Killer whales, or orca, are toothed whales related to dolphins, with a worldwide distribution. Southern Resident Killer Whales (SRKW) are an iconic species here in the Pacific Northwest, spending several months during summer and fall in Washington’s San Juan Islands and Puget Sound where they feed primarily on salmon.
Orca population was reduced substantially in the 1960s and 1970s by marine park captures, when the population reached a low of 71 individuals. Although the population grew in size into the 1990s, population growth has since stalled at an average around 80 individuals. In 2005, NOAA Fisheries designated Southern Resident killer whales as ‘endangered’ due to their low abundance and the variety of threats they face. NOAA then finalized a recovery plan in 2008.
The NWFSC Marine Mammal research group is leading the effort to understand potential factors in orca taxonomy, biology, ecology and behavior as well as human-caused environmental impacts that may limit orca population recovery. These factors may include quantity and quality of prey; toxic chemicals which accumulate in these top predators, disturbance from sounds and vessel traffic and any future oil spills. Our work helps NOAA's West Coast Region implement the Endangered Species Act and Marine Mammal Protection Act and inform species recovery and management actions.
This class will summarize a variety of topics related to understanding the current status of the southern resident killer whales, including: - How the Endangered Species Act considers populations and species - The recent evolutionary history of North Pacific killer whales - Breeding structure and life-history - Diet and distribution - Comparisons to other killer whale populations - Current ideas about why the southern resident population is not growing.
More information is available on the NWFSC southern resident killer whale website: http://www.nwfsc.noaa.gov/research/divisions/cb/ecosystem/marinemammal/southern_killer_whale.cfm.