Despite more than 40 years of largely voluntary efforts by federal, state, and local government, and tens of billions of US dollars of investment in conservation, nationwide progress on nutrient control has not yet been achieved. Concentrations of nitrogen (N) and phosphorus (P) in streams and groundwater are 2 to 10 times higher than recommended to protect aquatic life, and contamination of drinking water is still widespread, especially in rural areas (Dubrovsky et al. 2010). Complicating the matter, federal policies to protect water quality are at times at odds with policies designed to maximize commodity production and global exports (USEPA 2007).
The consequences of agricultural non-point source pollution are particularly evident where the Mississippi River enters the Gulf of Mexico. The Gulf’s hypoxic, or “dead zone” is the largest hypoxic region in the United States and the second largest in the world (Rabalais et al. 1991). In 2014 the Gulf’s hypoxic zone, measured annually by scientists at Louisiana Universities Marine Consortium, was 13,080 km2 (5,052 mi2). No environmental phenomenon of such ecological importance to coastal marine systems has changed so drastically in such a short time, threatening to “inexorably change the biology of the region,” including its US$2.8 billion commercial and recreational fishing industry (Diaz and Rosenberg 1995; USEPA 2008).
Porter, PA; RB Mitchell and KJ Moore. 2015. “Reducing hypoxia in the Gulf of Mexico: Reimagining a more resilient agricultural landscape in the Mississippi River Watershed.” Journal of Soil and Water Conservation 70(3):63A-68A.
Read the full paper (links to the JSWC website)