2013-12-12 / Nature

Pinnipeds Among Us

By Jack Kelly


Seals off Ocean Drive (Photo by Jack Kelly) Seals off Ocean Drive (Photo by Jack Kelly) The ocean waters and beaches of Aquidneck Island have a certain allure during the winter months that many can’t resist. A walk along the shore will often bring surprises from nature that include shells, sea glass, seabirds, sea ducks, and shorebirds. The coast of Rhode Island and Narragansett Bay also serve as wintering grounds for a number of seal species, including harbor seals, gray seals, harp seals and hooded seals that have migrated south from the North Atlantic. The food supply in our coastal waters draws these pinnipeds to our area.

Harp and hooded seals, also known as ice seals, are among those that inhabit local waters during winter. Ice seals breed and birth their young on the Arctic ice packs of eastern Canada and Greenland during late winter and early spring. Most of the harp and hooded seals sighted in this area are juveniles in their first year of maturity.

Gray seals, also called horsehead seals because of their elongated snouts, are occasionally found in Rhode Island waters, mixed with harbor seals. Adult male gray seals weigh 700-800 pounds and are 7-8 feet long. Adult females weigh 350- 450 pounds and are 6-7 feet long. On the breeding grounds of the far northeastern United States and eastern Canada, the males fight over the females in pitched, bloody combat. The necks and chests of the males can be scarred and furless as a result of these battles.

Harbor seals, the most numerous seal species in our area, are the smallest of the wintering breeds. They are between 4-5 feet long with a weight of 200-250 pounds. The males are only slightly larger than the females. The harbor seal varies in color and may be very light gray, tan, brown, or almost black, with extensive spotting on the body. Its belly is generally lighter than the back. Color differences between wet and dry seals is striking, with the dry seal much lighter. The typical dive for a harbor seal is about 3-4 minutes; however, biologists using satellite-linked telemetry tags recorded harbor seal dives of 30 minutes, to depths of over 500 meters, off the coast of Alaska in 2006.

Seals do not need to be in the water all of the time and will often “haul out” to rest and bask in the sun. Usually they haul out to rocky ledges, island rocks and sandy beaches during low tide. Some of the best spots locally to view seals are among the Island Rocks of Sachuest Point National Wildlife Refuge; Seal Rock, located almost a mile offshore Brenton Point State Park; and the waters of outer Newport Harbor. Binoculars or a telescope are needed to get the best view. Seals may also be observed during high tide, as they feed and swim in any of these areas.

Be aware that the federal Marine Mammal Protection Act of 1972 makes it illegal to hunt, kill, feed, touch, disturb or harass marine mammals. Humans and domestic pets, especially dogs, must keep a minimum distance of 50 yards from seals hauled out on rocks or beaches.

Human and canine interference can cause stress to the animal, which can be harmful to its health. Seals are extremely sensitive to disturbances, and they are capable of inflicting severe injuries to humans and dogs by biting or ripping with their flipper claws. Moreover, seals carry a number of bacterial diseases that can be transmitted to humans. These creatures want nothing more than to rest and warm their blubber in peace, so they should be observed from a safe distance both for their safety and the safety of others.

If a seal or other marine mammal is discovered sick, injured, or dead, contact local authorities, call Mystic Aquarium at 860-572-5955, ext. 107 or call the Rhode Island Department of Environmental Management at 401-222-3070.

Save the Bay has begun its winter seal cruises, which will continue on weekends and school vacations through April. For more information, go to savebay.org/seals or call 401-324-6020.

To read more on seals and other marine mammals visit MysticAquarium.org or uri.edu and navigate to the marine biology/oceanography portion of the website.

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