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 SealHalichoerus 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 StatesTake – “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 SealHaul 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 FloorWashington 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 North-East 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• 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.