Dead zones off Oregon and Washington likely tied to global warming, study says

Los Angeles Times: Peering into the murky depths, Jane Lubchenco searched for sea life, but all she saw were signs of death. Video images scanned from the seafloor revealed a boneyard of crab skeletons, dead fish and other marine life smothered under a white mat of bacteria. At times, the camera's unblinking eye revealed nothing at all -- a barren undersea desert in waters renowned for their bounty of Dungeness crabs and fat rockfish.

"We couldn't believe our eyes," Lubchenco said, recalling her initial impression of the carnage brought about by oxygen-starved waters. "It was so overwhelming and depressing. It appeared that everything that couldn't swim or scuttle away had died."

Upon further study, Lubchenco and other marine ecologists at Oregon State University concluded that that the undersea plague appears to be a symptom of global warming. In a study released today in the journal Science, the researchers note how these low-oxygen waters have expanded north into Washington and crept south as far as the California state line. And, they appear to be as regular as the tides, a lethal cycle that has repeated itself every summer and fall since 2002.

"We seem to have crossed a tipping point," Lubchenco said. "Low-oxygen zones off the Northwest coast appear to be the new normal." Although scientists continue to amass data and tease out the details, all signs in the search for a cause point to stronger winds associated with a warming planet.

If this theory holds up, it means that global warming and the build-up of heat-trapping gases are bringing about oceanic changes beyond those previously documented: a rise in sea level, more acidic ocean water and the bleaching of coral reefs. Low-oxygen dead zones, which have doubled in number every decade and exist around the world, have a variety of causes....

Photo of marine life killed by oxygen depletion by Kils, Wikimedia Commons