Teresa M Mongillo Gina M YlitaloLinda D Rhodes Sandie M O'Neill Dawn P Noren and M Bradley Hanson

"The distinct population segment (DPS) of Southern Resident killer whales (Orcinus orca) was listed as endangered under the Endangered Species Act (ESA) on 18 November 2005. The Southern Residents regularly occur in the inland waters of Washington and British Columbia during late spring, summer, and early fall. Less is known about their movements in the winter, but they occur in coastal waters from California to southeast Alaska. Many studies have indicated that they primarily consume Chinook salmon (Oncorhynchus tshawytscha). Several major threats were identified--both in the final determination to list the Southern Resident killer whale DPS as endangered, and in the Southern Resident killer whale recovery plan--one of which was exposure to high levels of organochlorine contaminants and increasing levels of emerging contaminants. The primary objectives of this Technical Memorandum are to review the contaminants that may pose a risk to the Southern Resident killer whales and to discuss the health implications of exposure to these contaminants. In this report, we focus on three persistent organic pollutants (POPs): polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), and dichlorodiphenyltrichloroethane (DDT) and its metabolites. We focus on these three POPs because they are found at relatively high levels in the whales and may cause adverse health effects. We also describe what is currently known about the whales' geographic distribution and diet, as well as contaminant levels measured in their prey. We review the factors that influence contaminant bioaccumulation and the development of biomarkers for exposure and toxicity. Lastly, we highlight data gaps and make recommendations for future studies"--Executive Summary. [doi:10.7289/V5/TM-NWFSC-135 (http://dx.doi.org/10.7289/V5/TM-NWFSC-135)]