Harbor porpoise

Puzzling encounters between endangered killer whales and harbor porpoises point to questions about prey availability and whale culture, scientists say. Are the whales playing, practicing their hunting skills, or is something else going on? 

Harbor seals and harbor porpoises in the Salish Sea are showing a relatively high presence of antibiotic-resistant bacteria. A 2021 paper in the journal Oceans suggests that these findings may indicate a wider problem among other species in the region.

A paper published in the journal Oceans in 2020 describes cases of prey-related asphyxiation in harbor porpoises along the U.S. West Coast. The findings suggest that a majority of cases involve non-native American shad and that asphyxiation tends to occur more with reproductively active females than other age and sex classes.

A 2020 paper published in Frontiers in Marine Science describes details of the fungal disease Mucormycosis which has caused the death of harbor porpoises, harbor seals and one orca in Puget Sound in recent years. The authors discuss the implications for local marine mammals, specifically the endangered southern resident killer whale population.

Harbor porpoises declined dramatically in the Salish Sea in the 1970s but their populations have since rebounded, increasing by more than 10% per year in recent decades. A 2020 report for the Encyclopedia of Puget Sound examines harbor porpoise status and trends, natural history and recent policy considerations for the species.

With a population growth of about 10 percent per year in inland waters, harbor porpoises are having an undetermined but growing effect on food dynamics in Puget Sound.