Sunday, July 29, 2007

The dead zone is the third largest ever mapped

No, it's not Bush's brain nor Cheney's heart, it's the ocean area off of Louisiana and Texas:
NEW ORLEANS, Louisiana (AP) -- The oxygen-poor "dead zone" off the Louisiana and Texas coasts isn't quite as big as predicted this year, but it is still the third-largest ever mapped, a scientist said Saturday.

Crabs, eels and other creatures usually found on the bottom of the Gulf of Mexico are swimming in crowds on the surface because there is too little oxygen in their usual habitat, said Nancy Rabalais, chief scientist for northern Gulf hypoxia studies.

"We very often see swarms of crabs, mostly blue crabs and their close relatives, swimming at the surface when the oxygen is low," she wrote in an e-mail from a research ship as it returned to Cocodrie from its annual measurement trip.

Eels, which live in sediments 60 to 70 feet below the water surface, are an even less common sight, she said.

The 7,900-square-mile area with almost no oxygen, a condition called hypoxia, is about the size of Connecticut and Delaware together. The Louisiana-Texas dead zone is the world's second-largest hypoxic area, she said.
I had no idea. Somehow this huge dead area is ... a common occurence? How long has this been happening?

Update: Bryan of Why Now?, Steve Bates of The Yellow Doggerel Democrat, and Hipparchia of Over the Cliffs, Onto The Rocks tell me it's been going on for a while, due to fertilizer run off and man made pollution, and offered links here and here and here.


Anonymous said...

It has been going on for decades, caused by the fertilizer runoff into the Mississippi which dumps into the Gulf. The fertilizer causes an algae bloom which sucks up all available oxygen in the water, and then dies out.

The higher water temperatures increase the problem.

Steve Bates said...

Ah. As so often is the case, Bryan has saved me the trouble. Here is a good summary of causes, consequences and possible remedies. Yes, ellroon, dead zones including the one in the Gulf of Mexico are regrettably common, and there are others elsewhere in the world.

This is another environmental problem that is in part caused by human activity and (at this point, at least) amenable to human remediation. Anyone who depends on seafood as part of their food supply would do well to learn more.

hipparchia said...

I'm late to the party [as usual] but here's a more technical description for the Gulf of Mexico [SB's link is a nicer one than mine].

It's happening elsewhere too.

ellroon said...

Thanks for the info and the links. Just one more thing to get infuriated over...

Anonymous said...

More assumed knowledge, Ellroon. Since we live on the Gulf Coast we assume that other people are aware of our problems, since we live with them daily.

You get smaller zones along the coast wherever a large river exits into the Gulf, not just the Mississippi.

This affects the availability of oysters and shrimp more than other species, but everything is connected, so everything is eventually affected.

ellroon said...

It's both shocking and predictable. And I probably read about it but never registered the enormity, the size of the problem.