by Samantha Ainsley
Along the coasts of the Atlantic and Pacific Oceans, the harbor seal can be found. Harbor seals range from Alaska to Mexico on the coast of the Pacific Ocean. And on the coast of the Atlantic, the shores of eastern Canada and New England are home to many harbor seals. The harbor seal or Phoca vitulina, meaning sea calf’ or “sea dog”, can also be found in Washington State’s inland seas, mainly in Puget Sound and along the shores of the San Juan Islands.
Harbor seals have oval-shaped bodies with a large back flipper, smaller side flippers, and dog-like faces. Their spotted coats come in many different colors that range from silver, bluegray, tan, to brown and black. Male harbor seals are slightly larger than the females. While the average male can grow from five to six feet in length, and weigh 200-300 pounds, the females grow to four and a half to five feet in length and weigh 150-200 pounds. Most harbor seals live to at least twenty-five years of age.
Harbor seals in eastern Puget Sound and the shores of the San Juan Islands give birth from mid June through August, and in southern Puget Sound from July through September.
Seal pups weigh anywhere between twelve and twenty pounds, and measure about two and a half feet in length. Harbor Seal pups feed off of milk for the first three to six weeks until they are weaned and able to care for themselves. Unlike most seals, harbor seal pups can swim, but they will ride on their mother’s back if they get tired. Mother seals are very protective of their young and will hide or carry them to protect them.
Harbor seals rely on the food source that is close to them. Depending on where they live, they are known to eat sole, flounder, sculpin, hake, cod, herring, octopus, and squid.
Harbor Seal Behavior
Harbor seals spend their time both on land and in the sea, about 50/50. They use their powerful back flipper not only for swimming, but also for moving on land. To move on land, harbor seals push with their back flippers and flop along on their bellies.
The average harbor seal can dive to 1,500 feet (457 m) for up to forty minutes. However, most harbor seals stay under water, on average, for about three to seven minutes in a very shallow depth. Harbor seals can swim as fast as fifteen knots.
Harbor seals like to “haul out” to bask in the sun and sleep. This takes place on beaches, spits, bars, rocks, and log rafts. They also haul out to digest food, rest, nurse their pups, or give birth.
While they are hauled out, harbor seals often raise the head and hind flippers and lie in a “banana-like” position. When they are resting in the water, harbor seals will lie in what is known as the ‘bottling” position. In this position, they tilt their head straight back and float on the surface (looking like a floating bottle).
The Harbor Seals of Puget Sound
In 1997, there were about 16,000 harbor seals living in Washington State. The population of harbor seals in Puget Sound has been increasing since the 1970’s. Nearly one half of the population lives in the waters off the San Juan Islands.
One of the reasons there has been such a dramatic increase in the population is the Marine Mammal Protection Act of 1972. This law protects harbor seals from bounties that were put on the seals because it was believed that they were eating too much commercial fish. It is now illegal to hunt, capture, kill, harass or in any way disturb seals or any other marine mammal.
Many other reasons harbor seals have been so successful in Puget Sound is the abundance of food (hake, herring, etc.) and puping sites. However, due human disturbance, there is a reduction of harbor seals in some areas.