Gulf “dead zone” growing

Oxygen too low to support life

Jon Boyd, Jul 01, 10.

The “dead zone” in the Gulf of Mexico will grow this year, says a report in the Houston Business Journal (HBJ):

The Gulf dead zone forms each spring and summer off the Louisiana and Texas coasts when oxygen levels drop too low to support most life in bottom and near-bottom waters, affecting the fishing industry. Farmland runoff containing fertilizers and livestock waste is the main source of the nitrogen and phosphorus that fuel the growth of algae blooms, that, in turn, create the dead zone.

HBJ quotes a researcher who predicts that this year’s dead zone will cover an area of 6,500-7,800 square miles, compared to the five-year average of 6,000 square miles.

HBJ writes:

In 2008, the dockside value of commercial fisheries was $659 million. The 24 million fishing trips taken in 2008 by more than 3 million recreational fishers further contributed more than $1 billion to the Gulf economy, according to NOAA.

Scavia says it is unclear at this point what impact the Deepwater Horizon oil spill will have on the size of this year’s dead zone.

“We’re not certain how this will play out. But one fact is clear: The combination of summer hypoxia and toxic-oil impacts on mortality, spawning and recruitment is a one-two punch that could seriously diminish valuable Gulf commercial and recreational fisheries,” said Scavia, a professor at the School of Natural Resources and Environment.