“Flashing Red Lights for a Black and White Porpoise: Dall’s Porpoise Declines Along the West Coast of North America”

Images above via NOAA

Description:
Dall’s porpoise is a cetacean you won’t forget if you’ve ever seen them – they are powerful fast swimmers that rip so rapidly across the surface they create a characteristic spray known as a “rooster tail” – a thrilling display. Recently there has been concern about the apparent decreasing numbers of Dall’s porpoise in the eastern North Pacific (ENP). In 2025, ACS awarded a research grant to Dr. Thomas Jefferson to address the concerns and evaluate available evidence for population declines. Please join us to hear the results of his study, evidence of the decline along the west coast, and suggested next steps for our understanding of threats to the Dall’s porpoise population.

About the Speaker: 

Dr. Thomas A. Jefferson has been studying marine mammals since 1983, when he was an undergraduate at the University of California, Santa Cruz. His Master’s degree is from Moss Landing Marine Laboratories, and his Ph.D. is from Texas A&M University. Tom is Director of Clymene Enterprises and of VIVA Vaquita, where his main interests are the development of marine mammal identification aids, and investigating the systematics and population ecology of the more poorly-known species of dolphins and porpoises. Most of his work has been related to conservation and management of marine mammals threatened by human activities. He has published over 200 books and papers on marine mammals.