A decline in Chesapeake Bay dead zones, showing that runoff reductions are working

Johns Hopkins University News: Efforts to reduce the flow of fertilizers, animal waste and other pollutants into the Chesapeake Bay appear to be giving a boost to the bay’s health, a new study that analyzed 60 years of water quality data has concluded. The study, published in the November 2011 issue of Estuaries and Coasts, was conducted by researchers from The Johns Hopkins University and the University of Maryland Center for Environmental Science.

The team found that the size of mid- to late-summer oxygen-starved “dead zones,” where plants and water animals cannot live, leveled off in deep channels of the bay during the 1980s and has been declining ever since. The timing is key because in the 1980s, a concerted effort to cut nutrient pollution in the Chesapeake Bay was initiated through the multistate-federal Chesapeake Bay Program. The goal was to restore the water quality and health of the bay.

“I was really excited by these results because they point to improvement in the health of the Chesapeake Bay,” said lead author Rebecca R. Murphy, a doctoral student in the Department of Geography and Environmental Engineering at Johns Hopkins. “We now have evidence that cutting back on the nutrient pollutants pouring into the bay can make a difference. I think that’s really significant.”

Don Boesch, president of the University of Maryland Center for Environmental Science, agreed. “This study shows that our regional efforts to limit nutrient pollution may be producing results,” he said. “Continuing nutrient reduction remains critically important for achieving bay restoration goals.”...

...Another part of the study looked at a trend that has troubled some bay watchers. In recent years, Chesapeake researchers have seen an early summer spike in dead zones. They feared that keeping more nutrients out of the bay was not improving its health. But the new study found that the early summer jump in dead zones was influenced by climate forces, not by the runoff of pollutants....

Sunset over the Chesapeake, shot by Nora lives, Wikimedia Commons, under the Creative Commons Attribution-Share Alike 3.0 Unported license