Presentation Abstract

Localized oil spills that contaminate nearshore spawning areas pose a threat to developing Pacific herring embryos. Fish embryos are particularly susceptible to the developmental toxicity of oil derived PAHs, which can be acutely lethal or, at lower exposure doses, lead to permanent changes in heart structure, craniofacial morphology, and metabolic processes that cause delayed mortality, or more subtle delayed impacts that may be associated with premature subadult mortality. A variety of localized oil spill scenarios simulating direct and delayed mortality to young of the year were used to examine the potential response of Puget Sound stocks. The healthy stocks remaining in Puget Sound could withstand short term impacts, but the growing number of depressed and unhealthy stocks are vulnerable to an increased risk of localized extinction. Model output predicted that for short term, low level impacts the stock abundance did not exceed the natural variability observed in the population demographic data. This indicates a limited ability to observe in the field any predictions made by the model. High mortality in a single year or impacts across multiple year classes may cause stock abundance changes that exceed natural variability. Despite this, the model does indicate the magnitude of impact on the intrinsic growth rate that could reduce productivity of affected stocks. Additional toxic endpoints and effects thresholds are currently being investigated, including sublethal impacts on cardiac function, immune function, and lipid metabolism that may all lead to delayed mortality. Characterizing these adverse outcome pathways may alter predicted impacts of oil spills on herring stocks.

Session Title

Modeling the Effects of Pesticides, Toxicants, and Multiple Stressors on the Fish Populations and Ecological Communities of the Salish Sea

Keywords

Oil spill, Population model, Herring stocks

Conference Track

SSE3: Fate, Transport, and Toxicity of Chemicals

Conference Name

Salish Sea Ecosystem Conference (Seattle, WA : 2018)

Document Type

Event

SSEC Identifier

SSE3-619

Start Date

5-4-2018 10:15 AM

End Date

5-4-2018 10:30 AM

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 5th, 10:15 AM Apr 5th, 10:30 AM

Modeling potential population-level impacts of localized oil spills on Puget Sound Pacific herring stocks

Localized oil spills that contaminate nearshore spawning areas pose a threat to developing Pacific herring embryos. Fish embryos are particularly susceptible to the developmental toxicity of oil derived PAHs, which can be acutely lethal or, at lower exposure doses, lead to permanent changes in heart structure, craniofacial morphology, and metabolic processes that cause delayed mortality, or more subtle delayed impacts that may be associated with premature subadult mortality. A variety of localized oil spill scenarios simulating direct and delayed mortality to young of the year were used to examine the potential response of Puget Sound stocks. The healthy stocks remaining in Puget Sound could withstand short term impacts, but the growing number of depressed and unhealthy stocks are vulnerable to an increased risk of localized extinction. Model output predicted that for short term, low level impacts the stock abundance did not exceed the natural variability observed in the population demographic data. This indicates a limited ability to observe in the field any predictions made by the model. High mortality in a single year or impacts across multiple year classes may cause stock abundance changes that exceed natural variability. Despite this, the model does indicate the magnitude of impact on the intrinsic growth rate that could reduce productivity of affected stocks. Additional toxic endpoints and effects thresholds are currently being investigated, including sublethal impacts on cardiac function, immune function, and lipid metabolism that may all lead to delayed mortality. Characterizing these adverse outcome pathways may alter predicted impacts of oil spills on herring stocks.