Tale of two dead zones: Gulf’s larger, Bay’s smallerBy Tim Wheeler, The Baltimore Sun
June 28, 2010
As if the
In the northern Gulf,
Researchers say it’s too soon to tell what impact the Deepwater Horizon blowout will have on the dead zone.
"We’re not certain how this will play out," Scavia said in a release. If enough oil gets in the waters normally subject to low oxygen, or hypoxia, the dead zone could be larger, as microbes in the water break down the oil, consuming that much more oxygen in the water in the process. But the oil might also limit the size of the dead zone, Scavia suggested, by stunting the growth of algae blooms that starve the water of oxygen when they die and decay.
Either way, the combination of a larger-than-normal dead zone and toxic oil are likely a "one-two punch" for the Gulf’s fish and shellfish, which sustain a $659 million fishery, said Scavia, whose work is underwritten by the National Oceanic and Atmospheric Administration.
Bay scientists parse the
Though heavy rains and snow melt last winter and early spring sent big pulses of nutrient-laden water into the Susquehanna River and the bay, flows in other months have been below-normal, leading to the milder dead zone prediction. The zone this summer could actually look a lot like the one mapped in 1988, as seen below, scientists say.
A smaller dead zone would definitely be an encouraging development for the bay. But senior scientist Denise Breitburg of the
GRAPHIC: (Gulf dead zone map: NOAA, Louisiana University Marine Constortium.
Posted by Tim Wheeler at 11:03 AM