By BECKY GILLETTE
Big, fat, juicy oysters have been a part of the Gulf Coast’s culinary traditions ever since the area was discovered more than 300 years ago by French explorers. At one time, Biloxi was known as the shrimp and oyster capital of the world. In recent years, there has been a steep decline in oyster production on Mississippi reefs, which has had a major impact on the economy.
Harvest of oysters in Mississippi was 400,000 sacks and accounted for $7 million in dockside landing value before Hurricane Katrina. However, harvest has decreased to less than 75,000 sacks and $1 million annually in dockside values since 2011, said Dr. Kelly Lucas, director of the Thad Cochran Marine Aquaculture Center at the University of Southern Mississippi (USM).
“The decline in oyster population on harvest reefs in Mississippi has been attributed to numerous environmental challenges in the past decade, including Hurricane Katrina, the Deepwater Horizon oil spill and the opening of the Bonnet Carré spillway,” Lucas said. “One of the recommendations listed in the Oyster Resource Resiliency Plan developed by Gov. Phil Bryant’s Oyster Council on Restoration and Resiliency called for a state hatchery capable of producing up to 10 billion eyed larvae of oysters. The plan suggested the hatchery should be located inland to decrease the chance of damage from tropical storms.”
Instead of building a new hatchery, the state is in the process of using funds from the BP oil spill settlement to purchase Aqua Green, LLC, located in Stone County, a recirculating aquaculture facility.
Lucas said the immediate need for the hatchery is for restoration of the oyster population in Mississippi waters.
“There is an economic benefit to oyster restoration,” Lucas said. “The dockside value is only one measure of economic impact. The commercial seafood industry in Mississippi accounts for more than $250 million in sales and supports 5,500 jobs. Restoring the harvest reefs in Mississippi also preserves our culture by continuing to support jobs, working waterfronts and communities.”
Lucas said there are also significant environmental benefits: More oysters in the water helps stabilize sediment, reduce erosion, improve water quality and create habitat for other commercial and recreational fish species helping to preserve and increase quality of life for residents and tourists.
While initially all the oyster larvae will be used for restoration efforts, there is also potential for sales to oyster culture entrepreneurs. Lucas said there could be additional economic benefits from creating new models for oyster harvest such as off-bottom aquaculture, a popular method for harvesting boutique oysters for the half shell market.
“Certainly, the hatchery could reach a production level that out paces the restoration efforts in Mississippi and allows for others to purchase product,” Lucas said. “However, as a research facility, it is our goal to transfer the technology to entrepreneurs who can create businesses that could sell oyster larvae. Creating business and industry is another economic benefit to the state.”
Aqua Green uses a recirculating aquaculture system that treats water reducing the amount of water required and making them sustainable systems for seafood production. Lucas said there are no other known inland recirculating aquaculture facilities in the country that are producing oyster larvae and certainly no known systems that would be at this scale.
“A great benefit of recirculating aquaculture systems is the ability to control the environment for optimum growing or spawning conditions,” Lucas said. “Artificial sea water is mixed to a desired salinity and the system can control for temperature and light conditions. The ability to grow algae to feed the oysters helps optimize nutrition requirements for growth.
“The system uses a biological filter where biological nitrification occurs. The nitrifying bacteria located in the filter process the dissolved nitrogenous waste products that are excreted by the aquaculture organisms. The filter generally consists of a material such as plastic or fiberglass that is designed to have considerable amounts of surface area exposed that allow nitrifying bacteria to colonize. The filter is necessary because cultured organisms produce waste as a product of the nutrition they receive.”
Gov. Phil Bryant announced the purchase of Aqua Green as part of Mississippi’s RESTORE Act projects in November 2016. Currently USM continues to work with the Mississippi Department of Environmental Quality, the state trustee for the BP oil settlement funds, to provide documentation to the U.S. Department of Treasury to complete the requirements for the grant that will be used to purchase the facility. The state hopes to complete the purchase this year.
USM has a long history with aquaculture research. The Thad Cochran Marine Aquaculture Center, located in Ocean Springs, is a $35 million-dollar facility with a 100,000-square foot of research space dedicated to aquaculture with marine finfish, shrimp and crabs. The acquisition of the Aqua Green facility expands USM’s footprint and research capability.
Oysters are currently the only animals being cultured at Aqua Green. Prior to the oyster pilot project, the facility produced tilapia, cobia, spotted sea trout and pompano. The facility will be renovated to accommodate the production of oysters as the primary aquaculture product. Lucas said as a research institution, it will look for opportunities to add species and technology development as space and funds permit. About nine people are working at the facility as part of the pilot oyster project.
Technology transfer is also envisioned from the Aqua Green project.
“We look forward to expanding our aquaculture research capabilities and transferring technology to the private sector,” Lucas said. “University academics will benefit from the facility by providing opportunities for hands-on learning, research and instruction. Renovations to the facility will include the addition of video network capabilities to other USM classrooms in Hattiesburg and on the Coast.”