Dead Zone

No, not the David Cronenberg movie with Martin Sheen foreshadowing his West Wing presidential role. The dead zone in question is a 70-mile-long zone of oxygen-depleted water, along the Continental Shelf between Florence and Lincoln City in Oregon. It has reappeared each year since scientists first noticed it in 2002. The zone is caused by the action of photosynthetic algae in the water. Explosive blooms of algae eventually die and sink to the bottom, they are then eaten by bacteria which use up the oxygen in the water. This leaves a zone of very low oxygen levels, a so called 'dead zone'. Although these are not toxic algal blooms they are having dramatic effects on the ecosystem causing a massive die-off of fish and invertebrate marine species.

The key question of course is what causes the algae to bloom. In contrast to other dead zones (eg in the Gulf of Mexico) the dead zone on the Oregon coast is not thought to be due to agricultural run off. Attention is now turning to whether it could be climate change related. This combination of catchy name ('dead zone'), dead fish and crabs, financial implications for fishing communities and a global warming tie-in makes for good headlines.

The San Francisco Chronicle today had a report and the story has also been covered by ABC, CBS, the New York Times, National Geographic and many others.