Dall’s porpoise is a cetacean you won’t forget if you’ve ever seen one or a group of 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 early 2025, ACS-SFBay chapter awarded a research grant to Dr. Thomas Jefferson to address the concerns and evaluate available evidence for population declines. Please join us to hear from our grantee on 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.

This free event is open to the public. REGISTRATION IS REQUIRED. A suggested donation of $10 per participant is encouraged and greatly appreciated. Donations help cover webinar costs and support our education and cetacean research grant programs. To donate, please visit our website https://www.acs-sfbay.org/donate. We are grateful for your support!

Bio

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 an Independent Researcher at the Southwest Fisheries Science Center, NOAA Fisheries, 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.