Once nearly exterminated, New England harbor and gray seals are on the increase in the Gulf of Maine. This rebound, the result of two decades of legal protection, is an environmental success story. It has also created a new set of environmental management problems: as seal populations have grown, encounters between humans and seals have also increased, both on shore and off. Commercial fishers and salmon farmers, in particular, are concerned that increasing seal populations are threatening their livelihoods -- a situation which is complicated by the concurrent collapse of wild groundfish stocks in the region.


In the 1900s, New England's harbor and gray seals were hunted to the brink of extinction due to bounty policies aimed at reducing their population. The seals began to make a slow comeback after the Massachusetts bounty was dropped in 1962, but they continued to be hunted because of their perceived threat to the fishing industry. In 1972, seals became a protected species under the Marine Mammal Protection Act. Since then, both harbor and gray seal populations have increased dramatically.

The Increasing Seal Population

Five species of seals live in the Gulf of Maine: harbor and gray seals year round, and harp, hooded and ringed seals in the winter months. Populations of both harbor and gray seals have risen substantially. Between 1973 and 1993, the harbor seal population has grown from an estimated 4,600 to approximately 28,000. In roughly the same period of time, the gray seal count in southern New England waters increased from less than 20 individuals to approximately 2,000. Because shifts in distribution may account for some of these increases, exact numbers cannot be determined.

Points of Conflict Between Seals and Humans

  • Fishers claim that increasing seal populations are partially responsible for low fishing stocks. Numerous scientific studies indicate that overfishing -- not seals -- is the primary cause of the fisheries collapse. However, seals do eat both commercial and non-commercial fish. There is not yet sufficient data to determine what effect increased seal populations are having on the catches of commercial fisheries in the Gulf of Maine.
  • Salmon growers report that seals kill or damage salmon in their pens, costing an estimated $1 million a year. (The total value of Maine-farmed salmon is about $40 million.) Maine salmon growers produce 7,000 tons of salmon annually, second only to Maine's annual harvest of wild lobster. Although salmon farmers employ deterrents such as double netting, acoustic seal scarers and life-size fiberglass models of killer whales (a natural predator), none are 100% effective. Studies have shown that regular net maintenance and other good farming practices do reduce predator loss.
  • Fishers claim that seals steal fish from nets, destroy fishing gear and take bait from lobster pots. Gray seals and, to a lesser extent, harbor seals, are known to bite fish out of gill nets. There is no scientific evidence to support claims that seals eat lobster.
  • An estimated 1,000 seals are incidentally killed or injured each year when they become entangled in fishing nets. The effect on the overall seal population is considered insignificant.
  • Small numbers of seals are shot, hit by four wheel vehicles, or injured by dogs each year. Small numbers of people are bitten by seals.

    Should Seals Be Managed or Should Humans?

    The question of whether and/or how to manage seal populations is a complicated one. Scientists lack sufficient data on population shifts and diet to accurately assess potential impacts. The issue is further clouded by public perceptions of seals, which are influenced by two opposite and emotionally powerful images: on the one hand, seals are widely perceived as "cute" and in need of protection; on the other, they are seen as a menace, threatening the livelihoods of hardworking fishers and their families.

    The New England Aquarium's Role

    The New England Aquarium is considered a leader in the conservation, research and care of marine mammals. The Aquarium launched its pioneering Marine Animal Stranding Program in 1968 and began rescuing and releasing baby harbor seals, then rare, in the early 70s. Since the program's inception, the Aquarium has released over 200 seals. The Aquarium's seal program does more than save individual seals -- it also provides unique information. Virtually everything that is known about seal population health has been learned from such programs. The Aquarium also responds to hundreds of phone calls about seals each year and releases an annual public service announcement on how to respond to a stranded pup. SEAL-TV, a live video program, brings Aquarium visitors behind the scenes to watch the real life rehabilitation of stranded and orphaned seal pups.

    The Aquarium is currently reviewing its seal programs in the light of the increasing population. It is also expanding its focus from saving seals to studying and managing seal populations, and mediating potential human/seal conflicts. As part of this effort, the Aquarium held a forum on seal/fisher issues in June, 1995. This neutral meeting brought together representatives from the fishing community, animal protection groups, experts in wildlife management ethics, researchers, and federal and state regulators to share data, identify critical issues, and define research priorities. The proceedings were published in a report, Pinniped Populations in the Gulf of Maine, available through the Aquarium's Public Relations Department.

    Through its stranding program and other initiatives, the Aquarium continues to monitor the distribution, health and status of seal populations. Aquarium staff are also conducting ongoing research on seal biology and studying the reintroduction success of released seals through satellite tagging.

    Aquarium Experts:

    Greg Early, Associate Curator of Animal Care/ Marine Mammal Stranding Program
    Scott Kraus, Associate Director of Research
    Maggie Mooney-Seus, Senior Conservation Associate/Policy Analyst
    Gregory Stone, Associate Director of Conservation Programs

    All inquiries should be directed to the Public Relations Office at (617) 973-5222 or (617) 973-5213.


    Susan Gedutis, Publicist
    New England Aquarium, Central Wharf, Boston, MA 02110
    Phone: (617) 973-5222, Fax: (617) 723-9705

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