces major challenges in five main areas: health and disease management,
feeds and ingredients, environmental and social accountability, investment capital and
market support. Of these, the first has probably been the most important one for the
last 25 years or so.
Aquatic animal diseases caused by bacteria, viruses, parasites, fungi and other pathogens continue to have impacts as our industry expands to meet the challenge of
increased production. Many factors contribute to aquatic disease emergence, including
production intensification, increased introductions of species and global trade in live
animals and their products, improper application of biosecurity measures and others.
Diseases have cost the global aquaculture industry billions of dollars during the last
25 years. Disease issues are often cited as a major concern by investors potentially interested in becoming involved with our industry.
At GAA’s GOAL 2013 meeting in Paris, GAA Executive Director Wally Stevens
added a sixth challenge, leadership, to the five mentioned above. I would like to challenge aquaculture leaders regarding what we are doing to effectively address disease
management.
Are we investing enough resources to effectively deal with health management issues
affecting farmed production of the major aquatic species? Are we adequately supporting
research? Are we really providing an investment-ready environment for potential investors in which disease has been adequately addressed?
Our industry has many valuable business “assets,” including vision, drive, experience
and entrepreneurship. But we need leaders to step up and become the catalysts that pull
together all these assets and make them work together toward effective solutions to our
challenges.
I believe in our industry. Aquaculture continues to be the fastest-growing food-producing sector globally, despite its challenges. We hope that in 2014 and beyond you
will, as was the theme of GOAL 2013, join us in our journey toward increased growth
with responsibility and sustainability.
I look forward to your input and feedback to help us improve our magazine and support GAA’s mission and vision. We appreciate your continuing support to make 2014
our best year together.
Sincerely,
Sincerely,
George Chamberlain
Darryl E. Jory
FOUNDING MEMBERS
Agribrands International Inc.
Agromarina de Panamá, S.A.
Alicorp SAA – Nicovita
Aqualma – Unima Group
Aquatec/Camanor
Asociación Nacional de Acuicultores de Colombia
Asociación Nacional de Acuicultores de Honduras
Associação Brasileira de Criadores de Camarão
Bangladesh Chapter – Global Aquaculture Alliance
Belize Aquaculture, Ltd.
Bluepoints Co., Inc.
Cámara Nacional de Acuacultura
Camaronera de Coclé, S.A.
Cargill Animal Nutrition
Chicken of the Sea Frozen Foods
Continental Grain Co.
C.P. Aquaculture Business Group
Darden Restaurants
Deli Group, Ecuador
Deli Group, Honduras
Delta Blue Aquaculture
Diamante del Mar S.A.
Eastern Fish Co.
El Rosario, S.A.
Empacadora Nacional, C.A.
Expack Seafood, Inc.
Expalsa – Exportadora de Alimentos S.A.
FCE Agricultural Research and Management, Inc.
High Liner Foods
India Chapter – Global Aquaculture Alliance
Indian Ocean Aquaculture Group
INVE Aquaculture, N.V.
King & Prince Seafood Corp.
Long John Silver’s, Inc.
Lyons Seafoods Ltd.
Maritech S.A. de C.V.
Meridian Aquatic Technology Systems, LLC
Monsanto
Morrison International, S.A.
National Fish & Seafood Co./
Lu-Mar Lobster & Shrimp Co.
National Food Institute
National Prawn Co.
Ocean Garden Products, Inc.
Overseas Seafood Operations, SAM
Pescanova USA
Preferred Freezer Services
Productora Semillal, S.A.
Red Chamber Co.
Rich-SeaPak Corp.
Sahlman Seafoods of Nicaragua, S.A.
Sanders Brine Shrimp Co., L.C.
Sea Farms Group
Seprofin Mexico
Shrimp News International
Sociedad Nacional de Galápagos
Standard Seafood de Venezuela C.A.
Super Shrimp Group
Tampa Maid Foods, Inc.
U.S. Foodservice
Zeigler Brothers, Inc.
3
Join the world’s leading
aquaculture organization
Aquaculture is the future of the world’s seafood supply.
Be part of it by joining the Global Aquaculture Alliance,
the leading standards-setting organization for farmed
seafood.
Access science-based information on efficient aquaculture management. Connect with other responsible
companies and reach your social responsibility goals.
Improve sales by adopting GAA’s Best Aquaculture
Practices certification for aquaculture facilities.
Annual dues start at U.S. $150 and include a subscription to the Global Aquaculture Advocate magazine,
GAA e-newsletters, event discounts and other benefits.
Visit www.gaalliance.org or contact the GAA office
for details.
Feeding the World Through Responsible Aquaculture
St. Louis, Missouri, USA – www.gaalliance.org – +1-314-293-5500
GOVERNING MEMBERS
Alicorp S.A. – Nicovita
Alltech
Aqua Bounty Technologies
Blue Archipelago Berhad
Capitol Risk Concepts, Ltd.
Cargill Animal Nutrition
Chang International Inc
Charoen Pokphand Foods PCL
Darden Restaurants
Delta Blue Aquaculture LLC
Diversified Business Communications
Eastern Fish Co., Inc.
Ever Nexus Sdn. Bhd.
Grobest USA, Inc.
High Liner Foods
Integrated Aquaculture International
International Associates Corp.
INVE B.V.
King & Prince Seafood Corp.
Lyons Seafood Ltd.
Maloney Seafood Corp.
Marine Technologies
Mazzetta Co. LLC
Megasupply
Morey’s Seafood International
National Fish & Seafood Inc.
Novus International
Pentair Aquatic Eco-Systems
Pescanova USA
Red Chamber Co.
Rich Products Corp.
Sahlman Seafoods of Nicaragua, S.A.
Sea Port Products Corp.
Seafood Exchange of Florida
Seajoy
Thai Union Group
Tropical Aquaculture Products, Inc.
Urner Barry Publications, Inc.
Wuhan Liangzhongxing Supply Chain
Management Co., Ltd.
Zeigler Brothers, Inc.
4
SUSTAINING MEMBERS
Akin Gump Strauss Hauer & Feld
Ammon International, Inc.
Anova Food Inc.
Aqua Star
Aquatec Industrial Pecuaria Ltda.
A.Z. Gems Inc.
BioMar Group
Blue Ridge Aquaculture
Camanchaca Inc.
Channel Fish Processing Co., Inc.
Direct Source Seafood
DNI Group, LLC
DSM Nutritional Products
Fega Marikultura P.T.
Fortune Fish Co.
Gorton’s Seafood
Great American Seafood Imports Co.
H & N Foods International, Inc./Expack
Hai Yang International, LLC
Harbor Seafood, Inc.
Harvest Select
International Marketing Specialists
iPura Food Distribution Co.
Mahalo Seafood LLC
Maritime Products International
Merck Animal Health
Mirasco, Inc.
North Coast Seafoods
Odyssey Enterprises, Inc.
Orca Bay Seafoods
Ore-Cal Corp.
PSC Enterprise LLC
Quirch Foods
Rubicon Resources
Seacore Seafood, Inc.
Seafood Industry Development Corp.
Seattle Fish Co.
Seattle Fish Co. of New Mexico
Seattle Shrimp & Seafood Co., Inc.
Slade Gorton & Co., Inc.
Solae, LLC
Star Agro Marine Exports Ltd.
Tampa Bay Fisheries, Inc.
Tampa Maid Foods
The Fishin’ Co.
The Great Fish Co.
United Seafood Enterprises, L.P.
ASSOCIATION MEMBERS
All China Federation of Industry
and Commerce Aquatic Production
Chamber of Commerce
American Feed Industry Association
Asociación Latino Americana
de Plantas de Rendimiento
Associação Brasileira de Criadores
de Camarão
Australian Prawn Farmers Association
Bangladesh Shrimp and Fish Foundation
China Aquatic Products Processing
and Marketing Association
Fats and Proteins Research
Foundation, Inc.
Indiana Soybean Alliance
Indonesian Aquaculture Society
International Fishmeal and
Fish Oil Organisation
Malaysian Shrimp
Industry Association
Marine Products Export
Development Authority
National Fisheries Institute
National Renderers Association
Oceanic Institute
Prince Edward Island Seafood
Processors Association
SalmonChile
Salmon of the Americas
Seafood Importers
and Processors Alliance
Soy Aquaculture Alliance
Thai Frozen Foods Association
Universidad Austral de Chile
U.S. Soybean Export Council
Washington Fish Growers Association
Washington State China Relations Council
World Aquaculture Society
World Renderers Organization
5
gaa activities
GAA’s EMS Webinar Draws 600 Registrants
Continued Progress
The webinar originated from Vietnam, where Donald Lightner
(left), Loc Tran, George Chamberlain and Steven Hedlund took
questions on EMS and its impacts.
The Global Aquaculture Alliance held its first-ever webinar,
titled “Early Mortality Syndrome In Shrimp: Managing ‘The
Perfect Killer,’” on December 10, 2013.
The free 60-minute webinar addressed efforts to better
understand and manage the disease and its impacts on shrimp
supplies. It featured GAA President George Chamberlain,
renowned University of Arizona shrimp pathologist Dr. Donald
Lightner and Dr. Loc Tran, also of the University of Arizona’s
Aquaculture Pathology Laboratory.
Six hundred seafood professionals from around the globe
registered for the webinar. Roughly half participated during the
live event. Attendees ranged from biologists and farm managers
to retail and foodservice buyers.
Based at the Sheraton Saigon Hotel and Towers in Ho Chi
Minh City, Vietnam, at the start of Asia-Pacific Aquaculture
2013, the webinar allowed attendees to ask Chamberlain, Lightner and Loc EMS-related questions as a follow-up to the presentations delivered at GAA’s GOAL 2013 conference.
Much progress has been made on EMS since May, when a
team led by Lightner identified the cause of EMS as a unique
strain of Vibrio parahaemolyticus that releases a potent toxin
inside shrimp. A polymerase chain reaction diagnostic test has
been developed, and multiple management solutions are being
implemented.
“There’s been a tremendous amount of progress in learning
about EMS,” Chamberlain said. “There’s progress in breeding,
there’s progress in hatchery management and pond management,
and there’s also likely to be [progress in] feed additives. This is
not a simple solution that will involve a single silver-bullet management method. The solution will involve a complex array of
management practices.”
Participant Questions
Chamberlain, Lightner and Loc fielded about 30 questions
solicited from attendees via e-mail. One attendee asked why
some countries such as Indonesia have so far escaped EMS,
while others have been hit hard by the disease.
“Our thought is that Indonesia has been very strong on the
importation of live animals, and live animals are one of the main
methods of transmitting the disease,” Chamberlain said.
Another attendee asked about the toxin responsible for the
hepatopancreas dysfunction caused by the pathogenic Vibrio and
the virulence genes involved in EMS.
“We don’t know what kind of toxin causes the dysfunction,
although we are working on that in my lab,” Lightner said. “At
least we know that there are no human marker genes. Two,
TDH and TRH, are marker genes for human virulence, but
those don’t occur in the EMS agent or any of the agents in my
collection.”
A few attendees inquired about the economic impacts of
EMS. Since 2009, EMS has caused global shrimp production to
fall 23% shy of expectations, which amounts to a loss of about
U.S. $5 billion, Chamberlain said.
BAP’s Peter Redmond Presents In Dubai
Peter Redmond talked about advancing responsible aquaculture
and the benefits of BAP certification.
The Global Aquaculture Alliance was among the organizations on hand at the SEAFEX 2013 exhibition to offer its sup-
6
port to a region that holds much potential in terms of seafood
consumption and aquaculture production growth.
Peter Redmond, vice president of business development for
GAA’s Best Aquaculture Practices (BAP) division, gave a presentation titled “Certification: Benefits Beyond Demands” as
part of the November 17 to 19 conference program in Dubai,
United Arab Emirates. He talked about GAA’s mission of
advancing responsible aquaculture and the benefits of BAP certification.
“The Middle East and North Africa region stands to be a
great resource for emerging production,” Redmond said. “We
hope to show that certification is a key to market entry and
responsible production.”
Roy Palmer, BAP market development manager for Australasia, also participated in the conference. Both Redmond and
Palmer walked the show floor, meeting with other organizations
and companies to promote the BAP program and responsible
aquaculture.
Saigon To Welcome GOAL 2014 In October
Following a site visit in December 2013, the Global Aquaculture Alliance finalized the venue and dates for the organization’s GOAL 2014 conference.
GOAL 2014 will be held at the Sheraton Saigon Hotel and
Towers in Ho Chi Minh City, Vietnam, from October 6 to 9,
2014. Located in downtown Ho Chi Minh City, the 470-room
hotel features 2,500 m2 of meeting space.
Registration for GOAL 2014 will open in early 2014. For
information on registration, including fees, please visit www.
gaalliance.org/GOAL2014/goal-registration.php.
An outline of the GOAL 2014 program will be available in
early 2014. Those interested in presenting at the event should
contact GAA Communications Manager Steven Hedlund at
[email protected].
Through GOAL, GAA strives to carry out its mission of
advancing responsible aquaculture by providing a venue at which
Wally Stevens To Lead
RAF Foundation
After seven years as executive
director of the Global Aquaculture
Alliance, Wally Stevens will be transitioning to a leadership role with the
Responsible Aquaculture Foundation
(RAF), a charitable organization
established with the assistance of
GAA to offer education and training
in responsible aquaculture.
Under Stevens, GAA has experiWally Stevens
enced unprecedented growth, evolving
into the world’s leading standards-setting organization for aquaculture
through the development of its Best Aquaculture Practices certification system. GAA also established itself as a leading voice for
responsible aquaculture through its various communications
vehicles, including the annual GOAL conference and Global
Aquaculture Advocate magazine.
“Like any organization, GAA should be judged for what it
stands, but of greater importance, for what it gets done,” Stevens
said. “We are a learning and teaching organization that advocates growing aquaculture production responsibly. I believe
GAA has and will continue to be a positive, science-based group
that will make a difference for aquaculture – not only where it
exists today, but also in countries around the world where there
are needs and opportunities.”
Stevens will continue to act as GAA executive director
through a transition period. Along with GAA President George
Chamberlain and Vice President Bill Herzig, he will seek a suitable replacement to recommend to the GAA board of directors.
Stevens will work with the new executive director and continue
to serve on the GAA board as he takes on leadership of RAF.
At RAF, Stevens will work to attract support for the education
of a new generation of leadership in the global aquaculture industry. Since its inception, RAF has undertaken projects with World
Bank support, including research on infectious salmon anemia in
Chile, early mortality syndrome in shrimp in Vietnam and white
leadership development, cooperation and education are encouraged.
It’s been nine years since GOAL was last held in Vietnam. At
that time, GOAL (Global Outlook for Aquaculture Leadership) was
called Global Shrimp Outlook and attracted about 450 attendees.
Vietnam’s aquaculture industry has grown significantly since
then. In 2012, the country exported U.S. $6.13 billion worth of
seafood, led by shrimp and Pangasius.
spot syndrome in shrimp in Mozambique and Madagascar.
Currently, RAF is finalizing a project with Dr. Steve Otwell
of the University of Florida involving food safety, working with
fish farmers and processors in Malaysia via online means.
“Education is in my DNA, as I suspect it is for most of us,”
Stevens said. “It is only through continual learning that individuals and enterprises have the greatest potential for success.”
Krueger GAA’s New
Relationship Manager
Sally Krueger has taken a new role
with the Global Aquaculture Alliance
as the organization’s relationship manager. In her new position, GAA’s former assistant director will focus on
maintaining existing relationships and
forging new relationships with GAA
members, GOAL sponsors and Global
Aquaculture Advocate advertisers.
Krueger is already well versed in
the
role, having previously managed
Sally Krueger
the organization’s membership renewal
and GOAL sponsorship campaigns.
She will coordinate advertising sales
for the Global Aquaculture Advocate magazine, a task previously
handled by the magazine manager. In addition, Krueger will continue to handle logistics for GAA’s annual GOAL conference,
which will take place in Ho Chi Minh City, Vietnam, in 2014.
Krueger had served as assistant director of GAA since March
2007, handling a number of responsibilities during a significant
growth period for GAA and the Best Aquaculture Practices thirdparty certification program.
In her advertising role, Krueger will distribute a redesigned
media kit for 2014. The new kit combines Advocate advertising
options with GOAL sponsorship and GAA membership opportunities. A PDF of the 2014 media kit is available on the GAA
website at www.gaalliance.org/cmsAdmin/uploads/mediakit2014emailsize.pdf.
Interested in advertising, sponsorship or membership opportunities with GAA? Contact Krueger at [email protected].
7
BAP Expansion Includes New Farms,
Plants, Feed Mills
Participation in the Best Aquaculture Practices (BAP) program continues to rise, as dozens of additional facilities earned a
spot on the list of certified aquaculture seafood operations over
the last few months. The new facilities include farms, plants and
feed mills – and operations that produce a range of seafood,
including shrimp, tilapia, catfish and mussels. The salmon and
tilapia sectors have seen the greatest level of BAP activity.
EWOS Canada Ltd.’s Surrey, British Columbia, feed mill
obtained BAP certification in late October 2013, allowing
Mainstream Canada and Skuna Bay Salmon to join the list of
suppliers that offer three-star salmon. EWOS is the exclusive
provider of feed to both companies.
Walcan Seafood, which processes Skuna Bay salmon, earned
BAP certification for its Quadra Island, British Columbia, Canada, processing plant in July 2013, joining Skuna Bay ’s 11 BAPcertified farms, which are owned and operated by Grieg Seafood
B.C. Ltd.
Owned by Cermaq ASA, Mainstream
Canada was British Columbia’s first
salmon supplier to offer two-star salmon
in December 2012. Mainstream Canada’s
Brent Island farm in British Columbia was the world’s first
salmon farm to receive BAP certification in December 2011.
Heartland Catfish Co., the United States’ largest catfishfarming and processing company, has attained BAP certification
for its processing plant in Itta Bena, Mississippi. The company’s
Greensboro, Alabama, plant, which has been repurposed into a
repacking plant, is also BAP-certified.
Heartland Catfish processes 27,215 to 34,000 mt of live catfish yearly from farms located in Mississippi, Alabama and
Arkansas. The vertically integrated company’s fresh, frozen,
breaded and marinated catfish products are marketed to retail
and foodservice customers across the United States.
Table 1. Additional recent BAP certifications around the world.
Facility
Location
Country
Species
British Columbia
Canada
Salmon
Farms
Mainstream Canada (4 farms)
Marine Harvest Canada Inc. (3 farms)
Northern Harvest Sea Farms (4 farms)
Canada
Salmon
St. Alban’s, Newfoundland and Labrador
Canada
Salmon
Region de los Lagos
Chile
Salmon
Salmones Camanchaca, S.A.(2 farms)
Salmones Cupquelan S.A. (3 farms)
Kalyan Aqua & Marine Exports India Pvt. Ltd.
Vo Hong Ngoans Farm
Puerto Montt, Llanguihue
Chile
Salmon
Prakasam District, Andhra Pradesh
India
Shrimp
Bac Lieu City, Bac Lieu Province
Vietnam
Shrimp
Hainan Haina Tilapia Breeding Base
Wenchang, Hainan Province
China
Tilapia
Hainan New Ocean Fisheries Farm
Haikou, Hainan Province
China
Tilapia
Lingao Golden Spring Aquaculture Co. Ltd.
Haikou, Hainan Province
China
Tilapia
Pematang Siantar, Sumatera Utara
Indonesia
Tilapia
Quellon, Chiloe
Chile
Salmon
P.T. Artha Lautan Mulya
Processing Plants
Salmones Pacific Star S.A.
Ananda Enterprises India Pvt. Ltd.
West Godavari District, Andhra Pradesh
India
Shrimp
P.T. Satu Tiga Enam Delapan
Banyuwangi, East Java
Indonesia
Shrimp
Leizhou, Guangdong Province
China
Tilapia
Banbueng, Chonburi
Thailand
Bongtorat, Muang, Samutsakorn
Thailand
Leizhou Zhulian Frozen Food Co., Ltd.
Feed Mills
Charoen Pokphand Foods Public Co., Ltd. – Banbueng
Charoen Pokphand Foods Public Co., Ltd. – MHC
Search The Past – Free!
Access thousands of articles from the Global Aquaculture
Advocate archives online with GAA’s Google Custom Search.
Enter keywords, author names and/or publication dates to view
PDF-format article files from the year 2000 forward.
Atlantic Aqua Earns
First BAP Mussel
Farm Certification
Atlantic Aqua Farms – a fully integrated, rope-culture mussel-farming and processing company based in Prince Edward
Island, Canada – became the first mussel operation in the world
to attain Best Aquaculture Practices (BAP) certification when all
of the company’s PEI mussel farm sites were certified on October
14, 2013.
“As industry leaders in the farming and processing of mussels,
we constantly strive to maintain the highest industry standards of
environmental stewardship, quality, food safety and customer service,” said Terry Ennis, president and CEO of Atlantic Aqua
Farms. “The entire team is passionate about producing the bestquality mussels on the market, and we aim to be consumers’ first
choice for mussels every day.”
Established in 1989, Atlantic Aqua Farms is North America’s
largest rope-grown mussel farming and processing company and
the continent’s top supplier of premium live mussels. The company’s products are marketed to retail and foodservice customers
across North America under the Canadian Cove brand. A variety
of product forms are available, including fresh mussel packs, frozen mussel packs and high-oxygen tray packs.
GAA, ASC, GlobalGAP
Identify Common
Requirements For
Fishmeal, Fish Oil
The Global Aquaculture Alliance, Aquaculture Stewardship
Council (ASC) and GlobalGAP issued a joint statement on
November 13, 2013, whereby the three standards-setting organizations identified common sourcing requirements for fishmeal
and fish oil.
The requirements included traceability to the species and, at
least, to the country of origin; no use of material sourced from
endangered species based on the International Union for Conservation of Nature’s red list; avoidance of fish sourced from illegal,
unreported and unregulated fishing; and preference for feed manufacturers with publicly available evidence of responsible sourcing.
Additionally, GAA, ASC and GlobalGAP encouraged the
aquafeed and livestock feed industries to apply these criteria as a
minimum set of requirements when sourcing fishmeal and fish oil
ingredients.
In April 2013, the groups signed a memorandum of understanding to work collaboratively to increase efficiency and reduce
duplication in the aquaculture auditing process. As part of the
agreement, the three organizations agreed to develop common
sourcing requirements for fishmeal and fish oil.
Google Custom Search
www.gaalliance.org/magazine/searcharticles.php
8
9
leadership profile
Yoram Avnimelech, Ph.D.
production
ems/ahpn update
Tilapia Could Enhance Water Conditions,
Help Control EMS In Shrimp Ponds
Biofloc Pioneer Calls For More Education, Research
Avnimelech in an interview from the Saigon Exhibition and Convention Center.
Loc H. Tran, Ph.D.
Practical, Profitable
Dr. Yoram Avnimelech is considered
one of the fathers of biofloc
technology.
Editor’s Note: The following is the first in a
series of columns by GAA Communications
Manager Steven Hedlund. The column will
profile aquaculture and seafood professionals
whose leadership, sense of innovation and
emphasis on education and communication
set them apart.
At the World Aquaculture Society’s
Asia-Pacific Aquaculture 2013 conference in Ho Chi Minh City, Vietnam, in
December, an entire day of the three-day
program was dedicated to biofloc technology. Thirteen scientists presented the
latest research, with presentations ranging from the effects of bacterial probiotics
on a Pacific white shrimp culture system
infected with Vibrio parahaemolyticus to
the development of a factorial model for
growth and feed management of cobia.
Chairing the discussion on biofloc
technology was Yoram Avnimelech,
Ph.D., a professor at Technion, the Israel
Institute of Technology in Haifa, Israel.
Early Work
Avnimelech is one of the fathers of biofloc technology. His work on bioflocs dates
to the mid-1980s, when, as a water and soil
scientist working on a project in the Sea of
Galilee in Israel, he discovered that the
nutrients from neighboring fish farms were
seeping into and polluting the 167-km2
freshwater lake. The study of the release of
water from these fish farms led to Avnimelech’s research on biofloc technology.
“I sort of fell into aquaculture,” said
10
Twenty years after the first publication of Avnimelech’s research, biofloc
technology is commonplace, particularly
among shrimp and tilapia culture systems. Biofloc technology involves the
recycling of nutrients in the water from
feed. When water exchange is minimized
in intensive farming systems with high
stocking densities, the nutrients proliferate into a community of microscopic
organisms large enough for shrimp or
finfish to eat. These microorganisms
detoxify waste products, primarily nutrients excreted by shrimp and finfish, and
act as a source of food – resulting in
reduced feed costs.
With biofloc technology, “farmers can
increase profitability because less feed is
used and less-expensive feed can be
used,” Avnimelech said. “It’s practical.”
Disease Protection
“A lot of farmers are working with
biofloc,” he said. “But there’s no one way
to do it. We’re still learning a lot. There’s
a lot of evidence that biofloc technology
gives some protection to shrimp and finfish to fight against disease.”
Perhaps biofloc technology is garnering
more attention as of late due to the prominence of early mortality syndrome, which
has impaired shrimp production in Asia
and recently spread into Mexico. Biofloc
technology has been identified by researchers as one of the potential solutions.
“I’m very optimistic we can use this
technology to help farmers solve disease
problems,” Avnimelech said. “There’s no
one solution, but this is one.”
Avnimelech has written about the
advantages of biofloc technology in the
pages of the Global Aquaculture Advocate.
In the May/June 2011 edition, he wrote
that it’s an environmentally friendly, costeffective means to intensify tilapia production. And in the March/April 2012
issue, he wrote about the potential for
using the natural enrichment of periphyton, algae and other biological sources of
protein as a means to follow protein
uptake in shrimp and finfish aquaculture.
School of Animal and Comparative
Biomedical Sciences
Department of Soil, Water
and Environmental Sciences
University of Arizona
1401 East University Boulevard
Tucson, Arizona 85721 USA
[email protected]
Steven Hedlund
Communications Manager
St. Louis, Missouri, USA
[email protected]
Kevin M. Fitzsimmons, Ph.D
Department of Soil, Water
and Environmental Sciences
Education
The challenge now, Avnimelech said,
is introducing biofloc technology to family farms through education. “They often
say that it’s biofloc, but it’s not being executed properly,” he explained.
If properly applied, biofloc technology
can increase production at a family farm
sevenfold, Avnimelech said. But universities that teach aquaculture need to do a
better job of incorporating biofloc technology into the curriculum.
What’s being taught now at many
universities “is not enough,” Avnimelech
said. “Education is the answer. … We
also need to set the stage and provide
training for family farmers.”
Research
Avnimelech also addressed the lack of
research and development in aquaculture,
particularly in Asia. A lot of R & D originates from North America and Europe,
but there is not a lot of aquaculture production there. Conversely, there isn’t
enough R & D currently coming out of
Asia, but there is a lot of production there.
However, things are changing
quickly, Avnimelech said. “I can promise
you that in 10 years, research output from
China, India and other Asian countries
will be much more than the output from
North America and Europe.”
“A lot of farmers are
working with biofloc, but
there’s no one way to do it.
We’re still learning a lot.”
Donald V. Lightner, Ph.D
School of Animal and Comparative
Biomedical Sciences
Ten days after exposure to pathogenic Vibrio parahaemolyticus, shrimp A1, A2, C2,
B1 and B2 show normal stomachs, hepatopancreases and midguts (arrows from top to
bottom). The remaining shrimp show signs of AHPN infection: empty stomachs, pale
hepatopancreases and empty midguts.
Summary:
Anecdotal reports have indicated polyculture and biofloc systems can reduce outbreaks of diseases at shrimp
farms. A laboratory study at the University of Arizona
examined the effects of tilapia in controlling acute hepatopancreatic necrosis (AHPN) infection and mortality
in Pacific white shrimp. Results suggested that practices
such as using tilapia in the reservoirs of shrimp farms
to induce beneficial algal and bacterial blooms in water
prior to filling ponds could promote healthy, balanced
biota communities that confer beneficial effects
in controlling AHPN.
Several anecdotal reports have indicated that some antibioticfree approaches such as polyculture and biofloc systems can
reduce the risks of disease outbreaks at shrimp farms. Polyculture
with tilapia has been known to confer some beneficial effects in
controlling luminescent bacteria, Vibrio harveyi, affecting shrimp.
Since V. parahaemolyticus, a virulent strain of which causes early
mortality syndrome (EMS), is closely related to V. harveyi, polyculture of tilapia with shrimp may confer similar effects against
this bacterial species.
Farm trials conducted in areas of Vietnam where EMS or
acute hepatopancreatic necrosis (AHPN) is endemic have shown
better survivability of shrimp grown in polyculture systems.
However, lab experiments with controlled environments and
standardized challenge models were needed to determine the
effectiveness of this approach.
AHPN Challenge Study
A laboratory study was conducted at
the University of Arizona to determine
the effects of tilapia in controlling infection and mortality in Pacific white shrimp, Litopenaeus vannamei, due to a pathogenic Vibrio parahaemolyticus strain. Five
treatments with three replicates each were used.
Treatment A was a negative control with culture tanks prepared without tilapia for 14 days prior to stocking with shrimp.
For treatment B, tanks held Oreochromis niloticus tilapia for 14
days, after which the tilapia were removed prior to stocking of the
shrimp. A 10-day AHPN challenge test followed after the addition of a bacterial suspension containing virulent V. parahaemolyticus that achieved a bacterial density of 3.105 cells/mL tank water.
In treatment C, tanks were prepared for 14 days with tilapia,
then the tilapia were put into a suspended cage inside each tank
prior to stocking of shrimp and a following AHPN challenge
test. Treatment D used tanks prepared for 14 days without tilapia prior to shrimp stocking and following AHPN challenge.
Treatment E was a positive control with tanks containing clear
water at 20-ppt salinity prepared one day prior to stocking of
shrimp and then followed by an AHPN challenge test.
Results
After 14 days of tank preparations to induce algal blooms
and establish balanced biotic communities mimicking field practices in shrimp farming, bacterial counts revealed the bacterial
density was not significantly different among treatments A, B, C
and D. However, their counts were 3 logs higher than for the
positive control.
Ten days after the addition of the bacterial suspensions in the
challenge tests, survival rates were significantly different among
treatments (Figure 1). The survival rates for treatments A, B, C,
D and E were 97.78%, 91.11%, 6.67%, 20.00% and 0%, respectively. The high survival rate in treatment A indicated the experglobal aquaculture advocate
11
The study suggested that the application of practices such as
using tilapia in the reservoirs of shrimp farms to induce healthy
algal and beneficial bacterial blooms in water prior to filling
ponds could promote healthy, balanced biota communities in the
pond water that could confer beneficial effects in controlling
AHPN.
100
90
80
Survival (%)
70
60
Discussion
Vibriosis diseases induced by luminescent bacteria have
caused serious problems in shrimp farming. Some farming practices that took advantage of “greenwater” technology in which
the green water was induced by tilapia could mitigate the luminescent vibriosis caused by Vibrio harveyi in Penaeus monodon.
Further works elucidating the mode of action of the greenwater technology have discovered that certain indigenous bacterial strains and algae in the greenwater had the ability to inhibit
the growth of V. harveyi, explaining the mode of action of the
greenwater technology or polyculture technology.
50
40
30
20
10
0
01 2345678910
Days After Exposure to AHPN Bacteria
Negative Control
Greenwater Without Tilapia
Greenwater Induced by Tilapia
Greenwater, Tilapia in Cage
Positive Control
Figure 1. Survival of shrimp in different treatments post-exposure
to virulent Vibrio parahaemolyticus.
imental conditions were suitable for the survivability of shrimp.
Meanwhile, the zero survival in the positive control showed the
high pathogenicity of the bacterial strain used in the study.
Although the AHPN bacteria were later isolated from the
water and shrimp in all the challenged treatments, histological
analyses showed that the infection rates and severities of the
pathologies in different treatments corresponded to the survival
rates. The bacteria counts in water samples showed a significant
drop in treatments B, C and D compared to the bacterial density
added by the challenged test. In contrast, bacterial density in the
positive control using clear saline water showed a marked bloom
of AHPN bacteria. This indicated that the native biota communities in water can interact with the AHPN bacteria and the
infection caused by this strain.
This study was the first step in demonstrating that the indigenous biota induced by tilapia or by tank preparation steps could
lower the number of AHPN bacteria in water, thus delaying
mortalities in challenged shrimp. However, an overbloom of
algae could produce unexpected effects due to eutrophication and
nutrient availability from dead algae that could benefit the
AHPN bacteria. In addition, without competition from the
indigenous biota, the AHPN V. parahaemolyticus could replicate
in water to a level that causes infection.
These findings helped explain an observation that AHPN
usually affected ponds that did not have algae or in which an
excessive bloom of algae occurred or recently crashed.
KeetonAqua.com/shrimp
800.493.4831 or 970.568.7754 (US)
Feed Additives Based On Quorum Sensing
Disruption Could Aid Fight Against EMS/AHPN
Bactericides, Antibiotics Reduce Number of Bacteria
Peter Coutteau, Ph.D.
Nutriad International N.V.
Schietstandlaan 2
2300 Turnhout, Belgium
[email protected]
Tim Goossens, Ph.D.
Nutriad International N.V.
Quorum Sensing Disruption Disturbs Bacterial Signaling
tems are now being explored to produce
juvenile shrimp throughout the critical
stages affected by EMS. These systems
allow superior control over nutrition and
the microbial environment compared to
direct stocking into growout ponds.
Microbial Control
Figure 1. Quorum sensing inhibition.
Summary:
Increase Yield
Maximize Survival
Improve FCR
ems/ahpn update
Perspectives
the scientific way to protect your investment
12
production
The pathogenicity of early mortality syndrome in shrimp is likely
regulated by quorum sensing,
which allows the Vibrio bacteria
that colonize shrimp guts to coordinate the release of the toxin
that damages shrimp digestive
systems. Research by the authors
has shown that synergistic blends
of natural antimicrobial compounds added to aquafeed can
function as powerful interrupters
of bacterial quorum sensing signaling in aquaculture pathogens
such as Vibrio harveyi at concentrations well below minimal
inhibitory concentrations.
Early mortality syndrome (EMS) or
acute hepatopancreatic necrosis (AHPN)
is a shrimp disease that has been disrupting production in major shrimp-producing countries since 2009. First reported in
China, it has spread to Vietnam, Malaysia and Thailand, and just recently to
Mexico and possibly India.
EMS outbreaks typically occur within
the first 30 days after stocking newly pre-
pared shrimp ponds, and mortality can
exceed 70%. EMS is caused by specific
strains of a relatively common bacterium,
Vibrio parahaemolyticus, which are transmitted orally, colonize the shrimp gastrointestinal tract and produce a toxin that
causes tissue destruction and dysfunction
of the shrimp digestive organ known as
the hepatopancreas.
As reported during sessions on health
management at GOAL 2013, the pathogenicity of EMS/AHPN is most likely regulated by a mechanism called quorum sensing, which allows the Vibrio colonies to
coordinate the release of the potent toxin.
EMS Management
Because EMS is caused by a Vibrio
that is difficult to eradicate from aquaculture production environments, its control
requires a very different approach than
the strategies used against white spot
syndrome virus, which are based on specific biosecurity measures. Avoiding early
contamination through the broodstock
and larval stages, combined with continued control of microbial development –
particularly during the initial month of
the cycle – will be crucial to control
EMS.
In this regard, intensive nursery sys-
The use of antibiotics to control
microbial development throughout the
production process is not desirable due to
the risk of building up resistance and
rejection by legislators and consumers.
The shrimp industry requires alternative
ways to control the microbial ecosystems
in production systems.
Sustainable approaches to modulate the
gut microflora in shrimp include the use of
probiotics, selected bacteria that inoculate
the gut; and specific natural compounds
called botanicals or phytobiotics, which are
capable of modulating the microflora
toward a favorable composition.
Provided botanical formulations are
heat stable, they can be easily incorporated into feed at the mill and therefore
be present in every meal from the starter
feed onwards without requiring major
adaptations of the production protocols
at nurseries or farms. Phytobiotics that
promote healthy gut microflora also support the establishment of probiotic bacteria and therefore enhance the effects of
probiotic inoculations in production systems. Various studies have demonstrated
the ability of natural products to improve
shrimp growth and survival
Functional Feeds
Functional feeds containing gut
health promoters allow delivering with
every meal an adequate concentration of
natural antimicrobial activities into the
shrimp gut. These feeds could be an
13
production
Table 1. Efficacy of a natural botanical product against aquaculture pathogens.
(Nutriad Technology Center, in-house results, 2012.)
Pathogenic species
Strain
Minimum
Inhibitory
Concentration
(% extract)
Flavobacterium columnare
Listonella anguillarum
Photobacterium damselae
Vibrio harveyi
Vibrio alginolyticus
Vibrio parahaemolyticus
Edwardsiella ictaluri
Edwardsiella tarda
Pseudomonas fluorescens
Pseudomonas putida
Yersinia ruckeri
Aeromonas hydrophila
Aeromonas salmonicida
Streptococcus iniae
LMG 10397
LMG 4411
LMG 7892
BB120
LMG 4409
LMG 4423
LMG 7860
LMG 2793
DVK1
DVK2
LMG 3279
LMG 2844
LMG 3780
CCUG 27303
0.06
0.23
0.47
0.47
0.94
0.94
1.88
1.88
3.75
3.75
3.75
7.50
7.50
8.00%
important component of any strategy to
prevent EMS. However, the success of
this approach will depend on the efficacy
of the selected gut health promoter
against the pathogenic bacteria involved
in EMS.
Synergistic blends of natural compounds can be selected on their bacteriostatic and bactericidal properties against a
specific range of pathogenic bacteria in
vitro. In work at the Nutriad Technology
Center, different Vibrio species, including
V. parahaemolyticus, appeared to be highly
sensitive to a natural feed additive composed of a synergistic blend of antimicrobial compounds (Table 1).
Quorum Sensing
Recent research has shown that, apart
from direct bactericide/bacteriostatic
effects, selected combinations of antimicrobial compounds are at the basis of
more complex mechanisms to steer
microbiota composition. In human medicine, compounds active in quorum sens-
Host Range
Quorum Sensing
Documented
Tilapia, freshwater fish species
Most marine fish species
Sea bream, seabass, sole
Sea bream, common snook, penaeid shrimp
Sea bream, grouper, most marine fish
Marine fish, penaeid shrimp (EMS)
Catfish
Turbot, tilapia
Striped bass, white perch, yellow tail
Ayu, freshwater fish species
Salmonids, mainly rainbow trout
Salmonids, cyprinids, catfish, freshwater fish species
Salmonids, cyprinids, freshwater fish
Trout, tilapia and other freshwater fish
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
ing (Q.S.) disruption are being increasingly investigated as potential alternatives
to antibiotics due to their efficacy at low
concentrations and the low chance of
bacteria developing resistance against
these non-lethal molecules.
Quorum sensing is a form of bacterial
communication based on the production
and secretion of signaling molecules that
can be detected by adjacent bacteria.
When population density rises, these
molecules accumulate in the extracellular
environment, thereby providing a means
for bacteria to quantitatively monitor the
presence of other bacteria. When these
signaling molecules reach a certain
threshold concentration, they initiate
intrabacterial signaling that culminates in
the activation of specific genes.
Quorum Quenching
As determined in work by researcher
Dr. Tom Defoirdt and co-workers in
2011, in most pathogenic bacteria for
which quorum sensing has been studied,
100
Survival (%)
80
60
40
20
0
Unchallenged
Vibrio
Vibrio + 0.3%
Vibrio + 0.1%
Vibrio + 0.03%
Control Extract ExtractExtract
Figure 2. Survival of Artemia challenged with Vibrio harveyi and treated with different
concentrations of an extract of natural compounds with antimicrobial activity.
14
Q.S. was associated with pathogenicity,
such as biofilm formation and the production of proteases, invasion factors or
other virulence factors. In recent years,
research focusing on ways to disturb Q.S.
signaling – also called quorum quenching
– has therefore gained interest.
Blocking communication is a novel
way to prevent bacteria from triggering
pathogenicity without exposing them to a
selective pressure to survive (Figure 1).
Research by the authors has shown that
synergistic blends of natural antimicrobial
compounds can function as powerful
interrupters of bacterial Q.S. signaling in
a typical aquaculture pathogen such as
Vibrio harveyi at concentrations well
below minimal inhibitory concentrations.
Recent scientific studies by Pande
Gde Sasmita Julyantoro and Defoirdt
have shown that quorum sensing-disrupting compounds are capable of increasing
survival of crustaceans challenged with
Vibrio harveyi, including larvae of giant
freshwater prawns, Macrobrachium species, and the brine shrimp Artemia.
Research by this article’s authors similarly
showed that strongly diluted extracts
from a synergistic botanical product could
protect Artemia during a challenge with
Vibrio harveyi (Figure 2).
The determination of Vibrio concentrations in varied challenge treatments
showed that the strong bactericide effect
of the botanical product was responsible
for this protection at the highest concentrations of the product. However, the
negligible effect on Vibrio concentrations
in Artemia as well as the culture water in
the treatment exposed to the lowest dosage indicated the Q.S. disruption mechanism was responsible for the protective
effect of the botanical extract at lower
concentrations.
Shrimp larvae with brown hepatopancreas (A, C) and a Vibrio
count of 3.50 x 103 CFU/g (D) had the best survival rate at a Thai
farm. The H.P. tissues of these larvae showed no sign of EMS
attack (B).
ems/ahpn update
Shrimp larvae with brown and white hepatopancreas (A, C)
and a Vibrio count of 1.08 x 105 CFU/g (D) had low survival.
The H.P. tissues of these larvae showed an initial condition
of Vibrio attack (B).
Hepatopancreas Colors Related To Vibrios
Predict Survival Of Shrimp To EMS
Summary:
Monitoring of Vibrio bacteria in shrimp larvae determined a relationship
among hepatopancreas color, bacteria concentration and signs of early mortality syndrome. Shrimp with brown hepatopancreases had 3.50 x 103 CFU/g
Vibrio with no EMS and high survival. Shrimp with white hepatopancreases
had 6.02 x 107 CFU/g Vibrio and died within 10 days. Some animals with both
brown and white hepatopancreas tissue had low bacterial concentrations, but
survival depended on pond conditions. Management procedures used after the
onset of mortality increased survival.
Outbreaks of early mortality syndrome (EMS) or acute hepatopancreatic
necrosis (AHPN) have been increasingly
seen at shrimp farms in Asia and other
parts of the world. At a farm in Thailand,
some ponds were hit with EMS, while
others were not. Different survival rates
were observed depending on the Vibrio
bacteria concentrations in the larvae in
the ponds.
H.P. Color Study
A study done at the farm revealed different survival rates depending on the
color of the hepatopancreas (H.P.) organs
in shrimp larvae stocked in the growout
ponds. H.P. macerates separated by color
were cultured in thiosulfate-citrate-bile
salts-sucrose agar to determine a total
number of colony-forming units (CFUs)
identified later as Vibrio species.
The higher concentrations (averaging
6.02 x 107 CFU/g) of Vibrio came from
larvae with white H.P. in ponds exhibiting mortality within the first 10 days of
culture. Lower concentrations (averaging
3.50 x 103 CFU/g) were observed in larvae with brown hepatopancreas tissue in
ponds with the highest survival rates, at
or above 60%.
Another group of larvae – with both
brown and white hepatopancreases – had
averaged bacterial concentrations of 1.08
x 105 CFU/g. The survival rate of the
shrimp improved when pond conditions
were improved, and adequate management procedures were applied.
The measures included avoiding over-
Dr. Chalor Limsuwan
Dr. Niti Churchird
Dr. Natthinee Munkong Wongsiri
Department of Fishery Biology
Kasetsart University
Bangkok, Thailand
Dr. Carlos A. Ching
Aquaculture Manager
Nicovita – Alicorp SAA
Av. Argentina 4793
Callao, Lima, Perú
[email protected]
feeding. The total feed for 100,000 postlarvae should not exceed 200 kg for the
first 30 days of culture. A consistent phytoplankton bloom should be achieved
during the first 40 days. In addressing
water quality, pH should be kept within a
range of 7.8 to 8.3, with alkalinity levels
maintained at 120 mg/L or greater.
Causes Of Unhealthy
Postlarvae
A survey of the broodstock and
hatchery facilities from which the
unhealthy larvae came identified some
problematic conditions.
15
Shrimp larvae with white hepatopancreas (A, C) and a Vibrio
count of 6.02 x 107 CFU/g (D) died within 10 days after stocking.
The H.P. tissues of these larvae showed an advanced condition of
EMS attack (B).
Unhealthy broodstock often had unilateral eyestalk ablation. Ablated females
usually died after the first spawn. Stocking densities were often high, at over 100
nauplii/L during larval rearing. Temperatures varied during larval culture instead
of being maintained within the proper
range of 30 ± 1° C. Microalgae populations were inconsistent, with pH values
outside the proper range.
Management After EMS
Some ponds at the farm improved
survival rates when the following management procedures were applied when
initial EMS mortality was detected.
• Stop feeding until mortality stops
Healthy hepatopancreas shows smooth epithelia and good lipid
content (A). Initial Vibrio damage is observed in shrunken H.P.
tubules (B, C). The final stage of EMS shows some collapsed
H.P. tubules with almost no lipid content (D).
and shrimp in feed trays look
healthy, then gradually start feeding
again.
• Use probiotic bacteria for improving
water quality.
• Apply lime to maintain pH at 7.8 to
8.0 in the morning and a maximum
of 8.3 in the afternoon.
• Turn on aerators fully for optimal
dissolved-oxygen concentrations.
• Maintain a consistent phytoplankton bloom.
Postlarvae Quality Standards
A survey made by Thailand’s Department of Fisheries set a recommended
standard for total Vibrio counts in shrimp
postlarvae at less than 1,000 CFU/g cultured in agar before stocking. Of these
1,000 colonies, a maximum of 100
CFU/g should be green, and the other
900 CFU/g should be yellow. V. parahaemolyticus colony count should not exceed
30, while no V. harveyi colonies should be
present.
Also, some Thai farmers are looking
at the H.P. tubules’ shapes and lipids
content. Tubules with smooth epithelia
and good lipids content are considered
healthy, while shrunken H.P. tubules
with low lipid concentration are considered unhealthy.
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16
17
production
ems/ahpn update
remains to be elucidated, and while there
are theories, it seems this is not an absolute effect. Some farms still report problems when they co-cultivate with tilapia.
Additional observations show that
farms that use well water in some ponds
and seawater in other ponds only have
the disease in the ponds with non-well
water. This further supports the theory
that the primary mechanism of movement of the pathogen is not between
shrimp but through a host of vectors similar to what we see in cholera. Furthermore, the incidence of the disease in
farms that use water with less than 5-ppt
salinity is much lower than in those with
higher salinities. In that Vibrio parahaemolyticus strains do not typically grow in
water that is less than about 1% sodium
chloride (10 ppt), this is expected.
Toxins
Evidence suggests that exclusion where possible and appropriate management of ecosystems offer hope in addressing AHPN.
Many farm facilities will require changes in infrastructure and management practices.
What To Do About EMS/AHPN?
point to potential approaches for dealing
with the disease.
Summary:
It is likely that acute hepatopancreatic necrosis will continue
to spread. Successful control
strategies will entail the use of a
variety of tools and must include
a far better understanding of
where the disease develops in the
environment and how it moves.
Ideally, farmers need to create
conditions that make it harder for
the pathogenic Vibrio that causes
AHPN to colonize animals’
stomachs and for the toxin to
produce its pathology. Exclusion
where possible and appropriate
management of ecosystems offer
hope in addressing AHPN.
A number of commonalities have
been observed among occurrences of early
mortality syndrome (EMS) or acute
hepatopancreatic necrosis (AHPN) in
shrimp in Southeast Asia and Mexico,
where its presence was only recently confirmed after affecting the aquaculture
industry for months. These observations
provide clues as to what is going on and
18
Disease Factors
It has been noted that when shrimp
are reared in cages off pond bottoms in
ponds where shrimp are dying from
AHPN, they are unaffected. It has also
been noted that when animals are held in
nursery raceways – even with the same
water used in ponds – they do not typically develop the disease. This suggests
AHPN is not transmitted through the
water column. This could be for a number of reasons, although the most logical
is that the virulent strain of Vibrio parahaemolyticus bacteria that causes AHPN
never reaches high enough levels to be
infective via the water column.
Bacterial loads in ponds vary considerably. Ponds develop very complex ecosystems with many species of bacteria,
algae, phytoplankton and zooplankton.
Vibrios are always present at some level,
although even in the middle of outbreaks
from obligate pathogens, the levels are
not typically very high. Attachment of
this pathogenic Vibrios to various substrates could readily explain transmission.
Since there is no evidence that this bacteria causes septicemia, it is highly likely that
Stephen G. Newman, Ph.D.
6722 162nd Place Southwest
Lynnwood, Washington
98037-2716 USA
[email protected]
molting disrupts the biofilm process. Given
that it takes time for the bacteria to progress
through the various stages of biofilm formation, this explains why we do not see the
disease in hatcheries.
Strains of V. parahaemolyticus are
ubiquitous, so it is not surprising to find
them in hatcheries, production tanks,
Artemia and algal production systems, as
well. No one has reported mortality in
broodstock held in nuclear breeding facilities, although there is no reason why, if
the pathogen were present in larger animals, it could not kill them.
Another interesting observation from
the field is that co-cultivating shrimp
with tilapia seems to lessen the incidence
and severity of the disease. It is common
knowledge that tilapia produce substances that inhibit a variety of bacteria,
including Vibrios. This is one of the
attractive features of greenwater culture.
The exact nature of these materials
The role of a toxin-producing gene is
of paramount importance, so determining
the nature of the toxin and how its production can be controlled could be
important in minimizing its impacts.
Many toxins have been identified in association with V. parahaemolyticus , and it is
probable that the toxin that is damaging
the hepatopancreas tissue of shrimp is not
something new.
Toxins are often produced as the
result of a phenomenon known as quorum sensing. Simply put, this is a means
by which bacteria communicate with each
other. Toxins are common substances
involved in the nutrition of bacteria. The
fact that they are toxic to specific hosts is
not their primary function. It is a side
effect of their presence.
Producing shrimp in stressful environments and using pseudoscientific culture
practices can play roles in the spread of the
disease. The evidence suggests that many
widely marketed probiotics have little if
any impact on the loads of Vibrios in the
environment. Eliminating the bacteria is
impractical, although one can develop
strategies that favor the growth of generally more benign yellow Vibrios over the
more problematic green Vibrios. Addressing the presence of potential vectors could
also lessen impacts.
Farm Controls, Treatments
What options do farmers have? At
this time, they are limited.
Some claim the AHPN problem
comes from broodstock and hatcheries.
Shrimp molt daily in hatcheries, making
the development of a stable biofilm problematic. While there is no doubt that V.
parahaemolyticus strains are present in
broodstock and throughout poorly managed hatcheries, given their ubiquitous
nature and strong evidence that the etiologic agent of AHPN is moved by vectors, it is not likely the source of the disease is broodstock or hatcheries.
Farms should apply biosecurity, of
course. Precautions should always be taken
to lessen the loads of potential pathogens,
and the technology to do this is well established. Certainly, considering the similarity to V. cholerae, it makes sense that controlling ingestion of materials that contain
the bacteria, whether detritus on pond
bottoms, zooplankton or algae, becomes
part of an apparent solution.
Ideally, farmers need to create conditions that make it harder for the Vibrio to
colonize the animals’ stomach and for the
toxin to produce its pathology. Theoretically, this can be done by changing the production paradigm and eliminating the
niches the bacteria occupies, or making it
more difficult for shrimp to ingest high
loads of the bacteria. One possible approach
might be to use higher water-exchange
rates to flush out nutrients and bacteria.
Blocking attachment of the bacteria to
the stomach wall and gastric mill warrants
a closer look, as does the use of compounds that kill the bacteria as they enter
the host or even during the early stages of
attachment. Likely a combination of several approaches might prove useful.
One approach might be to feed the
shrimp compounds that inhibit the bacterial growth. These would include antibiotics, monoglycerides and a host of other
substances that are potentially inhibitory.
However, if the biofilm is typical of that
noted in other bacteria, the AHPN Vibrio
will be protected by the biofilm. Timing of
delivery would be critical and problematic.
Out Of Balance
There is much speculation about
where AHPN originated and in what reservoirs it resides in the environment.
Shrimp farming by its very nature
encourages the growth of Vibrios. They
are present naturally in all environments,
and there are complex mechanisms in
place that typically moderate them. The
balance for V. parahaemolyticus has been
disturbed, and this could explain why the
bacterium is able to proliferate at the
expense of others.
The widespread use of chlorination to
eliminate white spot syndrome virus and
other vectors that might be present in
incoming water may be a contributing
factor, since this alters ponds’ microbial
19
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may limit the spread of AHPN. In areas where the problem is endemic, significant
changes in the production paradigm may be required.
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ecology. It is well documented that chlorine increases the ease with which organic
matter is assimilated, and there are
reports that this may stimulate bacteria
that form biofilms.
The irony in this is that the use of
chlorine is not the most effective
approach to control viral loads. The role
of secondary bacterial infections in animals weakened by the virus may be more
important in determining the outcome of
the disease process than the presence of
the virus itself.
Some vectors produce cysts that are
buried deep in sediments. Within a few
weeks post-chlorination, the virus is easy
to find in vectors and the environment
again. Whether active disease ensues is
environment-dependent.
Exclusion + Management
The preponderance of evidence to
date suggests that exclusion where possible and appropriate management of ecosystems might offer some hope in
addressing AHPN. Yet the “shotgun”
approach some producers are using
toward the disease – dumping anything
they can get their hands on into ponds
and the shrimp, as well – does not allow
ready determination of what methods are
successful in limiting the disease process.
It is clear is that the problem is likely
moved through many different vectors in
the water, and that shrimp’s consumption
of the bacteria plays a critical role in the
disease process. Not all exposed shrimp are
universally affected. Some die, while others
grow poorly and have poor feed conversion
or other symptoms, but don’t die.
The manipulation of a complex
aquatic ecosystem along with a foolish
production practice likely allowed the
AHPN Vibro bacteria to dominate in a
few ponds. From there, it readily spread,
much as cholera has and will again.
However, unlike cholera, AHPN appears
chronic. As long as animals are recolo-
nized with this particular pathogen, the
problem will persist.
Perspectives
To conclude, there are many analogies between the etiologic agents of
AHPN and V. cholerae. Unwise culture
practices could have led to the initial
transfer of genetic material that allowed a
strain with these particular properties to
develop and propagate. The pathogen is
readily spread through the water by a
myriad of vectors. The pathogen has been
able to establish itself and will likely continue to spread.
It is not likely that genetic selection
will allow the development of shrimp that
tolerate the toxin, and since it binds to
chitinous surfaces, this will not likely
change. Controlling the pathogen will
require a combination of environmental
manipulation techniques that allow balance to be restored, changing the production paradigm in areas where the problem
is endemic and balance cannot be
restored. Tools that lessen the overall
load of Vibrios at all stages of the shrimp
production process might be useful in
reducing the impacts of AHPN, ultimately allowing an ecological shift back
to a more favorable outcome.
In that this bacterial pathogen is
unlike anything reported in shrimp farming to date, many of the classic strategies
for controlling bacteria are not likely to
work. In the long run, the process of
elimination will winnow out marginal
farms and those farmers who consistently
fail to use the tools of proactive disease
management and science to ensure they
produce sustainable and consistent crops.
The end result will be a more robust and
healthier shrimp-farming industry.
Editor’s Note: This article is based on a longer
paper by the author. To read the full text,
visit www.sustainablegreenaquaculture.com/
uploads/5/3/7/2/5372499/what_can_
shrimp_farmers_do_about_ems.pdf.
food
BRC
certification
21
production
weekly, while clarified water near the top
flowed back to the raceway.
xxxxxxxxxxxx
Shrimp Culture
A covered biofloc raceway system with consistent water quality, aeration and temperature control yielded excellent production results.
Biofloc Trial Results In Fast Shrimp Growth,
Low FCR, High Survival
Summary:
A trial in a lined, greenhouseenclosed raceway evaluated the
use of a heterotrophic biofloc
system equipped with aeration,
supplemental oxygen injection and
centralized heating to achieve good
shrimp production. Shrimp grew
to 22.5 g in 82 days, indicating
it may be possible to grow more
than four crops of shrimp yearly.
Feed-conversion ratios were very
low at 1.2:1, survival was high, and
although the stocking density was
fairly low, the biomass production
reached 5.3 kg/m3.
Intensive biofloc shrimp culture systems allow for indoor production, low
water-exchange rates and high biosecurity
levels. Management of these systems varies, but one strategy is to add labile
organic carbon sources to the water to
raise the carbon:nitrogen ratio and facilitate heterotrophic assimilation of otherwise toxic nitrogen compounds.
Heterotrophic microbes in the water
use carbon for energy and build proteins
22
Andrew J. Ray, Ph.D.
Department of Coastal Sciences
Gulf Coast Research Laboratory
University of Southern Mississippi
703 East Beach Drive
Ocean Springs, Mississippi 39564 USA
[email protected]
Jeffrey M. Lotz, Ph.D.
Department of Coastal Sciences
Gulf Coast Research Laboratory
from nitrogen. These microbes may then
provide supplemental nutrition for
shrimp. This technique has the potential
to increase shrimp growth rates and lower
feed-conversion ratios (FCRs).
The authors conducted a trial to evaluate the use of a heterotrophic biofloc system
equipped with the latest in aeration and
centralized heating technology to achieve
good shrimp production.
Raceway Setup
A 50-m3 concrete raceway measuring
30.1 m long, 3.2 m wide and 0.5 m deep
was lined with high-density polyethylene
plastic and contained under a greenhouse
covered in clear plastic. Water was propelled around a central wall using two 1.5hp pumps. Each pump was connected to
seven nozzles evenly spaced near the bottom of one length of the raceway. The
nozzles drew air through a 2.5-cm-diameter pipe that extended above the water surface. One such pipe was outfitted to
receive pure oxygen gas, which was
injected on a precautionary basis at a rate
of approximately 2 L/minute.
The project was conducted during
winter months and therefore required
supplemental heating. Two hot water
boilers heated clean, fresh water that was
moved through a central piping system
via a pump. A digital thermostat maintained water temperature in the raceway
at 29° C. The thermostat operated a secondary pump that, when needed, moved
hot water through a titanium heat
exchanger within the raceway.
Just outside the greenhouse was a
760-L settling chamber with a coneshaped bottom and a 10-cm-diameter
pipe suspended in the center. Water from
the raceway was continuously pumped
through the settling chamber at a rate of
approximately 15 L/minute. Solids settled at the bottom and were removed
Shrimp were grown in a nearby nursery raceway until they weighed an average
of 1.5 g, at which point they were stocked
into the experimental production raceway
at a density of 250 shrimp/m3. The
shrimp were originally fed rations based
on an assumed FCR of 1.5:1, growth of
1.8 g/week and assumed mortality rate of
8% at stocking and 1%/week thereafter.
However, this feeding rate was adjusted
by routinely sampling for uneaten feed
using a dip net.
Feed rations were set such that no
uneaten feed could be found approximately
30 minutes prior to each subsequent feeding, and no feed could be found prior to the
first feeding of the day. Seventy percent of
the daily feed ration was dispersed evenly
throughout the raceway by hand, and the
remaining 30% was placed on two 12-hour
belt feeders for overnight feeding. Shrimp
weights were sampled weekly, salinity was
maintained at 20 ppt, and shrimp were
grown for 82 days.
Granulated sucrose was added daily at
a rate of 50% of the wet weight of added
feed to raise the carbon:nitrogen ratio
and encourage the function of heterotrophic microorganisms. In a few instances
where dissolved nitrite concentration was
high, extra sucrose was added to further
increase nitrogen assimilation. The carbon and nitrogen contributions of the
feed and sucrose are shown in Table 1.
Temperature, pH and dissolved-oxygen levels were measured twice daily, and
other water quality parameters were measured weekly. Morning pH readings were
used to decide how much sodium bicar-
bonate to add each day in an effort to
maintain high pH during the project. If
pH was below 7.9, 300 g sodium bicarbonate were added, and 500 g were added
if pH fell below 7.7. For pH below 7.5,
1,000 g were added.
Results
Water temperatures did not fluctuate
substantially between morning and afternoon measurements, likely because the air
temperature remained low, and water temperature was influenced primarily by the
heating system. High pH was maintained
near 7.8 through regular sodium bicarbonate additions. Dissolved oxygen was held at
a relatively high concentration by using the
aeration nozzles and added oxygen gas.
Mean values for these and other water
quality parameters are given in Table 2.
Ammonia concentrations remained
low during the project, but nitrite concentrations as high as 5.5 mg/L were
measured near the middle and end of the
project. However, no mortality or decline
in feeding behavior was observed in relation to the nitrite spikes. Although
nitrate concentration was not measured,
other raceways managed to favor heterotrophic nitrogen assimilation at the Gulf
Coast Research Laboratory had very little
nitrate accumulation.
Total suspended solids (TSS) concentrations were maintained slightly higher
than what other authors have recommended for biofloc systems, but shrimp
production metrics did not seem to reflect
any adverse effects. Also, the management
of solids concentration with a settling
chamber resulted in a total water exchange
of 5.8% of the volume of the raceway, not
including water lost to evaporation. When
the operating salinity of 20 ppt is mathematically adjusted to the 30-ppt levels in
Table 1. Carbon and nitrogen contributions of feed and sucrose.
Feed
Sucrose
Total
Carbon
(%)
Nitrogen
(%)
Weight
(kg)
Carbon
Added (kg)
Nitrogen
Added (kg)
Carbon:
Nitrogen
Ratio
41.7
41.0
82.7
5.8
0
5.8
348.0
179.6
527.6
145.1
73.7
218.8
20.2
0
20.2
7.2
–
10.8
Table 2. Mean water quality parameters during the project.
Parameter
Temperature
pH
Dissolved oxygen
Ammonia nitrogen
Nitrite nitrogen
Total suspended solids
Turbidity
Settled solids
Value
29.0 ± 0.5° C
7.8 ± 0.2
7.9 ± 0.8 mg/L
0.2 ± 0.2 mg/L
2.3 ± 1.9 mg/L
337.0 ± 52.0 mg/L
84 ± 15 NTU
14.5 ± 3.7 mL/L
recent studies by other authors, the total
water use would be 133 L/kg shrimp biomass. At 35 ppt, the salinity value of fullstrength seawater, water use would have
been 114 L/kg shrimp.
The average shrimp growth rate was
1.8 g/week. Shrimp grew from 1.5 to
22.5 g in 82 days, indicating that if the
conditions of this project can be maintained, it may be possible to grow more
than four crops of shrimp yearly. FCR
was very low at 1.2:1, and survival was
high at 96.6%. Although the stocking
density was lower than in similar projects,
the biomass production was relatively
high at 5.3 kg/m3 due to high survival
and moderate final weights of 22.5 g.
Perspectives
This raceway project represented an
effort to combine some of the latest technological innovations with biofloc management regimes that have been in development at the Gulf Coast Research
Laboratory. The consistent water temperature provided by the central heating
system likely contributed to good shrimp
production. Constantly high dissolvedoxygen (D.O.) concentrations probably
assisted the production metrics as well,
although a lower D.O. concentration may
have been adequate.
The authors are confident that the use of
oxygen gas can be conserved by using a continuous oxygen-monitoring system capable
of controlling oxygen injection. The aeration
system and water pumps may be capable of
maintaining adequate D.O. concentration
without supplemental oxygen.
Consistently high pH was accomplished using regular bicarbonate inputs.
However, it is unclear how this may
affect the mineral composition of the culture water if it is reused for multiple
shrimp crops. Heterotrophic nitrogen
assimilation functioned well, although
spikes in nitrite were troubling. The process of assimilation may be facilitated
more effectively using feeds with lower
protein content.
The shrimp production parameters
were very good, most notably growth rate,
FCR and survival. These results, along
with low rates of water use, may provide
impetus for using this technology at inland
locations, especially in cooler climates.
If the conditions of this
project can be maintained,
it may be possible to grow
more than four crops of
shrimp yearly.
23
Shrimp Growth (g)
production
20
18
16
14
12
Normal Control
Increased Control
10
8
6
4
2
0
Figure 1. Shrimp
growth.
42 50 58 647279 8693 97
Days of Culture
The production controls needed for
biofloc systems contribute to improved
biosecurity.
Most of the shrimp farms in Bali utilize aeration and operate under intensive production.
Intensive Farm In Bali, Indonesia,
Produces Shrimp In Biofloc System
Summary:
Although Bali is primarily a
tourist destination, several small
family-owned shrimp farms are
located here. The Ndaru Luat
Setio shrimp farm at Kubu raises
specific pathogen-free Litopenaeus vannamei in ponds that
apply basic biofloc technology
with zero water exchange. Ample
aeration and well-controlled dissolved oxygen maintain good
water quality in the culture environment. The farm has produced
45-55 mt/cycle since 2009 in a
stable and sustainable way without viral outbreaks.
Bali Island in Indonesia is a popular
tourist destination. However, a few aquaculture facilities, including small shrimp
farms, are located here – mostly on the
northern coast. Most of the shrimp farms
are family owned and operate under
intensive production, as the land area is
very limited. Ndaru Laut Setio shrimp
farm is located at Kubu, on the northern
coast of Bali not far from tourist dive
resorts. It raises specific pathogen-free
Litopenaeus vannamei in ponds.
24
Nyan Taw, Ph.D.
Consultant
Blue Archipelago Berhad
T3-9, KPMG Tower, 8 First Avenue
Persiaran Bandar Utama 4780
P.J., Selangor, Malaysia
[email protected]
Surijo Setio
Ndaru Laut Setio
Kubu, Bali, Indonesia
Farm
Twelve ponds with sizes ranging from
600 to 2,800 m2 operate with two reservoirs that reflect 16% of the total culture
pond area, just over 2 ha. All ponds and
reservoirs are fully concrete lined and
mostly rectangular in shape with an average depth of 1.2 m. The ponds have central drain systems.
Like a terraced rice field, the shrimp
farm is constructed at a slope on the edge
of the northern sea coast. Seawater from
the open sea is pumped into treatment
reservoirs at the highest level. This
enables technicians to distribute water to
the culture ponds by gravity.
Biofloc Technology
The ponds apply basic biofloc technology with zero water exchange. Grain and
present cycle, added efforts were applied
to reduce culture days with intensive feed
and controlled biofloc development. This
paid off, as shrimp grew faster and the
days of culture were reduced to just over
80, compared with the more typical 100
days of culture at the farm (Figure 1).
molasses are added to the culture water to
increase the carbon:nitrogen (C:N) ratio,
while added aeration supports the biofloc
suspended in the water column.
Initially, grain pellets made from wheat
flour were used at 10 to 20% of the normal
feed volume provided, but later only molasses was applied to increase the C:N ratio.
On a daily basis, ponds receive about 1 to 2
ppm molasses. The biofloc is maintained
below 12 mL/L. A well-known probiotic
product was tried during the cycle, but its
effects were not clearly seen.
The aeration system helps move excess
biofloc and sludge to the centers of ponds
or other designated locations to enable
removal, when required. In this respect,
the positioning of the aerators, which support 400 kg/hp carrying capacity, is very
important. A typical carrying capacity with
biofloc systems is 600 kg/hp.
Environment
Since ample aeration is supplied, and
dissolved oxygen is well controlled, water
quality in the culture environment is
maintained within normal limits. Biofloc
volume is controlled below 10 mL/L, as
measured in Imhoff cones. Temperature
ranges between 27 and 33° C during the
cycle, whereas salinity is kept between 33
and 38 ppt. At times near harvest, however, salinity can exceed 40 ppt.
Dissolved-oxygen levels are kept above
4 ppm, with pH and other parameters
within acceptable ranges. At harvest,
nitrate can reach 100 ppm, and ammonia
and nitrite run high at 8 to 10 ppm.
The farming cycles are scheduled to
avoid months with low temperatures,
which in Bali are January, February, July
and August. January and February reflect
a cool, unstable rainy season, whereas in
July and August, seawater temperatures
below 26° C can be expected. These conditions are known to contribute to the
likelihood of viral outbreaks.
Biofloc Benefits
The operation started in 2007 as a
conventional intensive system with L.
vannamei. All 12 ponds were operational
at the end of 2008, when shrimp farms in
Indonesia were hit hard by infectious
mionecrosis virus. The Bali farm was also
hit by the virus, but managed to run for
80 to 90 days of culture by using only
treated replacement water.
At the time, the biofloc system had
been introduced, but the biofloc density
control system was not in place. The biofloc volume went up to 15 mL/L, and
dissolved-oxygen levels dropped below
2.5 ppm. However, the biofloc technology was fully realized and functional in
early 2009. The farm has produced 45-55
mt/cycle since 2009 in a stable and sustainable way without viral outbreaks.
Production
Farm production data from 2012 are
provided in Table 1. Initially, only two
cycles were achieved in one year, but lately,
2.5 to 3.0 cycles have been targeted.
Recent farm production from 2 ha of
pond area for one cycle has been 45 to 55
mt or 90 to 110 mt in one year. In the
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Table 1. Farm production data, August to November 2012.
Pond
A2
A3
F1
F2
E1
E2*
B1
B2
B3
C1
C2
C3
2,400
2,600
2,800
2,800
1,000
750
2,000
2,000
2,000
600
600
600
Stocking density (postlarvae/m2)
170
148
150
145
150
180
155
155
155
175
175
175
Aeration (hp)
18
18
16
18
6
4
12
12
12
12
6
4
Days of culture
97
97
97
95
95
45
82
82
81
82
82
81
Body weight (g)
18.4
18.12
15.32
17.30
16.48
4.00
19.5
18.5
16.00
14.68
19.72
18.48
Feed-conversion ratio
1.26
1.35
1.49
1.29
1.46
–
1.20
1.40
1.25
1.35
1.10
1.14
Survival (%)
105.8
104.0
101.0
106.0
94.7
–
103.9
94.0
92.9
97.4
98.5
101.9
Production (kg/pond)
7,914
7,281
6,388
7,682
2,345
–
6,307
5,399
4,622
1,503
2,050
1,981
Production (kg/ha)
32,976
28,004
22,814
27,436
23,450
–
31,535
26,995
23,110
25,050
34,167
33,017
440
405
399
427
391
–
526
450
385
376
342
495
Pond size (m2)
Production/power input (kg/hp)
* Areation problem – Dissolved oxygen below 1.0 ppm
Farm total production: 53,472 kg (26,736 kg/ha)
In this cycle, ponds B1, B2, B3, C1, C2 and C3 were under heightened control with a shortened growout period
25
production
the bottom line
Table 1. Construction costs for a shrimp nursery
system for 20 million to 40 million postlarvae.
Units
Facility/Equipment
Cost (U.S. $)
1
20
Greenhouse structure, drainage system
10-m-diameter round tanks
with 1-mm HPDE liners
Plastic cover
10-hp regenerative blowers
5-hp diesel water pumps
30-kw diesel generators
Pipe and equipment
50,000
45,000
1
3
2
2
1
Total
Single-phase nursery tank systems are generally built in one of several configurations: round with a center drain, oval with a center wall
or rectangular. Stacked rectangular tanks are also used.
Hyper-Intensive Nursery Systems
Offer Advantages For Shrimp Culture
Summary:
Hyper-intensive nursery systems
for juvenile shrimp production
present significant opportunities
for shrimp farmers to increase
profits. Nursery culture results in
strong, healthy and uniform juveniles with great potential for compensatory growth when stocked in
production ponds. Nurseries produce a maximum number of juveniles of a desired weight, and their
use can reduce production costs by
shortening time in growout ponds
and increasing pond efficiency
through additional cycles per year.
Hyper-intensive nursery systems for
juvenile shrimp production have been
around for decades. In the last several
years, it has been recognized that they
represent one of the most significant
opportunities for the shrimp-farming
industry to increase profits. System
design and management have also
improved to facilitate a consistent, lowrisk “factory model” defined by foreseeable production inputs and stable, predictable operating results.
Nursery Systems
Hyper-intensive shrimp nurseries typically feature a biosecure production system built in or close to a shrimp growout
facility. They incorporate environmental
controls to grow postlarvae at high densities from 2 to 300 mg weight or greater.
Nursery culture results in strong, healthy
26
and uniform juveniles with great potential for compensatory growth when
stocked in production ponds. Sample
construction costs and proportional operational costs are shown in Tables 1 and 2.
The main objectives of nursery systems
include faster average growth in production ponds after transfer and preventing
disease by exclusion and using controlled
temperatures – above 32° C to address the
white spot syndrome virus, for example.
Nurseries also produce a maximum number of juveniles of a desired weight and
improve the health and resistance of animals to be stocked into ponds.
The benefits of these systems include
stocking farms earlier to meet health regulations, gains during seasonal cold temperatures and the option to buy postlarvae (P.L.) in periods of low demand and
lower prices. Nursery systems offer the
opportunity for compensatory gain,
which allows earlier harvests and entering
the market sooner to get better prices.
Correct use can reduce production costs
by reducing the time in large ponds and
increase pond efficiency through additional cycles per year.
Siting, Building
Considerations
At many farms, it is impossible to
construct this type of system in an ideal
location to meet all criteria, but it is recommended that the water should be
sourced from the intake channel or before
the pump station to allow draining and
dryout of the main reservoir channel
without affecting its operation. The water
should drain into the farm discharge
Neil Gervais
Technical Sales Manager –
Shrimp Feeds
[email protected]
Thomas R. Zeigler, Ph.D.
Senior Technical Advisor
Past President and Chairman
Zeigler Bros., Inc.
P. O. Box 95
Gardners, Pennsylvania 17324 USA
channel away from the intake.
To lower costs, it is advisable to locate
the nursery close to existing main and
emergency backup power sources. If possible, it should be located near the farm’s
main administration area – close to
offices, supplies and personnel. Ideally,
the facility should be constructed high
enough for good drainage and no more
than 10 minutes travel time away from
the farthest pond.
Single-Phase Nursery Tanks
Single-phase nursery tanks are typically designed to stock 2- to 10-mg postlarvae to produce 100-, 200- or 300-mg
juveniles. The tanks are normally from 40
to 200 m3 in volume and are built under
greenhouse or shade cloth coverings.
Single-phase nursery tank systems are
generally built in four different shapes.
Typically, they are round with a center
drain or oval with a center wall for good
circulation to keep solids in suspension.
Rectangular tanks typically have a water
inlet opposite water discharge, while
stacked shallow rectangular systems are
used for super-high densities and space
efficiency.
Most of these systems are built of
concrete, wire mesh, wood, plastic, fiberglass or formed soil with a liner or epoxy
covering. Stocking densities range
8-50/P.L./L to produce juveniles of 0.1to 0.3-g harvest size. Final biomass harvests yield 1-5 kg/m3.
Round tanks are inexpensive and easy
to build, with good circulation for feed
distribution and sludge removal. This
cuts down on investment, personnel
needs and human error. Their disadvantages are that they are not space efficient
and need large, unique cover designs and
support structures to house them.
Oval tanks have great circulation for
keeping solids in suspension and waste
removal, and fit well under greenhouse
roofing. Although they can be somewhat
more difficult to build and manage than
other designs, the highest biomasses have
been achieved with these systems.
The advantages of rectangular tanks
include ease of construction, space efficiency
under standard greenhouses and familiarity
of use by hatchery technicians. However,
sludge removal and feed distribution can be
less efficient, and the tanks are expensive to
8,500
11,000
2,000
20,000
13,500
150,000
Table 2. Proportions of operational costs
for intensive shrimp nursery systems.
Proportion of Costs (%)
46
12
7
13
12
10
Feed
Additives and buffers
Probiotics
Salaries
Energy
Miscellaneous
build, operate and manage. More personnel
are needed to operate them, and they offer a
limited final biomass.
Stacked shallow raceways can maximize biomass in a minimum footprint –
up to 10 times more mass than that of
other systems. Raceways are unmatched
in efficiency to control temperature, feeding and personnel inputs. They are ideal
for extreme environments where space
and temperature are limitations.
The stacked systems are relatively new
and considered unproven or complicated
to some, with few examples of how to buy,
build and operate them available. This
type of system will likely become much
more common in supporting hyper-intensive growout operations and inland shrimp
farming in cold environments.
Second-Phase Nursery Tanks
Second-phase nursery tanks are similar to single-phase systems, but operate
on a larger scale.
The reason for a second-phase nursery
at farm level is related to stocking a greater
number of larger juvenile shrimp into production ponds than would be possible
from a single-phase system. This strategy
is usually beneficial where crops are seasonal and where the first farms that harvest get higher prices. Second-phase tanks
can also support additional crop cycles.
These systems are typically built with
rounded central drain, oval or rectangular
tanks or ponds with sizes ranging from
300 to 7,500 m3. For stocking, 0.1- to
0.3-g juveniles are transferred from a firstphase system. Densities range
0.5-5.0/P.L./L to produce juveniles with
harvest weights of 1 to 3 g. Final biomass
volumes at harvest run 1-3 kg/m3.
Water Treatment, Monitoring
The water for nurseries should be as
clean as possible and come from the same
source used for production ponds. Water
can be pumped into reservoirs or directly
to production tanks.
To aid in biosecurity, most systems
use prefiltration and disinfection of
incoming water, such as initial sand filtration, 5- to 50-µ cartridge filtration and
20-ppm chlorination.
Designs demanding the highest levels
of biosecurity use additional filtration
and/or treatments with ozone or ultraviolet light and final cartridge filtration.
Mandatory support equipment
includes properly sized incoming water
pump and distribution pipes and blowers
with sufficient capacity and minimum
emergency backup power. Round tanks
usually use 0.5-1.0 hp/100m3 tank space.
Rectangular tanks usually use 2-3
hp/100m3 tank space. Newer designs
using venturis or air injectors both aerate
and circulate the water without the need
for blowers at all. These have lower initial
capital investments and lower operating
costs while increasing the carrying capacity
of the system.
Because of the considerable biomasses
found in intensive nurseries, continual
monitoring of various parameters is
essential. Essential equipment includes
gear to measure levels of dissolved oxygen, ammonia, nitrogen dioxide, alkalinity, free chlorine and hydrogen sulfide in
water, as well as temperature, pH, shrimp
weight and feed use.
Intensive Nurseries Versus
Direct Stocking
Hyper-intensive shrimp nurseries seek
to fulfill the same goals as the small, lowdensity pond nursery systems used by
producers for decades, but in a controlled
environment with high biosecurity.
Intensive nurseries allow much more efficient use of ponds’ carrying capacity than
direct stocking of postlarvae provides,
while at the same time reducing risk.
Because of shorter pond cycles, daily
fixed costs are also reduced for each kilogram of shrimp produced. An economic
comparison of direct stocking versus
transfer of juvenile shrimp from a nursery
is shown in Table 3.
Proven Benefits
The greatest economic gains from the
27
use of nurseries exist when there is opportunity to stock postlarvae at a farm when
temperatures are too low for open pond
stocking and to have a large quantity of
juveniles ready to stock when temperatures increase or regulations permit. Producers can also reduce time to harvest by
having juveniles ready to restock a pond
following a harvest, increasing cycles per
year or size of shrimp at harvest. Additional important benefits can be seen
when stocking ponds with low primary
water productivity and when juveniles of
sufficient size are needed to go directly
onto pelleted feeds.
Compensatory Growth
Gains from compensatory growth can
be realized when postlarval shrimp are in
a situation of controlled slow growth for a
period of time, such as in nurseries. When
growth conditions change favorably,
shrimp have the ability to regain lost
weight very quickly and achieve a normal
age-based weight – as seen after transfer
into growout ponds.
To obtain maximum compensatory
gains, juveniles need to be fed sufficient
high-quality feed specifically designed to
provide all the nutrients necessary to
obtain this rapid growth. The accelerated
growth is easily lost if shrimp receive feed
of poor nutritional quality or in insufficient quantities.
As an example of compensatory
growth, after direct stocking into a growout
pond, postlarvae can achieve a size of 1 to 2
g, depending on temperature. A juvenile of
0.1 to 0.3 g produced in a nursery for three
weeks can reach a size of 4 to 6 g about four
weeks after transfer to ponds.
28
Table 3. Economic calculations comparing profits expected
for systems using directly stocked postlarvae or juveniles
transferred from a single-phase nursery system.
Input Data
Direct
Stocking
Juvenile
Transfer
Pond size (ha)
Density (postlarvae/m2)
Growth rate (g/week)
Harvest weight (g)
Survival (%)
Postlarvae cost (U.S. $/1,000)
Sale price (U.S. $/lb)
Feed cost (U.S. $/lb)
Other costs (U.S. $/day)
1.0
12
0.80
15.00
65%
1.5
$3.00
$5.00
$0.50
$22.00
1.0
12
1.00
15.00
70%
1.3
$5.50
$5.00
$0.50
$22.00
–
–
0.20
–
0.05
(0.20)
$2.50
–
–
–
131.25
120,000
2,577.09
$12,885.46
$360.00
3,865.64
$1,932.82
$2,887.50
105.00
120,000
2,775.33
$13,876.65
$660.00
3,607.93
$1,803.96
$2,310.00
(26.25)
–
198.24
$991.19
$300.00
(257.71)
($128.85)
$577.50
Calculations
Cycle length (days)
Postlarvae stocked
Harvest weight (lb)
Market value (U.S. $)
Postlarvae cost (U.S. $)
Feed given (lb)
Feed cost (U.S. $)
Other costs (U.S. $)
Postlarvae cost (U.S. $)
Feed cost (U.S. $)
Other costs (U.S. $)
Transfer Profit
Advantage
0%
0%
25.0%
0%
7.7%
-13.3%
83.3%
0%
0%
0%
-20.0%
0%
0.2%
7.7%
83.3%
-6.7%
-6.7%
25.0%
Difference
$0.14
$0.75
$1.12
$0.24
$0.65
$0.83
Profit
Income over costs (U.S. $)
Additional growth
opportunity (U.S. $)
Difference
Difference
Cost/lb Sold
$0.098
$(0.100)
$(0.288)
70.2%
-13.3%
-25.7%
Difference
$7,705.14
$9,102.69
$1,397.54
$991.19
18.1%
$2,388.73
Note additional costs of growing juveniles produced in a single-phase nursery system:
Juveniles of 0.1-0.3 g, U.S. $2-3/1,000
Juveniles of 1.0-3.0 g, U.S. $4-5/1,000
Bottom Line: Implementation of hyper-intensive nursery
systems is a quick, relatively inexpensive way to lower risk
and increase efficiency and profits at shrimp farms.
Nursery Feeding Program
nutrition through innovation
Lower Your Risk,
Increase Your Prots.
Proper design and management of nursery systems for shrimp culture has been shown to greatly
increase protability while reducing risk at the farm. Feeds and feeding drive these systems and are
fundamental to juvenile performance and water quality.
After extensive research, Zeigler has developed a feeding program specically designed to support
hyper-intensive nursery systems.
Stage
Nursery 1
Nursery 2
Nursery 3
Nursery 4
Nursery 5
Particle Size
0.3–0.6 mm
0.6–0.8 mm
1.0 mm
1.5 mm
2.0 mm
Animal Size
2-10 mg
10-100 mg
100-400 mg
400-1500 mg
1.5-3.0 g
}
 Concentrated nutrient prole to compensate for
reduced feeding in managing water quality.
 Food particle sizes target animal weight, not stage.
 Customized feeding rates recommended based
upon specic nursery conditions.

Vpak added to support animal health and
disease resistance.
Contact a Zeigler representative to learn more about the program.
nutrition through innovation
717-677-6181 phone
www.zeiglerfeed.com
[email protected]
www.nutrimar.com.mx
January/February
2014 29
[email protected]
production
Inbreeding Cuts Growth,
Reproduction In Shrimp
Brad J. Argue, Ph.D.
Moana Technologies, LLC
73-4460 Queen Kaahumanu
Highway #121
Kailua-Kona, Hawaii 96740 USA
[email protected]
Geovanni Tolentino
Kailua-Kona, Hawaii, USA
J. A. Brock, DVM
Aiea, Hawaii, USA
First-Generation Inbreeding
Inbreeding quickly leads to reductions in growth and survival in shrimp.
Summary:
Shrimp-breeding programs
release only a small fraction of
their genetic material when they
sell seed to clients for growout.
This protects their large investment in developing the stocks
so clients return for their next
batch of seed instead of breeding the stocks themselves. In a
study, black tiger shrimp inbred
for three generations exhibited an
immediate decrease in growth,
while reductions in reproductive
performance were seen in later
generations. In the second generation, growth and reproductive
performance were halved.
Due to the limited stock protection
methods that can be scaled up to a commercial level, shrimp-breeding programs
often use inbreeding to help protect their
investment in producing specific pathogen-free, domesticated, selectively bred
animals. In theory, if customers try to
“copy” (breed) the shrimp seed supplied
to them, they will quickly encounter
decreased performance due to inbreeding.
The expectation is that a brother and
30
sister would have no problems producing
offspring together. However, the growth
and survival of the offspring would be
reduced, and if a stressor such as disease
or poor water quality were added, performance would decrease even more dramatically. The poor reproduction of these
inbred animals should discourage copiers
rather quickly and make them return to
the breeding company for more stock.
In a study by the authors, black tiger
shrimp were inbred for three generations
to quantify the differences in performance between inbred and non-inbred
Penaeus monodon.
Family Production
Moana Technologies, LLC’s closed
herd of Penaeus monodon is housed at the
Moana Nucleus Breeding Center in
Kona, Hawaii, USA. The last introduction of animals to the herd occurred in
2005. Since then, mating has been based
on a pedigree that only allowed crosses
with less than 3% inbreeding.
Starting in 2009, Moana purposely
inbred brother x sister families by artificial insemination for three generations.
The families produced in December 2009
were 25.0% inbred, while those in March
2011 were 37.5% inbred. In March 2012,
the shrimp families were 50% inbred.
After one generation of brother-sister
mating (25% inbreeding), non-inbred
shrimp grew 24% faster than inbred
shrimp, but survival was only 5% lower in
the inbred shrimp (Table 1). During a
disease challenge conducted at a biosecure testing facility, non-inbred and
inbred shrimp in an untreated control
tank also showed a 24% difference in
growth – 22.3 versus 17.9 g, respectively.
However, in tanks into which disease
agents were introduced, there was a 50% difference in growth between non-inbred and
inbred shrimp, which had 19.2- and 12.8-g
weights, respectively. This clearly showed
the danger of growing inbred shrimp if a
stressor is introduced to the population.
Moana spawns families within a small
time window to decrease the differences
in age among families. In March 2011,
the 25%-inbred shrimp had 36% of the
females spawn in a 10-day window, compared to 47% of the non-inbred females
spawning. Surprisingly, the inbred
females produced 71,500 nauplii/spawn,
while the non-inbred females produced
59,000 nauplii/spawn.
Second-Generation
Inbreeding
In March 2011, the 25%-inbred
shrimp were mated by artificial insemiTable 1. Growout performance
of non-inbred
and 25%-inbred shrimp.
Noninbred
Inbred
Harvest
Weight
(g)
Weight
Coefficient of
Variation
(%)
Survival
(%)
31.7
30.6
78.9
25.6
40.2
75.5
31
Table 2. Growout performance
of non-inbred
and 37.5%-inbred shrimp.
Noninbred
Inbred
Harvest
Weight
(g)
Weight
Coefficient of
Variation
(%)
Survival
(%)
33.9
30.4
53.5
21.8
36.2
36.0
nation for another generation of brother
x sister mating to produce 37.5%-inbred
shrimp. This level of inbreeding had a
very large effect on performance, as the
inbred shrimp grew 56% slower, and survival was 49% lower than for non-inbred
individuals (Table 2).
During a 10-day spawning period in
March 2012, 20.0% of the 37.5%-inbred
shrimp females spawned compared to
36.0% of the non-inbred shrimp. However,
there was a large difference in the number
of nauplii, with non-inbred females producing 86,000 nauplii and inbred shrimp
producing 27,000 nauplii/spawn.
Third-Generation Inbreeding
The 37.5%-inbred females were
crossed again with their brothers to
obtain 50%-inbred shrimp in March
Table 3. Growout performance
of non-inbred
and 50%-inbred shrimp.
Noninbred
Inbred
Table 4. Differences
in growth and survival between
non-inbred and inbred
shrimp after several
generations of inbreeding.
Harvest
Weight
(g)
Weight
Coefficient of
Variation
(%)
Survival
(%)
34.3
24.5
80.0
Generation
62.4
First
Second
Third
26.5
29.1
2012. There was a significant difference
in growout performance, although it was
not as large as seen in the 37.5%-inbred
shrimp (Table 3). None of the 50%inbred shrimp spawned in March 2013,
ending the study after three generations
of brother x sister mating.
Perspectives
Inbred Penaeus monodon had a large
decrease in performance compared to
non-inbred shrimp (Table 4). This was
immediately seen in growout performance and magnified further in the presence of disease agents. Twenty-five percent-inbred shrimp did not have a large
drop in reproductive performance, but
higher levels of inbreeding had serious
effects on reproduction.
This decrease in performance should
Growth
Difference
(%)
Survival
Difference
(%)
24
56
29
5
49
28
encourage potential copiers to return to
the breeding company for future seed to
maintain a high level of production on the
farm. In addition, farmers should demand
that they only receive original seed and
not “copied” seed to stock their farms to
increase their survival and growth.
This decrease in performance should encourage
potential copiers to return
to the breeding company
for future seed to maintain
a high level of production
on the farm.
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aquaculture
January/February 2014 33
production
sustainable aquaculture practices
Nitrite Toxicity Affected By Species
Susceptibility, Environmental Conditions
Claude E. Boyd, Ph.D.
Department of Fisheries
and Allied Aquacultures
Auburn University
Auburn, Alabama 36849 USA
[email protected]
isms and more than 500 mg/L for marine
species. On the other hand, nitrite is considerably more toxic.
Exposure to nitrite causes gill lesions
and edema in the skeletal muscles of fish,
but its main effect is on respiration.
Although relatively common in freshwater systems, nitrite toxicity is a lesser problem
When absorbed into the bloodstream,
in brackish and seawater culture systems.
nitrite combines with hemoglobin – or
hemocyanin in invertebrates – to form
methemoglobin or met-hemocyanin that
does not combine with oxygen.
Summary:
The percentage of methmoglobin or met-hemocyanin in the
Nitrite, an intermediate compound in the oxidation of
blood of aquatic animals increases as the nitrite concentration in
ammonia nitrogen to nitrate by nitrifying bacteria in
the blood increases, lessening the ability of the blood to transsoil and water, is considerably more toxic than nitrate.
port oxygen to the tissues. The effect of nitrite on respiration is
Exposure to nitrite causes gill lesions and edema in the
particularly pronounced when the dissolved-oxygen concentraskeletal muscles of fish, and also affects respiration.
tion is low in the culture water.
Nitrite concentration is affected by the dissolved-oxygen and chloride levels in water, as well as species’ difChloride Effects
ferences in nitrite susceptibility. Fish suffering brownThe chloride concentration in water also greatly affects the
blood disease quickly recover when moved
uptake of environmental nitrite across the gills and into the
to water with low nitrite concentration.
bloodstream of aquatic animals – especially freshwater animals.
Chloride ions have the same charge and are similar in size to
nitrite ions. Because of this similarity, chloride competes with
Nitrite is an intermediate compound in the oxidation of
nitrite for adsorption sites on the active carrier mechanism
ammonia nitrogen to nitrate by nitrifying bacteria in soil and
responsible for transporting environmental nitrite across the gill
water. It also can be a product of denitrifying bacteria in anaerolamellae to the bloodstream. By blocking the uptake of nitrite by
bic sediment or water. Nitrite is ultimately oxidized to nitrate in
the carrier, chloride lessens the amount of nitrite that would pass
the presence of dissolved oxygen. Nevertheless, aquaculture sysfrom water to the bloodstream of aquatic animals at a particular
tems usually contain small nitrite concentrations below 0.1 mg/L
nitrite-nitrogen concentration, thereby lessening the risk of
and under certain conditions, much greater amounts.
nitrite toxicity.
Nitrate – the most oxidized form of inorganic nitrogen in
water – is not highly toxic to aquatic animals. The concentration
Nitrite Toxicity
of nitrate-nitrogen lethal to 50% of test organisms in 96 hours
There is a large body of information on nitrite’s toxicity to
(96-hour LC50) typically is over 100 mg/L for freshwater organfish, shrimp and other aquatic organisms. The 96-hour LC50s
34
35
Table 1. Published 96-hour LC50s for nitritenitrogen in several species of aquatic animals.
Common Name
96-hour LC50
Freshwater
88.0 mg/L
117.0 mg/L
25.9 mg/L
29.4 mg/L
8.6 mg/L
0.5-0.6 mg/L
7.1-44.0 mg/L
45.0-70.0 mg/L
16.0 mg/L
140.0 mg/L
0.24-11.0 mg/L
Common carp
Catla
Mitten crab
Narrow-clawed crab
Freshwater prawn
Cutthroat trout
Channel catfish
Fathead minnow
Blue tilapia
Largemouth bass
Rainbow trout
Marine
Mud crab
Sea bass
European eel
Pacific white shrimp
Black tiger prawn
Sea trout
41.6-69.9 mg/L
154.0-274.0 mg/L
84.0-974.0 mg/L
9.0-322.0 mg/L
13.6 mg/L
980.0 mg/L
for nitrite-nitrogen typically range 10.00-30.00 mg/L for freshwater invertebrates and 0.25-100.00 mg/L for fish. The respective ranges for marine organisms are typically 10-300 mg/L and
100-1,000 mg/L. The 96-hour LC50s for several species of
aquatic animals are presented in Table 1.
Some of the variation in toxicity relates to the species’ differences in nitrite susceptibility. For example, the 96-hour LC50 in
Pacific white shrimp at 35-ppt salinity is 322.0 mg/L, while at
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36
the same salinity, the value for black tiger prawn is only 14.0
mg/L. At a chloride concentration of 22.0 mg/L, the 96-hour
LC50 for channel catfish is 7.5 mg/L, while for fathead minnows, it is 70.0 mg/L.
Water Quality Effects
Much of the variation in data from toxicity tests results from
differences in the water quality conditions under which animals
are exposed to nitrite. The LC50 tends to decrease with increasing temperature. For example, in a study with seabass, the LC50
declined from 274 mg/L at 17° C to 154 mg/L at 27° C. This
relationship is not surprising, because at a higher temperature,
organisms need more oxygen, and nitrite interferes with oxygen
transport in the bloodstream.
Salinity also influences nitrite toxicity. The 96-hour LC50 of
nitrite-nitrogen for European eels increased from 84 mg/L in
freshwater to 974 mg/L in water with 36-ppt salinity. In Pacific
white shrimp, LC50s rose from 61 mg/L at 15-ppt salinity to
322 mg/L at 35 ppt. This effect no doubt resulted from an
increase in chloride concentration in response to greater salinity
and provided protection against nitrite toxicity.
Coldwater species are much more sensitive to nitrite than are
warmwater species. For example, LC50s for rainbow trout are
four or more times lower than those for channel catfish.
The LC50 values from nitrite toxicity tests for aquaculture
species are difficult to interpret because of the various factors
that affect them. Moreover, aquaculturists want to avoid negative effects of nitrite on growth and increased susceptibility to
diseases that occur at much lower concentrations than the LC50.
Safe concentrations for continuous exposure of aquatic animals to nitrite and other common toxins often are estimated as
0.05 or 0.10 of the 96-hour LC50. Based on reported LC50s,
safe concentrations of nitrite-nitrogen in freshwater range
0.0125-0.5000 mg/L for coldwater fish and 0.5000-2.5000
mg/L for invertebrates and warmwater fish. For marine organisms, the ranges in safe concentrations are higher – 0.5 to 15.0
mg/L for invertebrates and 5.0 to 50.0 mg/L for fish.
Brown-Blood Disease
Nitrite toxicity is not a common problem in brackishwater and
seawater systems, but it is relatively common in freshwater. One
symptom of nitrite toxicity is easily recognized: The blood of fish
or shrimp will be brown in color as a result of the elevated bloodstream concentrations of methemoglobin or met-hemocyanin.
As a result, nitrite toxicity commonly is referred to as brownblood disease. The severity of brown-blood disease varies with
nitrite concentration, dissolved-oxygen concentration and other
factors. It is interesting to note that fish suffering brown-blood
disease quickly recover when transferred to water with a low
nitrite concentration.
Nitrite is relatively easy to measure,
and fairly accurate results can be obtained
with inexpensive test kits. In freshwater
aquaculture, pond managers who measure
elevated nitrite concentrations in waters
of ponds or other culture systems can
apply sodium chloride to increase the
chloride concentration.
A chloride concentration 20 times
greater than that for nitrite-nitrogen concentration will completely counteract
nitrite toxicity in channel catfish and
probably most other freshwater species.
Sodium chloride treatment does not
appear to be feasible in brackishwater and
marine aquaculture.
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Controls
Dissolved-oxygen concentrations below 3 mg/L for warmwater species and below 5 mg/L for coldwater species encourage
oxidation of nitrite to nitrate in the water and at the sedimentwater interface. They also provide a margin of safety for nitritestressed animals that are more susceptible to low dissolved-oxygen levels.
In channel catfish culture in the United States, farmers typically apply sodium chloride to ponds each year to maintain chloride concentrations of 50-100 mg/L that avoid brown-blood disease. This procedure is highly effective and could be used in
other types of freshwater aquaculture.
37
production
the end of the season. As a result, fish
farmers usually harvest fish that have
reached market size during the season to
reduce the biomass. The reservoirs are
equipped with harvesting equipment, such
as lifting nets attached to motorized
booms that are lifted with the catch.
The fish gather in a sleeve, which can
be detached and dragged to the reservoir
bank, where they are sorted and handled.
Some reservoirs have concrete harvest pits
at the ends of the outlet pipes by the
drainage canals. The pits have strainers for
separating the fish from the water, as well
as life-support systems to ensure the welfare of the fish.
Technology Improvements
Farmers use lift nets to harvest fish that have reached market size during the season to reduce the biomass. Photo by David Jansen,
Visible Voices Media, Israel.
More Tilapia, Higher Profit?
Reservoir Study: Fish Sizes/Prices Must Also Be Considered
Summary:
Israel has suffered from a chronic
water shortage for years. In recent years,
however, the situation has developed into
a severe crisis. The agricultural sector has
been heavily challenged, but in spite of the
obvious climatic constraints and overall
shortage of water, both agriculture and
aquaculture are highly developed in Israel.
A variety of methods are practiced to
maximize water use and enable the production of fresh fish. First and foremost
have been reservoirs to store rainwater
during the wet season. Many of these are
also used for fish culture in integrated
farming systems. With support from the
Ministry of Agriculture, fish farmers have
invested around 100 million new shekels
(U.S. $28 million) during the last three
38
decades in developing this unique dualpurpose reservoir culture system and associated technology.
Water Reservoirs
Traditionally, tilapia have been raised
in ponds with differing structures, bottom
types and depths. The main difference
between an earthen pond and a reservoir is
the depth of the water. Typical reservoirs
in Israel, which have areas between 5 and
20 ha, range between 4 and 15 m in depth.
Originally, irrigation reservoirs were
built to collect rain and flood waters in
winter and brackish spring water for use in
irrigating crops in summer. In order to
catch larger amounts of rainwater during
winter, the reservoirs were deepened.
Head of Aquaculture Division,
Extension Service
Ministry of Agriculture
and Rural Development
Agricultural Center
68 Hamadabeem Street
Rishon LeZion, Israel
[email protected]
The farmers of communal settlements
decided to use the irrigation reservoirs for
fish culture, in addition to their original
purpose. In a few years, it became evident
that rearing fish in such reservoirs was
profitable, although professional and technological know-how was still lacking.
The introduction of tilapia to irrigation
reservoirs improved the efficiency of water
usage and reduced the cost of water needed
for tilapia culture in conventional earthen
ponds. However, the main problem was
harvesting the fish, since the engineers who
planned the reservoir construction did not
take such activity into consideration.
Dramatic technological development
has occurred since then, and many new
The author recently evaluated the economic feasibility of tilapia growout at high
stocking density in irrigation reservoirs.
The main question was whether the
increase in fish yield resulted in higher
profits. The data analyzed were collected
from representative fish farms as well as
economic reports.
Current typical reservoirs yield about 1
mt/ha (1 kg/m3) annually, while intensively managed reservoirs can yield higher
volumes of fish. On average, fish weights
at harvest are above 500 g under typical
management and 400 g in the intensive
reservoirs. Size distributions and incomes
are presented in Figure 1. Farmers receive
average market prices of U.S. $3.19/kg for
large tilapia over 500 g in weight, $2.50/kg
for 400- to 500-g fish and $2.22/kg for
300- to 400-g tilapia.
With increasing stocking density,
farmers increase the number of paddlewheels for aeration by 25 to 35%, which
results in higher energy costs. Variations
among farms in production expenses for
fingerlings, feed, energy and fixed costs
not related to stocking density are due to
differences in tilapia size at stocking, mortalities during growout, culture periods
and management.
18,000
3.10
Fish Weight Over 300 g
Income
16,000
14,000
3.00
2.90
12,000
2.80
10,000
2.70
8,000
2.60
6,000
2.50
4,000
Tilapia Production
2.40
2,000
Due to the large volumes of the reservoirs, the fish output is much higher than
for earthen ponds, reaching 10,000-20,000
kg/ha yearly. This quantity of fish is too
large to be harvested from the pond pits at
Income (U.S. $/kg)
The introduction of tilapia to irrigation reservoirs in Israel improved the efficiency of water usage and reduced the cost of water needed for tilapia culture. Although requiring considerable investment, many dual-use reservoirs
were constructed and equipped for efficient harvesting. In a study, the author
found that increasing overall tilapia yields through higher stocking density
did not guarantee profitability. On the contrary, lower total yields consisting
of larger tilapia resulted in higher returns per kilogram of fish.
Yitzhak Simon
dual-use reservoirs were constructed and
equipped with a range of solutions for efficient harvesting. This has, in turn,
changed the emphasis such that in the
newly constructed reservoirs, tilapia culture became the primary activity and crop
irrigation a by-product.
Integrated reservoirs reduce the cost of
water for fish farming, as some of the costs
are recorded as irrigation expenses. These
reservoirs are usually deeper than 5 m to
allow irrigation during the summer and
ensure there is sufficient water until the
end of the tilapia production season in the
autumn. Heavy investments are necessary
to install the equipment required for tilapia production and harvest in reservoirs.
Yield (kg/ha)
Some reservoirs have concrete harvest
pits with strainers for separating the
fish from the water as well as life-support features to ensure the welfare
of the fish. Photo by David Jansen,
Visible Voices Media, Israel.
The desire of fish farmers to recoup
their investments in building reservoirs
within five to seven years has led them to
develop technologies that enable greater
production per unit area. While in conventional earthen ponds, yields consist of
0.5-0.7 fish/L water, those achieved in
reservoirs can approach threefold higher at
1-2 fish/L water. Various technical and
biological factors contributed to this dramatic rise in yield.
High-Density Study
0
Traditional
1234 5
Farm
2.30
Figure 1. Size distributions and average incomes in traditional ponds and representative
reservoirs at tilapia farms.
Table 1. Profit analyses for traditional ponds and representative reservoirs at tilapia farms.
Yield (kg/m3)
Fingerlings (U.S. $/kg)
Feed (U.S. $/kg)
Energy (U.S. $/kg)
Fixed costs (U.S. $/kg)
Total production cost (U.S. $/kg)
Income (U.S. $/kg)
Profit (U.S. $/kg)
Traditional
Farm 1
Farm 2
Farm 3
Farm 4
Farm 5
1.00
0.80
1.25
0.25
0.64
2.94
3.04
0.10
1.50
1.02
1.18
0.33
0.70
3.23
2.94
-0.29
1.35
0.64
1.22
0.33
0.61
2.80
2.61
-0.19
1.70
0.98
1.53
0.38
0.68
3.57
2.81
-0.76
1.25
0.97
1.53
0.38
0.73
3.61
2.56
-1.05
1.30
0.72
1.50
0.33
0.65
3.20
2.98
-0.22
39
Results
HELP SEASHARE
Table 1 shows the results obtained in five fish farms practicing intensive culture compared to the average values for conventional culture of tilapia. The table presents average income and
expenses for fingerlings, feed, energy and fixed costs – all calculated per 1 kg tilapia produced.
The bottom line was that the profits gained from tilapia production were higher in the traditional system than in the intensive culture management. Most farms lost money producing tilapia at higher production levels. Apparently, the other fish
produced in the reservoirs (15% of the total yield) enabled them
to not lose money altogether.
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The Israeli aquaculture industry has developed a unique technology for growing out fish in water reservoirs that attracts people
from all over the world. What impresses most visitors is the high
yield produced per unit area, a common measure for annual
returns on reservoir investment. However, profitability was never
evaluated based on the size distribution of the harvested fish,
since tilapia have a size-dependent market price.
The conclusion from the author’s study was that maximizing
yield did not guarantee profitability. On the contrary, lower total
yields consisting of larger tilapia under traditional management
resulted in higher returns per kilogram of fish.
Thus, increasing tilapia yields in reservoirs above current levels by increasing stocking density would not be profitable at current price levels. Production gains should be achieved by increasing
culture area and other inputs, including water, labor, energy, fingerlings and administration.
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40
41
production
Fishmeal-Free Feeds For Hybrid Tilapia
Table 1. Experiment
1 – mean fish performance and economic
evaluation.
Nathan Gur
Zemach Feed Mills
Zemach 15133
Mobile Post Jordan Valley
[email protected]
The use of plant-based protein sources for aquafeeds provides
flexibility in formulating diets for tilapia and other fish.
tional demands. Most studies reported so far suffered two main
drawbacks: They were conducted with small fish, single ingredient replacements were evaluated, and in most, palatability and its
effects on feed consumption were ignored.
Furthermore, earlier studies lost relevance due to the major
change in feed production method from pelleting to extrusion
and subsequent changes in nutritional values of some of the
ingredients. Current research on fishmeal substitutes is based on
composite feed content that is formulated from many protein
sources with minerals and palatability-enhancing additives.
Summary:
A series of experiments showed that fishmeal is not
an essential ingredient in tilapia feeds and that plant
protein-based diets can yield results similar to those
obtained with diets containing 10% fishmeal. It is possible to obtain profitable performance from various combinations of plant protein sources and poultry offal, depending on the availability and costs of these ingredients.
This offers more flexibility in formulating tilapia feeds
based on economical and marketing considerations.
For years, fishmeal has been considered an essential ingredient in fish and crustaceans feeds. Due to rising prices and the
ever-growing gap between fishmeal supply and demand, however, intensive research is being conducted to identify suitable
substitutes for fishmeal that support production levels equivalent
to those achieved with feeds containing fishmeal.
Fishmeal’s contributions to growth performance in cultured
fish are its high protein level, an amino acids profile similar to
that of fish carcasses, high digestibility, high palatability and
ability to attract fish to feed. Fishmeal lacks anti-nutritional elements, but contains essential omega-3 fatty acids and high levels
of minerals such as salt, calcium and available phosphate.
All these features can be obtained from substitute ingredients, but the challenge is to find an optimal combination that
results in feeds that are cheaper than those based on fishmeal.
Tilapia Testing
Tilapia are ideal candidates for the development of fishmealfree feeds because they are omnivores with relatively low nutri-
42
Experiment 1
Experiment 1 was a growth evaluation of hybrid tilapia fed
three diets containing decreasing levels (15, 10 and 5%) of fishmeal and three fishmeal-free diets based on plant protein sources
(soy meal, sunflower meal and dried distillers grains).
All diets were prepared as floating pellets with 30% protein
content and 3,000 Kcal/kg digestible energy. The experiment
was conducted for 110 days in 5-m3 tanks, with 4 replicate
tanks/treatment. Fish with an average weight of 92.3 g were
stocked at 80/tank. The results are presented in Table 1.
The diets with fishmeal supported higher growth and feed
efficiency. However, the soy-based diet resulted in fish performance not significantly different from that obtained with the
fishmeal diets. With the prices for feed ingredients and marketed fish at the time the experiment was conducted, the diets
containing 5 and 10% fishmeal were most economical.
Yield value (U.S. $/tank)
Feed cost (U.S. $/tank)
Net income (U.S. $/tank)
Treatment
Table 2. Experiment
evaluation.
Soy oil cake (%)
Sunflower meal (%)
Fishmeal (%)
Poultry meal (%)
Feather meal (%)
Blood meal (%)
Final weight (g)
Daily weight gain (g)
5%
Fishmeal
Soy
Meal
Sunflower
Meal
Dried
Distillers
Grains
422.30a
3.29ab
1.61cd
433.20a
3.42a
1.59d
418.40ab
3.29ab
1.64cd
412.40ab
3.19bc
1.71bc
397.70bc
3.03cd
1.79ab
382.40c
2.94d
1.84a
66.5
28.1
38.4
68.3
26.3
42.0
66.5
24.6
41.9
64.0
23.0
41.0
60.5
22.2
38.3
57.5
22.4
35.1
10%
Fishmeal
Poultry
Meal
Feather
Meal
Blood
Meal
Soy
Composite
Sunflower
Composite
37.0
31.5
37.6
40.9
30.8
26.5
5.0
5.0
3.0
4.0
5.0
3.0
4.0
10.0
325.00
2.38ab
1.73a
10.0
a
44.5
23.8
20.7
9.0
a
a
314.50
2.27ab
1.83a
315.30
2.22b
1.81a
326.40a
2.37ab
1.77a
333.80a
2.49a
1.75a
336.00a
2.47a
1.83a
42.0
22.1
19.9
41.8
22.6
19.2
43.5
23.0
20.5
45.0
23.0
22.0
41.5
22.2
19.3
Means in same row with same letter are not significantly different (P < 0.05).
Treatment
Feed Development
Work by the authors focused on evaluating the applicative
aspects of tilapia feeds, including testing feeds during growout to
market size and comparing extruded composite formulations to a
fishmeal-based control feed. All experiments were carried out at
the Ginosar Experimental Station of Israel’s Department of
Fisheries and Aquaculture using all-male Oreochromis niloticus x
O. aurea hybrids.
In the three-year study, a first phase evaluated the growth
performance of hybrid tilapia fed diets with varying levels of
fishmeal and fishmeal-free diets containing protein from various
plant sources. In subsequent phases, the growth performance of
tilapia fed fishmeal-free diets containing various combinations of
animal and plant proteins were evaluated. Calculations of yield
took into account the differences in size-dependent prices the
farmer received for fish obtained under the treatments tested.
Final weight (g)
10%
Fishmeal
Guy Rubinstein
Ginosar Research Station
Department of Fisheries and Aquaculture
Israel Ministry of Agriculture and Rural Development
Bet Dagan, Israel
Treatment
15%
Fishmeal
Table 2. Experiment
evaluation.
Soy +
Corn
10%
Soy
Gluten
Fishmeal Composite Meal
√
√
√
√
Soy +
Dried
Distillers
Grains
Soy + Corn
Gluten +
Distillers
Grains
√
√
√
√
√
Soy oil cake
Corn gluten meal
Fishmeal
Poultry offal
Dried distillers grains
Attractants
√
Final weight (g)
291.2
2.48
1.80
304.7
2.72
1.77
292.4
2.49
1.94
295.0
2.54
1.84
297.3
2.58
1.91
293.3
2.51
1.85
22.1
10.0
12.1
23.2
9.1
14.1
20.9
9.3
11.6
22.4
10.0
12.4
22.2
9.5
12.7
21.4
9.3
12.1
√
√
Soy + Corn
Gluten +
Attractant
√
√
Experiment 2
In a second experiment, the growth of tilapia fed diets containing soy or sunflower oil cakes supplemented with poultry
slaughter house offal containing poultry meal, feather meal and
blood meal was compared to fish given a control diet based on
soy oil cake plus 10% fishmeal.
content and 2,900 Kcal/kg digestible energy. Conducted in 5-m3
tanks with 4 replicates/treatment, the experiment lasted 84 days.
Fish of 126.5-g average weight were stocked at 80/tank.
The results are presented in Table 2. No significant difference was found among the fishmeal control and the animal protein substitute treatments in growth parameters and feed efficiency, as well as survival and condition. Overall, the soy-based
diet including all three substitutes was most efficient and economical, whereas the feather meal-based diet was inferior.
Experiment 3
feed based on soy oil cake plus 10% fishmeal and a diet based on
soy oil cake plus the poultry offal from experiment 2.
content and 3,150 MJ/kg digestible energy. During the 60-day
experiment, fish of 157.8-g average weight were stocked at 60
tilapia/5-m3 tank, with 4 replicate tanks/treatment.
The results are presented in Table 3. Fishmeal-free diets
based on plant protein ingredients supported growth performance as well as the diets containing 10% fishmeal. This was
made possible by increasing the level of digestible energy and
supplemention with the essential amino acids lysine and methionine at the same total protein content.
Although no significant difference (P < 0.05) was detected
among treatments, the soy composite diet containing poultry
wastes was most economical. Among the all-vegetable diets, the
feed with soy and dried distillers grains was slightly more economical than the others.
In experiment 3, tilapia received fishmeal-free diets containing plant protein ingredients compared to two control diets: a
43
production
Seabass Hatchery Feeds Artemia
Substitute To Increase Production Stability
Eamonn O’Brien
Skretting
Akkerhage 4
9000 Gent, Belgium
[email protected]
Seabass fry receive a micropellet diet rather than Artemia at the Aquastream
hatchery in France.
Summary:
After experiencing disappointing
survival rates following traditional
Artemia-based rearing protocols,
the French hatchery Aquastream
turned to a micropellet alternative to Artemia. The facility found
that feeding the alternative diet
could produce juvenile seabass of
high quality while increasing production consistency and significantly reducing costs. Aquastream
has also reduced variability in 60day survival rates and increased
the number of farming cycles.
Many hatcheries believe the quality of
Artemia metanauplii has become erratic. At
the same time, the sustainability and origin of this live feed have been called into
question. New alternatives to Artemia diets
are therefore being developed and implemented.
After experiencing disappointing survival rates following traditional Artemiabased rearing protocols, the renowned
French hatchery Aquastream turned to a
micropellet alternative to Artemia. The
facility found that feeding the extruded
pre-starter diet Gemma Micro could produce juvenile Mediterranean seabass,
44
Dicentrarchus labrax, of high quality while
increasing production consistency and significantly reducing costs.
Aquastream Seeks Alternative
Located in Ploemeur, Brittany, Aquastream produces seabass fingerlings at its
underground hatchery for many of
Europe’s leading fish farms. Founded in
2000, the company took the bold step to
apply the micropellet feeding protocol to
its entire production in 2009, although the
decision to move away from Artemia use
was taken three years earlier.
Between 2006 and 2008, Aquastream
experienced 60-day survival rates that fluctuated between 7 and 40% with traditional
rearing protocols. Disappointed and financially weakened by these results, it set
about trying to identify the reasons for the
larval mortalities, knowing that its problems were shared by many other European
hatcheries. The company’s attention
quickly turned toward the live prey Artemia, said Nathalie Le Rouilly, production
manager for Aquastream.
While this organism provides essential
nutrients for the development of marine
fish larvae, it is a live animal and therefore
quite variable – from its nutritional value
and where it is harvested, to how it is
enriched and packaged. Artemia can also
house bacteria. Feeding live prey to larvae
can cause problems such as enteritis and
stress. It can also create an imbalance in
the rearing environment, which can lead
to significantly reduced survival.
“Identifying a problem is one thing;
finding a resolution is another,” Le Rouilly
said. “We therefore decided to work in
parallel on two objectives. The first, to
improve the quality of our live prey. The
second, to partially or totally substitute the
live prey with microparticles.”
Positive Results
Aquastream had previously experimented with the micropellet feed with
seabream, Sparus aurata, with some success between 2004 and 2006. In 2008,
25% of the company’s larval tanks were
dedicated to the development of this new
protocol. The results were so positive, the
decision to apply the protocol throughout
the operation followed the next spring.
Since the launch of the new protocol in
2009, Aquastream has invoiced for
between 15 million and 20 million fingerlings yearly.
In the last four years, Aquastream has
significantly reduced the variability of the
60-day survival rates and increased the
number of farming cycles. It has reduced
Artemia use 97% and achieved a 90% savings on staff working on the live prey.
From a financial perspective, the company
has reduced the cost of larval food by close
to 45%. Looking ahead, the company’s
long-term aim is to completely remove the
use of Artemia.
“For the same costs, we produce at
least twice as many fingerlings,” Le
Rouilly said. “More importantly, the standardization of our production guarantees
the regularity of supplies to our customers,
and we can adhere to delivery deadlines
planned several months in advance.”
Reap The Benefits
Of Responsible Aquaculture
Through the development of its third-party
certification program, the Global Aquaculture
Alliance is carrying out its mission of responsible
aquaculture every day. Encompassing environmental and social responsibility, food safety,
animal welfare and traceability, the Best Aquaculture Practices program is the world’s most
comprehensive certification system for aquaculture facilities.
Currently, more than 600 farms, processing
plants, hatcheries and feed mills are BAP certified. The facilities are audited annually by independent, ISO-accredited certification bodies, and
training courses are conducted regularly to
ensure auditors are well informed of the latest
improvements to the BAP standards. Additionally, GAA’s market development works with retailers, foodservice operators and suppliers worldwide to promote the BAP program and
responsible aquaculture in the marketplace.
For more on BAP Standards, contact:
www.gaalliance.org • +1-314-293-5500
PL
Advanced larval &
post larval nutrition
for shrimp
w w w. s k r e t t i n g . c o m / s p e c t r u m
45
production
Ecuador Sets Legal Framework
For Offshore Fish Farm Development
Xavier Romero, M.S.
Local 27
Centro Comercial Plaza Quil
Guayaquil, Ecuador
[email protected]
Legal Framework
Almaco jack is one of the species under consideration for mariculture off the coast
of Ecuador.
Summary:
The government of Ecuador has
set the legal framework for leasing
mariculture sites and the conditions under which to apply for a
lease. This commitment to marine
fish farming was also shown by
the extension of credit lines. Biased
negative images that created opposition by local groups were
overcome in the publication of
Ministerial Accord 458. Its guidelines addressed environmental
impacts and the needs of local
fishers without being overly restrictive for marine fish producers.
Ecuador is a country well known for
its shrimp-farming industry, but now the
government is interested in encouraging
the development of offshore marine fish
farming, or mariculture. Although the
aquaculture sector has a lot of experience
in pond-based aquaculture, marine fish
farming represents a new challenge. Legal
and technical issues are being addressed,
but the industry still has a long way to go.
Marine Fish Farming
A few past trials in developing mariculture in Ecuador did not progress for
different reasons, but since 2007, interest
46
in this activity has been increasing, along
with pressure from potential investors to
set a legal framework and conditions
under which to invest.
Impressive growth has been seen in
nearby Chile, where salmon farming has
increased to record levels, but it is important to differentiate the conditions for
culture in Chile and Ecuador.
In Chile, salmon farming began with
technology and experience brought in by
international investors and companies. The
biology of salmon culture and the economics
associated with the activity were well known.
Pioneering efforts in the development
of tropical offshore marine fish aquaculture in the world have been considerably
less extensive. The ones closest to Ecuador have occurred in the Caribbean and
Hawaii. The main candidate species
under review are almaco jack, Seriola
rivoliana; cobia, Rachycentron canadum;
and mahi-mahi, Coryphaena hyppurus; but
several others will probably be studied.
The basic biology of the potential
candidate species is known, and there is
experience and data about growth rates
where the fish have been cultured. Further factors are also being considered as
Ecuador plans for marine farming, now
and into the future.
Through Ministerial Accord 458,
published in October 2012, the government of Ecuador set the legal framework
for leasing mariculture sites and the conditions under which to apply for a lease.
This commitment to encourage the
development of marine fish farming was
also shown by the credit lines for mariculture that Corporación Financiera
Nacional (National Finance Corp.) made
available for companies interested in
investing in this activity in Ecuador.
Two companies are in the process of
obtaining leases, which can take some
time. Multiple documents are required,
from the strictly business ones to those
related to the environmental issues and
technical areas of fish growth.
Potential Impacts
As the area to be leased is offshore,
there was need to coordinate among different government institutions and ministries regarding which role each would
have. In a world that is more and more
environmentally aware, the potential
impacts of mariculture development
became one of the main concerns for the
government bodies in whose fields of
action offshore farming could be included.
This concern was probably the main reason discussions have continued for several
years before the final approvals for leases.
Unfortunately, when a government
official or fishing community leader
searches for offshore fish farming information on the Internet, the first “hits”
that appear are often negative and mostly
biased information describing negative
consequences of marine fish farming.
Other general sources provide videos and
photographs of effects that are usually
localized, manageable and not widely
extended to whole ecosystems.
This biased negative image created
Legal guidelines require the use of
juvenile fish from hatcheries, rather
than wild sources. This helps control
disease and avoid conflicts with fishers.
opposition by local groups that on several
occasions did not allow workshops to
progress. Meetings could not reach positive answers to problems that have
already been managed and solved in other
places where marine fish farming has
developed on a large scale.
Technical, Legal Aspects
Creating legal documents for an
activity such as marine fish farming
requires an interesting mix of technical
knowledge combined with legal wording,
where lawyers meet several times with
technical people. It is not a “copy and
paste” process using regulations from
somewhere else, because the conditions
in a country may not support the legal
conclusions reached in other regions.
One key part of Ministerial Accord
458 establishes the length for mariculture
leases as 10 years, giving enough time to
recover the invested money and make a
profit. This period can be extended
another 10 years by presenting a request
three months before the end of the original lease. Marine fish farming is a longterm investment that needs conditions
like this to attract investors.
Accord 458 also bans the use of juvenile fish from wild sources, so basically all
stocked fish must come from hatcheries.
This helps disease management, as
potential pathogens can be excluded at
the hatchery level. It also avoids conflicts
with fishers for the same source of fish.
The environmental impacts of marine
fish farming are usually localized under the
production cages and do not extend to the
wider ecosystem. The accord includes
guidelines that state: “Environmental
impacts … will not cause an irreversible
deterioration of the marine ecosystem.” A
key word here is “irreversible,” so temporary changes that occur on the bottom of
the sea under the fish cages are accepted
under certain established parameters.
The total area allowed for setting
cages and infrastructure above the ocean
surface is 40 ha, with the effective area
extending up to 150 ha to include the
anchoring system, which depends on the
depth where the farm is located. Anyone
who has visited a salmon farm is aware
that the size of the area discussed in legal
documents is enough to set a sizable offshore fish farm that includes an area to
cushion its impacts.
Offshore fish farming is a very intensive aquaculture activity in which sea
cages do not occupy an extensive area, but
are mainly constructed based on the volume of fish they can hold. The intended
area for a project presented during the
request for a lease can be changed as long
as it does not exceed the legal limit, and
the authorities are informed.
Offshore Zones
One part of the legal lease document
that created a lot of comments was the distance from the shore where leases will be
allowed. The first 12.9 km close to shore
are designated only for projects of the organized artisanal fishermen organizations and
for pilot research projects. The local fishermen must feel part of this new activity, and
a major concern was not to negatively affect
their traditional fishing areas by the establishment of marine fish farms.
This decision is in agreement with
Ecuador’s government policy regarding
the social benefits of new development
and respect for traditional activities in
different groups of society. This distance
for logistics operations is not a surprise to
people with experience in salmon farming. For salmon farms in different parts
of the world, the distance between logistics ports and the actual farms can exceed
32.2 km. Farms can appear close to shore
in photographs, but the actual distance
covered to provide all the logistics is
many times more than 12.9 km.
Perspectives
Like any other regulations and laws
worldwide, legal documents related to
mariculture in Ecuador will continue to
evolve according to the demands and con-
ditions of the activity. One area that needs
to be considered is to give the marine
farming industry some freedom to develop
new technology and adapt to stay competitive in the very dynamic world economy.
At the moment, Ministerial Accord
458 does not regulate stocking densities.
Regulations should aim at measuring the
impacts of the fish farming on the bottom
under the cages using measurable parameters. Trying to regulate stocking densities
could “strait jacket” for a new industry,
not allowing flexibility in decisions concerning the economics of this business.
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47
production
Taste
Hybrid, Channel Catfish Show Similar
Immune Responses To Ich Parasite
Impressions
De-Hai Xu, Ph.D.
Every Chef’s
USDA Agricultural Research Service
Aquatic Animal Health Research Unit
990 Wire Road
Auburn, Alabama 36832 USA
[email protected]
Secret Begins
with Ingredients
Phillip Klesius, Ph.D.
USDA Agricultural Research Service
Aquatic Animal Health Research Unit
The authors cohabited hybrid catfish and channel catfish in the same tanks
and compared their immune protection against the parasite ich.
ter fish that leads to heavy economic losses
in aquaculture. The parasite has a life cycle
consisting of an infective theront, a parasitic trophont and a reproductive tomont.
Chemical treatment of ich infection is
difficult after the parasite penetrates the
fish skin and gills. Vaccination against the
parasite is an alternative to chemical treatments, since fish that survive an ich infection acquire immunity against reinfection
by the parasite.
Cohabitation Challenge
Summary:
In a study, the authors evaluated the immune responses
and host protection of hybrid catfish and channel catfish against the fish parasite Ichthyophthirius multifiliis
(ich). Both catfish species were immunized with live ich
theronts by immersion or intraperitoneal injection and
cohabited in the same tanks. After challenge with ich
theronts, the immunized hybrid catfish developed high
antibody levels, had no or light parasite infection and
showed high survival – results similar to those for the
channel catfish.
Recently, an increasing number of producers are showing an
interest in the culture of hybrid catfish (female channel catfish x
male blue catfish) instead of channel catfish, even though the
latter has been the dominant cultured species in the United
States for several decades.
Compared to channel catfish, hybrid catfish have been
reported to have faster growth, better feed conversion, greater
tolerance of low oxygen levels and higher fillet yields. The
hybrids are also more resistant to the bacterial pathogens Flavobacterium columnare, Edwardsiella ictaluri and Aeromonas hydrophila, but showed no greater resistance to channel catfish virus and
proliferative gill disease than channel catfish.
Ich Parasite
Ichthyophthirius multifiliis is a ciliated protozoan commonly
referred to as ich. The parasite causes serious disease in freshwa-
48
Since limited information is available on the immune protection of hybrid catfish against ich, the authors performed a study
to compare the serum antibody concentrations, parasite infection
levels and host protection in immunized hybrid catfish and
channel catfish. Disease-free catfish were initially obtained for
the study from the Catfish Genetic Research Unit of the United
States Department of Agriculture Agricultural Research Service
in Stoneville, Mississippi, USA.
The authors conducted the trial using a cohabitation challenge
method in which hybrid and channel catfish occupied the same
tanks. Cohabitation is considered one of the best models for evaluation of protective immunity, since two fish species are held in
the same rearing unit under the same culture conditions, thereby
decreasing the chance for variation among experimental units.
Hybrid catfish and channel catfish can be differentiated easily when they are alive, but not after death. To avoid misidentification, 140 channel catfish were marked with calcein before the
trial. Calcein is a green-fluorescent dye that binds to calciumrich tissues, such as fins and bones. Upon binding, an increase in
fluorescence can be observed under ultraviolet light.
When fish showed visible white spots five days after challenge with ich theronts, five hybrid and five channel catfish in
each aquarium were sampled to determine infection by the number of white spots on the body surface of each fish.
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Twelve tanks with 10 hybrid and 10 channel catfish per tank
were assigned for the trial. The mean body weight was 10.7 ± 1.3
(Continued on page 82.)
©2013 Eastern Fish Company
49
marketplace
seafood and health
New Year Wishes For Health And Seafood
Roy D. Palmer, FAICD
Improved training for seafood retailing joined a review of mercury risks in seafood
on the author’s wish list.
Summary:
To help increase seafood consumption and gain recognition for the many health benefits of seafood, the author
identified three wishes for 2014. Change the risk profile
of seafood to defuse the sensationalized status of mercury.
Professionalize the capability of the retail industry and
create an avenue for consistent, positive messages sent to
consumers. Increase education to girls and women about
the unique benefits of seafood.
As I write this column at the end of 2013, it is the time to
reflect on the year and consider what strategic issues on which
to concentrate in 2014. Bearing in mind this column is about increasing seafood consumption and getting recognition for the incredible
health benefits of seafood, here are my three wishes for 2014:
1. One issue continually raised to put people off seafood is
mercury. My wish is that a review of the methylmercury
limits set by the CODEX Alimentarius is undertaken and
that the risk profile is changed dramatically, thus taking
mercury out of the equation.
2. The Global Seafood Retail Development program will
change the face of the “window of the industry” to ensure
that we professionalize the capability of the retail industry
and create an avenue for consistent, positive messages to
go globally to consumers.
3. Increase consistent, quality education to girls and women
about the unique and special benefits of seafood.
Mercury Issue
As I have said many times, the topic of mercury is often used
in scare tactics – typically by anti-seafood organizations. But it is
such a minor issue that it needs to be taken out of the decisionmaking equation when consumers buy seafood. It is high time
governments acted on this issue and insisted on a review and
changes in the risk profile.
There are many reasons this needs to be done. I gave many
in my last column, but here are a few more.
50
GILLS
2312/80 Clarendon Street
Southbank VIC 3006 Australia
[email protected]
www.gillseafood.com
From a scientific point of view, risk from seafood is related to
how much you consume, and since the original suggested values
were defined many years ago, much more science became available. As reported in a recently published seven-year-long study
by Dr. Nick Ralston and colleagues, current U.S. Food and
Drug Administration methods for developing seafood consumption guidelines may not provide an accurate assessment of seafood safety. Ralston developed the “selenium health benefit
Value” criterion, which predicts risks or benefits of seafood species based on methylmercury and selenium content. None of this
work was available when the original decisions were made.
It has been brought to my attention that the excess of selenium
in some tuna species has a positive health benefit and is therefore
more likely to prevent methylmercury toxicity than contribute to
it. This integrated consideration of the elements’ molar ratios provides an improved safety standard for seafood and environmental
risk assessment that appears more useful than the criteria based on
evaluation of methylmercury concentrations alone.
As my great friend Professor Michael Crawford said: “The
reason for methylmercury toxicity is it takes out selenium, and
the selenium proteins are some of the strongest protectors of the
brain. There is so much selenium in fish like tuna that the methylmercury is powerless. If the contrary were true, the Japanese
and others on traditional seafood diets would have the highest
death rate from coronary heart disease. They have the lowest!
This is either sheer ignorance or willful attack.
“You have to ask why people attack fish and not beef poultry,
dairy, etc. But go to the FAO website, and you will see that fish
accounts for only a small portion of dioxin intake, as most of it
lands on the grass and crops, so the bulk of dioxin intake is from
vegetables, dairy, beef, poultry. So why pick on fish?”
Additionally, aquaculture is becoming the predominant harvest method for seafood, and fish to fish ratios have totally
changed. We are no longer talking about eating ocean predators
like we used to. Thus, the risk is minimized further.
Positive Messaging
Sometimes it is important to be repetitive to get a point
across. I referenced in the last issue the need to “raise the bar” in
seafood retailing to increase seafood consumption. While we
need to have a global approach, it is essential that retailers
take some responsibility to ensure that their staff have relevant skills and knowledge. Excuses of high staff turnover or
limited time behind the counter cannot be acceptable, especially when the retailers are demanding so much more from
the industry.
Changing the interface with consumers and giving them
consistent, positive information would be a solid education
platform that makes a difference. Making shopping for seafood a pleasurable experience and empowering consumers
with sound advice is definitely the way to go.
I love the work of Dr. Shakuntala Thilsted at WorldFish
Centre in Dhaka, Bangladesh, who takes a different approach
to nutrition advice. She highlights the importance of nutrients and especially micronutrients in small fish based on the
work she has done in Bangladesh.
“The amounts of nutrients and proteins in fish varies
greatly by species, but small, dried indigenous fish, when
consumed whole, are one of the best ways to consume a concentrated amount of these important nutrients,” Thilsted
said. “They are also a good source of essential fats and
DHA.”
Further, she said: “Although aquaculture has taken off in
many less-developed countries, the fish species farmed tend
not to be these most nutritious indigenous species, which can
help improve the lives of many women and young children
domestically. Instead, they tend to be fish which have a high
market demand in export markets.
“An example is the species mola in Bangladesh. This is an
indigenous fish that contains a very high amount of vitamin
A, but the dominant farmed species in the country are tilapia
and carp, which are less nutritious but are farmed because
they have a higher market value.”
So, following this advice, it is clear that aquaculture
therefore needs to start working to increase the consumption
of nutrient-rich fish, ensure the year-round availability of
these fish and ensure that these fish are accessible to women.
Educating Women
Education of young women, girls and even grandmothers,
who in many societies play a pivotal role in education, is a
must. Thilsted talks of how aquaculture can contribute to
giving children the best start in life and help raise a country’s
gross domestic product (GDP).
I have mentioned this in previous columns, but the “1,000
days” project promotes good nutrition for mother and child
during the first critical 1,000 days of life. The period covers the
nine months during pregnancy and the first months of life
out of the womb.
As Thilsted highlighted: “The good health and nutrition
of a woman during pregnancy and breastfeeding can be
linked to eating nutritious fish. Good nutrition from fish
during pregnancy also leads to optimal birth weight, good
brain development and generally sets the child off to a good
start in life. Similarly, it has been found that poor nutrition in
early life can negatively impact the overall economic development of a country. Improved nutrition can increase a country’s GDP by 2 to 3% a year.”
None of these wishes are too outlandish – all of them would
have enormous impacts on seafood consumption. Let us see
how we go. If we can get some traction on all of these wishes,
this industry will move forward like you have never seen.
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51
marketplace
food safety
and technology
xxxxxxxxxxxxx
Lipid Oxidation Results
From Heme Catalysis
George J. Flick, Jr., Ph.D.
University Distinguished Professor
[email protected]
David D. Kuhn, Ph.D.
Myoglobin content is minimal when compared to the hemoglobin content
in the light muscle tissues of mackerel.
Summary:
Iron compounds in fish contribute significantly to lipid oxidation in addition to oxidation
mediated by enzymatic activity. The main iron-containing
compounds are myoglobin and
hemoglobin. Several studies have
shown that the concentrations
of these compounds vary significantly among fish species and
between light and dark muscle
tissues. Bleeding during processing was able to reduce lipid oxidation during storage due to the
reduction in heme compounds.
For many years, the roles of dietary
eicosapentaeonic acid and docosahexaenoic acid have been related to improved
cardiovascular health and brain development in humans. The high degree of
these unsaturated fatty acids in fish
makes them a good source of the nutrients, but the close proximity of the fatty
acids to strong pro-oxidative systems predisposes them to oxidation, which con-
52
verts them into compounds that negatively affect the quality attributes of the
fish.
Rancid flavor is a well-known consequence of lipid oxidation, but changes in
color, texture and nutritional value can
also develop. The extent of undesirable
changes in fish lipids is due to the types
of compounds participating in the oxidation process.
Pro-Oxidants
Most well known among the pro-oxidants in fish are the transition metals,
such as iron and copper, which impact
several steps of the oxidation chain.
These metals are most active in their
reduced states.
A large part of the iron in fish muscle
is bound in hemoproteins such as myoglobin, hemoglobin and cytochromes.
The physiological functions of myoglobin
and hemoglobin are to carry and distribute oxygen to the different tissues. Hemoglobin is the main pigment in red blood
cells, and myoglobin is the main pigment
in muscle cells. Both myoglobin and
hemoglobin have catalytic properties due
to their ability to break down hydroper-
Assistant Professor
[email protected]
Food Science and
Technology Department
Center for Applied Health Sciences
Duck Pond Drive
Virginia Tech (0418)
Blacksburg, Virginia 24061 USA
oxides and their suggested activation by
hydrogen peroxide into the highly reactive porphyrin cationic radical.
About two-thirds of body iron is
found in hemoglobin, and smaller
amounts are in myoglobin. A very small
amount comprises components in various
iron-containing enzymes and in the
transport protein transferrin. The
remainder is present in the intracellular
storage proteins ferritin and hemosiderine. A small pool of non-protein nonheme iron provides “free” iron at micromolar concentrations in tissues.
Metals And Heme
Compounds
Both non-heme iron and hemoproteins can function as pro-oxidants when
in contact with pure lipids. However, the
situation with muscle is much more complex. Inorganic iron is a strong catalyst in
mackerel meat lipid oxidation, whereas
heme iron is the major catalyst of lipid
Model 61 Systems ad_Layout 1 10/29/12 12:24 PM Page 1
oxidation in mullet flesh.
The oxidative rancidity in cooked
meats has been attributed to both heme
and non-heme iron. It has been further
reported that the increased rate of lipid
oxidation in cooked meats is due to the
release of non-heme iron during cooking.
Heme pigments may be more active lipid
oxidation catalysts with iron in the ferric
state, whereas non-heme iron appears to
be more active in the ferrous state.
Research has shown that in raw meat and
model emulsions, ferric hematin pigments are powerful catalysts of lipid oxidation, whereas in heated meats, the system is more complex, and inorganic iron
may play a more important role.
Heme proteins have been considered
catalyzers of the propagation step and not
true initiators of lipid peroxidation. It has
been reported that active species formed
by the interaction of hydrogen peroxide
with metmyoglobin or methemoglobin,
the respective oxidized analogues of myoglobin and hemoglobin, could be
described as true initiators of lipid peroxidation. Microsomal oxidase systems coupled with ferric or ferrous iron may also be
initiators of lipid oxidation.
The loss of redness in meat is an indicator that lipid oxidation processes mediated
by hemoglobin are progressing. Just after
death, hemoglobin in muscle tissue is
primarily in a reduced state in which, for
example, the mixture of oxyhemoglobin
and deoxyhemoglobin possesses a red color.
With increased postmortem aging,
this reduced hemoglobin auto-oxidizes to
methemoglobin, a brown pigment. Methemoglobin is considered more pro-oxidative than reduced hemoglobin due to its
less tightly bound heme group and reactivity with hydrogen peroxide and lipid
peroxides to form hypervalent hemoglobin catalysts.
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Pro-Oxidative Properties
Numerous studies have shown that
certain hemoglobins promote lipoid oxidation more effectively than hemoglobins
from other species. For example, herring
and mackerel hemoglobins oxidized
washed cod lipids more effectively than
trout hemoglobins did. Oxygen affinity
appeared to play a role, in that those
hemoglobins with elevated deoxyhemoglobin contents at pH 6.3 (for example,
trout hemoglobin) promoted lipid oxidation most effectively at pH 6.3.
Hemoglobins from pollock, mackerel,
menhaden and flounder were found to be
equally pro-oxidative at pH 6.0, while
they differed significantly in their ability
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53
Table 1. Hemoglobin and myoglobin concentrations
and percent myoglobin present in trout whole muscle
and mackerel light and dark muscle from bled and unbled fish.
to oxidize cod membrane lipids at pH
7.2. The higher activities at pH 6.0 could
be explained by higher and more rapid
formation of deoxy- and methemoglobin.
Autoxidation in cold-adapted fish was
found to be 10-fold faster than in warmwater fish at all temperatures. The rate of
autoxidation was lower in monomeric
hemoglobins from, for example, hagfish
and lamprey than in tetrameric hemoglobins from carp and tuna.
Blood And Lipid Oxidation
There is a wide variation in the
amounts of hemoglobin extracted from
the muscle tissue of bled and unbled fish
(Table 1). Myoglobin content was minimal when compared to the hemoglobin
content in mackerel light muscle and
trout whole muscle. Hemoglobin made
up to 65 and 56%, respectively, of the
total heme protein by weight in dark
muscle from unbled and bled mackerel.
Bleeding significantly reduced rancidity
in minced trout whole muscle, minced
mackerel light muscle and intact mackerel
dark muscle, but not minced dark mackerel
a
b
Sample
Hemoglobin
(µmol/kg/
tissue)
Myoglobin
(µmol/kg/
tissue)
Myoblobin
In Total Heme
Protein (%)
Trout whole muscle, unbled
Trout whole muscle, bled
Mackerel light muscle, unbled
Mackerel light muscle, bled
Mackerel dark muscle, unbled
Mackerel dark muscle, bled
11.10 ± 4.95
7.39 ± 2.93a
6.07 ± 1.02
3.40 ± 0.48b
158.80 ± 21.00
121.80 ± 17.00
N.D.
N.D.
N.D.
N.D.
342.00
382.80
N.D.
N.D.
N.D.
N.D.
35
44
P < 0.01 bled and unbled fish
P < 0.001 bled and unbled fish
stored at 2° C. It was suggested that bloodmediated lipid oxidation in fish muscle
depends on various factors that include
hemoglobin concentration and type, plasma
volume and erythrocyte integrity.
Lipid oxidation in slices of bled and
unbled Asian seabass during 15 days of
ice storage showed that bled samples had
lower peroxide values and thiobarbituric
acid-reactive substances throughout the
storage period (P < 0.05). Bleeding effectively lowered the total heme and non-
heme iron contents of the samples.
The release of non-heme iron was
pronounced in the unbled samples during
storage. The level of heptanal, the major
volatile compound detected in the unbled
samples, was four-fold higher than in
bled counterparts. The contents of aldehydic compounds, including hexanal,
octanal, nonanal and nonenal, were also
higher in the former samples.
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55
marketplace
u.s. seafood markets
Peeled, Cooked Shrimp Imports Up Into Year-End Holidays
cerns and escalating raw material prices are price supportive.
Taking a look at landings, the National Marine Fisheries Service reported October 2013 landings at 14.492 million lb (headless weight) compared to 15.908 million in October 2012. This
brought the cumulative total to 97.510 million lb, or roughly
1.2% behind the January to October 2012 total.
ATTENTION SEAFOOD PROFESSIONAL
MAKE
SMARTER
CHOICES.
FASTER.
EVERY DAY.
Paul Brown, Jr.
P. O. Box 389
Toms River, New Jersey 08752 USA
[email protected]
Janice Brown
Angel Rubio
were up 2.3% MOM, but remained about 7.0% lower YTD. Peeled
shrimp imports were 16.0% higher MOM and about even on a
YTD basis. Cooked shrimp imports surged 22.0% higher MOM in
October, while YTD imports remained 11.0% lower. Breaded
imports were lower for both the month and YTD.
Global demand, especially from Asia, will significantly impact
first-quarter markets.
Shrimp Market
Summary:
While headless and easy-peel shrimp imports to the U.S.
rose some, peeled and cooked shrimp surged in October
2013. Supplies of black tiger shrimp remained limited.
The market now waits for the holiday pull-through.
Total year-to-date salmon imports in October reflected
a 2.13% increase from last year. Imports of whole salmon,
especially from Canada, continue to decrease, while
fresh fillet imports continue to rise. U.S. imports of fresh
and frozen tilapia fillets reached record levels in October.
However, shipments from Ecuador have declined as tilapia farms switch to shrimp production. Prices to packing
plants remained high due to shortages for overseas processors. Nearly 300,000 lb of channel catfish were imported in October, which caused tightness in the market.
Imports of Pangasius declined again, although demand
may rise as production ramps up in Vietnam.
Shrimp imports to the United States in October 2013 continued to show an increase month over month (MOM), while
year-to-date (YTD) imports remained slightly lower. October
imports were up almost 11.0% MOM with YTD imports 3.3%
lower (Table 1).
Thailand continued its dramatically lower exports to the
U.S., while MOM imports from Ecuador were also down a significant 17.6%. Imports from Indonesia, India and Vietnam
were all up sharply MOM and also YTD.
Imports of headless, shell-on (HLSO) and easy-peel shrimp
After a few barely steady to weak periods in late November
and early December, the white shrimp HLSO and value-added
markets appear to have mostly settled at current levels. The market now waits to look for buyer and consumer reactions at both
the retail and foodservice levels for pull-through during the holiday period. Carryover inventory – or the lack thereof – will
determine market conditions into the first quarter.
Of course global demand, especially from China and the rest
of Asia, along with production and replacement offerings, will
also have significant impacts on first-quarter markets. European
demand could slow after holiday needs, as well as demand from
China ahead of and just after the Chinese New Year on January
31. However, the current shrimp market has many moving parts,
including, importantly, the spread of early mortality syndrome
and ensuing production issues. So the market remains unsettled,
but again appears steady for the very near term.
Supplies of black tiger shrimp remain limited and are not
expected to improve in the short term. There has been separation between the white and black tiger shrimp market prices,
which will continue to result in buyers switching to white shrimp
where they can.
U.S. Domestic Shrimp
The market for headless shell-on shrimp from the Gulf
region took on a more steady tone in late November and early
December. However, a comparison to month-ago levels indicated some still firmer trade. Most of the industry’s attention has
now turned to peeled shrimp.
Sustained and robust buying interest, growing supply con-
Form
Shell-on
Peeled
Cooked
Breaded
Total
48,773
44,354
16,697
7,379
117,203
47,259
38,054
13,763
8,349
107,425
Change
(Month)
October 2012
(1,000 lb)
Change
(Year)
YTD 2013
(1,000 lb)
YTD 2012
(1,000 lb)
Change
(Year)
3.2%
16.6%
21.3%
-11.6%
9.1%
47,752
38,226
13,533
7,882
107,393
2.1%
16.0%
23.4%
-6.4%
9.1%
364,565
359,642
112,331
65,822
902,360
391,762
356,849
124,926
68,290
941,827
-6.9%
0.8%
-10.1%
-3.6%
-4.2%
Sources: Urner Barry foreign trade data, U.S. Department of Commerce.
56
comtell
®
Fresh Salmon Fillet
Imports Set YTD Record
Seafood Quotations and Analysis
.Uncover Opportunities
.Identify Market Conditions
.Capitalize on Volatility
.Negotiate with Confidence
Total year-to-date (YTD) volumes of salmon imported to the
United States in October 2013 reflected a 2.1% increase over
imports from the same time last year (Table 2). Fresh whole fish
imports continued to see YTD figures decrease almost 11.4%.
Whole Fish
foreign trade
data Import Data and
October 2013 YTD figures for fresh whole salmon continue
the year with a decrease. In contrast, a monthly comparison
revealed a slight increase from September to October 2013 of
1.9%. However, when looking at October 2013, imports were
18.9% lower than those in October 2012.
Imports from Canada showed the largest decrease: down
21.2%. The Northeast whole fish market during early December
was full steady to firm on all sizes of fish. Supplies were adequate
to barely adequate for a moderate to active demand.
Another factor affecting the market is the lack of European
whole fish in the U.S. market. The European whole fish market
was extremely firm in early December and advanced U.S. $0.93.
This situation decreased the amount of available fish from Europe
in the market and caused upward pricing pressure on both the
Northeast and West Coast Canadian markets. Similar to the
Northeast, the West Coast market during December was full
steady to firm on all sizes. Supplies were barely adequate for a
growing holiday demand.
Fillets
Table 1. Snapshot of U.S. shrimp imports, October 2013.
September
October 2013
(1,000 lb)
2013 (1,000 lb)
Reduced imports from Canada helped lead total whole salmon
import levels lower in October 2013.
Regulatory Updates
.Reduce Uncertainty
.Know Your Competition
.Understand Rules & Regulations
.Ask the Expert:
Richard Gutting, Jr.
Urner Barry offers tailored solutions for
businesses small and large.
To find out what we can do for your business,
arrange for a consultation session by
U.S. imports of fresh salmon fillets continued to rise in October 2013, with YTD figures showing an increase of 10.8%. October fillet imports showed a total of 19.4 million lb, which was 9.7%
over September 2013’s total. Imports in October 2013 were also
5.9% higher than in October 2012.
The U.S. imported 14.5 million lb from Chile during October.
Chile’s figure was 12.0% higher YTD, as 147.8 million lb have
been imported thus far for 2013. Overall imports are at the highest
levels to date at 187.6 million lb.
contacting Urner Barry today.
732-240-5330
[email protected]
57
The market during December was unchanged, and the
undertone was about steady if a bit unsettled. Delays of shipments from Chile to the U.S. have caused disruption in the distribution chain. Some discounted fish and carried fish were
reported to be available in the Miami spot market.
The current market situation is somewhat a surprise, since
most market participants anticipated a more active December.
However, all sizes were above their three-year price averages.
The European fillet market was also unchanged.
Catfish Imports Return As Pangasius Figures Fade
U.S. demand
for Pangasius
is expected to
rise as production ramps
up in Vietnam.
Table 2. Snapshot of U.S. salmon imports, October 2013.
Form
October
2013 (lb)
September
2013 (lb)
Change
(Month)
October
2012 (lb)
Change
(Year)
YTD 2013
(lb)
YTD 2012
(lb)
Change
(Year)
Fresh whole fish
Frozen whole fish
Fresh fillets
Frozen fillets
Total
14,514,442
690,366
19,417,142
9,010,036
43,631,986
14,238,879
336,575
17,693,201
7,731,762
40,000,417
1.94%
105.12%
9.74%
16.53%
9.08%
17,893,940
356,391
18,329,993
5,214,114
41,794,438
-18.89%
93.71%
5.93%
72.80%
4.40%
165,382,714
4,992,601
187,609,847
70,544,781
428,529,943
186,637,697
4,666,455
169,300,796
58,977,651
419,582,599
-11.39%
6.99%
10.81%
19.61%
2.13%
Channel Catfish
U.S. Fresh, Frozen Tilapia Fillet Imports Hit Highs
The U.S. imported
an all-time monthly
high volume of frozen tilapia fillets in
October 2013.
Frozen Whole Fish
Imports of frozen whole tilapia to the United States continued their 2013 strong trend in October. Import figures showed
an increase of about 15% from the previous month’s level and a
28% surge from the same month a year ago (Table 3). On a
year-to-date (YTD) basis, imports were 14% above those registered in 2012.
Fresh Fillets
Imports in October 2013 reached their highest level on
record for the month of October, while YTD imports continued
to be the highest on record. Despite the record import levels,
shipments from Ecuador declined over 30% year on year as tilapia farms switched to shrimp production. This means that other
supplying countries like Honduras, Colombia, Costa Rica and
now Mexico had to fill the supply gaps created by lack of product from Ecuador.
This shift to new markets forced U.S. buyers to compete for
product, and as a result, prices have remained supportive
throughout the year. For instance, the per-pound import price –
total value divided by total volume reported by the U.S. Department of Commerce – remained above U.S. $3.40 from August
to October. These were the three highest levels on record.
Some reports have suggested supplies could become tighter
in the near future, as shipments are expected to contract in the
upcoming months.
After imports of channel catfish to the United States were
nil in September 2013, import figures for October approached
300,000 lb of fish during that month (Table 4). This caused
some tightness in the market, as supplies had not been readily
available, despite the fact that demand had been contracting for
the past few years. YTD figures, however, were still well above
those registered a year ago and over the past three years.
The market adjusted higher in late October and November
2013. The undertone was generally strong at listed levels.
Pangasius
U.S. imports of Pangasius declined for the fourth consecutive
month after reaching their highest level on record in June 2013.
When compared to the same month a year ago, imports were 2%
down in October 2013. On a YTD basis, imports were basically the
same as last year. However, according to many, volume is expected
to increase over the next few months as demand in the U.S.
increases and production ramps up in Vietnam. Data from Europe
remained unchanged, as an update was not available.
The market continues to hold a relatively weak undertone as
U.S. inventories remain plentiful, according to reports. Large discounts have been noted in the spot market, which have resulted in
lower offerings across the complex, including those for premium
product holders.
Table 4. Snapshot of U.S. catfish imports, October 2013.
Frozen Fillets
The U.S. imported an all-time monthly high volume of frozen tilapia fillets in October 2013, but YTD imports were down
9% compared to 2012 figures – a difference of 27.7 million lb. In
fact, October marked the third straight month that tilapia shipments trended above year-ago levels. Despite this late-year rally
in imports, prices offered to packing plants remained comparably
high due to shortages of raw materials for overseas processors.
Consequently, these elevated replacement costs helped drive up
U.S. tilapia prices throughout 2013.
As of mid-December, the market held a strong undertone
with current offerings holding firm. According to the information collected throughout August and September, importers projected higher replacement costs for shipments arriving in October, November and December. October 2013 figures reflected a
small cost increase from the previous month, although many
importers said most of these higher costs would be reflected in
product arriving in November and subsequent months.
Figures should reflect behavior similar to that in 2010 for
replacement costs, but at significantly higher prices. In 2010, for
example, average YTD replacement costs for January through
September showed a decrease from the previous year. However,
during the fourth quarter of that year, replacement costs actually
rose over U.S. $0.20 from September to December.
Furthermore, although it is true that replacement costs –
according to the U.S. Department of Commerce – are comparatively high compared to last year, these were not above 2011 levels on a YTD basis. However, if replacement costs rise throughout the third quarter, as reported by many importers and suggested by their offering levels in the U.S., average replacement
costs should surpass the levels seen in 2011 and 2008.
Form
Pangasius
Channel catfish
Total
October
2013 (lb)
September
2013 (lb)
Change
(Month)
October
2012 (lb)
Change
(Year)
YTD 2013
(lb)
YTD 2012
(lb)
Change
(Year)
17,506,596
276,168
17,782,764
17,961,934
–
17,961,934
-2.54%
–
-1.00%
17,881,982
201,721
18,083,703
-2.10%
36.91%
-1.66%
186,686,992
9,574,937
196,261,929
185,851,703
5,318,725
191,170,428
0.45%
80.02%
2.66%
Table 3. Snapshot of U.S. tilapia imports, October 2013.
Form
October
2013 (lb)
September
2013 (lb)
Change
(Month)
October
2012 (lb)
Change
(Year)
YTD 2013
(lb)
YTD 2012
(lb)
Change
(Year)
Fresh fillets
Frozen whole fish
Frozen fillets
Total
4,873,368
8,476,182
35,850,834
49,200,384
4,598,638
7,367,698
29,097,654
41,063,990
5.97%
15.05%
23.21%
19.81%
4,465,947
6,592,822
29,916,843
40,975,612
9.12%
28.57%
19.83%
20.07%
50,454,911
74,110,556
272,826,399
397,391,866
46,735,105
64,979,792
300,535,330
412,250,227
7.96%
14.05%
-9.22%
-3.60%
58
59
innovation
March 21-25, 2014
Wuhan, China
China Food Products
and Ingredients Expo
Organized by Wuhan Lanesync Supply Chain Management Co. Ltd.
At Wuhan Science & Technology Convention & Exhibition Center
At the intensive pond aquaculture demonstration site, raceways are positioned within the pond for fed fish (left). Waste collects
in the quiescent zone at the end of the raceways (right).
New Intensive Pond Aquaculture
Technology Demonstrated In China
Summary:
An in-pond raceway system to intensify and gain efficiency in pond
fish production was successfully
demonstrated in China by the international marketing program of
the U.S. Soybean Export Council.
This intensive pond aquaculture
(IPA) technology enhances management control to yield greater
fish production at lower per-unit
cost through improved fish survival and feed conversion. The zeroexchange system captures nutrients for use as a crop fertilizer and
requires minimal use of drugs and
chemicals to ensure food safety.
An in-pond raceway system to intensify and gain efficiency in pond fish production was successfully demonstrated in
China in 2013 by the international marketing program of the U.S. Soybean
Export Council (USSEC). This intensive
pond aquaculture (IPA) technology was
developed in the United States as a
means to increase the productivity of
aquaculture in existing pond units by culturing fish in aerated raceways within
ponds and removing solid wastes.
60
Removal of the solid wastes allows a
threefold or greater increase in fish production over traditional pond culture
technologies.
The technology was transferred to
China by USSEC through a cooperative
project funded by the Iowa Soybean Association and the Wujiang Municipal Aquaculture Co. Ltd. (Wujiang), with technical
guidance from Dr. Jesse Chappell of
Auburn University. Pentair Aquatic EcoSystems has a license for this technology
and will be commercializing it in 2014.
Addressing Constraints
The IPA system was selected for demonstration in China as a means to address
the increasing demand for aquaculture
products in the face of mounting economic and environmental constraints to
the growth of Chinese aquaculture production. These constraints include rising
land values and increasing pond rental
costs that require greater economic return
from fish farms, limited water availability
and declining water quality issues, and
increasing food safety concerns.
With no land area to expand aquaculture production in China, intensification
of production in existing fish ponds is
needed to address these constraints and
ensure the economic sustainability of the
industry. The IPA technology addresses
Michael Cremer, Ph.D.
International Aquaculture Senior
Program Advisor
16305 Swingley Ridge Road, Suite 200
Chesterfield, Missouri 63017 USA
[email protected]
Jesse Chappell, Ph.D.
IPA Technical Advisor
Auburn University
Auburn, Alabama, USA
Zhang Jian
China Aquaculture Program Manager
Zhou Enhua
China Aquaculture Freshwater
Technical Manager
these constraints by allowing greater
management control that yields greater
fish production at lower per-unit cost
through improved fish survival and feed
conversion. The zero-exchange system
captures nutrients for use as a crop fertilizer and requires minimal use of drugs
and chemicals to ensure food safety.
Wujiang IPA System
The model IPA system was con-
Attend China’s largest annual food products and ingredients show to connect with top buyers
and see the latest products and services. Build business relationships with China’s major restaurant
chains and participate in bidding forums for individual food sectors.
Bigger and Better for 2014
• 500 suppliers in 15,000 m2 of display area
• Diverse products reflecting 10,000 types of seafood and other frozen foods
• 20,000 visitors, including thousands of retail and foodservice buyers
• Special cooking competitions
• Join in annual association meetings and conferences, too
The China Food Products and Ingredients Show is organized by Wuhan Lanesync Supply Chain Management Co. Ltd.,
the leading provider of frozen and refrigerated food supply-chain services to over 35,000 Chinese restaurants, foodservice
operators and retailers.
With Support From:
China Federation of Logistics and Purchasing
China Cuisine Association/HotPot Branch
Wuhan Bureau of Commerce
China Aquatic Products Processing and Marketing Association
China Aquatic Products Chamber of Commerce
For more information contact:
Ms. Sara Jing Yu
Ms. Fang Tong
Telephone: +86 15623781378 Telephone: +86 15337219866
Email: [email protected]
Jane Bi
Telephone: +1 (314) 642 4661
Visit the Expo site!
http://scj.lanesync.com/
61
Earthen Dike
cell was nearly 22.5 mt. The grass carp
survival rate was 98.5%.
The fish in cell 2 were transferred to
cell 1 for further growout. The estimated
fish production from cell 2 was 15.8 mt,
with the grass carp growing from 300 g
to 1.7 kg in 182 days (Table 1). Average
fish survival was estimated as 98.1% with
an FCR of 1.48.
Carp in IPA cell 3 were transferred to
cell 2 for further growout. Estimated fish
production from this cell was 3.7 mt,
with grass carp growing from 4 g to 150 g
from mid-July to mid-November (Table
1). The estimated fish survival was
83.3%. The estimated FCR for the fish
raised on the combination of USSEC
36/7 and 32/3 soy-based feeds was 0.56.
Quiescent Zone
Large-Volume Airlifts
Cell 3 (22 x 3 x 2 m)
Cell 2 (22 x 5 x 2 m)
Cell 1 (22 x 5 x 2 m)
Water Flow
Generator, Feed Storage,
Office
Diagram of the Wujiang farm IPA system.
structed at the Wujiang fish farm in
Jiangsu Province, China, in early 2013.
The Wujiang IPA system consists of
three concrete raceway cells constructed
within a 2.1-ha fish pond. The raceways
are 22 m in length, with two of the raceways 5 m in width and one raceway 3 m
in width. The average water depth in the
three raceway units is 1.5 m. A 13- x 3-m
quiescent zone was constructed at the
downstream end of the raceways for solid
waste settling and removal.
The raceways were designed to culture larger fish in the two larger raceways
and fingerlings in the 3-m-wide raceway.
At the head of each raceway, a high-volume air blower supplies air to diffuser
mats at the bottom, creating an airlift
system that lifts water that is deflected by
a stainless steel hood to create a constant
water current through each raceway cell.
The pond is subdivided by an earthen
dike to allow full circulation of the water
flowing through the raceways and around
the pond before reentering the raceways.
Grass carp were selected as the initial
test species for the Wujiang IPA system.
Grass carp are the leading fed fish species
in China, with 4.78 mmt cultured in 2012.
The Wujiang fish farm was selected based
on its designation as a national grass carp
research and demonstration unit and the
farm’s previous work in demonstrating
USSEC’s 80:20 pond technology.
IPA cells 1 and 2 of the IPA system
were stocked with 750-g and 300-g grass
carp, respectively, in mid-May 2013. IPA
cell 3 was stocked with 4-g grass carp in July
2013. Grass carp in all three cells were fed
four to five times daily from the time of
stocking until harvesting in November 2013.
The carp in cells 1 and 2 were fed
62
Perspectives
with a USSEC 32/3 grass carp diet for
the duration of the feeding demonstration. USSEC feeds are identified by their
protein and lipid contents, so the 32/3
feed had 32% crude protein and 3% crude
lipid. Grass carp in cell 3 received
USSEC 36/7 feed from a fish size of 4 g
to 50 g, after which they were fed the
USSEC 32/3 feed. Both the 32/3 and
36/7 feeds were least-cost formulated and
contained over 40% soybean meal as the
primary protein source.
Solid wastes were collected two or three
times daily by vacuuming from the quiescent
zone. The culture cells were periodically disinfected with approved chemicals for disease
control. Fish were sampled monthly to monitor growth and feed conversion.
The Wujiang IPA feeding demonstration yielded a total production of 42 mt of
grass carp from the 2.1-ha pond unit containing three IPA raceway cells. This represented nearly three times the average
pond yield of 7.2 mt/ha obtained in the
2.57 million ha of fish ponds currently
operated in China. The success of the initial USSEC IPA feeding demonstration
showed that the IPA technology can help
meet the demand for increased, sustainable aquaculture production in China.
GENERAL ENQUIRIES
Results
The carp in IPA cell 1 were harvested
for marketing on November 13, 2013
(Table 1). The 3-year-old grass carp in
cell 1 grew from 750 g to an average
weight of 2.6 kg in 182 days with a feedconversion ratio (FCR) of 1.89. The total
fish harvest weight from the 22- x 5-m
Grass carp production was 42 mt from
the three raceway cells.
CONFERENCE MANAGEMENT
[email protected]
Table 1. Stocking and harvest data for the 2013
USSEC IPA grass carp feeding demonstration.
3
Cell dimensions/water volume (m )
Fish stocking size (g)
Stocking density (fish/m3)
Fish stocked
Total stocking weight (kg)
Total harvest weight (kg)
Average fish harvest weight (g)
Fish survival (%)
Culture period (days)
Average daily gain (g)
Major
Sponsor
& Host
[email protected]
Cell 1
Cell 2
Cell 3
22 m x 5 m
176 m3
750.0
53
8,732
6,549
22,483
2,614
98.5
1.89
182
10.24
22 m x 5 m
176 m3
300.0
59
9,687
2,906
15,775
1,660
98.1
1.48
182
7.47
22 m x 3 m
105 m3
4.1
303
30,000
123
3,748
150
83.3
0.56
120
1.22
Conference
Sponsors
www.was.org
WAS Premier
Sponsors
Organisers
63
innovation
aquaculture engineering
Unit Processes In RAS Systems
Compact yet powerful
fluidized sand biofilters
utilize sand particles to
provide area for nitrifying bacteria to live and
consume potentially toxic
ammonia and nitritenitrogen. This CycloBioFilter system uses
tangential flow to reduce
the energy required
to expand the sand bed.
Courtesy photo.
Ammonia-, Nitrite-Nitrogen Concerns; Biofiltration
Thomas M. Losordo, Ph.D.
Director
Aquaculture Systems Engineering
Pentair Aquatic EcoSystems, Inc.
1791 Varsity Drive, Suite 140
Raleigh, North Carolina 27606 USA
[email protected]
Trickling filters are simple, reliable filters that provide stable nitrification, water
aeration and carbon dioxide degassing in one unit. In this example, water is sprayed
over two trickling filters with rotating arms. Photo courtesy of AquaOptima, A.S.
Summary:
Since un-ionized ammonia-nitrogen and nitrite-nitrogen are toxic to most
finfish, controlling their concentrations in culture tanks is a primary objective in the design of recirculating aquaculture systems. Biological filtration
is widely used to control these compounds. Trickling filters provide reliable
nitrification, aeration and some carbon dioxide removal in one unit. Fluidized bed filters use inexpensive media to offer high nitrification capacity in a
compact size. Moving bed reactors are compact and have low energy requirements and relatively stable nitrification.
In the November/December issue,
this column reviewed important unit
processes in recirculating aquaculture
system design and began to discuss
components used to remove waste solids
from the process water. This article
explains the importance of controlling
ammonia and nitrite-nitrogen concentrations and some of the processes and
components used to do so.
Ammonia-, Nitrite-Nitrogen
Total ammonia-nitrogen (TAN), the
combination of un-ionized ammonia and
64
ionized ammonia, is a by-product of the
metabolism of protein in aquaculture feed.
The un-ionized form of ammonia-nitrogen is very toxic to most finfish. The fraction of TAN in the un-ionized form
depends largely upon the pH and temperature of the water. At a pH of 6.8 to 7.2,
the majority of TAN is in the ionized
form, while at a pH of 8.75, nearly 30% of
TAN is in the toxic un-ionized form.
The lethal concentrations of ammonia-nitrogen for many species have been
established, but sublethal effects are not
well defined. Reduction in growth rates
may be the most important sublethal but
unquantified effect. A good rule of
thumb is that the concentration of unionized ammonia-nitrogen in tanks
should not exceed 0.05 mg/L.
Nitrifying bacteria in production systems
use ammonia-nitrogen as an energy source
for growth and produce nitrite-nitrogen as a
by-product. The nitrifying bacteria grow on
the surfaces of biofilter substrates, although
all production component surfaces have
these bacteria present to some extent.
While nitrite-nitrogen is generally
not as toxic as ammonia-nitrogen, it can
be very harmful to some cultured species
and must be controlled within culture
tanks. The toxicity of nitrite-nitrogen is
species-specific. For example, while tilapia are highly tolerant of nitrite-nitrogen
in the water, hybrid striped bass have a
very low tolerance. In freshwater systems,
it is a common practice to increase the
chloride concentration of the culture
water to help reduce the toxicity of
nitrite-nitrogen.
Fortunately, other types of nitrifying
bacteria (generally referred to as Nitrobacter) are also present in biological filters
that utilize nitrite-nitrogen as an energy
source. The end product of complete nitrification is nitrate-nitrogen, a relatively
non-toxic form of inorganic nitrogen.
Biofiltration Processes
Controlling the concentrations of unionized ammonia-nitrogen and nitritenitrogen in culture tanks is a primary
objective in the design of recirculating
aquaculture systems (RAS). Ammoniaand nitrite-nitrogen must be removed
from the culture tank at a rate equal to
the rate of production to maintain a safe
concentration.
While a number of technologies are
available for removing ammonia and
nitrite-nitrogen from water, biological
filtration is the most widely used in RAS.
In the biofiltration process, the substrate
has a large surface area, where nitrifying
bacteria attach and grow. As previously
noted, ammonia-nitrogen in the recycle
stream is oxidized to nitrite and nitratenitrogen by nitrifying bacteria.
Gravel, sand, plastic beads, plastic
rings, plastic tubes and plastic plates are
commonly used as biofiltration substrates.
The configuration of the substrate and
the manner in which it comes into contact with the process water defines the
water treatment characteristics and capabilities of the biological filtration unit.
Many biofilter components and configurations are available.
Trickling Filters
One of the primary configurations is
trickling filters. Used in RAS, these filters evolved from those used in domestic
sewage treatment. While they provide
one of the simplest forms of biofiltration,
trickling filters have provided a reliable
unit process for decades. This type of filter consists of a water distribution system
at the top of a reactor filled with a media
that has a relatively low specific surface
area – the surface area within the filter
media to be inhabited by the bacteria –
generally less than 330 m2/m3.
Trickling filters are operated in a
non-flooded configuration. Low specific
surface areas create large air spaces within
the filter medium. As such, trickling filters are larger in size than other biofilters
of similar capacity. However, as well as
reliable nitrification, trickling filters provide aeration and some carbon dioxide
removal all in one unit.
Volumetric nitrification rates of
approximately 90 g TAN/m3 biofilter
media/day can be expected in warmwater
applications with this type of biological
filter. When designing these filters for a
recirculating system, assuming that 3.5%
of the feed becomes TAN, a design criterion of 2.6 kg feed/day/m3 media should
be used.
Fluidized Bed Filters
Fluidized bed filters are essentially
sand filters operated continuously in an
expanded backwash mode. Water flows
up through a bed of sand at a rate sufficient to lift and expand or fluidize the
sand and keep the particles in motion so
they no longer are in continuous contact
with each other. Fluidized bed filters use
low-cost sand of smaller diameter than
that used in particulate solids removal
applications. A fluidized bed filter is an
excellent environment for the growth of
65
Moving bed reactors provide reliable, energy-efficient and compact biological filtration.
Small plastic media is kept in motion by aeration or water movement within the reactors.
Photo courtesy of North Carolina State University and The La Paz Group, LLC.
nitrifying bacteria that can colonize the
entire surface area of the filter medium.
Sand used as media in fluidized bed
filters has an extremely high specific surface area in excess of 5,000 m2/m3. As
such, the main advantage of fluidized bed
technology is high nitrification capacity
in a relatively compact unit. The sand
media also is extremely low cost when
compared to other plastic media used in
biofiltration.
Fluidization (pumping) requirements
depend upon the size and weight of the
media used. Keep in mind that the buoyancy of the media changes with the
amount of biological growth on it. This,
in turn, depends upon the water temperature, nutrient loading rate and degree of
bed fluidization. Unless there is a system
for recovering sand as water leaves the filter, the sand media will need to be replaced.
While fluidized bed filters require
energy to keep the sand bed fluidized,
their small “footprint” and associated
high capacity can be huge advantages.
However, fluidized bed filters can
become unstable in warmwater systems
where high concentrations of dissolved
organic nutrients occur. So while they are
powerful biofilter reactors, care must be
taken in their operation.
Moving Bed Reactors
Moving bed reactors (MBRs) are an
interesting cross between up-flow fixed
bed bead filters and fluidized bed sand filters. These filters use plastic media kept in
a continuous state of movement, usually
with aeration. The diameter of the plastic
media is much larger than that of sand, so
the media has a lower specific surface area
than sand of 450-850 m2/m3.
The media pieces are usually neutrally
buoyant or just slightly lighter than water.
With a coating of bacteria, the media
becomes slightly negatively buoyant. Placed
within an open top reactor vessel, the biofilter media is mixed with air or water.
Moving bed filters can be designed as
up-flow or down-flow filters based on the
required system configuration. Depending upon the nutrient concentration,
water temperature and salinity, design
nitrification rates should range 350-500 g
TAN/m3/day. Assuming that 3.5% of the
feed becomes TAN, a biofilter design criterion of 10-14 kg feed/day/m3 filter
media should be used. Given that MBR
vessels can be designed to be deep rather
than long or wide, the reactor can have a
large volume with a small footprint.
These filters can run with very little
head loss across the reactor (usually 10 to
20 cm) and hence require very little
pumping energy to operate. Typical
installations direct the effluent from a
screen filter component by gravity to the
MBR. Water is usually pumped from the
effluent side of the MBR or from a
pumping sump to the next process, which
is usually oxygenation and/or ultraviolet
sterilization. The main advantages of the
MBR design are its compact size, low
energy requirements and relatively stable
nitrification process.
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67
innovation
As has been noted in a wide variety of
other copepod species, P. crassirostris
reduces reproductive output when population density increases. Although algae
density, water quality and cannibalism of
young were investigated, only daily harvest and removal of nauplii from culture
alleviated density effects on female fecundity in the range of adult densities tested.
Advances In Intensive Copepod
Production Technology
Large-Scale Development
M. Dean Kline
Finfish Department
Oceanic Institute
41-202 Kalanianaole Highway
Waimanalo, Hawaii 96795 USA
[email protected]
Chatham K. Callan, Ph.D.
Charles W. Laidley, Ph.D.
These light micrographs of Parvocalanus crassirostris show an adult female (left)
and a typically smaller adult male.
Summary:
Research at the Oceanic Institute has been successful in overcoming bottlenecks associated with rearing small-mouthed fish larvae by finding a suitable first feed. Early work on the calanoid copepod Parvocalanus crassirostris
focused on parameters necessary for successful maintenance of stock cultures.
The authors’ further work with P. crassirostris has addressed refining methods
for intensive, pilot-scale production of nauplii with the goal of demonstrating
its potential for commercial application.
The expansion of the marine aquaculture industry is currently limited, in part,
by the inability to successfully bring large
numbers of larvae through the critical
first-feeding stage. Currently, a program
at the Finfish Department of the Oceanic
Institute is addressing this challenge by
developing methods to culture fish with
extremely small larvae that cannot be
reared using conventional rotifer- and
Artemia-based hatchery methods.
Included in this group are snappers,
groupers and many coral reef species.
Previous projects at the Oceanic
Institute were successful in overcoming
bottlenecks associated with rearing these
small-mouthed larvae by finding a suitable first feed, which ultimately allowed
the facility to rear several new species,
including the bluefin trevally, an important sport fish in Hawaii; the flame
angelfish, a highly valued species in the
marine ornamental trade; and the Gulf of
Mexico red snapper, a key Gulf species.
The authors achieved this success
through the identification of a local calanoid copepod species, P. crassirostris
crassirostris, that has very small and nutritious nauplii.
68
Calanoid Copepods
In addition to facilitating the culture
of highly challenging species, the copepods offer several advantages over traditional rotifer and Artemia-based technologies. Copepods are thought to be the
natural feed source for the larval stages of
many fish species. They can be obtained
locally, avoiding the use of non-native or
invasive species. In addition, their nutritional profile is superior to that of either
rotifers or Artemia.
However, intensive-production technology for copepods is relatively new and,
although successful at smaller scales,
required significant development to allow
broader application and commercial scale
up. Over the past few years, the authors’
work with P. crassirostris focused on refining methods for intensive, pilot-scale
production of nauplii with the goal of
demonstrating its potential for commercial application.
P. crassirostris Potential
Cultures of P. crassirostris originally
isolated locally from Kaneohe Bay in
Oahu, Hawaii, USA, have been maintained at the Oceanic Institute since
Finfish Department
Oceanic Institute
2004. Eggs hatch within seven hours at
25° C into stage 1 nauplii that are 49 µ
wide and 77 µ long, which then take
approximately eight days to mature to
adulthood at the same temperature.
Females are 420 µ long and visually distinct from the smaller 310-µ-long males,
both in overall body shape and length of
first antennae.
Females produce eggs in clutches of
four with healthy females producing up
to 28 eggs/day. Females are reproductive
throughout their lives, although peak
output is generally observed in younger
females. The female lifespan can extend
to 28 days after hatching. Male P.
crassirostris, with no observable mouth
parts, generally die within a week of
maturing to the adult stage.
Small-Scale Trials
Early work on P. crassirostris focused
on parameters necessary for successful
maintenance of stock cultures. The copepods were found to be euryhaline and
eurythermal, although cultures are generally maintained in 22 ppt water at 25° C.
Photoperiod studies revealed a wide tolerance to lighting regimens. P. crassirostris
are cultured under continuous light from
overhead fluorescent fixtures to allow
concurrent in situ algae growth.
Algal diets were evaluated in relation
to maturation, survival and adult reproduction. Tetraselmis species, Nannochloropsis species, Isochrysis galbana and Chaetoceros muelleri were tested singularly and
as combination diets.
Survival to the adult stage increased
when nauplii were fed a diet including I.
galbana, whereas female fecundity
Each nauplii production unit is comprised of a 1,500-L production tank (top left) and
200-L egg and nauplii harvest tank (lower right). Culture water containing eggs,
nauplii and algae passively drains into a harvest bucket submerged in the harvest tank.
increased with a diet of C. muelleri. Neither Tetraselmis nor Nannochloropsis,
either singularly or as mixed diets, led to
any noticeable increase in maturation,
survival or female reproduction. Therefore, cultures of P. crassirostris are currently maintained on a diet consisting of
150,000 cells/mL of each of the algae I.
galbana and C. mulleri.
The authors then focused on nauplii
production as a function of population
dynamics. In particular, extensive
research investigated the relationship
between adult copepod density and
female fecundity for the purpose of maximizing nauplii production to meet the
requirements of a marine fish hatchery.
A large-scale nauplii production system was designed and constructed based
on the results of earlier small-scale trials.
The system consisted of four conical-bottom, 1,500-L tanks with seven 1,000-L
tanks used for maturation of nauplii to
the adult stage.
Each nauplii tank was harvested daily
by passive flow through a 105-µ banjo filter into a 20-L harvest bucket with 38-µ
screen panels to retain eggs and nauplii but
allow the flow of culture water out of the
harvest bucket. Water was then pumped
back into the main nauplii production
tank at 30 L/minute to complete the circuit. Ninety-five percent of nauplii and
eggs can be removed from the production
tank with little effort in four hours.
Every day, eggs and nauplii from the
harvest are stocked into a clean maturation tank at 20/mL, while a maturation
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69
Egg/Nauplii Harvest
(million)
140
Changing the way fish,
and the industry, view protein.
120
100
80
60
40
20
0
1 3 5 7 9 1113 15 1719 21 23 2527 293133 35
Culture Day
Figure 1. Total daily harvest abundance of eggs and nauplii from four nauplii production tanks.
tank is harvested for adults to stock into the
nauplii production tank to maintain female
densities of 1-2/mL. In addition, each nauplii production and adult maturation tank
receives 150,000 cells/mL of both I. galbana
and C. mulleri, resulting in a daily need of
1.95 trillion cells of each alga for the entire
system, which are produced on site in the
algae production laboratory.
Harvest figures recorded over 36 days
for eggs and nauplii from four nauplii
production tanks are shown in Figure 1.
Daily harvests ranged from 36 million to
135 million eggs and nauplii, with an
average of 83 million eggs and nauplii.
The greatest variation in harvest yield
was due to algae culture shortages, which
led to subsequent nauplii production
declines in the system. The inadequate
supply of algae for the nauplii production
tanks resulted in an immediate reduction
in eggs and nauplii produced.
Normal production values returned
after several days of properly sustained
feed densities. However, if algae production could not be stabilized, a subsequent
lack of algae for the maturation tanks led
to a reduction in the quantity of adults
used to replace deceased females in nauplii
production tanks. Having fewer females
further reduced egg and nauplii harvests.
Perspectives
Future research on copepod produc-
tion at the Oceanic Institute will focus on
further refinement of the intensive nauplii production system – given the promising preliminary data showing more than
100 million eggs and nauplii harvested
daily. Specifically, it would be desirable to
develop more efficient algae culture
methods or, ideally, an appropriate live
microalgae substitute.
Although this system shows exciting
potential for supplying large numbers of
copepod nauplii, the expense of maintaining and operating an algae production
facility to support it represents a large
portion of the total cost. Therefore,
future efforts will continue to address
these important challenges.
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70
71
innovation
novus award submission
Submersible fish cages lower below the water surface to avoid potential damage during extreme weather conditions.
Automatic Submersible Fish Cage Systems
Counter Weather, Other Surface Problems
Summary:
The development of fish cage
technologies that can be submerged may be necessary to avoid
the operational challenges of
surface-based aquaculture, which
can include extreme temperature
and weather conditions, jellyfish
infestation, oil spills and many
types of biofouling. When adverse conditions occur, the cage
systems can be remotely or automatically submerged by operators
or an automatic control system.
As soon as the dangerous event
has passed, the systems can be
raised to the surface to resume
normal operations.
The development of offshore fish
cage technology has recently been driven
by the limitation of nearshore site expansion. Most offshore sites, however, are
exposed to heavy winds and waves, which
can severely stress the fish or damage the
cages. Furthermore, some sites can be
near shipping lanes, be exposed to harmful algal blooms and be difficult to access
during adverse weather conditions.
Therefore, the development of fish
cage technologies that can be submerged
may be necessary to avoid the operational
challenges of surface-based aquaculture.
Subsurface aquaculture may also help
operators avoid surface-related issues
72
such as jellyfish infestation, unsuitable
temperatures, high pollutant levels, oil
spills and many types of biofouling.
Experimental
Submersible Cages
Two small-scale automatic submersible fish cage systems – a remotely operated fish cage with tethered surface control system and an autonomous submersible cage system using air control – have
recently been developed for deployment
in the waters off Korea. The cage systems
can move vertically within the water column by adjusting the weight and buoyancy of the cages with an automatic control system.
The next step in development will be
to design a commercial-size system and
perform engineering and economic analyses to investigate whether these systems
could be effectively incorporated into the
wider marine aquaculture industry.
Remote Cage
With Tethered Control
The primary objective of developing
the submersible fish cage system was to
provide the capability of reducing the
mortality of farmed fish due to toxicity
from algal blooms in coastal waters. The
cage design consists of 12 angled rigid
frame components with both containment and cover nets, 12 upper floats, 12
tanks for fixed and variable ballast, mooring ropes, anchors, a control station and
surface control panel.
Taeho Kim, Ph.D.
Associate Professor
School of Marine Technology
Chonnam National University
Yeosu 550-749, Republic of Korea
[email protected]
The upper frame includes 12 fixed
flotation tanks, while the lower frame has
six fixed flotation tanks and six variable
ballast tanks. The fixed ballast tanks
enable workers to adjust the buoyancy
manually, while the buoyancy of the variable ballast tanks is remotely adjustable
with the control system.
The mechanical components of the
control system are attached to the top of
the fish cage and tethered to the surface
control panel. This allows operators at
the surface to regulate the flow of air or
seawater to the variable ballast tanks. The
surface control panel regulates a compressed-air source with six two-way and
12 three-way valves and includes three
clinometers, four electrical terminals and
necessary air hose connections.
The watertight control station is
attached to the center of the upper frame
of the cage with stainless steel turnbuckles and wire rope. It is also connected to
the surface control panel (located on a
service vessel) by electrical cables.
Ballast System
The variable ballast system consists of
tions. An accelerometer may be more
effective than a wind gauge, as wind
gauges are routinely damaged under
adverse weather conditions.
From an operational perspective, it is
important to tighten slack in all of the
attachment line connections while the fish
cage is submerged. If not, the cage can
experience excessive movement that may
be detrimental to the caged fish stock.
A worker checks the control station on top of a remotely operated submersible
fish cage system.
a regulator to control the pressure of the
air released from the air compressor, a
motor valve for controlling the opening
and closing of the piston valve, a motor
valve for adjusting air pressure inside the
tank, a pilot valve for controlling the
motor valve and a piston valve. To submerge the cage, compressed air is
expelled through the motor valve, allowing seawater to enter through the piston
valve and reduce buoyancy in the tank.
The cage system can be submerged to
a predetermined depth and then resurfaced after a specified time with a
remotely operated control system. To
surface the cage, air released from the
compressor displaces seawater in the variable ballast tanks, increasing buoyancy.
The motor valves are operated electrically
by the control system from the surface
control panel. Although biofouling on
the ballast tanks increased during a fivemonth test, the piston valve closed and
opened normally.
Autonomous Cage System
A fully automatic rigid fish cage system was also developed. The automatic
control system monitors environmental
parameters such as wave height and wind
speed so the cage can be submerged in
extreme sea conditions and then surfaced
after the weather has passed.
In the autonomous cage system, vertical positioning in the water column is
done with a control system that first
senses surface wind speeds. At a predetermined “extreme” value, the control
system operates a combination of variable
ballast tanks that can be filled with water
for sinking. When the surface conditions
become calm, the water in the tanks is
displaced with air, and the system comes
back to the surface.
The 12-sided cage structure incorporates a steel framework with a 5.92-m
diameter and depth of 2.91 m. Attached
to the steel framework are a housing for
motor valves that control variable ballast
tanks, eight housings for two air compressors, a main control system, four batteries,
a reserve air tank, four high-pressure air
tanks, 12 variable ballast tanks and a seawater pump housing. The net of the fish
cage is tightened across the frame to minimize volume reduction due to currents.
Control Station
The cage is outfitted with a control
station above the valve housing that
adjusts buoyancy by utilizing compressed
air stored in air tanks. The mechanical
components of the ballast systems are
operated by automated software that
incorporates control and monitoring algorithms when a preselected sea state occurs.
The control station has a wind gauge,
wireless communication printed circuit
boards and a transmitting antenna. During
operation, it monitors wind speed, so the
cage can be submerged before extreme
conditions cause damage and then surfaced after the bad weather passes.
Possible Improvements
Many of the system and subsystem
assemblies of the control system can be
simplified to minimize potential failure
points and reduce the amount of maintenance required. Combining pressure
housing units may decrease potential
leakage issues.
Improvements could also be made in
sensing critical surface weather condi-
Editor’s Note: This article is based on the
author’s research on automatic submersible
fish cage systems. Dr. Kim’s work was considered for the Novus Global Aquaculture Innovation Award, the first of which was presented by the Global Aquaculture Alliance at
the GOAL 2013 conference in Paris, France.
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73
innovation
Data-Driven Management Technology
Can Transform Aquaculture
Aquanetix data management is in beta
testing at a seabass
and sea bream farm
in Greece.
Diogo Thomaz, MBA,
Ph.D.
Aquanetix
22a Lena Gardens
London W6 7PZ United Kingdom
[email protected]
Stella Adamidou, Ph.D.
Aquanetix
With Aquanetix, workers can record feed quantities and start/end times for feedings on
a convenient wrist-mounted smartphone. In the process, they also report fish behavior.
Summary:
Aquaculture is a complex industry, but extensive knowledge of
its varied facets exists. While the
resources required for aquaculture
face limitations, production efficiencies are improving. Today’s
industry needs better information-based management strategies to increase its performance
and sustainability. Effective
information gathering needs the
collaboration of every farm hand.
The Aquanetix project aims to
use Cloud technologies, smartphones and a game-like graphical
interface to make knowledge of
aquaculture management practices more accessible to even the
smallest operations.
In its various shapes and forms, aquaculture is one of the most complex animal
production industries today. Be it tilapia
farming in lakes in Brazil, barramundi
growout in recirculating plants in Vietnam or salmon cage farming in Norway’s
fjords, aquaculture is a biotechnology that
encompasses many complex steps, from
larval rearing to controlling water chemistry to managing complex feeding processes. Even at the simplest fish or
74
shrimp farms, success depends on the
correct balance of applied biology, husbandry and technology.
In the last few decades, research projects around the world have added much
knowledge and know-how on the culture
of various species using different farming
methods. Nutritional requirements for
many species are known, and feed production technologies have reached quite
advanced levels.
Resources, Efficiency
Today aquaculture is called upon to
solve some of the critical problems caused
by an expanding human population coupled
with the unprecedented destruction of fisheries resources. Aquaculture’s growth,
however, is leading to pressures on both the
environment and raw materials.
In answer, farmers are finding lowerimpact feed sources and becoming more
efficient in the use of existing resources.
Since the public image of aquaculture
directly determines the value of what it
produces, the industry is also reducing
impacts on water resources and seeking
greater efficiencies in attaining a sustainable mode of production.
Going forward, research performed in
laboratory settings must be more directly
related to practices at commercial operations, where variability in the farming
environment, diseases and other causes of
stress can negatively affect production out-
comes. For example, studies in the salmon
industry have shown that despite the use
of advanced technologies, 10 to 40% of the
feed used is left uneaten. At Pangasius
farms, where the species can theoretically
be grow with a feed-conversion ratio of 1,
conversion values are often above 2.5.
The existing expertise regarding
health and sanitation practices, feeds and
feeding management, husbandry processes, and operations and human
resources management could all, if well
implemented, significantly improve the
industry’s performance. However, the
implementation of this knowledge is a
limiting factor for aquaculture today.
Information
The “inventor” of modern business
management, Peter Drucker, may not
have said it, but the quotation “If you
can’t measure it, you can’t improve it”
attributed to him is considered a maxim
in today’s management science. It basically stresses the key role that information
should play in management decisions.
This is an area where aquaculture, as
many other primary production industries, is very deficient.
There is very little automation in this
industry, and due to its complexity,
improvements will take a long time.
Therefore the men and women working in
aquaculture represent the key resource
upon which business success or failure will
depend. If we are to gather information to
better manage our fish and shrimp farms,
we need to get the men and women working in the field to gather it in a reliable and
timely manner so that it can be used in
good management decisions.
Motivation, Management
Aquaculture is an industry in which
each daily feeding counts toward the success of the business and understanding of
the health and environmental conditions
matters for the good biological performance of the livestock. Yet in aquaculture
companies around the world, the workforce tends to be somewhat poorly paid,
poorly trained and usually expected to do
repetitive tasks under difficult weather
conditions.
No matter how good the processes at a
farm are, the people who work in the field
must be motivated to do a good job to
achieve satisfactory results. Motivation is
the result of three factors that impact performance in a positive way: having a purposeful mission, autonomy to progress
according to the mission and mastery of
the skills necessary to perform well.
These factors should be addressed in
any management program, especially in
industries like aquaculture. They require
a management attitude that values the
workforce, but also mechanisms where
information is gathered as operations
happen, in real time, and feedback given
frequently to workers as to the quality of
their performance. Staff members who
are engaged in their work are motivated.
Training should, ideally, be supplied
almost continuously to support staff in
their everyday decisions.
Aquanetix Project
Aquaculture is clearly a complex
industry, which today struggles with
issues of efficiency and sustainability that
can be improved greatly by better management. People play a key role, and
improving motivation will deliver results.
Data and information link all the above
and act as the glue that binds performance, people and management in a way
that delivers the further efficiencies
needed to make aquaculture even more
viable and sustainable.
The Aquanetix project uses technologies that allow real-time data collection
by workers and applies the information
from every person at a fish or shrimp
farm. Data collection focuses on feeding,
environmental parameters, stock behavior
and health status, infrastructure conditions and other parameters that affect
farm performance.
The vast majority of this data has to
be collected and recorded by workers at
the very moment they perform their
assigned tasks. Today we have technologies that make this possible and accessible
to even small family businesses through
the use of Cloud technologies and mobile
equipment such as smartphones and electronic tablets.
Data-recording applications can
deliver knowledge such as the best
growth and feeding models scientists
have developed. They can also provide a
form of crowd-learning advice to farmers
that derives from the experiences of hundreds or thousands of other operations
similar to theirs.
Ultimately, gathering all this data in
one place allows us to understand the factors that really affect production –
whether nutritional, environmental or
husbandry-related – in the real world of
farms, as opposed to the laboratory.
work by Drs. Thomaz and Adamidou to
develop better information-based management strategies to improve the performance
and sustainability of aquaculture systems.
This work was considered for the Novus
Global Aquaculture Innovation Award, the
first of which was presented by the Global
Aquaculture Alliance at the GOAL 2013
conference in Paris, France.
75
innovation
Simple Soil Solution Removes Egg Adhesive
To Enhance Carp Seed Production
innovation
Sustainable Grouper Farming
Vaccines, Virus-Free Hatchery Support Greater Production
This transformation of eggs is due to the interaction of the
adhesive or gumming substances with water. In both normal
breeding and hatcheries, the sperm can fail to penetrate the
adhesive covering surrounding the eggs and fertilize the eggs
only at the periphery of the egg balls. This results in decreased
fertilization and poor availability of hatchlings. Due to the shortage of eggs and fingerlings, farmers are not interested in culturing these fish.
Huey-Lang Yang, Ph.D.
Merit Ocean Biotech
Number 51, Keji 5th Road
Annan District
Tainan City 709 Taiwan
[email protected]
Han-You Lin, Ph.D.
Chi-Chu Lin
Degumming Eggs
Fish eggs form ball-like structures on contact with water and
clump further over time.
To increase fertilization rates, several procedures have been
developed for degumming eggs. Some authors advocate the use
of tannin in a solution of 15 g tannin/10 L water. However, tannin is poisonous to fish eggs, and its prolonged use can generate
various negative impacts. An alternative method is the use of a
urea-sodium chloride solution, but this approach is also not
effective and there is potential for contamination. The use of
amul milk at a solution of 200 g/10 L water is an effective, but
costly approach developed by N. R. Chatterjee and co-workers.
Institute of Biotechnology
National Cheng Kung University
Tainan, Taiwan
Grouper fingerlings raised in an indoor hatchery with established operating procedures
and biosecurity exhibited much better growout survival than fingerlings from conventional hatcheries.
New Procedure
Summary:
In carp and other freshwater fish, the adhesive substance
that covers their eggs can be a barrier to fertilization.
Sperm can fail to penetrate the adhesive and fertilize
only at the periphery of the egg balls. The resulting
decreased fertilization and poor availability of hatchlings has limited farmers’ interest in culturing these
fish. In field studies, the author discovered that some
soils from Bengal, India, proved effective in removing the adhesive component from eggs. Treated eggs
showed increased fertilization rates.
Prof. N. R. Chattopadhyay
Department of Aquaculture
Faculty of Fishery Sciences
West Bengal University of Animal
and Fishery Sciences
5no. Buderhat Road
P. O. Panchasayar
Chakgaria, Kolkata 700094 India
[email protected]
The common carp is a multiple breeder that produces adhesive
eggs. After sex play, the female’s eggs, laid on submerged weeds or
other suitable substrate and held by the eggs’ adhesive, are then
fertilized by the milt released by a male. On contact with water,
the eggs immediately assume the shape of round balls before being
fertilized. With the passing of time, agglutination increases further. This also happens with Pangasius sutchi, indigenous catfish
and some ornamental fish that lay adhesive eggs.
76
In field studies to find an inexpensive, yet effective treatment
to remove adhesive from eggs, the author discovered that some
soils from a certain region of Bengal, India, proved effective in
removing the adhesive component.
Eggs and milt were collected through stripping followed by
fertilization by use of a feather. The fertilized eggs were placed
in a tray containing 10 L of water into which a handful of the
soil was mixed.
The water/soil solution removed the adhesive glue from eggs
produced by two successive games. Individual eggs separated
from each other, and fertilization was enhanced.
After through mixing and separation of individual eggs, the
eggs are stocked into the tank for further development. The
released mixture adds a yellowish tint to the water.
Perspectives
Although common carp is an important species for stocking
in multispecies operations, farmers generally do not consider the
species for more concentrated farming due to the lack of availability of seed. Fish farmers depend mainly on wild seed for
stocking carp. Some seed producers in India, particularly in Bengal, also take the risk of common carp seed production through
stripping eggs.
The soil-based approach for removing carp egg adhesive to
improve fertilization opens a new dimension for standardized
seed production that can help increase production. The technology is also being studied with , for which increased fertilization
and hatching rates are expected.
Editor’s Note: This article is based on the author’s research to develop
methods to increase the seed production of important freshwater fish.
This work was considered for the Novus Global Aquaculture Innovation Award, the first of which was presented by the Global Aquaculture Alliance at the GOAL 2013 conference in Paris, France.
Summary:
In targeting grouper for new and
sustainable farming technology,
the authors developed an oral
vaccine to control nervous necrosis virus (NNV) infection at the
larval stage and multivalent injective bacterial and viral vaccines
for the growout stage. At a pilotand production-scale virus-free
indoor grouper hatchery, over
70 successful production cycles
yielded healthy NNV specific
pathogen-free fingerlings. Since
the growout vaccine is challenging to administer, the fingerlings
were vaccinated before shipping
to farmers.
Current aquaculture practices in developing countries are often plagued by the
shortcomings of traditional aquaculture.
The intensive farming patterns of back
yard-style aquaculture have often caused
disease outbreaks, leading to high mortality and unstable production. Attempts to
normalize production have usually taken
the form of antibiotic and chemical drug
use, which can result in lower-quality fish
products with drug residues and potential
damage to the farming environment.
For example, Taiwan was previously
known as the “Kingdom of Tiger
Shrimp,” with an annual production of
80,000 mt in 1987. In 1990, the shrimp
industry was nearly destroyed by white
spot syndrome. When farmers changed
to the culture of white shrimp, Taura
syndrome appeared. Most recently, early
mortality syndrome has reduced output.
The overall survival rate of fish
farmed in Southern Asia is around 20 to
40% due to various bacterial, viral and
parasitic diseases. Similar scenarios have
occurred globally.
To meet the increase in global
demand for seafood, the aquaculture
industry clearly needs new concepts,
products and biosecurity technology to
address these significant bottlenecks.
Vaccines
As vaccines have been employed successfully to control diseases in human and
domestic land animals, such prophylactic
approaches have prevented disease outbreaks, decreased the abuse of antibiotics
and assisted the industrialization of coldwater fish aquaculture in developed countries. Vaccines have significantly
advanced the salmon industry in Norway
and the sea bream and seabass industries
in the Mediterranean Sea.
Unlike land animals that live in air
and have constant body temperatures,
fish live in water where the temperature,
salinity and farming methods vary and
alter the population of microorganisms.
Warmwater fish, in particular, have
diverse epidemics and pathogens in different farming environments. Therefore,
there is need for the development of fish
vaccines using concepts appropriate for
aquaculture in developing countries,
where 80% of fish farming takes place.
Grouper Aquaculture
Grouper are high-value fish wellliked by Asians and Arabians in the Middle East. They are familiar to consumers
and have a stable market demand, which
makes the species a candidate for
expanded culture.
Grouper are demersal fish that live in
coral reefs and are difficult to catch by
conventional net fishing, so illegal methods of grouper fishing are used, including
explosives and poisons that have
destroyed their natural habitats. Consequently, several species of grouper have
been listed as near endangered and even
endangered, so farming of grouper is necessary to supply the market demand and
reduce fishing pressures.
According to Food and Agriculture
Organization of the United Nations estimates, in 2020, the grouper demand will
reach 500,000 mt – met in equal shares by
fishing and aquaculture. Grouper farming
will expand threefold from 2008 levels,
with accompanying needs for additional
grouper fry and culturing technology.
Most grouper are currently farmed in Asia.
Among the top producing countries are
China (61%), Taiwan (14%) and Indonesia (13%), followed by Malaysia (9%).
However, in Taiwan and neighboring
77
Table 1. Performance of grouper fingerlings at an NNV-free
indoor hatchery and current outdoor hatchery.
Method
Outdoor hatchery
Indoor hatchery
Reproduction
Frequency
Deformity Productivity
Rate (%)
(fish/mt)
1/10
Stable
20-40%
Under 5%
south Asian countries, grouper fingerling
production has suffered due to major
mortalities from severe nervous necrosis
virus (NNV) infection that resulted from
careless farming behavior. At the growout
stage, grouper have been found to be
infected by NNV, Irido virus and bacterial pathogens such as Vibrio species,
Aeromonas, Streptococcus and parasites.
Vaccine Development
In 2001, the authors built a marine
fish research team at National Cheng
Kung University in Taiwan that has since
grown into a team of five principal investigators and over 40 graduate students.
The group selected grouper as a target
fish for which to develop new and sustainable farming technology. In the process, the authors developed an oral vaccine for grouper to control NNV
infection at the larval stage and multivalent injective bacterial and viral vaccines
for the growout stage.
As NNV is mostly found at the juvenile larval and postlarval stages, vaccines
must be administered early before infection. While several NNV subunit vaccines have been developed, there are
issues regarding administering those vaccines to larvae while they are sensitive to
handling stress. Injective and immersive
immunizations are impractical, leaving
oral vaccination the only option.
The primary bottlenecks for oral vac-
NNV has been found in the waters of
most farming areas, as well as in broodstock, fertilized eggs and commercial live
starting feeds at current outdoor grouper
hatcheries. To help control further viral
epidemics, the authors designed and constructed a pilot-scale virus-free grouper
hatchery.
This facility and its stable supply of
virus-free larvae enabled detailed studies on
the parameters of grouper embryo development, which included step-by-step analyses
of their chemical, physical and nutritional
requirements. These data base then facilitated the assembly of electronic standard
operating procedures for the indoor production of disease-free fingerlings.
Other
Wages
Feed
Fingerlings
Total Cost
400
300
200
100
0
20% 30% 40%50% 60%70%80%
Taiwan $1 = U.S. $0.03
Survival Rate
Figure 1. Grouper production costs relative to survival rates.
20-50%
80%
NNV-Free Hatchery
500
Cost (Taiwan $/kg)
2-30
Over 1,000
cination are palatability and the gastrointestinal digestion of the antigen. As a
result, the success of an oral vaccine
depends on its ability to attract the fish to
eat the vaccine, protecting the antigen
during digestion and effectively delivering
it to the hindgut of the fish, which is near
the immune organ.
The authors have developed an oral
vaccine using Artemia or rotifers to encapsulate the inactivated recombinant subunit
vaccine containing the specific antigen. In
addition, the authors established a multivalent injective vaccine that with one
immunization can prevent most viral and
bacterial diseases for the grow-out stage.
600
78
Subsequent
Survival Rate
In the virus-free hatchery, over 60 consecutive successful fingerling production
cycles were achieved. That demonstrated
the ability of the indoor hatchery to produce healthy NNV specific pathogen-free
(NNV-SPF) grouper fingerlings (Table 1).
Vaccinated Fingerlings
After the injective vaccine was developed, it was very difficult to get farmers
to vaccinate their fish. Immunization by
injection of 5-cm-long fingerlings is labor
intensive and highly technical. It was also
difficult to convince farmers to inject
their healthy fish for preventive purposes.
Therefore, the NNV-SPF fingerlings
were vaccinated before shipping to farmers. The immunized fingerlings are resistant to several diseases and can elevate survival rates and decrease production costs
(Figure 1).
The performance of a million fingerlings was tracked at over 30 farms in various locations in Taiwan with different
farming conditions and stocking densities. In a one-year growout period, over
80% of the farms achieved 75 to 85% survival rates, versus the 20 to 40% survival
typically noted using other fingerlings.
Market Potential:
Frozen Fillets
Grouper are mainly produced to supply the whole fish market, especially the
live fish market for Chinese restaurants.
The distribution of live whole fish
requires sophisticated and expensive
transporting methods. The live fish form
also limits distribution to other markets.
Production of frozen fish fillets would
allow the distribution of grouper to international market outlets.
Several species of grouper have been
successfully reared using the indoor
hatchery, including Epinephelus maculates,
E. fuscoguttatus, E. coioides, E. lanceolatus,
Plectropomus leopardus, the coldwater E.
bruneus and the hybrid Sabah giant grouper. Giant grouper is a very high-quality
white-meat fish that grows quickly –
reaching 15 to 25 kg in three years versus
the growth of salmon to 4 to 8 kg in the
same period. As a demersal fish, grouper
should also have better feed conversion.
authors’ research to develop vaccines to protect cultured grouper from various diseases.
This work was considered for the Novus
Global Aquaculture Innovation Award, the
first of which was presented by the Global
Aquaculture Alliance at the GOAL 2013
conference in Paris, France.
79
innovation
PTC Ceramic Chips Improve Safety,
Reliability Of Electric Immersion Heaters
Water temperature can significantly
affect the growth, breeding, feeding,
metabolism, disease susceptibility and
mortality rates of aquatic organisms.
Depending on the species and volume of
water, temperature fluctuations can have
inconsequential to harmful adverse effects.
Lower water temperatures, for example,
can cause fish metabolic rates to decline,
reducing appetite and making the fish less
resistant to bacterial and fungal infections.
In order to optimize environmental
conditions, fish farmers and hatchery
owners raise species in controlled or semicontrolled settings. Electric immersion
heaters and temperature and level controls
are frequently used to regulate water temperatures in these environments.
Hot
Zone
New PTC electric immersion heaters,
which utilize ceramic chips as a heat
source, do not require thermal
protectors for safety. Photo courtesy
of Process Technology.
Summary:
Typical electric immersion heaters used in aquaculture use resistance wire as the source of heat.
When the “hot zone” of a resistance heater operates in air or
becomes covered with deposits,
the rapidly rising temperature can
potentially damage plastic tanks
and liners. A heater design that
uses positive temperature coefficient ceramic chips as the source
of heat offers a self-limiting
capability that eliminates heater
failures and shutoffs to lessen
operational risks and improve
system reliability.
80
Resistance Heaters
Typical electric immersion heaters
used in aquaculture, known as resistance
heaters, use resistance wire as the source
of heat. Resistance wire is usually made
of a nickel/chromium alloy that can reach
approximately 482° C during normal
operation. The heat output is a function
of the supply voltage and the heater resistance (Watts = Voltage2/Resistance).
Since the resistance measurement of
the wire is constant, the heat output is
constant regardless of the surrounding
environment. When the “hot zone” of a
resistance heater operates in air – usually
due to the water level dropping – or
becomes covered with a build-up of hard
water deposits or biological waste, the
heat is not able to radiate quickly enough.
This results in a rapid increase in the
temperature of the internal wire and/or
heater surface and leads to hazardous
overheat conditions.
Thermal Protection
To prevent the dangers associated with
overheating, industry standards dictate
that resistance heaters be equipped with a
high temperature cutoff device known as a
protector. The protector senses the surface
temperature of the heater and trips when a
safe temperature is exceeded. This shuts
down the heater to prevent overheating
and the risk of a fire.
While the protector is a necessary
safety device, a down side is that after the
®
Christine Venaleck
Director of Advertising
Process Technology
7010 Lindsay Drive
Mentor, Ohio 44060 USA
[email protected]
Ed Dulzer
Product Training Manager
Process Technology
device trips, the heater remains off until
the protector is replaced. If no replacement protector is available on site or the
area is unattended, the tank or pond can
suffer a loss of temperature that threatens
aquatic life. For a supplier or keeper of
live fish, the detrimental effects can
include increased mortality.
As Don Campbell of First Ascent Fish
Farm in Buhl, Idaho, USA, explained, this
is one of his primary concerns with his
current equipment. “We train our customers in both programming and care of the
heater/controller,” he said. “However, too
frequently, the folks we train are not the
folks cleaning the tanks between deliveries,
and the heater is not unplugged, leading to
a blown protector fuse.”
Ceramic Chips Replace Wire
If a heater is not operated with a thermal protector, the potential for damaging
or even igniting plastic tanks and liners
significantly increases. To address these
safety concerns, an electric immersion
heater design was developed that incorporates positive temperature coefficient
(PTC) ceramic chips to replace the resistance wire as the source of heat.
PTC chips inherently limit the temperatures of electric immersion heaters, so
the heaters do not require external temperature protection, since the protection is
built into the heater core. This technology
offers a self-limiting capability that eliminates heater failure, burnouts and shutoffs.
Heaters using PTC chips are selflimiting because their resistance value is
not fixed. The heater resistance increases
with temperature, meaning that when the
chip temperature increases, its electrical
resistance value also increases and results
Resistance wire made of nickel/chromium alloy (top) is commonly used as the
heat source in the cores of resistance
immersion heaters. PTC ceramic chips
(bottom) offer an alternate heat source
for electric immersion heaters.
in decreased heat output.
The change in the resistance of a
PTC chip is not linear. If the heater hot
zone is exposed to air or covered in buildup, the heat output quickly drops by
more than 80%, while the internal temperature stays at its designed limit. If a
portion of the hot zone of a PTC heater
becomes exposed to air or is covered in
build-up, only that portion exhibits
reduced heat output. The portion of the
hot zone that remains immersed in water
continues to heat.
Safer Operation
PTC immersion heaters that are certified by Underwriters Laboratories and
C.E. certified for compliance with European directives have a maximum surface
temperature of 270° C when energized in
air. This temperature is far below the
ignition temperatures of materials used in
tank and liner construction (Figure 1).
Therefore, these heaters will not ignite
tanks, pond liners or other containers
made from polyethylene, fiberglass, polypropylene, polyvinyl chloride or other like
materials.
However, the maximum surface temperature of these heaters is high enough
to melt these materials when in direct
physical contact. This can be avoided by
ensuring that a minimum 12-mm gap
separates the hot zone from any plastic
material. Heater bumpers and feet provide these minimum clearances.
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81
600
Perspectives
400
300
200
100
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authors’ research on new water heating technology. This work was considered for the
Novus Global Aquaculture Innovation
Award, the first of which was presented by
the Global Aquaculture Alliance at the
GOAL 2013 conference in Paris, France.
500
Temperature (° C)
Reliably heating water is a necessary
part of optimizing the health and growth
of aquaculture organisms, but can present
some unique challenges. By advancing
electric immersion heater technology to
ensure safe and efficient heating in aquaculture applications, aquaculturists will be
better equipped to face those challenges.
Figure 1. Ignition temperatures of common culture tank materials.
Ich Responses (Continued from page 48.)
g for hybrid catfish and 10.5 ± 1.0 g for channel catfish. These fish
were divided into four triplicate groups and immunized as follows:
immersion at a dose of 10,000 theronts/fish followed by daily formalin treatment for five days, intraperitoneal (I.P.) injection at a
dose of 10,000 live theronts/fish, I.P. injection with 5% bovine
serum albumin (BSA) and a non-immunized control.
Six hybrid catfish and six channel catfish were sampled from
Immobilization Titer
Hybrid Catfish
Channel Catfish
Immune Responses
7,500
6,000
4,500
3,000
1,500
0
Immersion
I.P. Injection
BSA Injection
Cumulative Survival (%)
Figure 1. Immobilization titers in serum of hybrid catfish and channel
catfish 21 days after immunization against Ichthyophthirius multifiliis.
Hybrid Catfish
Channel Catfish
100
60
40
20
0
Both hybrid and channel catfish showed high antibody levels
21 days following exposure to live theronts by immersion or I.P.
injection (Figure 1). The immobilization titers ranged 7,000 for
hybrid catfish to 7,600 for channel catfish when immunized by
immersion. Similarly, high immobilization titers were detected
for hybrid catfish (7,700) and channel catfish (8,100) when
immunized by I.P. injection with live theronts. No anti-ich antibody was detected in non-immunized fish.
No or light infection below 50 trophonts/fish was observed
in fish immunized by immersion or injection. There was no statistical difference in parasite infection level between the immunized hybrid catfish and channel catfish. In fish that received
BSA injections and the non-immunized control groups, all
hybrid catfish and channel catfish showed heavy infection levels
over 100 trophonts/fish.
Immune Protection
80
Immersion
I.P. Injection
BSA Injection
Figure 2. Cumulative survival of immunized hybrid catfish and
channel catfish following challenge with ich theronts and observed
21 days. All catfish in non-immunized controls died (not shown).
82
each immunized group 14 and 21 days after immunization to
collect blood serum and determine the antibody levels against ich
by an immobilization assay. In the assay, increasing dilutions of
the serum determined the antibody level (expressed as immobilization titer) at which the parasite theronts ceased swimming and
aggregated into theront masses.
After 21 days of immunization, water volume was adjusted to
10 L in each of the 12 tanks. Theronts were added to each tank
at a dose of 10,000 theronts/fish. Then flowing water was
resumed, and mortality of fish in each tank was recorded daily
for three weeks after theront exposure for one hour.
All hybrid catfish and 97% of the channel catfish immunized
with live theronts by immersion survived the theront challenge
(Figure 2). For the fish immunized by I.P. injection, 97% of the
hybrid catfish and 90% of the channel catfish survived the
theront challenge. Only 30% of the hybrid catfish and 27% of
the channel catfish survived in the group given BSA injections.
All of the non-immunized control catfish died.
There was no statistical difference in survival between the
hybrid and channel catfish. There was a positive correlation
between anti-ich antibody levels and fish survival. The fish
immunized with live theronts had high anti-ich antibody level
and showed high survival.
83
industry news
Chilean Salmon Producers Unite
Under New Brand
Chilean salmon producers Australis, Blumar,
Camanchaca and Yadran
have formed a new alliance
to “conquer” the Chinese
market.
The companies, which
together currently ship
around 3,000 mt of salmon
annually to China, are targeting a volume of 10,000 mt of salmon exports in a range of
forms to the country in the first year. The producers are uniting
their efforts under a new brand, New World Currents.
“So far, Chilean salmon production has focused on certain
markets like the U.S. and Brazil, where the product is already
known, and the competition is strong,” said Erwin Campos, who
has been named director of the project. “What we seek with this
initiative is to diversify these markets with importers and local
distributors, allowing us to position the product in a country that
has enormous growth potential, especially within the middle
class that is rapidly emerging.”
Campos will be responsible for implementing the New
World Currents brand from his Shanghai office, but business
executives from each of the four companies will oversee the
efforts through an executive committee.
Fish T1K To Expand Fish
Genome
The China National Genebank (CNGB) recently launched
the 1,000 Fish Transcriptome Project (Fish T1K), a groundbreaking study designed to unveil the mysteries of the origin,
evolution and diversification of the largest group of vertebrates.
Such findings could enable scientists to pursue innovative strategies in addressing fish breeding, disease control, seafood safety
and biodiversity conservation.
Only about 10 fish genomes have been sequenced to date.
Fish T1K has assembled a world-class team of researchers from
multiple institutions to complete sequencing and assembling
transcriptomes of 1,000 fish species within a high-quality transcriptomic database over the next three to five years.
All data generated from Fish T1K will be made available
publicly through CNGB, ensuring that scientists may better
grasp the new trends in fish research and the use of RNA-seq
technology.
The project is extending an invitation to researchers worldwide to submit proposals and contribute fish specimens for
sequencing. Scientists addressing questions about fish with
unique adaptations, economic and medical value are particularly
welcome to join the project.
For more information, visit www.nationalgenebank.org and
www.genomics.cn.
84
People, Products, Programs
Please send short news items and photos for consideration to:
Darryl E. Jory
Fax: +1-314-293-5525
A new choice
in hormone-free
tilapia fry
is coming.
International Partnership Brings
Hormone-Free Tilapia Choice
To North America
A recent partnership between Canada-based Noa Fisheries and
Til-Aqua International will bring the Holland-based company’s
Natural Male Tilapia to Canada for the first time. The partnership
means that commercial tilapia operations can now order stock that
is all-male yet hormone-free through all generations – a move sure
to please organic and environmentally conscious customers.
“It’s the next step in our commitment to provide our commercial
growers with the highest-quality all-male, hormone-free fry and
fingerlings,” said Jason Oziel, co-founder of Noa Fisheries.
“Commercial farmers require faster-growing, all-male tilapia to
produce a profitable harvest,” Oziel said. “There are two ways to
produce all-male tilapia – with hormones or using the hormone-free
YY masculinization process technology.”
Hormone use is illegal in Canada and other countries. Canadian
growers have been purchasing tilapia fry and fingerlings sex-reversed
with hormones from the United States. Til-Aqua International will
now begin shipping all-male stock directly from Holland to commercial clients until the Noa Fisheries hatcheries are fully established in late 2014.
For more information, contact 416-546-6623 or e-mail info@
noafisheries.ca.
Stevia Corp. Now Marketing
Aquaculture Bioformulas
Stevia Corp., a farm management company focused on economic development of the sweetener stevia, has announced its
proprietary aquaculture-focused products are now being marketed in several Asian countries with plans to enter South America in 2014. These innovative products include a line of specialized water conditioners and a high-quality feed additive for both
shrimp and finfish.
“Based on our trial results and subsequent customer orders,
we expect to ramp up sales rapidly over the next two quarters,”
Stevia Corp. President George Blankenbaker said. “We believe
that our bioformula product line has the potential to become the
largest contributor to our bottom line within a year.”
Stevia Corp. is also leveraging its position to help market its
customers’ products under the Stevia Quality Mark, which
emphasizes the naturally fed and sustainably produced attributes
of the seafood produced using Stevia products.
“This is analogous to the ‘Intel Inside’ concept, where we are
creating value by branding our technology while simultaneously
enhancing the image and value of our customers’ products,”
Blankenbaker said.
Further details can be found at www.steviacorp.us.
Joe Bundrant New CEO
Of Trident Seafoods
Joe Bundrant has been appointed chief executive officer of
Trident Seafoods, one of the largest vertically integrated seafood
companies in the United States. Joe Bundrant is the son of Trident Seafoods chairman and founder Chuck Bundrant.
Chuck Bundrandt said: “I am confident that Joe is prepared
to take on the task of leading Trident Seafoods, that he will carry
on the great traditions and successes that the company has
enjoyed, and that he will help Trident improve and grow for
generations to come.”
The younger Bundrant said he was “honored and humbled to
take the helm of such a remarkable company” and “blessed to be
surrounded by so many incredible people who have literally built
this company from the ground up.”
Last year, Trident announced Joe Bundrant would head the
company following the retirement of President Paul Padgett,
who continues as a strategic advisor into 2014.
Chuck Bundrant founded Trident Seafoods in 1973. Among
the top five seafood companies in Alaska, family-owned Trident
is the only one that has not been sold to overseas seafood companies or investor groups.
Vietnam’s Seafood Exports
Reach Record High
Vietnam’s seafood exports reached an all-time high of U.S.
$776 million in October 2013, up nearly 30.0% year on year.
The rise was mainly due to sharp increases in exports of shrimp,
especially whiteleg shrimp. A 6.4% recovery in Pangasius exports
and 7.0% increase in cephalopod exports also contributed to the
overall increase in seafood exports.
The value of Vietnam’s shrimp exports reached U.S. $404 million, including $229 million in white shrimp and $153 million in
black tiger shrimp. To overcome raw material shortages, domestic
shrimp processors are importing raw material for processing.
Thanks to rising exported shrimp prices and a decreasing global
supply of raw shrimp, Vietnam’s shrimp exports through October
2013 reached nearly $2.5 billion, up 33.0% year on year and making up 44.0% of a total $5.6 billion in seafood exports.
Pangasius sales recovered somewhat in October 2013. However, the figure through October was down 0.5% year on year.
Tuna exports remained on a downward trend. Total October
shipments fell 14.0%, while the year-to-date figure slid 5.4%.
85
calendar
JANUARY 2014
India International
Seafood Show
January 10-12, 2014
Chennai, Tamil Nadu, India
Phone: +91-484-2311979/2311803
Web: www.indianseafoodexpo.com
National Fisheries Institute
Global Seafood Market
Conference
January 14-16, 2014
Miami Beach, Florida, USA
Phone: +1-703-752-8898
Web: www.cvent.com/events/2014global-seafood-market-conference/eventsummary-3946281008d84beeb021
cae9e53dcba2.aspx
Auditor Course
January 18-23, 2014
Chennai, Tamil Nadu, India
Phone: +1-352-563-0565
Web: www.aquaculturecertification.
org/index.php?option=com_
content&task=view&id=3&Itemid=4
Myanmar Agribusiness
Investment Summit 2014
January 21-22, 2014
Yangon, Myanmar
Phone: 603-4045-5999
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FEBRUARY 2014
Innovations in Feeding
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February 4, 2014
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MARCH 2014
North Atlantic Seafood Forum
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Mark your calendar now for GOAL 2014. Join seafood professionals and thought leaders from around the world
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