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Coastal Ocean Dead Zones Increasing at Exponential Rate Worldwide
The number of areas in coastal waters with too little oxygen to support most marine life, otherwise known as dead zones, has greatly increased since the 1960s according to NOAA (CSCOR) - funded research. Four hundred systems worldwide, including 166 in US waters, now have documented dead zones. A review paper (SCIENCE Aug 15 2008) by Robert Diaz of the Virginia Institute of Marine Science, and Rutger Rosenberg of the University of Gothenburg, attributes this dramatic trend to increasing nutrient pollution and the burning of fossil fuels. Diaz is funded by the Coastal Hypoxia Research Program, one of two national hypoxia research programs managed by NOAA’s Center for Sponsored Coastal Ocean Research and authorized by the Harmful Algal Bloom and Hypoxia Research and Control Act.
SCIENCE Vol 321 Aug 2008
Hypoxia can cause large scale mortality of organisms which live on or near the bottom, organisms which mobile fish and crabs would naturally consume. The authors estimate that, in the Chesapeake Bay, about 5% of prey for mobile predators is lost due to hypoxia every summer. The primary solution is “to keep fertilizers on the land and out of the sea,” according to the authors.
As a steward of coastal resources, NOAA has a strong interest in improving understanding of dead zones and their causes in order to inform coastal management. NOAA’s long-term investment in hypoxia research and development of predictive capabilities have provided the basis of management plans for reducing nutrient loading to coastal systems, most notably, in the Gulf of Mexico. For the hypoxic zone in the northern Gulf of Mexico, NOAA-funded models estimated that a 45% reduction in nitrogen and phosphorus was required to reduce the size of the largest dead zone in North America to the goal set by an interagency task force. This year the size of the dead zone in the Gulf of Mexico was measured at 8000 square miles, 2nd largest since systematic measurements began in 1985.
Link to Virginia Institute of Marine Science (VIMS) press release
Link to SCIENCE
Link to CSCOR Hypoxia and Nutrient Pollution page
Link to CSCOR Gulf of Mexico Hypoxia Feature Story