Scientists predict Chesapeake Bay dead zones in 2016– sections that lack oxygen and kill fish — to measure about 2.3 million Olympic-size swimming pools. And that’s the good news!
NOAA-sponsored researchers at the University of Maryland Center for Environmental Science and the University of Michigan say the amount of dead zones will be unusually low this summer. They think it’s due to low river flow and less nutrient runoff from the Susquehanna and Potomac rivers this spring.
They’re technically called hypoxic low-oxygen zones, an area of low to no oxygen that can kill fish and aquatic life. And scientists believe that the Chesapeake Bay will have approximately 1.58 cubic miles of them. That’s about as good as the long-term average since 1950, according to NOAA’s 2016 ‘dead zone’ report.
The Bay’s hypoxic and anoxic zones are caused by excess nutrient pollution. That’s primarily fertilizer, pollution run-off, farm animal poop and such. The nutrients suck-out oxygen, leaving areas where the oxygen levels are insufficient to support most marine life.
And, NOAA reports, habitats near-bottom waters, where crabs, oysters and other fisheries live, are threatened.
U.S. Geological Survey estimates that the Susquehanna River delivered 66.2 million pounds of nitrogen to the Bay from January to May 2016, which is 17 percent below average conditions.
Go to EcoCheck, a website from the University of Maryland Center for Environmental Science, for the history of hypoxia in the Chesapeake Bay since 1985.