... the zone forms when fertilizers wash off farm fields throughout the Mississippi River basin and into the Gulf of Mexico. The fertilizers cause the growth of algae, which eventually depletes oxygen in the water and kills marine life. Government officials hope to reduce fertilizer runoff and shrink the zone to the size of Delaware by 2015. But that goal could be more difficult to reach due to federally-mandated efforts to increase annual biofuel production to 36 billion gallons by 2022, the study says.
The scientists studied the potential effects of increased biofuel production on the "dead zone," with a life-cycle analysis of nitrate fertilizer use on biofuel crops such as corn, soy, switch grass and stover (corn stems and leaves). They conclude that meeting the biofuel production goals will likely increase the depletion of oxygen compared to current levels in the Gulf due to more nutrient runoff.
Read study abstract from Environmental Science & Technology,
