Is Climate Change to Blame?

The Oregon dead zone appears to be spreading to the north, reaching as far as central Washington, according to researchers at Oregon State University and other institutions.

The scale of the problem is hard to measure, but the stories from fishermen suggest some grim statistics. Crab fishermen, for example, have reported pulling up their crab pots along the Washington coast and finding them filled with dead crabs.

Along much of the coastline, hundreds of dead fish have washed up on the beaches. And scientists fear thousands more have drifted off or been eaten by other animals, leaving a very unclear picture.

"Many marine species live in fairly specialized ecological niches, and any time you change the fundamental physics, chemistry and nature of the system, it's a serious concern," said Jack Barth, an oceanographer at Oregon State and at the Partnership for Interdisciplinary Studies of Coastal Oceans, a marine research consortium of West Coast universities.

Is Climate Change to Blame?

Scientists on the West Coast say they have looked at the possibility of agricultural runoff, or various toxins, causing the Oregon dead zone, and they believe they have ruled that out. Measurements of oxygen in the water show that it is depletion of oxygen, caused by a fundamental change in wind patterns, that is at work there.

At first, scientists weren't even sure of what they were seeing. Is the dead zone really new, or could it be that scientists were just beginning to take the measurements that proved it was there?

To answer that, the scientists turned to those who know the waters best: commercial fishermen. "We've met with some old timers who've spent four or five decades on the water, and we asked them if it's normal to pull up a crab pot and find dead crabs," Chan said. "The answer is definitely no."