Gulf of Alaska Portfolio Effects

Applying portfolio effects to the Gulf of Alaska ecosystem: Did multi-scale diversity buffer against the Exxon Valdez oil spill?

Principal Investigator(s): 

Kristin Marshall, Anne Beaudreau, Richard Brenner, Mary Hunsicker, Eric Ward, and Ole Shelton

Understanding how ecosystems respond to environmental variability and large perturbations is a central problem in ecology. The Exxon Valdez oil spill was an extremely large perturbation to the Gulf of Alaska (GOA) ecosystem. However, because species and populations differ in the timing and magnitude of response to perturbations, the effects of the oil spill may be difficult to detect.

This NCEAS Working Group will apply portfolio theory in the GOA using novel spatiotemporal modeling approaches. We will synthesize time-series from the GOA ecosystem and fisheries. The group will: 1) synthesize the temporal and spatial scales of biomass, growth, and recruitment variability for herring, salmon, groundfish, and crabs, and compile existing studies on climate forcing on these taxa in the GOA; 2) examine the role of diversity in stabilizing temporal dynamics of plankton and focal fish species, and catch portfolios in the GOA pre- and post- oil spill; and 3) investigate evidence for changing species interactions and community resilience using multispecies models applied to plankton, fish, and Steller sea lions in Prince William Sound and the GOA.

This synthesis effort will improve understanding of the role of multiple sources of variability in structuring GOA communities and advance new methods in spatiotemporal modeling. The methodology developed will be broadly applicable to exploited marine ecosystems around the world.

The Gulf Watch Alaska project is funded by Exxon Valdez Oil Spill Trustee Council (EVOSTC) and state and federal agencies.

More information for project participants