By: Nikki Buskey – Staff Writer – dailycomet.com
HOUMA — Gulf of Mexico researchers hope a new oyster-farming technique will make the Louisiana industry more productive and get oystermen back to work more quickly after crops were wiped out during the Gulf of Mexico oil spill.
As much as 50 percent of Louisiana’s oyster crop was wiped out this summer not by oil, but by freshwater diversions opened up by the state to attempt to flush oil out of wetlands east of the Mississippi River and in Barataria Bay.
Researchers John Supan, with the Louisiana Sea Grant and LSU AgCenter, and Bill Walton, with Auburn University, aim to get Louisiana to adopt off-bottom oyster culturing methods to supplement the state’s traditional harvest. They say the method produces more efficient and faster harvests.
“I think it’s a part of the future of the Louisiana oyster business,” said Mike Voisin, owner of Motivatit Seafood in Houma and a member of the state’s Oyster Advisory Committee. “As we move forward with these coastal-restoration projects, I think it will allow us to grow faster and more productively.”
Traditionally, oysters are grown and harvested on reefs on the water bottom. Oyster larvae must attach to a hard surface on the bottom and build up their reefs. But oyster crops actually grow faster and more successfully when they’re suspended and grown on structures high in the water column because they’re better protected from predators that typically pick off an oyster crop. They’re also exposed to a better water flow, and the oysters feed better and their risk of being fouled by sediment or algae growth is reduced.
“We’re a bottom-farming community now, but what you get is what’s left. We’re getting the crumbs on the bottom and we still get a lot of oysters,” Voisin said.
Many other states and countries that farm oysters have already employed the technique, Voisin said.
Oysters that would typically take two to three years to grow to market size can be grown in one year with off-bottom culture, Voisin said.
“Through proper planning, off-bottom culture can work in harmony with other water uses and users,” Supan said. “It can support both part- and full-time incomes, just like natural fisheries, but with greater control over the natural variability that dominates bottom harvesting.”
The project developing off-bottom oyster cultivation began before the Deepwater Horizon spill, but with the major effects the freshwater wipeout had on the oyster industry, the researchers said it’s cultivated more interest in the project.
“We have received more calls and questions about oyster farming in the last four months than we have combined over the prior 12 months,” Walton said. “The spill has created a window of opportunity where traditional oystermen are eager, even desperate, to find ways to get back to working on the water as soon as possible.”
Voisin added that the new farming techniques will aid oystermen as the state moves forward to curb coastal erosion and build major freshwater diversions that will change salinities in most of the major basins and make oyster farming impossible in some traditional areas. That’s because it’s possible the off-bottom oyster growing structures could be mobile, and they could be moved when freshwater diversions are turned on because the river is high, Voisin said.
The spill has also created a source of money to implement the oyster cultivation program, Voisin said. Instead of just seeding and rehabilitating traditional oyster grounds, the state can research productive new techniques to catch Louisiana up with the rest of the country.
“Catastrophe causes change,” Supan said. “The challenge is to direct change to improve conditions, not to settle for status quo. This project will attempt to do just that.”
Both the Auburn University Shellfish Laboratory on Dauphin Island, Ala., and the Sea Grant Bivalve Hatchery at the Louisiana Department of Wildlife and Fisheries Marine Research Laboratory on Grand Isle will provide oyster seed for the project. Wildlife and Fisheries officials are also working with Plaquemines Parish to develop plans for a facility that would raise oysters to larval stage, called an oyster “spat,” to be used by the industry to help promote oyster growth.
A series of workshops are planned for 2011 and 2012 to teach oystermen the new technique, addressing issues such as appropriate culture systems, oyster seed stock, growing market-quality oysters and developing practices and regulations in collaboration with state agencies. For more information, contact Supan at firstname.lastname@example.org or Walton at email@example.com.