Raising millions of baby oysters takes a lot of hard work. Just ask Marine Extension and Georgia Sea Grant’s aquaculture extension agents based at the UGA Shellfish Research Lab on Skidaway Island. Since 2015, the shellfish team has been producing single oysters and working with shellfish farmers on the Georgia coast who grow them to market size oysters.
A large part of growing oysters in the hatchery requires feeding them a nutritious diet that consists of algae. In the beginning, researchers at the lab would purchase algae food from outside vendors or depend on natural sources of algae coming in from the Skidaway River, but a few years ago, Aquaculture Extension Specialist Rob Hein started experimenting with growing his own algae culture at the lab to supplement the store bought and natural food.
“It’s so much cheaper and better quality,” says Hein, who’s become the lab’s in-house algologist. “I think what prompted it was traveling to other hatcheries and seeing how they operate. I have been slowly expanding every year.”
Hein’s experimental algae research has since turned into a larger scale algae operation. The lab has retrofitted space at the hatchery to make room for large algae tanks, both inside and outside. Thanks to fundraising efforts through Marine Extension and Georgia Sea Grant’s annual Oyster Roast for a Reason, the lab has been able to acquire several flat bottom algae tanks that can hold up to 5,100 gallons of algae. Having larger tanks for algae culture in an environmentally controlled space has greatly increased the reliability of the cultures, meaning they now have a more consistent source of highly nutritious food for the oysters.
“We’ve been able to increase the amount of food that we can provide to the nursery, greatly improving survival and growth while reducing costs,” Hein says.
Hein and the rest of the team are now growing a variety of live algae species that are fed to the oysters at different stages of their life cycle. The Shellfish Lab currently operates the only oyster hatchery in Georgia, but the team hopes to share what they have learned about algae culture with new hatcheries that become established on the coast.
“Every strain, let alone every species, has a slightly different nutrient profile and slightly different habitat tolerances. It is kind of a balancing act to produce complete nutrition for the oysters while maximizing growth rates based on the environmental conditions and water quality that changes throughout the year,” he says. “We are looking forward to using our new algae tanks as we continue to make our hatchery more efficient at producing oyster seed for the industry.”