A close-up look into a coastal dead zone

csmonitor.com: In Oregon, a close-up look into a coastal dead zone

OFF CAPE PERPETUA, ORE. – 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.
[Read on]