The oxygen-starved "dead zone" along the Pacific Coast that is causing massive crab and fish die-offs is worse than initially thought, scientists said.

Weather, not pollution, appears to be the culprit, scientists said, and no relief is in sight. However, some said there is no immediate sign of long-term damage to the crab fishery in the dead zone, a 70-mile stretch of water along the Continental Shelf between Florence and Lincoln City.

Oregon State University scientists looking for weather changes that could reverse the situation aren't finding them. They say levels of dissolved oxygen critical to marine life are the lowest since the first dead zone was identified in 2002. It has returned every year.

Strong upwelling winds pushed a low-oxygen pool of deep water toward shore, suffocating marine life, said Jane Lubchenco, a professor of marine biology at OSU.