In Oregon, a close-up look into a coastal dead zone

A half-dozen scientists huddle in a cramped lab aboard the research vessel Elakha, bracing themselves against the rolling swells. As they stare at a pair of TV monitors, images of an aquatic graveyard glide across the screens.

Some 150 feet below, a robotic submersible – looking more like a portable generator with thrusters than a svelte submarine – motors just above the bottom, capturing macabre images of Oregon's newly minted and poorly understood "dead zone."

The zone is a bottom-hugging layer of water with oxygen levels so low that it can't support the variety of marine life that typically lives in these near-shore coastal waters. The bottom is littered with dead crabs, worms, and starfish. White anemones, brilliant in the submersible's spotlights, look as if they are taking their last gasp. In two runs lasting roughly an hour each, not one fish – dead or alive – appears on screen.

Unlike the dead zone that sets up each year in the Gulf of Mexico, Oregon's version can't be traced to the effects of nutrient-laden river run-off. Here, as in a handful of other coastal regions worldwide, the culprit may be global warming.

To be sure, the jury is still out on that connection, says Jane Lubchenco, a marine zoologist at Oregon State University who is heading up this day-long expedition. But, she adds, what she and her colleagues see is consistent with projections of global warming's effects on coastal winds in the spring and summer, which drive upwelling of nutrient-laden water.

These effects – identified as early as 1990 by researcher Andrew Bakun, then with the National Oceanic and Atmospheric Administration's fisheries lab in Monterey, Calif. – turbocharge the upwelling. This overloads the waters with nutrients and spawns large algae blooms. The algae sink, die, and decompose, in a process that sucks oxygen out of the water and the topmost layer of sediment on the bottom, where many worms and shellfish live.

First discovered in 2002, Oregon's low-oxygen, or hypoxic, zone is longer, thicker, and more oxygen-deprived this year than at any time in the past four years. "This hypoxia is noteworthy because it's telling us that the ocean is changing," Dr. Lubchenco says. "We don't understand completely why or what it means. But we're listening; we're paying attention."

In the process, the investigation is raising so many questions about the near-shore ecosystems that it is exposing a gap in America's oceanographic research: essentially from a depth of 150 feet up to the tidal zones along the shore.

It's a region rich in biology and important physical processes. But much of it is too shallow for large research ships to explore, often too turbulent for regular research dives, and – as today's cruise shows – it's no picnic for scientists on smaller boats.

With a length of 54 feet and berths for four, the Elakha is modern, but she's essentially a day-cruiser.

Scientists aren't out long enough to find their sea legs. Everyone spends nine hours bending, leaning, and shifting weight to retain their balance.

"We'll sleep well tonight," quips Francis Chan, a biogeochemist at Oregon State who is gathering water samples from the bottom to monitor their oxygen content.

Scientists discovered the hypoxic zone during a project aimed at seeing what was living in the rocky offshore reefs just north of Florence, Ore., says Hal Weeks, a project leader in the Oregon Department of Fish and Wildlife's marine resources program. The area is remote, so it isn't heavily fished. This made it ideal for serving as a model of what a healthy Oregon reef community ought to look like.

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