According to researchers at the Louisiana Universities Marine Consortium,
the flood waters flowing from the Mississippi and Atchafalaya Rivers could produce the largest ever dead zone in the Gulf of Mexico. A dead zone, an area of oxygen depleted water, forms annually off of Louisiana's coast.Each year LUCOM sends out a research cruise to measure it. The largest recorded was in 2002 and measured 8,484 square miles.
Last year's was 7,722 square miles, or the size of the state of Massachusetts.
The larger the dead zone the bigger the setback for fishermen trying to recover from last year's oil spill.
A huge dead zone will be another setback for fishermen trawling the Gulf in hopes of making up for last year’s spring fishing season, which was shut down in much of the state by the BP oil spill, said Louisiana Universities Marine Consortium researcher Nancy Rabalais, Marine organisms, especially bottom-feeders like crabs and shrimp, must flee the oxygen starved waters or die, creating large areas of “dead” fishing that lend the annual phenomenon its name.
...
While scientists have been reluctant to throw out numbers because they’re “so huge,” Rabalais said this year’s dead zone could be five to 10 percent bigger than the largest ever recorded. That was in 2002, measuring 8,484 square miles.
...
The dead zone, a phenomenon known as hypoxia, is fueled mostly by nitrogen and phosphorus found in agricultural runoff such as fertilizer that flows down the Mississippi River. The extra nutrients, coupled with the warm summer sun, trigger an explosion of algae growth that soon sinks, decomposes and consumes most of the life-giving oxygen supply in the water.
With record levels of river water coming downstream into the Gulf, heavier loads of nitrogen and phosphorus will be coming with it, said Matt Rota, water resources director with the Gulf Restoration Network, a New Orleans-based environmental nonprofit that focuses of Gulf of Mexico issues.
Rabalais said nutrients exploding out of spillways and the Atchafalaya River could cause dead zone effects stretching from east of the Mississippi River and west of the Atchafalaya.
The large dead zone will further stress marine life, especially bottom feeders that have already been stressed by the effects of the oil and dispersants.
Agricultural runoff may not be the only threat to the Gulf.
The rising water is still expected to threaten a variety of oil and gas production facilities within the Atchafalaya Basin, according to state and federal officials. There are 589 producing oil and gas wells within areas that will be inundated with the opening of the Morganza Floodway, according to the state Department of Natural Resources, representing 19,300 barrels of oil a day and 252.6 million cubic feet of gas.
...
The oil and gas wells and other manufacturing facilities have been directed by both the state Department of Environmental Quality and the Louisiana Oil Spill Control Office to be prepared for the floodwaters and to secure loose equipment.
In addition to the wells, there are believed to be 97 storage tanks, 10 pipelines and 86 bulk liquid petroleum transportation facilities, as well as a number of retail, light manufacturing and other commercial sites in the path of high water.
The US Geological Survey's National Stream Quality Network will be sampling and testing the water for several months. They will be testing for nutrients, pesticides, suspended sediment, turbidity, alkalinity, and oil and grease. They will post their data at
http://la.water.usgs.gov/.
|
