Large dead zones predicted this summer for Chesapeake Bay, Gulf of Mexico
Federal scientists are predicting large “dead zones” to form this summer in the Gulf of Mexico and the Chesapeake Bay, with runoff from agricultural areas resulting in hypoxic zones incapable of supporting marine life.
In the Gulf of Mexico, scientists from the National Oceanic and Atmospheric Administration are expecting the third-largest dead zone ever recorded. The hypoxic zone is expected to reach 8,200 cubic miles – about 50 percent larger than the dead zone’s summer average of 5,300 cubic miles – which is roughly the size of Connecticut.
In the Chesapeake, the dead zone is expected to reach 1.89 cubic miles, or the equivalent volume of 4.2 million Olympic-sized swimming pools.
The dead zones are the result of a complex chain of events, caused primarily by higher water levels in rivers, primarily due to greater-than-average rainfall, pushing fertilizer and grass-growing chemicals downstream. When those nutrients and chemicals arrive in a larger body of water, such as the bay or the gulf, it results in plankton blooms. The plankton then die and their decay uses up the oxygen in the surrounding area.
While fish tend to swim away to areas with higher oxygen, bottom-dwelling organisms that are unable to move suffocate and die as a result of the hypoxic zones. Research earlier this year blamed hypoxia along Louisiana's coast for price spikes for jumbo shrimp.
Fish and other marine animals capable of swimming to areas with higher oxygen are more likely to escape from the dead zones, but bottom-loving organisms that are unable to move suffocate and die. Research blamed hypoxia along Louisiana's coast for price spikes for jumbo shrimp during last year’s summer bloom, according to the New Orleans Times-Picayune.
“The Gulf’s summer hypoxic zone continues to put important habitats and valuable fisheries under intense stress,” said Rob Magnien, director of NOAA’s Center for Sponsored Coastal Ocean Research. “Although there is some progress in reducing nutrients, the effects of the dead zone may further threaten the region’s coastal economies if current levels remain.”