Found in coastal habitats of both the North Pacific and North Atlantic Oceans, harbor seals are often seen swimming in the surf off sandy beaches of the northern United States. There are five subspecies in the world; in our area, the subspecies is P.v. concolor, which ranges from northeastern Canada, Greenland, and Iceland south along the U.S. coast to New Jersey.
The harbor seal is medium size with a short, spindle-shaped body, up to six feet in length. The short, thick fur ranges from tan to silver in color, with dark and light spots. The head is dog-like, with a broad snout and whiskers which help the sealís sense of touch. The nostrils close during rest. The flippers are relatively short, with five blunt claws on the fore flippers. Adult males may be slightly larger than females, weighing up to three hundred fifty pounds. Harbor seals have a life span of twenty-five to thirty years.
The seals return to breed in the same location born, giving birth to one pup in the spring. Within an hour the pup is able to swim. The attentive mother weans the pup after four to six weeks. While in the water the adult seal is usually solitary. During molting, groups come on land in haul-out sites, numbering up to several hundred seals. The majority of time on land is spent resting, raising their hind flippers in the air, and always alert for potential threats. Pups have a sheep-like call to which their mothers respond with a call or by navigating towards them.
Harbor seals feed on crustaceans, fish, squid, and mollusks depending on availability. They do not chew their food, often swallowing it in large chunks, and crushing the shells of crustaceans and mollusks with their flat back teeth. Harbor seals spend about eight-five percent of the day diving and foraging for food. Staying at sea for weeks, they dive to depths of thirty to five hundred feet, each lasting a few minutes.
There are believed to be close to one hundred thousand harbor seals in the Western North Atlantic, and worldwide approximately five hundred thousand. Protected from hunting in the United States waters, legal hunting in other countries and entanglement in fishing gear are major concerns. Predators include sharks, bears, coyotes, foxes, and large birds.