Groundfish are an ecologically and economically important part of the marine ecosystem in the Gulf of Alaska. However, there is still uncertainty surrounding the long-term impacts of the 1989 Exxon Valdez oil spill on this community of fish. To address this gap, the Gulf of Alaska Portfolio Effects working group analyzed 31 years of fisheries surveys to examine the oil spill's consequences. Their findings were published in a recent article in ICES Journal of Marine Science.
The researchers found that while the oil spill and control areas were indistinguishable in terms of temporal variability and measures of community synchrony, there was a decrease in total biomass in areas affected by the spill relative to the control areas. They estimated a 1-2% decline in overall biomass, consistent with a small reduction in productivity. This change was driven primarily by a reduction in the abundance of apex predators, including lingcod, Pacific cod, and Pacific halibut. Overall, their analysis supports the notion that the oil spill had mild consequences for groundfish communities, but suggests that long time-series and assessments of changes at the community level can help to reveal sub-lethal effects in marine communities.
Spatio-temporal models reveal subtle changes to demersal communities following the Exxon Valdez oil spill
Shelton, A.O., Hunsicker, M.E., Ward, E.J., Feist, B.E., Blake, R., Ward, C.L., Williams, B.C., Duffy-Anderson, J.T., Hollowed, A.B., Haynie, A.C.
ICES Journal of Marine Science, May 2017, doi: 10.1093/icesjms/fsx079