ATHENS, Ga. – University of Georgia fisheries researchers have received a 5-year $299,912 grant from the Georgia Department of Natural Resources to help in the agency’s efforts to restore an ancient native fish to Georgia rivers.
Lake sturgeon, the largest freshwater fish in North America, once swam U.S. waters from the Great Lakes south to the Mississippi, Missouri and Tennessee rivers. They extended as far South as the Coosa River drainage in North Georgia, including such major tributaries as the Etowah and Oostnaula rivers. The large, slow-moving fish feed off the bottom, sifting through mud and silt in search of worms and insects. They haven’t been seen in the Coosa River for nearly 20 years, mostly, experts say, because of overfishing, pollution and the sturgeon’s slow maturity and reproductive rates.
“These fish can live up to 150 years and grow to 300 pounds or more,” said Douglas Peterson, a fisheries biologist in UGA’s Warnell School of Forest Resources. “But they don’t mature and reproduce in northern climates until they’re 15 to 20 years old. We hope they will mature a little earlier here in the South, but at this point, no one really knows.”
In Michigan, lake sturgeon were “reintroduced” in several river systems during the 1990s through experimental stocking programs. While the fish never completely disappeared in Wisconsin, management agencies began supplementing wild populations through stocking in the early 1980s. The sturgeon’s comeback there has been so successful, it now supports a lucrative sport fishery.
Peterson, who worked with wild populations of lake sturgeon in upper tributaries of Lake Michigan, has been eager to aid restoration efforts in Georgia since coming to UGA last year. He said one important goal is to standardize hatchery rearing methods and to establish a rigorous protocol for evaluating stocking success.
“We don’t want to raise sturgeon and simply turn them loose without having an effective monitoring program in place to evaluate and steadily improve our techniques,” said Peterson, “especially since our goal is to re-establish a self-sustaining population.”
Peterson said the lake sturgeon reintroduced here will come initially from Michigan and Wisconsin and “from as many different parents as possible to ensure maximum genetic diversity.” He is encouraged by the Georgia DNR’s cautious approach to the reintroduction as indicated by their support for establishing a monitoring program prior to releasing hatchery-reared fish. And while officials can look to the success of on-going recovery efforts in the Great Lakes, questions remain about how the fish will survive here in the South.
For example, scientists are studying how many fish to release initially and the best way to monitor their survival. Peterson wants to try a somewhat novel approach here by releasing about 75 percent of the sturgeon fingerlings and holding 25 percent or so in the hatchery “in reserve.”
“In Michigan, the DNR has experimented with releasing both fry and fingerlings,” he said. “At Black Lake, for example, we captured wild larvae from their natal stream and grew them out for six months within the protected environment of a hatchery. This greatly increased their survival rate without compromising the genetic diversity of the wild population. We may try some techniques like that here in Georgia to help them along.”
Some of the released sturgeon will be marked with a coded wire tag, so they can be identified if recaptured during the monitoring assessments. Others will be marked with small computer chips, which will also provide additional data about where and when the fish were stocked and at what size. This system will allow the researchers to test several stocking strategies to determine which size and how many fish to release the following year.
“We have no wild sturgeon population to study here,” said Peterson, “so there’s no recipe to follow. We’ll use the best information currently available, supplement that with the data we collect each year, and go from there. If efforts go as we hope, the lake sturgeon could become the poster fish for future aquatic restoration efforts.”
NOTE TO EDITORS: A photograph of Douglas Peterson with a 100-lb. Lake sturgeon is available at www.photo.alumni.uga.edu.