Indiana among top states contributing to Gulf pollution

INDIANAPOLIS – Indiana is among a group of states considered the worst contributors to a nearly 8,000 square mile patch in the Gulf of Mexico that is inhospitable to marine life, according to research by the U.S. Geological Survey.\nAnimal manure and fertilizer flowing from Indiana and nine other states into the Mississippi River has significantly contributed to a seasonal “dead zone” – an area that is so depleted of oxygen that most aquatic life cannot survive.\nAlong with Indiana, Illinois, Iowa, Missouri, Arkansas, Kentucky, Tennessee, Ohio and Mississippi were the worst contributors to the dead zone.\nThe nine states represented one–third of the 31-state Mississippi River drainage basin, but were responsible for more than 75 percent of the nitrogen and phosphorous that deplete oxygen from the Gulf, killing fish, crabs, clams and shrimp, according to the study.\nThe excessive amount of nitrogen in the Gulf was mainly caused by corn and soybean farming, and the overabundance of phosphorous was primarily caused by animal manure on pasture and rangelands, the survey said.\n“Conventional thinking has been that the pasture and rangelands don’t contribute as much as the cultivated cropland,” said Richard Alexander, a research hydrologist and lead investigator on the study. “The thinking has been that the row crops would contribute more phosphorous.”\nThe study found 37 percent of phosphorous delivered into the Gulf comes from animal manure on pasture and rangelands.\nCorn and soybean farming accounts for 52 percent of nitrogen contributions.\nIndiana was the third worst contributor of nitrogen at 10.1 percent and sixth worst contributor of phosphorous at 8.4 percent among the states in the basin. Illinois was the worst offender for contributions of both substances.\n“This is one more piece of strong evidence about the source of nutrients and about the serious action that should be taken to reduce the nutrients,” said Nancy Rabalais, who serves as executive director of the Louisiana Universities Marine Consortium and researches the dead zone.\nShe said regulation may be difficult because the nitrogen and phosphorous are coming from the land and atmosphere rather than from pipelines.\nBruno Pigott, an assistant commissioner with the Indiana Department of Environmental Management’s Office of Water, said the agency was reviewing the report but had been working on nutrient issues for years.\nHe said the sources of nutrients in groundwater were diverse, including wastewater treatment plants and lawn fertilization as well as runoff from farming and other activities.\n“We think there has to be a broad-based approach to reducing nutrients,” he said.\nMeanwhile, Pigott said Indiana Department of Environmental Management is using public funds to reduce pollutants to waterways and developing statewide criteria for nutrients.\nThe agency also has phosphorous limitations in place for wastewater treatment plants upstream of lakes, especially in the Great Lakes region, he said.