Seal the Deal on Conservation
If you see a harbor seal go underwater—or laying still on the floor of its tank, as is sometimes the case at the Zoo—it may be a while before you see it surface again. Harbor seals spend about 85 percent of the day diving and actively foraging in the water or seabed and can actually sleep for short periods underwater. They may dive to depths of 500 ft. with dives lasting up to 20 minutes.
In the water, harbor seals often assume a posture known as “bottling”—the seal’s body remains submerged, but the face pokes above the surface like a snorkel allowing the animal to breathe regularly while sleeping or resting. This helps them in the wild where they are often forced to sleep in the water during high tides when hauling grounds are scarce or unavailable.
Harbor seals make their homes in temperate coastal habitats including beaches and rocky outcrops on the coasts of North America (from Baja California to the Arctic on the west coast and from New England to the Arctic on the east coast). Non-migratory mammals, they may live their entire lives along a relatively small home range of familiar coastline. Several thousand harbor seals live at the Channel Islands of southern California.
Part of the “true seal” family, they are characterized by their lack of external ears as well as limited locomotion on land due to small forelimbs. They are the least vocal of all pinnipeds. Brief grunts and growls are used as warnings to neighbors on land to keep at least a flipper’s length distance away.
A serially monogamous species, Harbor seals adults mate in the water and females give birth (after an 11-month gestation period) during spring and summer to a single young. The pups are born able to swim and only after a few days, they are able to dive for up to two minutes.
The typical diet of a harbor seal includes fish, crabs, shrimp, squid, and has even been known to include some kinds of seabirds.
Pollution and uncontrolled fishing worldwide endanger many, perhaps most, pinniped species. Harbor seal populations have declined in some areas with the increase in commercial trawl fisheries. Declines are also due to long-term ecosystem changes, oil spills, and distemper and influenza viruses. Protected in U.S. waters, harbor seals are still killed in Canada, Norway, and the U.K.
While the harbor seal is listed as Least Concern by the International Union for Conservation of Nature (IUCN), others in Family Phocidae, such as the harp and gray seals don’t fare as well. International Day of the Seal sheds light on the tragedy many of these seals face in the wild and is a call to action for their protection.
The L.A. Zoo currently has three harbor seals.