Sustainable Aquaculture: Georgia Sea Grant opens state's first oyster hatchery
By Emily Woodward, Georgia Sea Grant
The University of Georgia Marine Extension and Georgia Sea Grant has opened the state's first oyster hatchery, bringing the popular shellfish back to the forefront on the Georgia coast after more than 50 years and diversifying the state's aquaculture industry.
Hatchery manager Justin Manley checks on the health of oysters growing in one of the hatchery tanks at the Shellfish Lab facilities on Skidaway Island
In the early 1900s, Georgia led the nation in oyster production, annually harvesting eight million pounds of oyster meat, primarily for the canning industry. By the 1940s, the industry was in decline due to over-harvesting and decreasing demand for canned oysters. The last shucking houses in coastal Georgia closed in the 1960s.
Today, the industry is poised for a comeback through the production of single oysters for the lucrative half-shell market. With funding from Georgia Department of Natural Resources Coastal Management Program, Marine Extension and Georgia Sea Grant launched the hatchery in 2015 at the Shellfish Research Lab on Skidaway Island. Researchers at Shellfish Research Lab are using established hatchery techniques to produce spat and are working on refining growing techniques to grow them into single oysters.
"We hope eventually to attract a commercial hatchery to supply large amounts of seed," says Tom Bliss, director of the Shellfish Research Lab. "Then our hatchery could focus on research in genetics and developing broodstock, improving grow-out methods, and looking at other species suitable for aquaculture."
Growing oysters in a controlled environment has been no easy feat. Bliss, along with hatchery manager Justin Manley and extension agent Rob Hein, have spent the last year perfecting their growing techniques.
"Environmental conditions like salinity, substrate, pH, water quality and food supply all play in important role in oyster productivity," says Manley. "Here at the hatchery we have the ability to manipulate these conditions and ensure maximum seed production."
Day-to-day hatchery work ranges from feeding algae to the larvae twice a day to sterilizing tanks and other equipment to sorting the baby oysters based on size.
"It takes a lot more work than you'd think to grow a healthy 4-6 millimeter oyster, which is roughly the size of a pencil eraser," says Manley.
In 2016, the UGA Oyster Hatchery produced between 500,000 – 750,000 spat. Producing the seed is an important first step, but successfully reviving the industry means moving beyond the confines of the hatchery and establishing relationships and working with shellfish growers along the coast.
When oyster spat reach a certain size, they are delivered to the 10 growers along the coast who take the seed their shellfish leases for cultivation. Leases are located in coastal waters approved for shellfish harvest and monitored by the Georgia Department of Natural Resources Coastal Resources Division.
These seed deliveries sometimes involve nothing more than a quick handshake, though on many occasions, extension agent Rob Hein will spend hours with growers, accompanying them in the field, discussing aquaculture industry updates, or offering advice on how to modify growing techniques to yield greater success.
"As an extension agent, it's my job to serve as a resource for our growers by sharing new techniques and training them on best methods for cultivating singles," says Hein. "This whole operation wouldn't be possible without the shellfish growers. They're putting time and resources into this effort, so it's important for them to be able to count on us to provide guidance."
Most of the growers are weathered watermen who have spent years navigating Georgia's vast expanse of marshes and meandering tidal creeks. They have the local knowledge and expertise when it comes to growing shellfish, though many will admit that it takes more maintenance, money, and specialized equipment to grow the single oysters to the two-inch market size.
Researchers at the Shellfish Research lab monitor cages filled with single oysters raised in the UGA Oyster Hatchery
"You have to put a lot of labor the way we're doing it right now," says John Pelli, owner of Savannah Clam Company. Pelli has farmed clams and harvested wild oysters for nearly 15 years. He expanded to growing single oysters when Marine Extension and Georgia Sea Grant started the hatchery.
"Tom, Rob and Justin have been really helpful in advising everybody on how to do it," says Pelli. "Providing the seed was a big incentive to try to make it work and those guys did a lot of testing beforehand to see what works best. Some people count sheep, they count oyster spat."
While grateful for the assistance from the hatchery team, Pelli readily admits that growing singles has been hit or miss since the launch of the project. This, in part, is due to the maintenance involved and the need for improved field equipment.
"We use the cages but you really need a winch on your boat to be able to move them once the oysters get to a certain size," says Pelli. "The cages worked in the beginning because we hadn't experimented with alternatives, but over time I think we [Marine extension and Georgia Sea Grant and shellfish growers] can work together to find useful methods that may work better."
Many of the growers are finding success through trial and error.
"I had to learn how to do it on the water, through hands-on experience," says Earnest McIntosh Sr., who co-owns E.L. McIntosh & Son Seafood with his son, Earnest McIntosh Jr. He tried moving his oysters to various locations on his lease in an effort to figure out where they grow best.
"It took a while to catch on, but I think I'm figuring out what it's going to take to be successful with it," says McIntosh.
Marine Extension and Georgia Sea Grant is also working to connect growers with seafood distribution companies and restaurants across Georgia to increase awareness of the single oyster. Single oysters generate three to four times the market value of wild oysters.
Once the hatchery is operating at full capacity, it will produce 15 million spat, with an estimated harvest value of $3 million to $5.25 million. By continuing to lay the groundwork through research and outreach, Marine Extension and Georgia Sea Grant plans to create a sustainable, robust oyster industry in Georgia.