Tire leachate recapitulates the pathophysiology, unique sensitivity, and mortality of coho salmon acutely exposed to urban road runoff
Presentation Abstract
Coho salmon (Oncorhynchus kisutch) spawners returning to spawn in streams receiving urban road runoff suffer high rates of pre-spawning mortality. Direct exposure of spawners to road runoff causes a significant loss of blood ions, drop in pH, and increase in hematocrit, followed by death within hours of exposure. Neither the pathophysiology nor the mortality is seen in concurrently exposed chum salmon (O. keta). Contaminants in road runoff are dominated by vehicles sources including fluid leaks, and particulates from exhaust emissions, brake friction materials, and tire wear. Chemicals that leach from tires or tire particles can be acutely toxic to aquatic animals including fish. We tested whether particles from tires could leach sufficient toxic chemicals into water to be acutely lethal to coho salmon. Fine tire particles were generated and placed in a 100-m mesh filter sock, inserted into an HDPE filter housing, and continuously leached with a fixed volume of clean well water for 22 h. The resulting filtrate (leachate) was essentially clear and devoid of visible particles. Adult coho salmon returning from Puget Sound were placed in well water or a dilution of well water and tire leachate. The lowest concentration that killed all coho spawners within 5 h (0.32 g/L) was used for subsequent testing. At this concentration, all coho exposed to the tire leachate died within 24 h whereas none of the exposed chum spawners died. Finally, blood sampled from coho exposed for 3 h to 0.32 g/L tire leachate showed significant loss of Na and Cl, drop in pH, and increase in hematocrit whereas the blood of chum concurrently exposed did not show these changes. Tire particles may be an important source of the unknown chemicals contributing to pre-spawning mortality in coho salmon exposed to urban road runoff.
Session Title
Biological Indicators of Stormwater Impacts and Mitigation Effectiveness in the Salish Sea
Conference Track
SSE3: Fate, Transport, and Toxicity of Chemicals
Conference Name
Salish Sea Ecosystem Conference (2018 : Seattle, Wash.)
Document Type
Event
SSEC Identifier
SSE3-469
Start Date
6-4-2018 8:45 AM
End Date
6-4-2018 9:00 AM
Type of Presentation
Oral
Genre/Form
conference proceedings; presentations (communicative events)
Contributing Repository
Digital content made available by University Archives, Heritage Resources, Western Libraries, Western Washington University.
Subjects – Topical (LCSH)
Coho salmon--Effect of water quality on--Salish Sea (B.C. and Wash.); Urban runoff--Environmental aspects--Salish Sea (B.C. and Wash.); Tires--Environmental aspects--Salish Sea (B.C. and Wash.); Coho salmon--Mortality--Salish Sea (B.C. and Wash.)
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
Tire leachate recapitulates the pathophysiology, unique sensitivity, and mortality of coho salmon acutely exposed to urban road runoff
Coho salmon (Oncorhynchus kisutch) spawners returning to spawn in streams receiving urban road runoff suffer high rates of pre-spawning mortality. Direct exposure of spawners to road runoff causes a significant loss of blood ions, drop in pH, and increase in hematocrit, followed by death within hours of exposure. Neither the pathophysiology nor the mortality is seen in concurrently exposed chum salmon (O. keta). Contaminants in road runoff are dominated by vehicles sources including fluid leaks, and particulates from exhaust emissions, brake friction materials, and tire wear. Chemicals that leach from tires or tire particles can be acutely toxic to aquatic animals including fish. We tested whether particles from tires could leach sufficient toxic chemicals into water to be acutely lethal to coho salmon. Fine tire particles were generated and placed in a 100-m mesh filter sock, inserted into an HDPE filter housing, and continuously leached with a fixed volume of clean well water for 22 h. The resulting filtrate (leachate) was essentially clear and devoid of visible particles. Adult coho salmon returning from Puget Sound were placed in well water or a dilution of well water and tire leachate. The lowest concentration that killed all coho spawners within 5 h (0.32 g/L) was used for subsequent testing. At this concentration, all coho exposed to the tire leachate died within 24 h whereas none of the exposed chum spawners died. Finally, blood sampled from coho exposed for 3 h to 0.32 g/L tire leachate showed significant loss of Na and Cl, drop in pH, and increase in hematocrit whereas the blood of chum concurrently exposed did not show these changes. Tire particles may be an important source of the unknown chemicals contributing to pre-spawning mortality in coho salmon exposed to urban road runoff.
