Researchers: Grow oysters in suspended bags

LSU and Auburn University researchers say a new approach to growing oysters n in mesh bags strung between posts n could boost harvests and create jobs.

The “long-line system” is used to grow oysters commercially in Australia and now it is being used at the Fisheries Research Laboratory in Grand Isle.

John Supan, an oyster expert with the Louisiana Sea Grant College Program, said the technique could allow Louisiana commercial fishermen to become oyster farmers or help existing oyster farmers to increase their businesses.

Oysters can be grown in salty water when they are strung from posts because they are out of reach from predators like oyster drills and black drum, which lurk on the bottom where oysters grow naturally.

The oysters in the research project reach market size in around 15 months, compared to two to three years for reef-grown oysters, Supan said. That’s because the research project oysters are sterile and more of their energy goes into growth than reproduction.

The survival rates for the bag-grown oysters are much higher than for reef oysters, Supan added. Close to 100 percent of the seed oysters in the bags survive, compared to roughly a third of that, at best, for reef-grown oysters.

Bill Walton, an Auburn University aquaculture and fisheries specialist, said “off-bottom” culture could be an important addition to the traditional oyster industry.

“It’s clean, green and energy-efficient,” Walton said.

Supan wants to work with the Louisiana Wildlife and Fisheries Department and other state agencies to create zones for aquaculture parks or marine enterprise zones, areas of water designated for this specific use.

“It’s like applying industrial park concepts to the water,” Supan said.

In designating the marine enterprise zones, state agencies would take into account coastal restoration plans, the locations of pipelines and wells, wildlife refuges, and areas affected by pollution, Supan said.

Coastal communities would then hold town hall meetings to decide if they want to put in the aquaculture parks, Supan said.

“So you know, the shrimpers could come in and say, ‘Well, let’s not put it there. That’s where I push for shrimp,’” Supan said.

“The ideal entity to start up an aquaculture park is a port commission, in my opinion,” Supan said. “That’s because port commissions are responsible for private navigational aids in their region. They’re responsible for economic development, and they’re made up of local people that the governor appoints.”