Exxon Valdez Oil Spill Fish Projects:
Pink Salmon Oil Impacts on Straying

Principal Investigators:

Alex Wertheimer
(907) 789-6040
Alex.Wertheimer@noaa.gov

Ron A. Heintz
(907) 789-6058
Ron.Heintz@noaa.gov

John Thedinga
(907) 789-6025
John.Thedinga@noaa.gov


View Poster:  Pink Salmon Straying


Researchers at Auke Bay Laboratory's Little Port Walter facility are examining the effects of oil exposure during embryonic development on the straying and gamete viability of pink salmon. Investigators hope that by understanding the effect of exposure of eggs to oiled substrate during incubation on subsequent straying of the returning adults, it will help them better interpret the measurements of straying observed in Prince William Sound (PWS) following the Exxon Valdez oil spill.

Fertilized pink salmon eggs were incubated in oiled gravel, and fry from those incubators were marked to identify treatments and released to migrate to the Gulf of Alaska. Progeny of adults which returned in previous years were tagged and released to examine the cross-generational inheritance of reduced reproductive viability due to oil exposure as embryos.

Overall straying was 5.1% after adjusting for sampling effort. Straying was much lower in this study than for the intertidal streams in PWS, where straying rates as high as 54% have been measured. We cannot contribute the high rates of straying in PWS to oil, and although coded-wire tagging may influence straying, the magnitude of this effect also does not explain these rates. Factors such as regional stock differences and incubation and initial estuarine environment appear to be major determinants of the natural straying rates of pink salmon.


Publications:

• Wertheimer, A. C., R. A. Heintz, J. F. Thedinga, J. M. Maselko, and S. D. Rice. 2000. Straying of adult pink salmon from their natal streams following embryonic exposure to weathered Exxon Valdez crude oil. Trans. Am. Fish. Soc. 129: 989-1004.
  
• Thedinga, J. F., A. C. Wertheimer, R. A. Heintz, J. M. Maselko, and S. D. Rice. 2000. Straying of two stocks of pink salmon (Oncorhynchus gorbuscha) in southeastern Alaska. Can. J. Fish. Aquat. Sci. 57: 2076-2085.
  
  

EVOS Trustee Restoration Annual Report 96076
Wertheimer, A.C., S.D. Rice, J.F. Thedinga, R.A. Heintz, R.F. Bradshaw, J.M. Maselko, and A.G. Celewycz. 1997. Effects of oiled incubation substrate on straying and survival of wild pink salmon, Exxon Valdez Oil Spill Restoration Project Annual Report (Restoration Project 96076), National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Auke Bay Laboratory, Juneau, Alaska.

Up