LinkThe "dead zone" in the Gulf of Mexico, an area on the seabed with too little oxygen to support fish, shrimp, crabs and other forms of marine life, is nearly the largest on record this year, about 8,000 square miles, researchers said this week.
Only the churning effects of Hurricane Dolly last week, they said, prevented the dead zone from being the largest ever.The problem of hypoxia -- very low levels of dissolved oxygen -- is a downstream effect of fertilizers used for agriculture in the Mississippi River watershed. Nitrogen is the major culprit, flowing into the Gulf and spurring the growth of algae. Animals called zooplankton eat the algae, excreting pellets that sink to the bottom like tiny stones. This organic matter decays in a process that depletes the water of oxygen.
Researchers expected the dead zone to set a record -- even more than the 8,500 square miles observed in 2002 -- after the Mississippi, swollen with floodwaters, carried an extraordinary amount of nitrates into the Gulf, about 37 percent more than last year and the most since measuring these factors was begun in 1970.
The researchers set out July 20 aboard the Pelican, a 115-foot academic research vessel, and braved 12-foot waves and 35-mph winds from the outer bands of Dolly to take samples. The hypoxia began to appear about halfway to the bottom in waters ranging from 10 to 130 feet deep, said Nancy Rabalais, executive director of the Louisiana Universities Marine Consortium, which conducted the study. Some water samples from the bottom of the water column showed no oxygen at all, and instead bore the signature odor of hydrogen sulfide emerging from underlying sediments.
So, if Water has no oxygen is it just hydrogen?
