Presentation Abstract

Expansions in the transportation of diluted bitumen (dilbit) products in coastal regions of British Columbia potentially increase the risk of exposure of early life stage (ELS) Pacific salmon by both acute as well as sublethal effects. The objective of present study was to investigate the effects of dilbit exposure (from the embryonic to swim-up sockeye (Oncorhynchus nerka) on their swimming performance and exercise recovery at later life stages (juveniles). Embryos were exposed to 4 concentrations (0, 13.7, 34.7 and 124.5 μg/L total PAH [TPAH]) of the dissolved fraction of Cold Lake Winter Blend dilbit immediately following fertilization until swim-up. The mortality of embryos and alevins were recorded through the exposure period, and at the end of the exposure, a subset of individuals from each treatment group were tested for the burst swimming speed (Uburst). Remaining fish were reared separately for 8 months under non-exposure conditions. Subsets of fish were subsequently tested for Uburst after 1, 3, 6, and 8 months in uncontaminated water. At 8 months, subsets of the survivors were re-exposed to same concentrations of dilbit for 24h, 96h, or 14 d, then again tested for Uburst and exercise recovery. Plasma osmolality, [cortisol], [glucose], [lactate], [Na+], [Cl-], white muscle [glycogen] and [triglyceride] were measured pre- and post- swimming. Dilbit exposure during embryonic development decreased fish’s Uburst, but no prolonged effects on Uburst, metabolic or ionic recovery were found after 8 months under non-exposure conditions. Fish that received re-exposures exhibited reduced Uburst and slower recovery from exhaustive exercise. Significant alterations were observed in plasma ion concentrations and biochemical measures in re-exposed individuals, which may underlie the reductions in physiological performance. These results indicate that embryonic exposures may exacerbate effects if fish are exposed again at a later life stage.

Session Title

Persistent Organic Pollutants and PAHs in Freshwater & Marine Fish

Keywords

Diluted bitumen, Sockeye salmon, Toxicity

Conference Track

SSE3: Fate, Transport, and Toxicity of Chemicals

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE3-200

Start Date

4-4-2018 4:45 PM

End Date

4-4-2018 5:00 PM

Type of Presentation

Oral

Contributing Repository

Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.

Geographic Coverage

Salish Sea (B.C. and Wash.)

Rights

This resource is displayed for educational purposes only and may be subject to U.S. and international copyright laws. For more information about rights or obtaining copies of this resource, please contact University Archives, Heritage Resources, Western Libraries, Western Washington University, Bellingham, WA 98225-9103, USA (360-650-7534; heritage.resources@wwu.edu) and refer to the collection name and identifier. Any materials cited must be attributed to the Salish Sea Ecosystem Conference Records, University Archives, Heritage Resources, Western Libraries, Western Washington University.

Type

text

Language

English

Format

application/pdf

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Apr 4th, 4:45 PM Apr 4th, 5:00 PM

The effects of diluted bitumen (dilbit) exposure during embryonic development on the future swimming performance and metabolic and ionic recovery post-exercise in sockeye salmon (Oncorhynchus nerka)

Expansions in the transportation of diluted bitumen (dilbit) products in coastal regions of British Columbia potentially increase the risk of exposure of early life stage (ELS) Pacific salmon by both acute as well as sublethal effects. The objective of present study was to investigate the effects of dilbit exposure (from the embryonic to swim-up sockeye (Oncorhynchus nerka) on their swimming performance and exercise recovery at later life stages (juveniles). Embryos were exposed to 4 concentrations (0, 13.7, 34.7 and 124.5 μg/L total PAH [TPAH]) of the dissolved fraction of Cold Lake Winter Blend dilbit immediately following fertilization until swim-up. The mortality of embryos and alevins were recorded through the exposure period, and at the end of the exposure, a subset of individuals from each treatment group were tested for the burst swimming speed (Uburst). Remaining fish were reared separately for 8 months under non-exposure conditions. Subsets of fish were subsequently tested for Uburst after 1, 3, 6, and 8 months in uncontaminated water. At 8 months, subsets of the survivors were re-exposed to same concentrations of dilbit for 24h, 96h, or 14 d, then again tested for Uburst and exercise recovery. Plasma osmolality, [cortisol], [glucose], [lactate], [Na+], [Cl-], white muscle [glycogen] and [triglyceride] were measured pre- and post- swimming. Dilbit exposure during embryonic development decreased fish’s Uburst, but no prolonged effects on Uburst, metabolic or ionic recovery were found after 8 months under non-exposure conditions. Fish that received re-exposures exhibited reduced Uburst and slower recovery from exhaustive exercise. Significant alterations were observed in plasma ion concentrations and biochemical measures in re-exposed individuals, which may underlie the reductions in physiological performance. These results indicate that embryonic exposures may exacerbate effects if fish are exposed again at a later life stage.