Marine Animals, Pacific Northwest
The Dall’s Porpoise is quite beautiful, and common to the waters of the Pacific Northwest. They can reach up to 2.5 m and weigh up to 220 kg. Males are slightly larger and thicker than females. Those in the eastern Pacific are smaller than those in western Pacific waters.
Dall’s porpoises have a small head, with little or no beak, and a thick body. The flippers are small, and located forward on the frame. The dorsal fin is in the middle of the back. The tail stock and keel are exaggerated, creating a pronounced hump. Adult males have a thicker tail stock than do the females.
The body is dark gray or black in coloration, with variable contrasting white panels and white frosting on the dorsal fin & tail which distinguishes it from other species. These porpoises are usually found in groups of up to 25, but have occasionally been seen in larger, loosely associated groups, sometimes with more than a thousand porpoises.
They love to bow-ride and often are seen riding the bow waves of ships but they will also ride the bow waves of other larger whales. They feed on small fish like anchovies, herring, smelts, as well as squid & octopus, and occasionally crabs & prawns. Feeding usually occurs at night. Dall’s porpoises reach sexually maturity by 8 years of age. The calves are nursed by their mothers for for up to one year. These cetaceans can live up to 22 years.
This species prefers temperate waters where temperatures stay below 17°C. They are found from California to the Bering sea, with many along the BC coast. Dall’s porpoises are accidentally caught, or otherwise interact with a number of fisheries. They are commonly killed when they interact with trawlers. The Japanese target these porpoises in the western North Pacific as a source of meat for human consumption.