Wednesday, April 2, 2008

U.S. dead zone plan adrift

Environmental Science & Technology: Last summer, a swath of Gulf of Mexico waters the size of New Jersey was virtually lifeless. For the past 40 years or so, dead zones have formed in the Gulf. Nutrients, mostly from farm fertilizers and other agricultural land use, run down the Mississippi River and feed huge algal blooms that choke off oxygen supplies.

In 2001, after years of talk, federal and state agencies pledged for the first time to shrink the dead zone. But they have failed. Now, a second federal–state task force, led by the U.S. EPA, is in the final stages of revising the 2001 action plan, and many experts say this latest attempt at life support for the Gulf is likely to fail as well unless Congress approves new funding.

The new plan (PDF size: 553 KB), which is scheduled for release in June, maintains the goal of shrinking the dead zone to about one-quarter of last summer's size, or 5000 square kilometers, by 2015. However, it does not set targets for curtailing nutrient levels entering the Gulf. The 2001 plan (PDF size: 6.2 MB) recommended 30% cuts in nitrogen, and in 2007, EPA's science advisory board (PDF size: 4.8 MB) recommended tougher measures—45% cuts in both nitrogen and phosphorus. The new revision recognizes that 45% reductions "may be necessary" but does not set official goals.

Algae laden waters off the Florida Keys, NASA, Wikimedia Commons

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