Blue Crab US Atlantic Coast, Chesapeake Bay

 Blue Crab Callinectes sapidus © U.S. Food and Drug Administration US Atlantic Coast, Chesapeake Bay, Gulf of Mexico Crab Pot and Trot Line April 3, 2012 Toni Mizerek, Consulting Researcher Disclaimer Seafood Watch® strives to ensure all our Seafood Reports and the recommendations contained therein are accurate and reflect the most up‐to‐date evidence available at time of publication. All our reports are peer‐
reviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science or aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch program or its recommendations on the part of the reviewing scientists. Seafood Watch is solely responsible for the conclusions reached in this report. We always welcome additional or updated data that can be used for the next revision. Seafood Watch and Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation. 2
Final Seafood Recommendation The following analysis focuses on the U.S. domestic blue crab pot fishery which is located along the US Atlantic Coast and in the Gulf of Mexico. The blue crab (Callinectes sapidus) pot fisheries in the US Atlantic Coast, Chesapeake Bay and Gulf of Mexico are ranked as Good Alternatives. The Chesapeake Bay trotline fishery is ranked as a Best Choice. Species/ Stock Gear/ Region Impacts on the Impacts on Stock other Species Lowest scoring Rank species Score Rank*, Subscore, Score Blue Crab, Virginia Virginia Green 3.83 Blue Crab, South Atlantic South Atlantic Blue Crab, Gulf of Mexico Gulf of Mexico Habitat Manage‐ and ment Ecosystem Overall Rank Score Rank Score Recommendation
Score Diamondback Terrapin Red, 1.41,1.27 Yellow 2.45 Yellow 3.12 GOOD ALTERNATIVE 2.54 Yellow 2.64 Diamondback Terrapin Red, 1.41,1.27 Yellow 2.45 Yellow 3.12 GOOD ALTERNATIVE 2.31 Yellow 3.05 Diamondback Terrapin Red, 1.41,1.27 Yellow 2.45 Yellow 3.12 GOOD ALTERNATIVE 2.4 Blue Crab, Delaware, Delaware; Green Maryland, Maryland, 3.83 New Jersey New Jersey Diamondback Terrapin Red, 1.41,1.27 Yellow 3 Yellow 3.12 GOOD ALTERNATIVE 2.67 Chesapeake Chesapeake Green Bay Trot Bay Trot 3.83 Line Line 5 Green, 5,5 Yellow 3 Yellow 3.12 BEST CHOICE 3.66 Scoring note – scores range from zero to five where zero indicates very poor performance and five indicates the fishing operations have no significant impact. 3
Table of Contents Final Seafood Recommendation ................................................................................................................... 2 Executive Summary ....................................................................................................................................... 4 Introduction ................................................................................................................................................... 6 Analysis ....................................................................................................................................................... 10 Criterion 1: Stock for which you want a recommendation ..................................................................................... 10 Criterion 2: Impacts on other retained and bycatch stocks .................................................................................... 16 Criterion 3: Management effectiveness ................................................................................................................. 20 Criterion 4: Impacts on the habitat and ecosystem ................................................................................................ 30 Acknowledgements ..................................................................................................................................... 32 References ................................................................................................................................................... 32 Appendix A: Review Schedule ..................................................................................................................... 38 About Seafood Watch® ............................................................................................................................... 39 Guiding Principles ........................................................................................................................................ 40 4
Executive Summary The following analysis focuses on the US domestic blue crab pot fishery in the Chesapeake Bay, the southern US Atlantic coast and the Gulf of Mexico. Stock abundance of blue crab has generally been increasing in recent years as management efforts focused on specific targets that promote population persistence and sustainable fishing practices. Trotlines used in Chesapeake Bay to catch crabs do not operate with hooks; the bait is tied to a line and the crabs grasp the bait. While holding the bait, the crabs are hauled onto the boat. The use of a manually operated dip net to catch individual crabs produces no bycatch of other species. The blue crab pot fishery has the potential to catch other, unintended species, and crab fishing has had some impact on endangered, threatened, and species of special concern. Crab pot bycatch primarily consists of sublegal blue crabs, as well as small amounts of non‐
target finfish (mostly released alive and making up no more than 0.12% of the catch), and diamondback terrapins. The most significant bycatch impact from the crab pot fishery is on diamondback terrapins (Malaclemys terrapin), a population of special concern. However, the states of New Jersey, Delaware and Maryland have specific terrapin bycatch reduction regulations that effectively mitigate the bycatch of terrapins, which is the greatest conservation concern for this fishery. As one of the most ecologically and economically significant species in the country, there has been increasing attention given to more effective management of the stocks. Maryland, Virginia, and the Potomac River Fisheries Commission are all working closely to sustain a healthy fishery in Chesapeake Bay. Gulf Coast States also work collaboratively to help ensure that blue crab populations and the associated fishery are healthy. Management of the target species for all blue crab fishing regions is working sufficiently, while bycatch management needs some improvement. Blue crab populations naturally fluctuate spatially and temporally and in order to be able to manage effectively with such fluctuations, adequate data needs to be gathered and shared and management targets established. The management of blue crabs in most states is not based on recent fishery independent data. Both anthropogenic and natural processes such as harvesting, habitat quality and quantity, water quality, and recruitment strength greatly affect blue crab population dynamics, thus effective management depends on detailed data collection and analysis that will determine the relative effects of these threats in order to manage stocks appropriately. The implementation and enforcement of bycatch reduction devices (BRDs) and the removal or reduction of ghost fishing would lessen the impact of the blue crab fishery on non‐targeted species. Research has shown the effectiveness of BRDs in protecting species of concern, especially the diamondback terrapin. Current management efforts are set to limit the impact on terrapins by restricting locations of commercial crab pots (particularly in Maryland) but the 5
effect could be greater by enforcing the requirement of BRDs throughout the fishery. During the latest Workshop on the Ecology, Status, and Conservation of Diamondback Terrapins, survey responses from individuals representing all regions and academic, regulatory, and private institutions concluded that crab pot mortality was one of the major threats to diamondback terrapins. Most states have also coordinated derelict crab pot removal programs to reduce terrapin bycatch associated with ghost fishing. Crab pots are a passively fished gear type and impact the substrate through the wire structure that rests on bottom. The primary threat from the gear comes from lost or abandoned (i.e. derelict) pots which are not actively fished. Derelict gear is also referred to as “ghost fishing” because abandoned pots can continue to trap a variety of species, both blue crab and non‐
target species, contributing to unnecessary mortality. Trotlines, similar to bottom longlines (but without hooks), rest along the benthos and are held in place at each end with anchor and chain. Trotlines are set in primarily sand and silt. All crab fisheries in this report have minimal mitigation of the gear impacts from pots and trotlines because fishing intensity is effectively controlled, but is not actively being reduced. There are currently no exceptional species caught in the fishery, and there are no efforts to fully assess ecosystem impacts from the blue crab fishery. 6
Introduction Scope of the analysis and ensuing recommendation The following analysis focuses on the US domestic blue crab pot fishery which is located along the US Atlantic Coast, as far north as Rhode Island, and south in the Gulf of Mexico. Blue crabs in the United States are found along the Atlantic and Gulf coasts in state waters. While management of the species remains with the respective state, this report divides the US population into four regions where states are grouped according to similar and sometimes collaborative management, and where vital rates, fishing effort, and other threats tend to be common within the region. Regions include: (1) Virginia; (2) New Jersey, Delaware and Maryland that has been grouped together due to their progress on regulating effective terrapin bycatch reduction strategies (these two regions also collectively encompass the Chesapeake Bay region referred to in this report) region; (3) the South Atlantic fishery is based primarily on the fishery in North Carolina, the most productive blue crab fishery of the region but also includes South Carolina, Georgia, and the east coast of Florida and (4) the Gulf of Mexico region includes all states in the Gulf, including Louisiana, Florida, Texas, Alabama and Mississippi. Louisiana is one of the most productive states in the country (accounting for approximately 70% of the landings in the Gulf of Mexico), and therefore drives the Gulf of Mexico analysis in this report. In addition to the four regions, the Chesapeake Bay trotline fishery, which makes up approximately 20% of the landings in Chesapeake Bay (approximately 10% of landings along the US East coast), has been highlighted because of the high efficiency of this fishing method with no concerns over bycatch. Overview of the species and management bodies The blue crab, Callinectes sapidus, is a member of the swimming crab family, Portunidae, which inhabits estuarine and coastal waters. The species is significant both ecologically and economically. Blue crabs contribute to the ecological processes in estuarine and coastal food web dynamics as both prey and predator to a number of other species. Economically, the fishery also represents a great resource; blue crab is one of the most significant domestic commercial fisheries nationally as well as for many individual states, in terms of monetary value and in weight (NMFS 2010). Management of the blue crab fishery is governed by many federal policies, but direct management responsibilities fall upon the states in which fisheries are present (Guillory, Perry et al. 2001b). State natural resource departments are generally responsible for managing blue crab fisheries under the direction of their respective regulatory commissions (Guillory, Perry et al. 2001b). Regional Fishery Management Councils established by the Magnuson‐Stevens Fishery Conservation and Management Act do not have a direct hand in management because almost all US landings are in state waters (Guillory, Perry et al. 2001b). The primary influence of 7
federal law on blue crab fisheries is the regulation of coastal water quality, habitat protection, and pollution control (Guillory, Perry et al. 2001b). Chesapeake Bay and Delaware Bay present slightly unique situations where there is jurisdiction overlap in the estuarine waters. While Maryland, Virginia, and the Potomac River Fisheries Commission each have their own regulations within the Chesapeake Bay, and the same exists for Delaware and New Jersey in Delaware Bay, there is some coordination in information gathering and sharing and in management efforts. Maryland, Virginia and the Potomac River Fisheries Commission share the management of blue crab fisheries in Chesapeake Bay and are coordinated as signatories to the Chesapeake Bay Blue Crab Fishery Management Plan (FMP). The first FMP in 1989 recognized the importance of the blue crab resource, identified areas of concern, and recommended strategies to stabilize fishing effort across the three jurisdictions. A second FMP in 1997 focused on conserving the stock in the bay to maintain the ecological value and long‐term use of the resource. The Delaware Bay Blue Crab FMP was prepared by the State of Delaware in cooperation with the State of New Jersey as a result of decreased bay‐wide landings in 1996. Blue crab management in the Gulf of Mexico is regulated by the respective states in which they are found and caught but there is also a collaborative management effort through the Gulf States and the Gulf States Marine Fisheries Commission. Evaluation and modification of management efforts in any Gulf Coast state must consider the activities of the neighboring states. The Commission can make management recommendations to a state but ultimately, the state remains responsible for management of the species (Guillory, Perry et al. 2001b). Small‐scale commercial blue crab fishing dates as far back as the 1800s. Crab pots were introduced in the 1920s and 1930s, with minor improvements made thereafter (Guillory, Perry et al. 2001b). Landings increased with rising effort through the latter part of the century and peaked in the mid ‘90s as gear became more efficient. High landings in the ‘90s may be attributed to several factors, including increased effort due to optimal economic conditions and high recruitment and growth of blue crab populations (Henry 2010). Production statistics From 2000 to 2010, the US domestic blue crab fishery was in the top eleven fisheries when measured by weight ranging from 151,590,455 pounds caught in 2001 to 184,455,049 pounds in 2010 (Figure 1). Blue crab landings in 2010 made the fishery the 8th largest of any fishery in the nation. At least 75% of reported blue crab landings during this period are from four states: Louisiana, Maryland, North Carolina, and Virginia (NMFS 2010). 8
Figure 1. Total annual value of the US domestic blue crab fishery from 1950 to 2010. NMFS 2012. Importance to the US/North American market Blue crabs are one of the most economically important commercial species in the US. In 2010, the fishery ranked as the US’s 5th largest in value ($211,942,013) which has been increasing annually since 2006 (NMFS 2010). Import and export sources and statistics The National Marine Fisheries Service (NMFS) reports imports of crabs of the Family Portunidae (swimming crabs). Imports of frozen and preserved swimming crab meat totaled almost 19,000 metric tons and over 20,000 metric tons in 2009 and 2010 respectively (NMFS 2010), which is one quarter of the domestic fresh blue crab fishery. The US Food and Drug Administration reports that imported crabmeat is often sold as blue crab crabmeat in US markets (FDA 2009). The true nature of the imported crab is highly uncertain. FAO does not specifically report capture or aquaculture of Callinectes spp. in Indonesia, China, Thailand, or Vietnam. Data reported by Food and Agriculture Organization (FAO) for these four countries in 2007 is summarized below (FAO 2009a; FAO 2009b; FAO 2010): • Aquaculture in China produced large quantities of unspecified crab of family Portunidae. • Aquaculture in China, Indonesia, and Thailand produced crab of genuses Scylla and Portunus, which are also members of the swimming crab family Portunidae. • Capture production of blue swimming crab Portunus pelagicus is reported for Indonesia, China, and Thailand. • Indonesia’s and Vietnam’s imports of crab (in various forms) are much lower (only about 2% by weight) than the countries’ exports. Re‐exports are not reported. • China and Thailand import crab products equivalent to about 60% of exports (by weight). 9
The available information is limited, and there is high uncertainty regarding the sources of imported blue crab crabmeat. This report only assesses the US wild‐capture fishery for blue crab. Common and market names Callinectes sapidus is commonly referred to as the blue crab. Within the industry, crabs have specific names based on sex and maturity (Zinski 2006): Jimmy–A male blue crab Sally or She‐crab–An immature female Sook–A mature female Sponge Crab–An ovigerous (egg‐bearing) female crab, named for the appearance of her egg mass (“sponge”) Egg‐bearing females are also referred to as spawn crabs, blooming female crabs, and mother crabs (PRFC 2009b). Crabs are categorized as hard, soft, or peeler crabs based on their stage of molting. Softie is another name for a soft‐shell crab, and bust crab or busted crab describes a crab that is in the process of shedding its exoskeleton (Sea Grant Virginia 2006). Primary product forms Most blue crab crabmeat is sold fresh, but some is frozen or pasteurized (Guillory, Perry et al. 2001b). 10
Analysis Scoring guide All scores result in a zero to five final score for the criterion and the overall final rank. A zero score indicates poor performance, while a score of five indicates high performance. The full Seafood Watch Fisheries Criteria that the following scores relate to are available on our website at www.seafoodwatch.org. Criterion 1: Stock for which you want a recommendation Stock Inherent Stock Status Fishing Vulnerability Mortality Rank Rank (Score)
Rank (Score)
Blue Crab, Virginia Low Low Concern (4) Low Concern (3.67) Green 3.83 Blue Crab, South Atlantic Low Moderate Concern (3) Moderate Concern (2.33) Yellow 2.64 Blue Crab, Gulf of Mexico Low Low Concern (4) Moderate Concern (2.33) Yellow 3.05 Blue Crab; Delaware, Low Maryland, New Jersey Low Concern (4) Low Concern (3.67) Green 3.83 Chesapeake Bay Trot Line Low Concern (4) Low Concern (3.67) Green 3.83 Low Criterion 1 Rank Score 11
Synthesis Blue crabs exhibit a low inherent vulnerability which makes a stock more likely to allow for recovery from fishing pressure. Stock abundance has generally been increasing in the recent past as population fluctuations may have increased naturally and management efforts have become more focused on specific targets that promote population persistence and sustainable fishing practices. Justification of Ranking Factor 1.1 Inherent Vulnerability: Low Key relevant information: Blue crabs have a low inherent vulnerability primarily due to their life history characteristics of fast growth to maturity, high fecundity, and rapid recruitment into the fishery. Life history parameters may vary regionally depending on water temperature variations but these differences do not significantly decrease the inherent resilience of any stocks. Detailed rationale: Resilience attribute Blue Crab Score Source Average age at maturity 12‐18 months 3 (Van Engel 1958) (Perry 1975) (Tatum 1982) Average maximum age 2‐6 years 3 (Rugolo, Knotts et al. 1997) (Fischler 1965) Reproductive strategy Brooder 2 (Churchill 1919) Density dependence Compensatory at low 3 (Fogarty and Lipcius population sizes 2007) (Miller 2012) Average Score 2.75 According to the Seafood Watch Productivity‐susceptibility analysis (PSA), blue crabs have a resilience score of 2.75. Factor 1.2 Stock status Key relevant information: Virginia and Delaware, Maryland, New Jersey: Low concern Although in recent years stock abundance was above the target, in 2012 the abundance of spawning age crabs decreased, falling slightly below the previous target of 200 million spawning age crabs for the first time since it was set in 2008 (MDNR 2012; Figure 2a). In addition, female crab abundance is below the target for healthy female abundance (215 million spawning age females) and is almost at the threshold (MDNR 2012; Figure 2b). At this time, it is unknown what impact this reduction in female abundance will have on the reproductive capacity of the stock. 12
South Atlantic: Moderate concern The stock status in South Carolina is unknown and more data collection is necessary to determine the status (Harris 2000). The 2007 assessment of Florida’s blue crab stock concluded that the status was uncertain but that commercial landings were rebounding from a past period of low abundance and harvest (Murphy, McMillen‐Jackson et al. 2007). As of 2011, the stock status of blue crabs in North Carolina, which is the state with the highest blue crab landings in the South Atlantic, is considered of concern due to periods of recent reduced landings after record‐highs during the late 1990s (Figure 3a). In 2009 and 2010, landings were recorded at the 4th and 5th lowest in the previous decade (NCDENR 2011). Harvest effort has also declined concurrently with landings due to market forces during recent years (Figure 3b). Therefore, reduced landings are not solely due to a decline in resource availability. Gulf of Mexico: Low concern There is no cumulative, quantitative assessments of the Gulf of Mexico blue crab stock but it is believed that the stock as a whole is currently healthy due to lack of any difficulty and concern from the fishery (Guillory, Perry et al. 2001b; VanderKooy 2012). The Louisiana blue crab stock, which makes up the majority of the Gulf of Mexico stock, has been classified as not overfished aside from 1995 to 1996 with overfishing occurring in 2002, however, blue crab has remained above biomass target reference points, indicating a healthy stock (Figure 4) (West, Blanchet et al. 2011). The 2011 stock assessment indicates that since 2005 the fully‐recruited blue crab stock biomass has been building, and the 2010 stock biomass of 35 million pounds is above the target biomass level of 23.3 million pounds, however, there is a high degree of uncertainty that the stock is above the point where recruitment is impaired (SCS 2012). Detailed rationale: Figure 2a. Winter Dredge Survey; A fishery‐independent measurement to determine abundance of blue crabs in Chesapeake Bay. Figure from MDNR 2012 13
Figure 2b. The Chesapeaake Bay target for healthy fem
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14
Figure 3a: Total blue crab
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North Carolinaa, 1950–2009 (NMFS –1993; NCDMFF Trip Ticket Daata 1994–2009
9) (NCDMF 20112). data 1950–
Figure 3b: Total blue crab
b landings (harrd, soft, and pe
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North Carolinaa, 1994–2011 (NCDMF Trrip Ticket Data 1994–2009) (NCDMF 2012) and effort for the same period. Figure 4. B
Biological refere
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biomass estimate. Biomass units are millions of pounds. Fishing mortality rate units are years ‐1 (West, Blanchet et al. 2011). Factor 1.3 Fishing pressure Key relevant information: Virginia and Delaware, Maryland, New Jersey: Low concern The most recent assessment of the Chesapeake Bay blue crab population found that overfishing was not occurring and the population was not overfished. (Miller, Wilberg et al. 2011). However, the blue crab in Chesapeake Bay is considered a data poor species due to uncertainties over the age structure in the population, uncertainties over key vital rates (e.g., natural mortality, reproduction) and uncertainties in the reliability of the harvest time series (Miller, Wilberg et al. 2011). Therefore it is probable that fishing pressure is at a sustainable level given the recent stock assessment, but there are uncertainties in the assessment. Figure 5: Annual estimates of whether the Chesapeake Bay population is being overfished or overfishing is occurring based on fishery‐independent data and the exploitation fraction (Miller, Wilberg et al. 2011) South Atlantic: Moderate concern The results of the 2012 assessment suggest the North Carolina blue crab stock is not being overfished even though the status cannot be determined with certainty because available data are not sufficient to produce reliable estimates of fishing mortality (NCDMF 2012). Landings in South Carolina were at or above the maximum sustainable yield (MSY) even though commercial effort was below that which would have produced MSY (Harris 2000). Gulf of Mexico: Moderate concern In Louisiana, overfishing occurred only in 2002 when the fishing mortality rate exceeded the limit and in 1995‐1996, the stock was overfished as the biomass was below the stock biomass limit (Figure 4) (West, Blanchet et al. 2011). The stock assessment report has target and limit reference points and control rules that are not currently exceeded (West, Blanchet et al. 2011; SCS, 2012; Figure 4), therefore it is 16
probable that fishing pressure is at a sustainable level given the recent stock assessment, but there are uncertainties in the assessment, and reference points may not be sufficiently conservative (SGS 2012). All Regions: Derelict fishing gear also contributes to blue crab mortality across all regions. Mortality from ghost pots compared to fishery landings is unknown but is estimated as a small proportion (NCDENR 2008). Studies in Louisiana, North Carolina, and in Chesapeake Bay found blue crab deaths due to ghost pots can be up to 50 crabs per pot per year (Casey and Daughterty 1989; Arcement and Guillory 1993; Guillory 1993; Havens, Bilkovic et al. 2008; NCDENR 2008; Giordano 2012). A survey of derelict pots in Chesapeake Bay found that approximately 77% of the bycatch was blue crabs, the majority of which contained mature females (Havens, Bilkovic et al. 2011). Unintended removal of these individuals has the potential to negatively impact the breeding population. The threat to the blue crab population from derelict gear, though not major, has been recognized and is being addressed in each region. These efforts are detailed in the management section below. Criterion 2: Impacts on other retained and bycatch stocks All regions, pot: Stock Inherent Vulnerability Rank Diamondback High Terrapin Stock Status Rank (Score) High Concern (2) Fishing Mortality Rank (Score) Stock Status Rank (Score) Fishing Mortality Rank (Score) High Concern (1) Subscore Score Rank (subscore*discard (based modifier) on subscore)
1.41
1.27 Red Chesapeake Bay Trotline: Stock Inherent Vulnerability Rank No other main species caught Subscore Score Rank (subscore*discard (based modifier) on subscore)
5
5 Green 17
Synthesis Gear used in the blue crab fishery has the potential to catch other, unintended, species, and crab fishing has had some impact on endangered, threatened, and species of special concern. Crab pot bycatch may consist of sublegal blue crabs, as well as non‐target finfish and terrapin turtles (Guillory, McMillen‐
Jackson et al. 2001a). There has been some concern over marine mammal and sea turtle bycatch, but these interactions are thought to be very rare (NMFS, 2007, 2009). The most significant bycatch impact from crab pots is on diamondback terrapins (Malaclemys terrapin), a population threatened due to mortality in crab pots, habitat reduction/modification, and predation (Seigel & Gibbons, 1995). Finfish, if caught, have been shown to live for prolonged periods in crab pots and are caught in very low numbers. The Chesapeake Bay trotline fishery does not use hooks; the bait (typically chicken or turkey necks, beef tripe and bull lips) is simply tied to the line and the crabs hold onto the bait with their claws and other appendages (Roosenberg pers. comm. 2012; also see bluecrab.info/crabbing/trotline.html). By law, "trotline" is defined as a length of rope or line, buoyed at both ends with one or more anchors, which is baited without hooks or snares at intervals for the purpose of catching crabs (Maryland DNR 2012). Blue crab is caught and brought into the boat either by hand hauling the line or by using an hydraulic line hauler that brings the line up to the boat to enable the crabs to be “dipped” or landed individually with a net that is manually operated by the crabber, resulting in no bycatch of other species. If there were any bycatch species holding onto the bait, they would be released alive before being netted (Roosenberg pers. comm. 2012). “In my more than 30 years' experience trotlining for crabs, I have only once dipped a turtle, which was immediately released unharmed; if any bycatch is encountered, crabbers would let the animal drop off the line unharmed and not let it get into the boat.” (Roosenberg pers. comm. 2012). Thus, there are no bycatch species in the Chesapeake Bay blue crab trotline fishery. Justification of Ranking Diamondback terrapin Factor 2.1 Inherent Vulnerability: High Key relevant information: The inherent vulnerability of diamondback terrapins is high primarily because of their minimal reproductive output and due to the fact that they are a long‐lived species (Roosenburg 1991). Population persistence is dependent on high adult survival and therefore impacts to the species as bycatch in another fishery can present a serious impact. Factor 2.2 Stock status: High concern Key relevant information: Diamondback terrapins live along the US Atlantic Coast from Cape Cod to Galveston Bay in the Gulf of Mexico (Roosenburg 1991) and throughout the range, the population sizes in the states are primarily unknown or declining and few are considered stable (Seigel and Gibbons 1995; Butler, Heinrich et al. 2006). There are seven distinct subspecies which are managed as different units. Moving south along the coast, population sizes tend to decrease so that those in Cape Cod and Chesapeake Bay are the highest, and those in the Gulf of Mexico and south of Chesapeake Bay are low and of concern (Roosenburg 2012). The Tortoise & Freshwater Turtle Specialist Group of the IUCN classified the species as Near Threatened (IUCN 1996; 2012). Diamondback terrapins are also federally recognized as a 18
species of special concern by the US Fish and Wildlife Service. State listings vary widely and some terrapin status is not listed by state, therefore we use the federal listing for stock status http://www.fws.gov/northeast/ecologicalservices/turtle/month/diamondback.html (species of special concern). Factor 2.3 Fishing mortality Key relevant information: High Concern Crab pots are considered to be one of the largest threats to diamondback terrapin populations, along with habitat degradation and other commercial and recreational fisheries (Seigel and Gibbons 1995; Roosenburg 2007). Bycatch in crab pots can range from 0.0 to 0.49 terrapins/day/pot depending on area fished and water depth (Roosenburg 2004; 2007). If a terrapin enters a crab pot, it will be trapped inside and, because pots are not frequently monitored to allow for the release of any bycatch, the terrapin is likely to drown. BRDs have been shown to greatly reduce terrapin bycatch, without reducing crab catch, however these BRDs have yet to be widely used and regulated (Hart and Crowder 2011; Rooke et al. 2010; Dorcas et al. 2007). Still, New Jersey requires bycatch reduction devices in commercial crab pots that are in tributaries less than 150 feet wide; Delaware regulates the use of BRDs in shallow inlets, and Maryland has spatial restriction on crab pots to minimize terrapin bycatch (Rooke et al. 2010). Although these measures may reduce terrapin bycatch, there are no state‐wide mandates to install BRDs, which would ensure best practices were being used to minimize bycatch to the greatest extend practicable. In addition, all states have derelict pot removal programs in place to minimize terrapin bycatch and some spatial management measures in place (Bilkovic et al. 2012; Roosenburg 2004; 2007). But, although total bycatch numbers and terrapin populations are unknown throughout the regions covered in the report, it is believed that the blue crab fishery is a substantial contributor to declines in diamond back terrapin populations and it is most likely that the blue crab fishery is impeding recovery of this species (Bilkovic et al. 2012; Roosenburg 2004; 2007).
*Note: Bycatch of terrapins is a serious concern that is a borderline critical issue, but there remains some uncertainty about the impact of the fishery on terrapin populations. This factor is currently ranked as a High Concern. However, research is ongoing and further research into the impact will be required as a condition on the Marine Stewardship Council (MSC) certification of the Louisiana fishery in the next two years. Seafood Watch will reassess the blue crab fishery in 2014 and, if the new information demonstrates that the fishery is impeding the recovery of the species, this will be considered a critical concern, thus ranking the blue crab fishery as red, unless bycatch reduction requirements (or management demonstrated to be equally effective) are put in place. Maryland, Delaware the New Jersey already have some effective measures in place. Factor 2.4 Overall discard rate: Pot – 40‐60%; Trotline – <20% Key relevant information: The overall discarded bycatch to landings ratio in the active blue crab fishery is less than 1% (Table 1) (NMFS 2010). Pots are designed to trap crabs but occasionally, turtles, sublegal blue crabs, and finfish can enter pots. All states but Delaware, New Jersey, Alabama, and Mississippi require cull rings which allow most sublegal blue crab to escape (CCRM 2008). The amount of terrapin bycatch is unknown but thought to be a small portion of the blue crab landing weight and, given that terrapins are a species of special concern, the impact can be notable for the species. Ghost pots contribute most significantly to unintended mortality from the blue crab fishery but mortality due to derelict gear is low (Davis 2012). 19
A two‐year survey of derelict fishing gear in Chesapeake Bay found that blue crabs comprise just under 80% of the catch, while oyster toadfish, whelk, black seabass and Atlantic croaker made up just under 20% of the catch (Havens, Bilkovic et al. 2011). Atlantic Coast menhaden (Brevoortia patronus) is the main species used for bait and makes up approximately 40%–55% of the blue crab catch by weight (SCS 2012). Stock assessments are conducted for Atlantic Coast Menhaden (Atlantic States Marine Fisheries Commission). Based on the latest assessment (ASFMC 2011), the Atlantic menhaden stock is not overfished nor is it experiencing overfishing; therefore, the Atlantic menhaden stock is not of conservation concern. However, the high ratio of bait‐use to catch is considered an impact similar to the impact of discarded bycatch. Thus, overall discards and bait‐use is ranked as 40%–60%. Table 1: 2010 Percent of landings by weight. Landings for species commercially caught in crab pots expressed by weight (NMFS 2010). Species that make up less than 0.01% of landings were excluded. Species landed per region Chesapeake Bay Blue Crab Catfishes and Bullheads Snail (Conches) Atlantic Croaker South Atlantic Blue Crab Finfishes Snail (Conches) Catfishes and Bullheads Gulf of Mexico Blue Crab Black Drum Stone Claws Shellfish Percentage of landings by weight 99.83% 0.08% 0.06% 0.01% 99.68% 0.22% 0.03% 0.02% 99.80% 0.12% 0.04% 0.01% 20
Criterion 3: Management effectiveness Fishery Management: Harvest Strategy Management: Bycatch Criterion 3 Rank (Score) Rank (Score) Rank Score Virginia Moderate Concern (3) High Concern (2) Yellow 2.45 South Atlantic Moderate Concern (3) High Concern (2) Yellow 2.45 Gulf of Mexico Moderate Concern (3) High Concern (2) Yellow 2.45 Delaware, Maryland, New Jersey Moderate Concern (3) Moderate Concern (3) Yellow 3 Chesapeake Bay Trot Line Moderate Concern (3) All species retained (N/A) Yellow 3 Synthesis As one of the most ecologically and economically significant species in the country, there has been increasing attention given to more effective management of the stocks. Maryland, Virginia, and the Potomac River Fisheries Commission are working closely to promote blue crab population persistence to sustain a healthy fishery in Chesapeake Bay. Gulf Coast States also work collaboratively to help ensure that blue crab populations and the associated fishery are healthy. Management of the target species for all blue crab fishing regions is moderately effective, while bycatch management in most regions needs some improvement, with the exception of Maryland, Delaware and New Jersey and when using trotline gear. Blue crab populations naturally fluctuate spatially and temporally, and to manage them effectively with such fluctuations, adequate data needs to be gathered and shared and management targets established. The management of blue crabs in most states is not based on recent fishery‐independent data but these data help decouple trends in fishing pressure from natural trends in abundance. However, in 2002, the Chesapeake Bay region developed biomass and exploitation thresholds and exploitation target reference points with stock assessments, based on both fishery dependent and independent data conducted nearly annually. The South Atlantic region developed an FMP in 1998, with amendments completed in 2004 and in 2012 to ensure healthy stocks, and the Gulf of Mexico has had an FMP in place since 2001 that provides management considerations and recommendations as well as research needs. The implementation and enforcement of bycatch reduction devices (BRDs) and the removal or reduction of ghost fishing throughout the entire range of the fishery would lessen the impact of the blue crab fishery on non‐targeted species. Research has shown the effectiveness of BRDs in protecting species of concern, especially the diamondback terrapin. Current management efforts are set to limit the impact to terrapins by restricting locations of commercial crab pots in the commercial fishery (particularly in Maryland). But the effect could be greater by enforcing the requirement of BRDs throughout the range 21
of fishery. During the latest Workshop on the Ecology, Status, and Conservation of Diamondback Terrapins, survey responses from individuals representing all regions and academic, regulatory, and private institutions concluded that crab pot mortality was the highest ranking threat to diamondback terrapins (Butler, Heinrich et al. 2006). Most states in all regions also have coordinated derelict crab pot removal programs to reduce the effect of ghost fishing. Justification of Ranking Factor 3.1 Management of fishing impacts on retained species: Moderate concern Fishery Mgmt strategy and implement Recovery of stocks of concern Scientific Scientific research advice and monitoring Enforcement Track record Moderately Effective Virginia Moderately Effective N/A Moderately Highly Effective Effective South Atlantic Moderately Effective N/A Moderately Moderately Moderately Effective Effective Effective Stakeholder inclusion Moderately Highly Effective Effective Moderately Moderately Effective Effective Gulf of Moderately Moderately Moderately Moderately Moderately Moderately Mexico Effective N/A Effective Effective Effective Effective Effective Delaware, Maryland, Moderately Moderately Highly Moderately Moderately Highly New Jersey Effective N/A Effective Effective Effective Effective Effective Chesapeake Bay Moderately Moderately Moderately Moderately Moderately Highly Trotline Effective N/A Effective Effective Effective Effective Effective Key relevant information: FMPs have been adopted by a number of states or regions which define strategies and goals to establish effective management that would allow for a productive fishery. The status and details of each of these FMPs varies but all work toward a similar, common goal. These FMPs identify what future research is needed in order to effectively accomplish the goals identified. Few states or management bodies use fishery‐independent data in their stock assessments or analyses. Stock assessments in most states are primarily based on landing data (Guillory, Perry et al. 2001b; SCDNR 2004; SCDNR 2007). Detailed rationale: 22
Virginia and Delaware, Maryland, New Jersey Management Strategy and Implementation: The original Chesapeake Bay FMP was adopted in 1989 and recognized the importance of the blue crab resource, identified areas of concern, and recommended strategies to stabilize fishing effort. The 1997 revised FMP has the same overall goal of managing blue crabs to conserve the bay‐wide stock, protect its ecological value, and optimize long‐term use of the resource. Management is aimed at reducing exploitation fractions and focuses on conserving female crabs. From previous management recommendations, female‐specific exploitation rate and female‐specific abundance reference points were established and followed, resulting in a favorable response by the population (Miller, Martell et al. 2005; Miller, Wilberg et al. 2011). The FMP process has been iterative to recommend management options, test them and update management as a result. A bay‐wide stock assessment committee was established in order to evaluate fisheries and identify data need for stock assessment models in Chesapeake Bay. Recommendations suggest improvements in collecting catch, effort, and biological data from landings, and surveys for estimating abundances. Biomass and exploitation thresholds and exploitation target reference points were established in 2001. The stock assessments, based on both fishery dependent and independent data, have been conducted nearly annually and the status of the stock determined relative to the reference points. Due, in part, to management efforts, blue crab stocks in the Chesapeake Bay have increased since the very low abundance in the 1990s, however, recent stock status has dipped below target reference points and female abundance is well below target reference points, therefore management strategy and implementation is in need of increased precaution, and therefore management strategy and implementation is deemed moderately effective. Recovery of stocks of concern: There are no species of concern targeted in this fishery, therefore ranked as N/A. Scientific Research and Monitoring: Fishery‐independent data from the Winter Dredge Survey (dependent on annual and vessel‐specific estimates of catchability) are included in the stock assessment of Chesapeake Bay blue crabs. It is also combined with landing data to determine the stock status and evaluate the effectiveness of management strategies with respect to established reference points. These surveys and reference points based on both fishery‐dependent and independent data have allowed for some effective management of the fishery, though additional data need to be verified, collected, analyzed, and/or applied to increase effectiveness. This research and monitoring is moderately effective. Scientific Advice: Blue crab stock assessments in Chesapeake Bay provide detailed scientific advice for management based on very quantitative measures of the population. Management of the stock is based on results of the scientific assessments and adapted accordingly (Miller, Martell et al. 2005; Miller, Wilberg et al. 2011). 23
Bushel limits set by scientific assessments are routinely followed (Davis, pers. comm. 2012). The application of the scientific information is deemed Highly effective. Enforcement: Regulation of commercial blue crab fishery management is set by a number of licenses which limits the number of traps. Trotline gear used from the boat may not exceed 1,200 feet in length for the baited portion (Maryland DNR 2012). When a reduction in blue crab take is necessary, fishing effort thus number of traps is reduced, however, there are potential future issues of overcapacity with over 5,000 licenses issued in Maryland. Although all of these licenses are not all currently used, there remains the possibility, which would result in overcapacity. In an effort to minimized this risk, there is an effort to buyback unused licenses and there has been a reduction of 1,000 female harvest licenses and some additional male only licenses (Davis, pers. comm. 2012). Stock status, due in part, to management measures (see track record below) has greatly improved since the 1990s (see figure 2a), however, there are no standard enforcement measures in place, as enforcement is generally based on a “heads‐up” surveillance, with managers randomly being alerted to non‐compliance (Davis, pers. comm. 2012). Still, there is a point system that is being put in place, which can result in suspension of licenses depending on how many points you have accrued, and this has made a large impact on improving regulation compliance (Davis pers. comm. 2012). Due to the uncertainties of the effectiveness of enforcement and the lack of independent surveillance, enforcement is ranked as moderately effective. Track Record: The management of blue crabs in Chesapeake Bay has been adapted with new research and information available in order to maintain sufficient population sizes. Triggers of low landings and low estimates of population sizes estimated from fishery‐independent winter dredge surveys have prompted quantitative targets (biomass and exploitation thresholds, exploitation target reference point) and effective changes in management which have helped maintained a healthy stock and avoid overexploitation of the population (CBC 2003; CBC 2004; CBC 2005; Miller, Martell et al. 2005; Miller, Wilberg et al. 2011). These measures have been effective over the short‐term (15 years) and have mirrored overall blue crab population increasing trends but have not been in place for enough time to determine long‐term maintenance, therefore ranked as moderately effective. Stakeholder Inclusion: In an effort to improve industry leadership and coordination, as well as increasing co‐management among managers and industry, a stakeholder group (by region, interest and gear) was formed by the industry to review, evaluate and propose new blue crab management options. The Blue Crab Industry Design Team is a volunteer, industry‐led group charged with assessing and thinking long‐term about the future of the Chesapeake Bay commercial crab fishery. In addition, there are Blue Crab Management Advisory Committee meetings. This transparent process of management with a variety of stakeholder involvement is ranked highly effective for stakeholder inclusion. 24
South Atlantic Management Strategy and Implementation: The North Carolina FMP was adopted in 1998, an amendment completed in 2004 and, in 2012, a second amendment will be adopted. The stated FMP objectives include: “maintenance of the stock at a level that maximizes reproductive potential; promote harvesting practices that minimize waste; habitat protection and restoration; distinguishing between conservation goals and allocation issues; providing resource utilization for all users; conflict minimization; identifying and promoting biological, social, and economic research; maintaining the blue crab fisheries as a major source of income for commercial fishermen; and promoting education” (NCDMF 2004). However, blue crab stock management in states along the South Atlantic coast has been hindered by inadequate catch and effort data (GSMFC 2001). Without this information, establishing reference points and documenting whether these targets are met is not possible. Although the South Atlantic region has maintained a productive blue crab fishery and fishing there is need for greater precaution, and generating data that will lead to established reference points, therefore Seafood Watch deems management strategy and implementation as moderately effective. Recovery of Stocks of concern: There are no species of concern targeted in this fishery, therefore ranked as highly effective. Scientific Research and Monitoring: The Pamlico Sound Survey and other North Carolina Division of Marine Fisheries surveys are used to collect fishery‐independent data for North Carolina. Proper stock assessments could not be conducted, but instead the stock has been characterized by a Traffic Light Stock Assessment method, which synthesizes a variety of information (NCDMF 2012). Management efforts can be improved with the collection and use of fishery‐independent data and are therefore ranked as moderately effective. Scientific Advice: Management of blue crabs in the South Atlantic and Gulf of Mexico has typically been based on changes in landings and fishery dependent data. Management of these stocks does not always follow scientific advice primarily due to the lack of necessary information to make recommendations (Guillory, Perry et al. 2001b; NCDMF 2012). Therefore Seafood Watch deems scientific advice as moderately effective. Enforcement: Regulation of commercial blue crab fishery management is set by a number of licenses which limits the number of traps. When a reduction in blue crab take is necessary, fishing effort, thus number of traps, is reduced. These measures seem to promote the stock; thus, illegal effort does not appear to be a primary problem. Enforcement measures are in place (license limits) yet there is no independent scrutiny of enforcement of regulations, therefore ranked as moderately effective. Track Record: 25
Without sufficient information and research on blue crab stocks, management has primarily been reactive to trends in population fluctuations. Long‐term maintenance of stock abundance and ecosystem integrity has not been established, and therefore ranked as moderately effective. Stakeholder inclusion: Stakeholders have participated in the evaluation and recommended management of blue crab through the North Carolina Marine Fisheries Commission Regional Stakeholder Advisory Committee system. Various stakeholder interests have been represented, but consensus has been difficult, and additional interest must be included for more transparent and effective management. Stakeholder inclusion is moderately effective. Gulf of Mexico Management Strategy and Implementation: The 2001 FMP for the Gulf of Mexico provides management considerations and recommendations as well as research needs (Guillory, Perry et al. 2001b) for management of blue crabs in the Gulf. Louisiana Department of Wildlife and Fisheries and Louisiana State University have suggested the need to define overfishing and overfished limits so that management actions can be established to avoid approaching critical limits and for recovery of the stock (West, Blanchet et al. 2011). These reference points are currently being defined to improve future management (VanderKooy 2012). Although management of the blue crab fishery by the Gulf States Marine Fisheries Commission (CGMFC) (Table 2) has led to the maintenance of the stock in the long‐term, there is clear need for increased precaution, and fishery‐
independent date collection, therefore, management strategy and implementation is deemed moderately effective. Recovery of Stocks of concern: There are no species of concern targeted in this fishery, therefore ranked as highly effective. Scientific Research and Monitoring: The assessment of blue crabs in Louisiana is based on catch‐survey analyses which incorporate abundance indices, harvest estimates and natural mortality (stock‐production models). Estimates of exploitable biomass and recruitment as well as fishing mortality are produced from these models. Indices of abundance are derived from the Louisiana Department of Wildlife and Fisheries fishery‐
independent trawl survey. Additional research and monitoring for the entire Gulf including fishery‐
independent data, a time series of observed landings, and corresponding abundance indices for recruits and exploitable life stages are required to accurately assess the blue crab stock and fishing mortality. Scientific research and monitoring in the Gulf of Mexico is moderately effective. 26
Scientific Advice: Management of blue crabs in the Gulf of Mexico has typically been based on changes in landings and fishery dependent data. Management of these stocks does not always follow scientific advice primarily due to the lack of necessary information to make recommendations (Table 2) (Guillory, Perry et al. 2001b; NCDMF 2012; VanderKooy 2012), therefore Seafood Watch deems scientific advice as moderately effective. Table 2: An evaluation of the effectiveness in implementing the 2001 GSMFC blue crab FMP recommendations. GSMFC Fishery Management Plan Summary Blue Crab Establish fees and permits to identify commercial and/or recreational effort Establish minimum carapace width of 5" for hard blue crabs Establish a trap identification system Mandate biodegradable escape panels Crab traps tended during daylight only Require removal of traps not actively fished Mandate use of escape vents (or rings) Allow harvest of egg‐bearing crabs Establish data collection for commercial harvest of hard and soft crabs Establish data collection for recreational harvest of hard and soft crabs Establish recreational license Establish data collection for size, sex, and maturity of commercial and recreational harvest Establish commercial effort limitations Individual Recommendation (Percent Compliance Gulf‐wide) 93 100 100 40 100 60 60 40 100 20 60 40 40 Enforcement: Regulation of commercial blue crab fishery management is set by a number of licenses and thus traps. When a reduction in blue crab take is necessary, fishing effort is reduced. These measures seem to promote the stock thus illegal effort does not appear to be a primary problem. Management is enforced and information is verified through trip ticket programs where dealers and fishermen report a variety of information about their catch including but not limited to: gear, area fished and species landed (Donaldson 2012). The trip ticket program is used to verify catch. Thus enforcement is ranked as moderately effective. 27
Track Record: Without sufficient information and research on blue crab stocks, management has primarily been reactive to trends in population fluctuations. Long‐term maintenance of stock abundance and ecosystem integrity has not been established. Because management measures have not been in place long enough, the track record is uncertain, making the management track record moderately effective. Stakeholder Inclusion: Stakeholders can participate in the evaluation and recommended management of blue crab through the Louisiana Crab Task Force and Gulf States Marine Fisheries Commission Technical Coordinating Committee Crab Subcommittee. However, there is limited transparency in the process, which makes the stakeholder inclusion moderate. Factor 3.2 Management of fishing impacts on bycatch species: Virginia; South Atlantic; Gulf of Mexico – High Concern Delaware, Maryland, New Jersey – Moderate Concern Chesapeake Bay Trotline – N/A (all species retained) Fishery Virginia South Atlantic Gulf of Mexico Delaware, Maryland, New Jersey Chesapeake Bay Trotline All Mgmt strategy Scientific Species and research and Retained? implementation monitoring Scientific advice Enforcement No Moderately Effective Moderately Effective Moderately Effective Moderately Effective Moderately Effective Moderately Effective Ineffective Moderately Effective Moderately Effective Moderately Effective No Moderately Effective Moderately Effective Highly Effective Moderately Effective Yes No No Ineffective Ineffective Key relevant information: Management Strategy and Implementation: Bycatch reduction devices are effective at preventing diamondback terrapins from entering crab pots unharmed without negatively impacting the blue crab fishery (Roosenburg and Green 2000; Cole and Helser 2001; Butler and Heinrich 2007; Rook, Lipcius et al. 2010; Hart and Crowder 2011). The most 28
effective management strategy to reduce terrapin mortality in the blue crab fishery is to exclude commercial crab pots in areas where there is significant overlap with terrapin habitat (Roosenburg 1991; Seigel and Gibbons 1995; Roosenburg 2004). A significant reduction in terrapin mortality has not been documented because the use of BRDs is not mandatory in most commercial crab pot fisheries and quantitative goals are not set for the reduction of terrapin mortality. Still, New Jersey requires bycatch reduction devices in commercial crab pots that are in tributaries less than 150 feet wide((NJDFW) 1998). Maryland restricts waters where commercial crab pots are allowed and Delaware requires BRDs on any trap set in tidal creeks less than 50 meters wide. Bycatch mortality may be reduced where there are fewer crab pots in terrapin habitat, although these bycatch reduction techniques have not been in place long enough to fully understand their effectiveness. Another important source of mortality comes from derelict pots and their removal has been an ongoing management measure to reduce terrapin bycatch through the blue crab fishery. Conservative estimates of fishing effort and traps lost in the Gulf of Mexico estimate that approximately 250,000 derelict traps are added to the Gulf of Mexico annually (GSMFC 2012). All regions have implemented derelict crap pot removal programs in order to reduce the potential for ghost fishing (Parry, Guillory et al. 2008; LDWF 2010b). The Gulf States have recognized the threats of derelict crab pots and have initiated crab pot cleanup programs, in which they collectively removed approximately 60,000 abandoned ghost pots from 2002 to 2007 (Perry et al. 2008). On the southeast Atlantic coast, since 1995, South Carolina has established a successful crab pot cleanup program and has collected approximately 46,000 crab pots (Guillory et al. 2001). Chesapeake Bay has been actively removing approximately 42,000 derelict pots since 2007 (NOAA 2012). Management strategy and implementation is deemed moderately effective because these pot removal programs are in place and are reducing terrapin bycatch, but the effectiveness is not certain and there is need for increased precaution and the broader use of BRDs. 29
Scientific Research and Monitoring: Diamondback terrapin population sizes are unknown or declining (Seigel and Gibbons 1995). There continues to be fishery‐independent research conducted on the population size of terrapins and effects of crab pots on terrapin mortality to determine how to better maintain the blue crab fishery while limiting the take of unintended species, but this is only moderately effective due to limited data collection. Research is primarily conducted through the Diamondback Terrapin Working Group (http://www.dtwg.org/). The Diamondback Terrapin Working Group was formed in 2004 by individuals from academic, scientific, regulatory and private institutions/organizations working to promote the conservation and research into bycatch reduction of the diamondback terrapin, the preservation of intact, wild terrapin populations and their associated ecosystems throughout their range. Scientific Advice: Management in most regions has not been active in adopting the scientific advice which concludes that BRDs will significantly reduce diamondback terrapin bycatch, therefore this sub‐factor is ranked as ineffective. However, the states of New Jersey, Delaware and Maryland regulate the use of specific terrapin bycatch reduction measures (bycatch reduction devices in crab traps and spatial restrictions) that have been recommended and advised as effectively mitigating the bycatch of terrapins (see Hart and Crowder 2011). Thus, New Jersey, Delaware and Maryland are ranked as highly effective for following scientific advice. Enforcement: Enforcement of the use of BRDs is not a major factor in this fishery as BRDs are very infrequently mandated. There are no known concerns with enforcement and compliance in the commercial fishery, although in Maryland, where BRDs are required in recreational crab pots, compliance with the regulation is only 30% (Radzio et al., in press). This factor is therefore ranked the same as “enforcement” under 3.1, as moderately effective. 30
Criterion 4: Impacts on the habitat and ecosystem Fishery Impact of gear on the Mitigation of gear substrate impacts EBFM Criterion 4 Rank (Score) Rank (Score) Rank (Score) Rank Score Virginia Low Concern (3) Minimal mitigation (0.25) Moderate Concern (3) Yellow 3.12 South Atlantic Low Concern (3) Minimal mitigation (0.25) Moderate Concern (3) Yellow 3.12 Gulf of Mexico Low Concern (3) Minimal mitigation (0.25) Moderate Concern (3) Yellow 3.12 Low Concern (3) Minimal mitigation (0.25) Moderate Concern (3) Yellow 3.12 Low Concern (3) Minimal mitigation (0.25) Moderate Concern (3) Yellow 3.12 Delaware, Maryland, New Jersey Chesapeake Bay Trot Line Synthesis Crab pots, as a passively fished gear type, have a light impact on benthic habitat. The primary threat from the gear comes from lost or abandoned derelict pots which is not actively fished and can be naturally swept across the habitat. Derelict gear is also referred to as “ghost fishing” because abandoned pots will continue to trap a variety of species, both blue crab and non‐target species. Being unmaintained, they contribute to unnecessary mortality with the potential to alter ecosystem or food web dynamics. Trotlines, similar to bottom longlines (but without hooks), rest along the benthos and are anchored at both ends with anchors and chain. Trotlines are set in primarily sand and silt habitats. Justification Factor 4.1 Impact of the fishing gear on the substrate: Low concern Key relevant information: Pots are less damaging than highly mobile gears, such as trawls or dredges. Although they are bottom gear, they are not very mobile and have contact with a substantially smaller area of the seafloor than do other types of gear. Relative to blue crab habitat, pots are less likely to cause damage on sand or mud‐
bottom substrate as opposed to submerged aquatic vegetation or live bottom substrate (Barnette 2001). Pots can affect habitat, however, because they do not always remain entirely stable on the seafloor (Chuenpagdee, Morgan et al. 2003). Trotlines, similar to bottom longlines (without hooks), rest along the benthos and are anchored at both ends. Along the mainline there are a series of baits attached at intervals of two to six feet. The baits are attached to the main line by slipknots or by shorter 31
lines called dropper lines (known as trots or snoods). At each end of the line is an anchor with a line that goes to a float and then another line that goes to a section of about 10 links of chain for stability. Trotlines are set in primarily sand and silt habitats. Factor 4.2 Modifying factor: Mitigation of fishing gear impacts: Minimal mitigation Key relevant information: Fishing effort throughout the blue crab fisheries is controlled but not actively reduced and is therefore deemed as minimal mitigation by Seafood Watch. Most states have had or currently have established derelict pot removal programs (CCRM 2008; GSMFC 2012; Guillory 2012; TampaBayWatch 2012). Quantifying and identifying the location of ghost pots for their eventual removal contributes to the mitigation of impacts from derelict pots, however, there are no robust programs in any region that fully address and mitigate ghost traps; therefore ranked as minimal mitigation. Quantifying and identifying the location of ghost pots for their eventual removal contributes to the mitigation of impacts from derelict pots. Conservative estimates have approximately 250,000 derelict traps added to the Gulf of Mexico annually from fishing effort (GSMFC 2012). All states in the region have implemented derelict crap pot removal programs in order to reduce the potential for ghost fishing and negative ecosystem impacts and since 2002, over 60,000 pots have been removed (Parry, Guillory et al. 2008; LDWF 2010b). Factor 4.3 Ecosystem and Food Web Considerations: Moderate concern Key relevant information: The blue crab fisheries in this report do not catch exceptional species and there are currently no efforts in place to fully assess and manage ecosystem impact of the fishery. Therefore, Seafood Watch deems ecosystem and food web considerations as a moderate conservation concern. In addition to recommendations to maintain regulations enacted by the states, limit access to the fishery, prevent exploitation, and improve research and monitoring, the 1997 Chesapeake Bay Blue Crab FMP incorporates an enhanced habitat section recommending protection and restoration of bay grasses and water quality. These concerns are very important in Chesapeake Bay because it is such a large and very productive estuary. In this system that is more closed than many coastal environments, the ecosystem and food web dynamics are crucial. Outside of the Chesapeake, there are numerous restoration activities but the efforts are most often not specifically coordinated as part of blue crab population management. Efforts to restore habitats are done to promote a variety of species for the health of the entire ecosystem and food web dynamics. There are no efforts to fully assess ecosystem impacts from the blue crab fishery. 32
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Appendix A: Review Schedule Gulf States: revised Fishery Management Plan 2013 add links/refs/contact info (VanderKooy 2012) Gulf States Stock Assessment 2013 (VanderKooy 2012) Louisiana blue crab fishery was MSC certified in March 2012 MSC – SCS Report: Species: Blue Crab (Callinectes sapidus) Geographic Area: Gulf of Mexico, State Waters of Louisiana, FAO statistical area 31 Fishing Method: Traps Fishery Management: State of Louisiana through the Wildlife and Fisheries Commission and the Department of Wildlife & Fisheries, Division of Marine Fisheries 39
About Seafood Watch® Monterey Bay Aquarium’s Seafood Watch® program evaluates the ecological sustainability of wild‐caught and farmed seafood commonly found in the United States marketplace. Seafood Watch® defines sustainable seafood as originating from sources, whether wild‐caught or farmed, which can maintain or increase production in the long‐term without jeopardizing the structure or function of affected ecosystems. Seafood Watch® makes its science‐based recommendations available to the public in the form of regional pocket guides that can be downloaded from www.seafoodwatch.org. The program’s goals are to raise awareness of important ocean conservation issues and empower seafood consumers and businesses to make choices for healthy oceans. Each sustainability recommendation on the regional pocket guides is supported by a Seafood Report. Each report synthesizes and analyzes the most current ecological, fisheries and ecosystem science on a species, then evaluates this information against the program’s conservation ethic to arrive at a recommendation of “Best Choices,” “Good Alternatives” or “Avoid.” The detailed evaluation methodology is available upon request. In producing the Seafood Reports, Seafood Watch® seeks out research published in academic, peer‐reviewed journals whenever possible. Other sources of information include government technical publications, fishery management plans and supporting documents, and other scientific reviews of ecological sustainability. Seafood Watch® Research Analysts also communicate regularly with ecologists, fisheries and aquaculture scientists, and members of industry and conservation organizations when evaluating fisheries and aquaculture practices. Capture fisheries and aquaculture practices are highly dynamic; as the scientific information on each species changes, Seafood Watch®’s sustainability recommendations and the underlying Seafood Reports will be updated to reflect these changes. Parties interested in capture fisheries, aquaculture practices and the sustainability of ocean ecosystems are welcome to use Seafood Reports in any way they find useful. For more information about Seafood Watch® and Seafood Reports, please contact the Seafood Watch® program at Monterey Bay Aquarium by calling 1‐877‐229‐9990. Disclaimer Seafood Watch® strives to have all Seafood Reports reviewed for accuracy and completeness by external scientists with expertise in ecology, fisheries science and aquaculture. Scientific review, however, does not constitute an endorsement of the Seafood Watch® program or its recommendations on the part of the reviewing scientists. Seafood Watch® is solely responsible for the conclusions reached in this report. Seafood Watch® and Seafood Reports are made possible through a grant from the David and Lucile Packard Foundation. 40
Guiding Principles Seafood Watch™ defines sustainable seafood as originating from sources, whether fished1 or farmed, that can maintain or increase production in the long‐term without jeopardizing the structure or function of affected ecosystems. The following guiding principles illustrate the qualities that capture fisheries must possess to be considered sustainable by the Seafood Watch program: Stocks are healthy and abundant. Fishing mortality does not threaten populations or impede the ecological role of any marine life. The fishery minimizes bycatch. The fishery is managed to sustain long‐term productivity of all impacted species. The fishery is conducted such that impacts on the seafloor are minimized and the ecological and functional roles of seafloor habitats are maintained. Fishing activities should not seriously reduce ecosystem services provided by any fished species or result in harmful changes such as trophic cascades, phase shifts, or reduction of genetic diversity. Based on these guiding principles, Seafood Watch has developed a set of four sustainability criteria to evaluate capture fisheries for the purpose of developing a seafood recommendation for consumers and businesses. These criteria are: A. Impacts on the species/stock for which you want a recommendation B. Impacts on other species C. Effectiveness of management D. Habitat and ecosystem impacts Each criterion includes: Factors to evaluate and rank Evaluation guidelines to synthesize these factors and to produce a numerical score A resulting numerical score and rank for that criterion Once a score and rank has been assigned to each criterion, an overall seafood recommendation is developed on additional evaluation guidelines. Criteria ranks and the overall recommendation are color‐coded to correspond to the categories on the Seafood Watch pocket guide: 1 “Fish” is used throughout this document to refer to finfish, shellfish and other invertebrates. 41
Best Choices/Green: Are well managed and caught or farmed in environmentally friendly ways. Good Alternatives/Yellow: Buy, but be aware there are concerns with how they’re caught or farmed. Avoid/Red: Take a pass on these. These items are overfished or caught or farmed in ways that harm other marine life or the environment.