Marine biologists research 'dead zones' off Bay Area coast

OAKLAND, Calif. (KTVU) -- Bay Area researchers are analyzing new data Wednesday about a troubling phenomenon happening right off the coast that is leaving hundreds of sea creatures dead.

KTVU spent the day aboard Bodega Marine Lab's research vessel Mussel Point on Tuesday with a team of scientists who are searching for answers to a deep-sea mystery with climate connections.

The vessel traveled 20 miles off shore to the Cordell Bank National Marine Sanctuary where albatross are drawn from thousands of miles away and curious sea lions frolic.

It has been one of the most spectacular and healthy habitats off our coast, but now the Cordell Bank is suddenly threatened by strange surges of low-oxygen water that some call 'dead zones.'

"That's a concern, definitely some animals and fish suffer under those conditions," said Bodega Marine Lab scientist John Largier.

He says the fear is algae-dense brown water like the dead zones that occurred off the Oregon coast over the last several years.

A mysterious and poorly understood threat that he says could easily expand to Bay Area commercial and sport fishing zones.

"[From] outside of Golden Gate, then it can go into San Francisco Bay and that low oxygen water will be seen as a pollution impact," said Largier.

Researchers say to unravel that mystery they're using sophisticated sensor arrays to find out exactly what's going on underneath the waves.

Lowered by cable, sensors test the water at intervals from the surface to the bottom. Preliminary results indicate the water has about half the normal oxygen.

Very far offshore and very deep, say 1,000 feet or more, ocean water typically has a dead layer containing less than a quarter of normal oxygen. But now that dead water seems to be welling-up closer to shore and within ten feet of the surface.

Researchers also scooped up plankton in large nets. Early analysis suggests a developing dead zone, according to Cordell Bank marine biologist Danielle Lipski.

She says it could be serious.

"If we continue to see that throughout the year; hard to know right now," said Lipski. "That's something we'll keep an eye out for as we continue to do plankton tows."

Scientists are confident it's caused by climate change, through a complex interaction of ocean temperature and upwelling that that triggers these very low oxygen levels. And just as if you were to climb to the top of a mountain, sea creatures are finding it difficult to breathe.

"We can't stop the low oxygen water from coming onto the Bank," said Lipski. "What we can do is continue to protect Cordell Bank."

And she says researchers will continue studying the threat. Lipski and her team set out long duration underwater sensors hoping to discover where dead zones occur and how long they last.

Suspended below colorfully marked deep water buoys, sensors are to collect data over the next four months and, for the first time, reveal the magnitude of this new threat to our ocean.