Ecopol Project - Portland State University

Dead zones hit close to home: an Oregon Field Guide update lends insight into a problem effecting our oceans

The summer of 2002 dead zone off Oregon’s coast near Newport/Yachats turns out not to be an isolated incident. In these areas oxygen levels are plummeting every summer now, having reached an all-time low of 0% (anoxic level) in 2006, and having returned with varying degrees of hypoxia every year since. Unlike the dead zones that are occurring on the Gulf and East Coasts due to increased fertilizer runoff and pollution, Oregon’s zones are primarily a result of seasonal upwelling. Upwelling is the mixing of the nutrient-rich deeper water with the surface water to produce increased rates of phytoplankton reproduction. The increased amount of decomposing phytoplankton pulls an equal amount of oxygen from the sea floor. Upwelling is a typical occurrence on these coasts as a result of wind conditions, but its severity is increasing. According to OSU oceanography professor Jack Barth, "It’s less clear if the stronger, more persistent winds in recent years are tied to climate change. But global warming models predict more winds off Oregon’s coasts if temperatures rise. Warming would increase the temperature differential between land and ocean, a key driver of wind".
To view the Oregon Field Guide update on dead zones, please follow the link below.
http://www.opb.org/programs/ofg/segments/view/1747

Fig.1-Depiction of the growing area effected by oxygen depletion between 2006 and 2007 on the Oregon Coast

If you are unfamiliar with the 2002 events, or want more background information, check out the 2003 Oregon Field Guide episode entitled "Bend Badland, Dead Zones, Portland Sewers or simply click http://www.opb.org/programs/ofg/segments/view/1484 for the video. Scientists from OSU and other local organizations are deploying an army of fisherman and 24 hour sensors, including a diving robot explorer sending remote data to learn what’s changed in our ocean.