Post by LSDeep on Sept 1, 2005 10:14:16 GMT -5
TAMPA BAY, Florida (1 Sep 2005) -- An oxygen-free dead zone at the bottom of the Gulf of Mexico may be headed toward recovery, thanks to Hurricane Katrina.
Though the eye of the storm missed the Tampa Bay area by hundreds of miles, its winds and waves broke up a warm- water, cold-water layer that scientists say caused a massive die-off of marine life on the Gulf bottom.
On Wednesday, scientists with the state's Fish and Wildlife Research Institute found dissolved oxygen in areas off Clearwater Beach that had none last week.
These anoxic (without oxygen) areas had been trapped in a death locker created when a dense layer of warm water settled on top of colder water near the bottom.
This stratification, called a thermocline, trapped red tide toxins near the bottom, killing crabs, shrimp, coral and other marine life.
As the organisms decomposed, they consumed what dissolved oxygen was left.
The thermocline kept oxygen from filtering down to the anoxic bottom.
''Katrina had enough winds or surge to mix up the water to get rid of the stratification,'' said Cindy Heil, senior scientist at the institute.
''That means dissolved oxygen was normal on the whole water column from top to bottom. This is the first stage in recovery,'' Heil said.
Heil cautioned that the institute's boats only were able to test sites up to 15 miles from the coast because of rough weather.
The agency has been testing dissolved oxygen levels off Clearwater since early August.
''We didn't get out to 20, 25 and 30 miles because it was too rough,'' Heil said.
''But the shelf is shallow, so I would expect those sites to be the same.''
The institute began testing the water after divers from Sarasota County to Pinellas County reported a devastated ocean bottom.
Although there are no official estimates of the economic effect, divers and charter boat captains have said the die-off has killed their respective businesses.
Red tide continued to cause scattered fish kills this week, the latest at the mouth of Tampa Bay and in the Panhandle.
A number of redfish in the 40-pound range washed ashore at Fort DeSoto Park on Tuesday.
That same day, massive fish kills were reported off Franklin County southwest of Tallahassee.
Last week, fish kills were reported off Taylor County.
Heil said scientists do not know if the latest red tide outbreaks in northern Florida are related to the bloom that has gripped Southwest Florida since January.
SOURCE - TBO
Though the eye of the storm missed the Tampa Bay area by hundreds of miles, its winds and waves broke up a warm- water, cold-water layer that scientists say caused a massive die-off of marine life on the Gulf bottom.
On Wednesday, scientists with the state's Fish and Wildlife Research Institute found dissolved oxygen in areas off Clearwater Beach that had none last week.
These anoxic (without oxygen) areas had been trapped in a death locker created when a dense layer of warm water settled on top of colder water near the bottom.
This stratification, called a thermocline, trapped red tide toxins near the bottom, killing crabs, shrimp, coral and other marine life.
As the organisms decomposed, they consumed what dissolved oxygen was left.
The thermocline kept oxygen from filtering down to the anoxic bottom.
''Katrina had enough winds or surge to mix up the water to get rid of the stratification,'' said Cindy Heil, senior scientist at the institute.
''That means dissolved oxygen was normal on the whole water column from top to bottom. This is the first stage in recovery,'' Heil said.
Heil cautioned that the institute's boats only were able to test sites up to 15 miles from the coast because of rough weather.
The agency has been testing dissolved oxygen levels off Clearwater since early August.
''We didn't get out to 20, 25 and 30 miles because it was too rough,'' Heil said.
''But the shelf is shallow, so I would expect those sites to be the same.''
The institute began testing the water after divers from Sarasota County to Pinellas County reported a devastated ocean bottom.
Although there are no official estimates of the economic effect, divers and charter boat captains have said the die-off has killed their respective businesses.
Red tide continued to cause scattered fish kills this week, the latest at the mouth of Tampa Bay and in the Panhandle.
A number of redfish in the 40-pound range washed ashore at Fort DeSoto Park on Tuesday.
That same day, massive fish kills were reported off Franklin County southwest of Tallahassee.
Last week, fish kills were reported off Taylor County.
Heil said scientists do not know if the latest red tide outbreaks in northern Florida are related to the bloom that has gripped Southwest Florida since January.
SOURCE - TBO