Lynn Betts/USDA Natural Resources Conservation Service
fertilizer
Lynn Betts/USDA Natural Resources Conservation Service
Charles O'Rear/Flickr
NASA Scientific Visualization Studio
Jacob Tosch/Porter County SWCD/USDA
Lynn Betts/USDA NRCS
GABRIELE ONORATO/FLICKR
Map of the US highlighting the hypoxic "dead zone" in the Gulf of Mexico and the watershed that feeds it. Photo: NOAA