Identifying Local Sources of Pollutants that affect Southern Resident Killer Whales in the Salish Sea
Presentation Abstract
It generally assumed that legacy pollutants and chemicals of emerging concern affecting the health of Southern Resident Killer Whales (SRKW) in the Salish Sea originate in remote, off-shore locations that cannot be controlled by pollution reduction efforts in Canada. In this study we tested this hypothesis using different lines of evidence. First, we compiled concentration data for Polychlorinated biphenyls (PCBs) in sediments of the Salish Sea that demonstrate that concentrations of PCBs in sediments of various locations in the Salish Sea, including the Strait of Georgia and Puget Sound are elevated. Secondly, we conducted a “fingerprint analysis” of PCBs in sediments, Chinook salmon and SRKW that indicates that PCBs in SRKW match those in both local Chinook salmon and local sediments. Thirdly, we observed a similarity in the temporal response of concentrations of PCBs in SRKW and those in both Chinook salmon and sediments in the Salish Sea. Fourth, bioaccumulation models suggest that concentration of PCBs in SRKW can be explained based on the concentrations of PCBs in the Salish Sea. The four lines of evidence indicate that PCBs in SRKW are to a large degree obtained from local sources in the Salish Sea. This implies that local reductions in PCB discharges to the Salish Sea can be an effective strategy for reducing PCB contamination in SRKW, Chinook salmon and the entire Salish Sea food-web. We recommend that an effort is undertaken to identify sources of PCBs to the Salish Sea, followed by actions to reduce PCB inputs into the Salish Sea. This strategy can be expected to reduce the health risks to the SRKW from local sources of pollution in accordance with the objectives of the Canada’s Species at Risk Act and Canada’s commitments to the United Nations Stockholm Convention.
Session Title
Session 1.2B: Contaminants in the Salish Sea: Sources, Movement, and Fate
Conference Track
Contaminants, Plastics, Microplastics, Toxicology & Stormwater
Conference Name
Salish Sea Ecosystem Conference (2020 : Online)
Document Type
Event
SSEC Identifier
2020_abstractID_1195
Start Date
21-4-2020 12:30 PM
End Date
21-4-2020 2:00 PM
Genre/Form
presentations (communicative events)
Subjects – Topical (LCSH)
Polychlorinated biphenyls--Bioaccumulation--Salish Sea (B.C. and Wash.); Killer whale--Effect of contaminated sediments on--Salish Sea (B.C. and Wash.); Chinook salmon--Effect of contaminated sediments on--Salish Sea (B.C. and Wash.); Polychlorinated biphenyls--Environmental aspects--Salish Sea (B.C. and Wash.)
Geographic Coverage
Salish Sea (B.C. and Wash.)
Rights
Copying of this document in whole or in part is allowable only for scholarly purposes. It is understood, however, that any copying or publication of this document for commercial purposes, or for financial gain, shall not be allowed without the author's written permission.
Type
Text
Language
English
Format
application/pdf
Identifying Local Sources of Pollutants that affect Southern Resident Killer Whales in the Salish Sea
It generally assumed that legacy pollutants and chemicals of emerging concern affecting the health of Southern Resident Killer Whales (SRKW) in the Salish Sea originate in remote, off-shore locations that cannot be controlled by pollution reduction efforts in Canada. In this study we tested this hypothesis using different lines of evidence. First, we compiled concentration data for Polychlorinated biphenyls (PCBs) in sediments of the Salish Sea that demonstrate that concentrations of PCBs in sediments of various locations in the Salish Sea, including the Strait of Georgia and Puget Sound are elevated. Secondly, we conducted a “fingerprint analysis” of PCBs in sediments, Chinook salmon and SRKW that indicates that PCBs in SRKW match those in both local Chinook salmon and local sediments. Thirdly, we observed a similarity in the temporal response of concentrations of PCBs in SRKW and those in both Chinook salmon and sediments in the Salish Sea. Fourth, bioaccumulation models suggest that concentration of PCBs in SRKW can be explained based on the concentrations of PCBs in the Salish Sea. The four lines of evidence indicate that PCBs in SRKW are to a large degree obtained from local sources in the Salish Sea. This implies that local reductions in PCB discharges to the Salish Sea can be an effective strategy for reducing PCB contamination in SRKW, Chinook salmon and the entire Salish Sea food-web. We recommend that an effort is undertaken to identify sources of PCBs to the Salish Sea, followed by actions to reduce PCB inputs into the Salish Sea. This strategy can be expected to reduce the health risks to the SRKW from local sources of pollution in accordance with the objectives of the Canada’s Species at Risk Act and Canada’s commitments to the United Nations Stockholm Convention.
