Oil Spill Vulnerability Models

Modeling the Vulnerability of Seabirds to Oil Spills

Researchers took a closer look at how oil spills affect different species of Pacific Northwest seabirds.

Principal Investigator

Julia Parrish, University of Washington, School of Aquatic and Fishery Sciences

Co-Principal Investigator

Timothy Jones, University of Washington


When oil coats a seabird’s feathers, it causes them to mat and lose their waterproofing. Because of this and other factors, seabirds are among the most vulnerable animals to oil spills. This project took a closer look at how oil spills affect different species of Pacific Northwest seabirds. The project employed two independent methods, one using historical data to assess the relative abundance of taxon groups in oil spill samples relative to a beached bird baseline data (a method called hindcasting). The second method modeled the likelihood of particular groups of birds washing up on the shore by using cumulative spatiotemporal data on at-sea distribution, fine-scale ocean circulation modeling, and the extent of how far and when a given spill spread. The project’s long-term goal was to create a set of tools to simulate past spills and model the vulnerability of various groups of Pacific Northwest seabirds to future oiling.

Research Updates


Marine birds are considered important environmental indicators of coastal ecosystem health and are particularly sensitive to oil spills. But many spill sources are unidentified and certain species may be more susceptible than others. Understanding the impacts of spills on species of commercial, cultural or ecosystem importance is vital for resource management.

Results Thus Far 

Researchers predicted dispersal and relative beaching rates of oiled birds under a series of scenarios using circulation models. They leveraged citizen science data collected by COASST and compared baseline beaching rates to data collected during three previous oil spills to identify those most susceptible to oil spills. 

As of 2018, the team identified species in beached bird surveys from non-spill years versus spill years. They collated, proofed and evaluated historic records of beached bird data from the Nestucca, New Carissa and Tenyo Maru oil spills and additional data on chronic oiling along the Washington and Oregon outer coasts. They completed baseline modeling to gauge probability of birds being beached.