Experts probe Valdez spill's 10-year legacy

by Bruce Mason
Staff writer

Just after midnight on March 24, 1989, the Exxon Valdez oil spill seized world attention. As the 10th anniversary of the Alaskan ecological disaster approaches, researchers at UBC's Fisheries Centre are using a new method to help answer the key question then and now: what is the lasting impact of this catastrophe?

Tom Okey, a visiting scientist at UBC, and Fisheries Centre Prof. Daniel Pauly have co-ordinated a scientific collaboration to construct an ecosystem model of the main area affected by the spill, Prince William Sound.

"Many excellent research teams have been studying the impacts, but their specialized focus has generally inhibited their ability to answer whole ecosystem questions," says Okey, who helped conduct an emergency study immediately after the costly spill a decade ago.

Using data contributed by experts on the biology of the region, Okey and Pauly have constructed a food web model of the ecosystem and the flows of energy among its components.

While images of oil-soaked sea otters -- the disaster's poster animal -- linger in the world's collective memory, scientists have only determined that the area is in recovery, with some species making more progress than others.

"The sea otter and other animals are only one of myriad components of the ecosystem," says Okey. "Otters feed on herbivores which in turn feed on plants that support a whole suite of other organisms. We need to assess these interactions to quantify and comprehend the impact of the Exxon Valdez, other oil spills and other kinds of environmental impacts."

Okey will summarize the work to date on the model at an upcoming symposium, "Legacy of an Oil Spill: 10 Years After the Exxon Valdez," in Anchorage, Alaska March 23-26.

The UBC-led research program is increasing overall knowledge and helping to change marine resource management. In particular, a dynamic simulation routine developed by Prof. Carl Walters, also of the Fisheries Centre, helps provide resource managers with new insights into the functional responses of the ecosystem given changes in fishing or other stressors.

The Windows-based modelling approach is user-friendly, with the potential to give communities increased participation in resource management decisions. It has been presented to Alaska and U.S. agency representatives who are considering incorporating it into marine management and protection plans.

The UBC Fisheries Centre research group will include the model of Prince William Sound with three other Alaska models in a CD-ROM, "Alaska's Aquatic Ecosystems," to be used by marine resource managers and in Alaskan science education.

Citing the recent oil spill on the Oregon coast, Okey says, "It's really just a matter of time until oil is spilled along B.C.'s spectacular coastlines. The question is whether damage can be minimized. The Exxon Valdez disaster demonstrated that an ounce of prevention can literally be worth billions of dollars."