Near Record Gulf of Mexico Dead Zone Documented
National Centers for Coastal Ocean Science’s (NCCOS) Center for Sponsored Coastal Ocean Research (CSCOR)-supported scientists from the Louisiana Universities Marine Consortium (LUMCON) have documented the size of this year’s Dead Zone as 20,721 km2, the second largest since measurements began in 1985. This represents a land area greater than the state of Massachusetts, and is slightly lower than forecast predictions. Over the past 5 years, the Dead Zone has averaged 17,010 km2, substantially larger then interagency Gulf of Mexico/Mississippi River Watershed Nutrient Task force goal of reducing the Zone to 5,000 km2.
Earlier this summer, a CSCOR-supported forecast model developed by Louisiana State University scientists predicted this year’s Dead Zone would be a record-breaking 23,000 km2. Another CSCOR-supported forecast model by the University of Michigan also predicted a record Dead Zone that would measure between 21,530 and 22,568 km2. These model estimates were based on high nitrogen loads and high freshwater flows from the Mississippi and Atchafalaya Rivers during the spring. The difference between the measured and predicted size of the Dead Zone can be attributed to Hurricane Dolly, which partially disrupted the Dead Zone. Winds and waves associated with outer bands of the hurricane re-aerated parts of the bottom waters in portions of the Dead Zone just before measurements were taken, especially near shore and along its western edge. National Marine Fisheries Service (NMFS) groundfish surveys (SEAMAP project) conducted prior to the LUMCON cruise found widespread hypoxia that extended well into Texas waters, confirming that the Dead Zone area was reduced substantially by Hurricane Dolly.
For more information see our current feature story.
click here for press release