Pacific Whitesided Dolphin

Lagenorhynchus obliquions

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Robust and intricately colored, the Pacific Whitesided Dolphin is one of the most visually striking cetaceans in Oregon waters. The dolphin has a small beak and sleek, tapered flippers. It was once known as the “hookfin porpoise” because of its deeply-curved dorsal fin — even though it is not a porpoise. The animal’s lips, back and the tops of its flippers are black. It has a white belly and gray patches broken by black along its sides. A large gray patch under the dorsal fin resembles the letter “Y”. Its coloration sometimes causes it to often be misidentified as a Dall’s Porpoise although its body type is very different.

Adult dolphins will measure between 5.5 and 8 feet (1.7 to 2.5 m) and will weigh a maximum of 400 lbs (180 kg). Like other dolphins, they feed on a variety of invertebrates and fish, including squid, herring, sardines and capelin.

Playful and highly social, the Pacific Whitesided Dolphin lives in large family groups known as pods. They may congregate in larger groups numbering up to 10,000 individuals or be seen swimming with other cetaceans like Risso’s Dolphins. The will frequently approach boats to bow ride or demonstrate amazing acrobatics by hurling themselves out of the water and flipping in mid-air. 

Range and Distribution

The Pacific Whitesided Dolphin is found only in the temperate waters of the north Pacific Ocean. Current estimates for the population living in California / Oregon / Washington waters is around 60,000 individuals, although they are mostly presently only during the summer months.

Conservation Status

Common. This dolphin is classified as “Low Risk / Least Concern” under the The International Union for Conservation of Nature and Natural Resources (IUCN) Red List. The primary threats to this species are accidental bycatch by the fishing industry and marine debris such as discarded or lost fishing nets. Like all cetaceans, they are protected by the Marine Mammal Protection Act of 1972.