Sealing the Deal:
The Grey Seal Problem in the U.S. Northeast
A case study created by Matthew S. Kaufman for the course Seminar in
Biodiversity Conservation at Washington University, St. Louis, Missouri
The Grey Seal
Halichoerus grypus
• Also known as the Atlantic Grey Seal.
• 2.5-3.3m long and weighing up to 300kg.
• Their range extends as far south as Virginia off
the coast of the U.S., but can be found year
round off the coast of Maine and
Massachusetts.
• Predatory animals that rely mostly on fish for
their diets.
History of New England Fishing
Problem
• Beginning of 20th century – hunted nearly to
extinction
– They were hurting the fish industry
– Hunted for products
• Was considered extinct in the US until 1958
• In 1972, Congress passed the Marine Mammal
Protection Act
1972 Marine Mammal Protection Act
• Prohibits the taking of marine mammals off the
coasts of the United States
Take – “harass, hunt, capture, or kill, or attempt to
harass, hunt, capture or kill any marine mammal”
• Secretary of Commerce – cetaceans and
pinnipeds
• Secretary of Interior – sea otters, polar bears,
walruses, manatees
1972 Marine Mammal Protection Act
Exceptions
• Scientific research
• Incidental take associated with commercial
fishing operations
• To prevent from damaging public and private
property
• If taken by an Indian, Aleut, or Eskimo for
subsistence purposes
1972 Marine Mammal Protection Act
– Amended in 1994
• Further reduced the exceptions
– No longer okay to take marine mammals
during fishing practices
– Assessments of all marine mammal stocks in
U.S. waters
– Called for studies on pinniped-fishery
interactions
1972 Marine Mammal Protection Act
– A Huge Success
Endangered Species List
New England Fisheries
 Thriving shellfish farming industry and the lead
producer of farmed Atlantic salmon in the United
States
 Total farm-raised finfish:
- 0.45 million kilograms in 1988 to 16.33 million
kilograms in 2000
 Fish farms are densely packed off the coast of
Maine and Massachusetts
Effects of Grey Seals on Fishing
Industry
• Swipe at nets and make holes
• Loss of marketable product through direct
injury or mortality
• Can result in stress, disease, escapements
of fish
– Natural salmon populations
Effects of Grey Seals on Fishing
Industry - according to fishermen
• Of all salmon losses to predation between
2001 and 2003, 84% were from seals
• Seals most often attack market sized fish,
making a huge impact
Proximity to Winter Harbor Seal
Haul out Sites
• Probability of having seal predation if 1km away
is 65%
• Probability of having seal predation if 4km away
is 24%
• “The predicted number of fish lost to deal
predation decreases by 4053 fish for every 1 km
increase about the average distance between a
farm and the nearest harbor seal haul-out”
(Nelson & Gilbert, 2006)
• Also, location next to other fish farms increases
likelihood of predation
Canada
• Has a current hunt for seals
• Seals for Meals
• Currently scrutinized:
– Called unacceptably inhumane
– Not economically valuable
– Not greatly improving fishing industry
Projected Culling Methods on
Canadian Seals
Effects on the Seal Consumption of
Fish in Canada
Mitigation Measures for Pinniped
Conflict
•
Harassment methods
–
–
–
–
–
•
Firecrackers
Cracker Shells
AHDs
Predator Sounds
Tactile Harassment
Aversive Conditioning
– Taste Aversion
•
Exclusion
– Predator models
•
Non-lethal Removal of Individuals
– Capture and relocation
– Capture and placement in
captivity
•
Lethal Removal of Offending
Individuals
Recommendations?
Senator Jack Kenny*
304 Russell Bldg.
Third Floor
Washington D.C. 20510
(202) 555-2742 - Phone
(202) 555-8525 – Fax
To the Chatham City Counsel:
I have recently become aware of the Grey Seal problem affecting the NorthEast part of our country. With a new Democratic House and Senate in control, I
feel that we can accomplish a solution to this problem. One place we might
begin is with the Marine Mammal Protection Act of 1972 as amended in 1994. I
would like the people of Chatham to submit a recommendation to me as to
whether and how the Marine Mammal Protection Act should be amended, with
special attention to how it relates to the Grey Seal problem.
Please keep all affected parties in mind when drafting this recommendation. I
will take your suggestions very seriously when drafting a new amendment, and
plan to bring it to the Senate floor before the end of this year. Thank you for
your time.
Sincerely,
Senator Jack Kenny
*This letter is fictional and a creation of the author; at time of publication there is no Senator Jack Kenny of Massachusetts.
Credits
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•
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Slide 1: Licensed photo of seal ©Patricia Hofmeester/Fotolia.com.
Slide 7: Baraff, Lisa S., and Thomas R. Loughlin. 2000. "Trends and Potential
Interactions Between Pinnipeds and Fisheries of New England and the U.S. West
Coast." Marine Fisheries Review 62(4): 1-39. MFR is an official publication of the U.S.
government.
Slide 8: Landsat7 image of Cape Cod, Massachusetts; Data: NASA. Image: Dave
Pape. Public Domain. Source: Wikimedia Commons (http://commons.wikimedia.org/).
Slide 9: "Endangered Species Act." NOAA Fisheries. Office of Protected Resources.
Last accessed: June 23, 2008. http://www.nmfs.noaa.gov/pr/laws/esa/.
Slides 15 & 16: McLaren, Ian, Solange Brault, John Harwood, and David Vardy. 2001.
Report of the Eminent Panel on Seal Management. Communication Branch. Fisheries
and Oceans Canada.