Harbor Porpoise Facts
The harbor porpoise (Phocoena phocoena) is a shy species of porpoise that inhabits the Salish Sea year-round. They are the smallest species of cetacean (a group that includes whales, dolphins, and porpoises) in the Salish Sea. They reach an average length of 5 to 5 ½ feet and weighing up to 170 pounds. Harbor porpoises generally live in groups of 2 to 3 and are widely distributed throughout the Salish Sea. While they are one of the most abundant and frequently sighted cetacean in the Salish Sea, we know very little about their ecology, such as their population, life cycle, genetics, and behavior.
DID YOU KNOW?
Harbor porpoises are acoustic animals that produce underwater clicks to help them navigate and find their prey which includes fish and cephalopods. Studies have shown that they echolocate most during the night.
Although they regularly surface for a breath of air, harbor porpoises may be difficult to spot because of their short, triangular dorsal fin that hardly raises out of the water when they surface. In the Salish Sea, harbor porpoises only spend about 23% of their time at the surface. The maximum recorded dive for a harbor porpoise was 740 feet!
Immature harbor porpoises cannot dive as deep as adults, therefore limiting the underwater habitat that calves live in. Increased boat traffic on the surface may be affecting porpoise calves much differently than adults.
Harbor porpoises are the most commonly stranded cetacean in the Salish Sea. This may be due to a growing population of harbor porpoises and increased surveillance by marine mammal stranding networks.
Photos by Florian Graner.