Water "dead zones" doubling each decade

A recent study shows that the number of "dead zones" in bodies of water across the globe has doubled every decade since the 1960s, reports Joel Achenbach of The Washington Post. Fertilizer in agriculture run-off and air pollution are two factors that are causing hypoxia in coastal waters. "A few hypoxic ecosystems have improved in recent years because of better management of pollutants...Globally, however, only 4 percent of the dead zones are improving."