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Mon July 25, 2011
Artificial Reefs One Piece In Coastal Restoration Plan
By Eileen Fleming
New Orleans, La. – The Nature Conservancy had just about finished setting up an artificial oyster reef in Vermilion Bay when vessels it needed were diverted to contain the BP spill. The group had carefully selected the location, as conservation program director Richard Martin explains.
"The land is actually owned by National Audubon Society, and we partnered with them to try to explore the idea of using a living reef to protect coastal shoreline. There's some erosion going on in this part of the world, and we're looking at using oysters as a way to both protect coastline and provide important marine fisheries habitat."
It's one of several projects the Conservancy is conducting along 3 and a half miles of the Louisiana coast. The Vermilion project involves sets of concrete rings set on top of each other, like a long string of Olympic rings just offshore. Oyster spat in the water attaches to the rings, which in time develop into fish habitat. It's also hoped that the rings will protect the shoreline from wave erosion. University of New Orleans environmental science professor Denise Reed says it's one of many challenges facing wetlands.
"If we can build a hundred yards of reef then maybe we can protect 100 yards of coastline from some of those waves. It's important that in perspective. Those waves across the bays are only one of the things that's causing wetlands to deteriorate."
The wetlands are starving for sediment as sea levels rise and the land subsides. Salt water is attacking fresh water swamps through canals, many cut to accommodate oil and gas drilling. The America's Wetland Foundation estimates that more than 10 square miles of wetlands are lost every year.
Louisiana State University is working with scientists on the Vermilion artificial reefs. Biology professor Steven Hall is interested in how much sediment will collect behind the concrete rings along the shore, and the amount of oysters that will attach.
"There's some juvenile oysters that are growing on here. There's others. There's barnacles and other species that are growing. So they are starting to do what they're designed to do."
The Vermilion wetlands aren't as torn apart as other areas closer to the oil and gas industry. But they're affected by Mississippi River diversions, much from the Old River Control Structure in central Louisiana. It diverts water though the Atchafalaya River in a shorter route to the Gulf of Mexico. High water this year prompted officials to open the Morganza Spillway north of Baton Rouge. But The Nature Conservancy says that at its peak, the Morganza system was only discharging at 1/6th the rate of the Old River complex, and is not expected to have a major impact.
UNO professor Reed says artificial reefs have proven to be useful as one method to slow erosion. She says it's vital to stop the development of open water that's eating through wetlands.
"Once they're gone they're gone, unless we can get land building going on in Louisiana again. One of the problems we have is land loss. We're losing land to open water. Geologically we had land loss thousands of years ago. But then it was always balanced by land building. So we had loss and gain, loss and gain, loss and gain. What we have now at the beginning of the 21st century is loss. We've essentially cut off the gain. All of the sediment that could really build us some land is going into the deep water of the Gulf of Mexico."
Earlier this month Governor Bobby Jindal announced plans for using more than $500 million of BP funds to restore the Gulf. Most of the projects focus on restoration and protection as a first step in the Natural Resources Damage Assessment process.
For WWNO, I'm Eileen Fleming.