“Dead zones” doubling every decade
August 14th, 2008 by Jim JustA study released today by marine biologists Robert Diaz and Rutger Rosenberg finds that ocean “dead zones” are increasing exponentially:
“Dead zones in the coastal oceans have spread exponentially since the 1960s and have serious consequences for ecosystem functioning. The formation of dead zones has been exacerbated by the increase in primary production and consequent worldwide coastal eutrophication fueled by riverine runoff of fertilizers and the burning of fossil fuels. Enhanced primary production results in an accumulation of particulate organic matter, which encourages microbial activity and the consumption of dissolved oxygen in bottom waters. Dead zones have now been reported from more than 400 systems, affecting a total area of more than 245,000 square kilometers, and are probably a key stressor on marine ecosystems.”
The study was published online by the journal Science (subs. recq’d.).
Kevin Drum has posted this graph at The Washington Monthly:
An article about the study in the Washington Post quotes Douglas N. Rader, chief ocean scientist for the Environmental Defense Fund:
“The next big challenge, after global warming, is going to be addressing the massive upset of the world’s nitrogen cycle.”
The chaos in the planet’s nitrogen cycle is not only creating dead zones but also inciting the spread of toxic algae, such as the pfiesteria that has appeared in recent years in the Chesapeake.