Basically because of pollution 5800 sqmiles of water in the Gulf of Mexico is devoid of life...how scary is that?!
http://story.news.yahoo.com/news?tmpl=story&cid=570&e=1&u=/nm/environment_deadzone_dc
http://story.news.yahoo.com/news?tmpl=story&cid=570&e=1&u=/nm/environment_deadzone_dc