October 21, 2014 — The Croatian Pride pushes off the dock and cuts slowly through the grey Gulf of Mexico, its engine growling. The air hangs thick and steamy, and the movement of the 40-foot oyster boat brings relief as it breezes past marshy areas where blue herons stand sentinel. The boat’s captain, John Tesvich, is a fourth generation oysterman, but on this early fall day, it’s journalists, not oysters, that he’s hauling.
Reporters are on board the Croatian Pride to learn about Louisiana’s $50 billion plan to restore the state’s rapidly vanishing coastline, a crisis the New York Times Magazine termed “existential,” and the impact those plans will have on Louisiana’s legendary oyster fishery. The discussion jumps, however, from coastal restoration, to the lingering impacts of the Deep Water Horizon spill, to Hurricane Katrina, and finally the Gulf’s “dead zone,” a huge swath of ocean the size of Connecticut that forms every summer and is essentially devoid of life.
Coastal Louisiana faces a complex web of environmental challenges from land loss, to declining fisheries, water quality problems and climate change. On the Croatian Pride this September day, the stepchild issue is water quality, or more specifically the nutrient-laden agricultural fertilizer and wastewater that wash into the Gulf and boost algae and microbe blooms that gobble up oxygen and kill other marine life—while creating the second largest dead zone in the world.
Nitrogen run-off from the nation’s booming Corn Belt is the single largest source of nutrient pollution in the Mississippi River basin, which drains a stunning 41 percent of the waterways in the contiguous United States. Massive amounts of water, sediment and nutrients wash off cornfields from as far away as Minnesota, enter the Mississippi River system, and eventually reach the Gulf.
The problem may worsen if the Environmental Protection Agency (EPA) raises the ethanol mandate for blended gasoline next month—despite earlier commitments to reduce it. Fully one-third of corn grown in the U.S. already goes to ethanol refiners today, and that number could climb.
The Gulf of Mexico’s dead zone forms far offshore, but even oysters are not immune to the low-oxygen condition, called hypoxia, that agricultural wastes can create.
Shallower marsh waters can get hit as well. “You hear of it,” says Tesvich, who chairs the Louisiana Oyster Task Force. “Crabbers see it too.”
“If you get a dead zone over your bed, it’ll wipe you out,” adds Tesvich. Some summers he says he’s lost 20 to 30 percent of his oysters from it. “You’ll see the water is a brownish color or there’s algae on top. Maybe you’ll see some fish floating on the water or dead crabs. When you start to see some dead oysters, you get out.”