Whales - Sites@Duke

Whales
Hayley Farless, Zoe Abedon, and Zack Reavis
University of Alaska Southeast-Juneau
mascot, Spike the Humpback Whale
Disney Pixar, Finding Nemo (2003).
What really is a Whale?
Simply put, whales are large, aquatic mammals that spend their entire lives in
water. Whales’ most recognizable anatomical traits include their blowholes, their
blubber, and their two flippers and singular dorsal fin. They often migrate
thousands of miles each year, but the specifics of migration vary for each
particular species and its given feeding and reproductive behaviors.
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Whales belong to the order Cetacea, which also includes dolphins and
porpoises.
Whales are further divided into two sub-orders: Mysticeti and Odontoceti
“What is a whale?” Enchanted Learning. http://www.enchantedlearning.com/subjects/whales/
Cetacean Suborders
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Mysticetes, baleen whales
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Utilize baleen, a keratin comb-like structure to filter small organisms from the water as a
source of food.
Have two blowholes.
Produce very low-frequency “songs” as a means of communication.
Examples include Humpback Whales, Gray Whales, Fin Whales, and Blue Whales.
Odontocetes, teethed whales
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Utilize their teeth to hunt fish and other small aquatic creatures, which they don’t chew.
Have one blowhole.
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Hunt their prey by using echolocation, in which they emit clicks that bound off of objects and
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return back to the lower jaw bone. They then move on to the ear and the brain, where the echo
of the clicks is utilized to interpret the characteristics of the object.
Examples include Orcas, Dolphins, and Beluga Whales
“What is a whale?” Enchanted Learning. http://www.enchantedlearning.com/subjects/whales/
Mysticeti Physical Characteristics. http://whales.findoutnow.org/images/whale%20anatomy%20diagram.JPG
Toothed Whale Anatomy. http://schools.look4.net.nz/science/biology/marine/fish/fish_files/Toothed_Whale.jpg
Whale Evolution
-The hippopotamus is the closest living relatives to whales or cetacea.
-They shared some common ancestor and each evolved into
aquatic mammals separately.
-The common ancestor would have likely been a land mammal as one
of the oldest whale ancestors, the Pakicetus, was mostly a land
mammal.
-Despite the Pakicetus not looking like a whale, the skull resembles
that of a present day whale and is unlike any other mammal.
The evolution of whales. http://evolution.berkeley.edu/evolibrary/article/evograms_03
Whale Evolution
-The hippopotamus evolved around 15 million years ago.
-The baleen and toothed whale branched from a common ancestor
around 34 million years ago, when the baleen whale evolved baleen
in place of teeth for filter feeding and when the toothed whale
evolved echolocation for better hunting.
The evolution of whales. http://evolution.berkeley.edu/evolibrary/article/evograms_03
Whales in the Ecosystem
-Whales enhance both the stability and predictability of marine ecosystems.
-They eat many types of fish and invertebrates, some fall prey to other species
(such as killer whales), and they distribute nutrients throughout the ocean.
-Even upon death, their carcass drops to the ocean floor and provide a habitat for
many species, some of which can only survive in these, “whale falls”.
-One interesting and important positive feedback loop seen, is whale feces
promoting plankton growth, which promotes overall fish population growth, which
inherently will promote whale populations.
Whales as ecosystem engineers. http://www.uvm.edu/~uvmpr/?Page=news&storyID=18797
Whales in Kenai Fjords National Park
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Gray Whale
Humpback Whale
Fin Whale
Orca (Killer Whale)
Beluga Whale
Pacific White-Sided Dolphin
Kenai Fjords National Park
(Photo by Hayley Farless)
Other Whales Present in Alaska
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Blue Whale - Present around the Aleutian Islands, mostly the westernmost islands.
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Right Whale - Has been seen in the Gulf of Alaska but the right whale population is less than 450,
so these are extremely rare to see.
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Minke Whale - Present in Alaska’s Kachemak Bay, Glacier Bay and Prince William Sound.
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Bowhead Whale - Present in Northern Alaska around the ice.
The Whales of Alaska. http://www.whale-watching-alaska.com/whale/bluewhalesalaska.html
Alaska’s Population of Bowhead Whales. http://www.adfg.alaska.gov/index.cfm?adfg=wildlifenews.
view_article&articles_id=42
North Pacific Right Whale. http://www.adfg.alaska.gov/index.cfm?adfg=rightwhale.main
The Whale’s of Alaska. http://www.whale-watching-alaska.com/whale/minkewhalesalaska.html
Gray Whales, Eschrichtius robustus
Length: 44 to 48 feet
Weight: 30 to 40 tons
Average Life Expectancy: 50 to 70 years
Appearance: Dark gray with white patches
Gray Whale Facts. http://www.whalefacts.org/gray-whale-facts/
Source: Voices in the Sea on ucsd.org
Habitat and Migration of the Gray Whale
-Gray whales are mostly found in the Eastern North Pacific Ocean and near Korea
in the Western North Pacific Ocean.
-Their migration route takes them as far south as Baja and as far north as Alaska.
Source: https://www.learner.
org/jnorth/images/graphics/gwhale/maps
/map_annual.gif
Gray Whale Facts. http://www.whalefacts.org/gray-whale-facts/
Gray Whale Diet
-Gray whales swim to the bottom of the ocean and scoop up sediments from the
ocean floor, which then allow them to filter food through their baleen.
-Gray whales are mostly benthic crustaceans, but consume other small prey in
their path.
Source: http://news.berkeley.
edu/2011/07/06/gray-whales-likelysurvived-the-ice-ages-by-changing-theirdiets/
Gray Whale Facts. http://www.whalefacts.org/gray-whale-facts/
Gray Whale Breaching by Flickr user Eric Neitzel.
Used under Creative Commons License.
Gray Whale Skeleton by Flickr user Dave Nixen. Used under Creative
Commons License.
Humpback Whales, Megaptera novaeangliae
Length: 40 to 48 feet
Weight: 25 to 40 tons
Average Life Expectancy: 45 to 50 years
Source: http://acsonline.org/fact-sheets/humpback-whale/
Appearance: Black on the upperside and mottled black and white on the
underside.
Humpback Whale. http://acsonline.org/fact-sheets/humpback-whale/
Habitat and Migration of the Humpback Whale
-Found in all of the world’s oceans
-Follow a pretty normal migration route, with a migration to the polar regions for
the summer and the tropical waters for the winters.
Source: http://www.grida.
no/graphicslib/detail/the-long-migration-of-thehumpback-whale_9cd5
Humpback Whale. http://acsonline.org/fact-sheets/humpback-whale/
Humpback Whale Diet
-Feeds primarily krill, small crustaceans, and small fish.
-Eats up to one and a half tons of food per day!!!!!!!!!!!!!!!
Source: http://www.freakingnews.com/funnypictures/whales-pictures.asp
Humpback Whale. http://acsonline.org/fact-sheets/humpback-whale/
Humpback Whales in Kenai Fjords National
Park (Photos by Hayley Farless)
Breaching male Humpback Whale in Kenai Fjords by Flickr user
jdegenhardt. Used under Creative Commons License.
Humpback Whale by Flickr user Christopher Michel. Used under
Creative Commons License.
Fin Whales, Balaenoptera physalus
Hard Facts
Length: 70 - 80 feet
Weight: 40 - 80 tons
Speed: Up to 20 mph
Life Expectancy: Up to 100 years
Source: Whale Wiki on
GreenPeace.org
“Fin Whale - Balaenoptera Physalus.” National Park Service. https://www.nps.gov/kefj/learn/nature/fin-whale.htm
Fin Whale Skeleton by Flickr user Daniel Mennerich. Used under Creative
Commons License.
Fin Whale by Flickr user chris buelow. Used under Creative
Commons License.
Habitat of the
Fin Whale
Live in the deep
waters of every
ocean in the
world
Generally only
spotted in the
Kenai Fjords in
early May and
August
“Fin Whale - Balaenoptera
Physalus.” National Park Service
https://www.nps.
gov/kefj/learn/nature/fin-whale.
htm
Photo by Hayley
Farless
Fin Whale Diet
Filter feeders
500 - 900, 3-foot long baleen plates hanging
from the roofs of their mouth
64 ventral grooves allow their mouths to
expand
Diet consists of krill, copepods, and small
schooling fish like herring and halibut
Source: huntsmanmarinesciencecenter.com
“Fin Whale - Balaenoptera Physalus.” National Park Service https://www.nps.gov/kefj/learn/nature/fin-whale.htm
Reproduction of Fin Whales
Source: loretobluewhales.com
Breed and give birth off the coast of Mexico in the winter
Gestation lasts a year and mothers only give birth once every two years
A newborn fin whale is normally 4 - 8 tons and around 22 feet
Sexual maturity occurs around the age of 6 or 7
“Fin Whale - Balaenoptera Physalus.” National Park Service https://www.nps.gov/kefj/learn/nature/fin-whale.htm
Source: gatorwoman.com
Orcas, Orcinus orca
Hard Facts
Length: 23 - 26 feet
Weight: 4 - 8 tons
Male dorsal fins can be up to 6 feet long
Life expectancy: Unknown → Could be 30
- 50 years, but it is thought that some
orcas live to be about 80 - 90 years old
“Killer Whale - Orcinus Orca.” National Park Service. https://www.nps.gov/kefj/learn/nature/killer-whale.htm
Source: pixabay.com
Orca Species
There are three genetically distinct types of orcas that do not interbreed or mingle:
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Resident: Eat fish (silver salmon, halibut, and herring) and have a range of up
to 800 miles
Transient: Eat marine mammals (harbor seals, porpoise, and sea lions) and
have a range of up to 1,500 miles
Offshore: Usually live in open ocean areas → Diet is mostly unknown, but they
are thought to possibly eat sharks and even baleen whales
“Killer Whale - Orcinus Orca.” National Park Service. https://www.nps.gov/kefj/learn/nature/killer-whale.htm
1 salmon in a
school of mixed fish
How precisely an orca can use their echolocation
“Killer Whale - Orcinus Orca.” National Park Service. https://www.nps.gov/kefj/learn/nature/killer-whale.htm
Reproduction of Orcas
Matriarchal, multigenerational
societies
Pods mate with other pods during
late summer/early fall →
“Superpods” form during mating
16 - month gestational period →
Birth in winter or early spring
Orca calves: 7 - 9 feet and 400
pounds
“Killer Whale - Orcinus Orca.” National Park Service. https://www.nps.gov/kefj/learn/nature/killer-whale.htm
Orcas in Kenai Fjords National Park
(Photos by Hayley Farless)
Orca by Flickr user Victoria Hoete-Dodd. Used under
Creative Commons License.
Orca by Flickr user Kim. Used under Creative
Commons License.
Beluga Whales,
Delphinapterus leucas
Length: 13 - 20 ft
Weight: 2000 to 3000
pounds
Life expectancy: 35 - 50
years
Appearance: White with
rounded forehead and no
dorsal fin
Source: oceanviewer.org
“Beluga Whales.” National Geographic. http://animals.nationalgeographic.com/animals/mammals/beluga-whale/
Beluga Whale by Flickr user Fundación Caja Mediterráneo. Used
under Creative Commons License.
Beluga Whale Fluke by Flickr user Vince Smith. Used under Creative
Commons License.
Beluga Diet, Habitat, and Social Structure
Belugas eat fish, crustaceans, and worm
They can be found in arctic and subarctic waters, but migrate southward when the
ice starts to freeze over → Belugas that don’t make it out of the ice become
trapped and die as they become prey for polar bears, killers whales, and people
Belugas live together in small pods → They communicate using a complex series
of whistles, clicks, and clangs
“Beluga Whales.” National Geographic. http://animals.nationalgeographic.com/animals/mammals/beluga-whale/
Beluga Point at Cook Inlet near Anchorage, AK
Beluga Point on the Seward Highway near
Anchorage, Alaska. This section of the
Turnagain Arm is home to around 350
belugas.
Source: http://www.alaska.org/detail/beluga-point
Pacific White-Sided Dolphin, Lagenorhynchus obliquidens
Length: 7 to 8 feet
Weight: ~300 pounds
Average Life Expectancy: 37 to 46 years
Appearance: Backside is black, sides are striped light and dark gray, and underside
is white.
Pacific White Sided Dolphin. http://wildwhales.org/pacific-white-sided-dolphin/
Habitat and Migration of the Pacific White-Sided Dolphin
-Found in temperate, coastal waters of the Northern Pacific.
-The Pacific White-Sided Dolphin doesn’t necessarily migrate, rather it moves
about a range from Amchitka Island in the Aleutians to the Gulf of Alaska to the tip
of Baja California.
-Can also be found around the Kuril Islands of Japan.
Pacific White-Sided Dolphin. http://acsonline.org/fact-sheets/pacific-white-sided-dolphin/
Pacific White-Sided Dolphin Diet
-Pacific White-Sided Dolphins eat mostly squid and small schooling fish, like
anchovies and sardines.
-It is largely believed that these dolphins eat mostly at night.
Source: http://www.itsnature.
org/sea/aquatic-mammals/pacific-whitesided-dolphin/
Pacific White-Sided Dolphin. http://acsonline.org/fact-sheets/pacific-white-sided-dolphin/
A pair of Pacific White-Sided Dolphins by Flickr user
NOAA Fisheries West Coast. Used under Creative
Commons License.
Threats to Whales
Biggest dangers to whales:
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Collisions with ships
Entanglement in fishing gear (bycatch)
Pollution
Shipping activity→ Can damage whale’s hearing
There is an international ban on the trade of whale
products, but countries such as Iceland continue to hunt
whales despite the threats of the International Whaling
Commission
Climate change is affecting the food source of whales
“Whales.” WWF. http://www.worldwildlife.org/species/whale
Source: snopes.com
Whale Conservation
Research Methods:
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Satellite tagging
Acoustic recording
Photo identification
Genetics
List of Organizations Helping Out the Whales
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World Wildlife Fund
Whale and Dolphin Conservation Society
World Cetacean Alliance
Planet Whale
Sea Shepherd
“Whale Conservation.” CaboTrek. http://cabowhaletrek.com/whale-info/whale-conservation/
Whales in the Alaskan Economy: Whaling
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Whales have historically been hunted for meat, oil, bones, and blubber to
produce a profit, but commercial whaling was ended by the International
Whaling Commission in 1986 to preserve population numbers. 1
After successfully lobbying, some native communities are permitted to take a
certain number of whales- generally Bowhead Whales- per season for
subsistence. In Alaska, these communities include Gambell, Savoonga, Wales,
Little Diomede, Kivalina, Point Hope, Point Lay, Wainwright, Barrow, Nuiqsut,
and Kaktovik.2
“History and Purpose.” International Whaling Commission. https://iwc.int/history-and-purpose
“Our Whaling Villages.” Alaska Eskimo Whaling Commission. http://www.aewc-alaska.com/whaling-villages.html
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Whales in the Alaskan Economy: Whale Watching
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With commercial whaling a banned practice, the industry of whale watching
has become the primary way in which Alaska’s whales contribute to its profit.
Alaska’s southeastern coast its most visited location in the summer monthsby tourists and by whales-, which makes it an ideal economic location for the
wildlife tourism industry and whale watching.
As of 2008 Alaska saw over 500,000 whale watching tourists, which brought
in over $460,000,000 (p. 214).
Increasing transportation availability and traveling opportunities have likely
increased these numbers even further.
Whales in Alaskan Native Culture
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The hunting of whales, particularly Bowhead Whales, is an extremely
significant cultural facet of many Arctic Native communities in Alaska and
has been going on for thousands of years. With imported products available
only at enormously inflated prices in many Native villages, aboriginal whaling
currently provides the communities with subsistence.
Seals are first hunted by men, and their skins are dried by women and used to
carefully craft the traditional whaling boats.
Some Alaskan Native cultures deem whaling a rite of passage for its men,
while Native women often prepare food for the whaling events.
“In Hunt for Bowhead Whale, Alaska Native Village Preserves Its Past.” Julia O’Malley, 2015. http:
//america.aljazeera.com/multimedia/2015/7/whaling-alaska-native-village-preserves-its-past.html
Whales in Alaskan Native Culture
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The whales are harvested by the male boat crews through harpooning, and
the traditional methods of butchering and sharing the meat and resources
take place in a celebratory fashion.
Community feasts and festivals are often held as a way of demonstrating
unity and community adhesion.
The continuation of the whaling practices allows for the communication of
Native culture through generations and preserves tradition while providing
sustenance for communities that are often isolated from affordable foods
and other necessary goods that whales can provide.
“Subsistence Hunting Activities and the Inupiat Eskimo.” Cultural Surivial, 1998. https://www.
culturalsurvival.org/publications/cultural-survival-quarterly/united-states/subsistence-hunting-activitiesand-inupiat-es
Photo by Marco Queral