Harbor Seals (Phoca vitulina)

Harbor Seals on the Ledge: Harbor seals typically are found on the Ledge during the fall, winter, and spring, when they are most common along the shoreline. Although we tend to think of seals as being found near land, they can spend up to several months at a time at sea, and can frequently be seen on the Ledge. During the summer, a number of recently weaned seal pups can be found wandering around; they will often swim up to boats. As seal populations have increased, the number of sightings have increased as well. Some fishermen now claim that seals have learned to take bait out of their lobster and fish traps, and are becoming a "nuisance" because of it. Size: Approximately 5 feet as adults; males are six inches longer than females on average. Weight: approximately 200 pounds in males, 150 pounds in females Distinctive Characteristics: A dark coat with heavy spotting (heavier above than below); animals which have been out of the water for a prolonged period may appear lighter as the coat dries. Diet: Fish and invertebrates as available; preferred prey includes herring, squid, alewife, flounder, sand lance, and mackerel. Pups nurse for only a month after birth before shifting to solid food. Distribution: Breeding occurs as far north as the ice-free waters of the arctic, south to New Hampshire. There are significant concentrations of harbor seals in Maine and throughout eastern Canada; some breeding now occurs as far south as Massachusetts. During the winter, the population moves south, and is primarily found from southern Maine to Long Island. Life History: Females give birth to pups in mid-April to mid-June in haulout areas, usually away from other juveniles and males. The pup will nurse for a month, during which time the bond between the pair is strong. Mothers recognize their pups through a combination of smell and sound. After a month, the pup is weaned, having grown from 22 pounds to 55 pounds! After that, though, it has to figure out much of life for itself. Mortality is high - almost 30% of pups die in their first year. Most pups initially feed on small prey which is easy to catch, like small amphipods and shrimp. Mating takes place in the water shortly after a pup is weaned. During summer, both males and females moult (shed their coat and grow a fresh one). Population Status: Harbor seals were once so abundant that both Maine and Massachusetts placed bounties on them in the late 1800's (bounty was $1 a seal!). Maine lifted its bounty in 1905; in Massachusetts, it was in effect as recently as 1962. Seals acquired protection with the passage of the Marine Mammal Protection Act in 1972, which protected all marine mammals. Since then, the population in New England has increased dramatically. It was last surveyed in 1986, when it was estimated that 14,500 seals were summering in Maine (as opposed to 5,800 in 1973). Other Sites: Link #1    Link #2    Link #3