Coastal Dead Zones Go Global

The dead zone is a region where algae dies and the oxygen becomes depleted as micro-organisms consume it as part of the decay process. Fish and other animals have to move out of the oxygen-depleted region or else perish. Last year I directed you to a CNN article saying that the 2007 dead zone off the coast of Louisiana was the largest it had been in 22 years of measurements (8,543 square miles). This year CNN writes that the coastal dead zone is more global than coastal. Robert J. Diaz and Rutger Rosenberg are reporting in today's issue of Science that there are 400 dead zones worldwide. That is twice the number of dead zones reported by the United Nations two years ago. The new dead zones are found in the Southern Hemisphere. Some of these zones may have occurred before and just recently been discovered, but some are actually new. Scientists believe pollution and fertilizer run-off are the most likely causes of the algae bloom that leads to the formation of the hypoxic areas. The dead zones are indicative of a serious environmental problem that has no easy solution.