Invasive flathead catfish found by Georgia Department of Natural Resources in Ogeechee River

The Georgia Department of Natural Resources’ Wildlife Resources Division has captured a non-native flathead catfish while sampling the Ogeechee River. 

Joel Fleming, fisheries biologist with the Georgia DNR Wildlife Resources Division, said it is unclear how the non-native catfish species made it into the free-flowing blackwater river.

Flatheads pose a significant ecological risk to the Ogeechee, according to Fleming, because the flathead catfish is an apex predator and will make a meal out of anything almost the size of them. This includes the red breast sunfish.

“Historically, this species was released by people not knowing any better,” said Fleming. “They appeared in Savannah about 10 years ago. We've had a removal program in the Satilla River for quite some time now. With the high flows during the 2021 to 2022 timeframe, the Savannah River population has really expanded.”

Fleming said the catch per unit effort so far shows about one fish per hour is caught.

“It’s a small population right now,” said Fleming. “We’re looking at a several mile area ― just about I-95 is where we’re catching most of the fish. We’re sampling the area above and below it just to be sure the fish aren’t outside of where we’re looking. And we’re removing everything that we’re seeing.”

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Fleming explained that in a short amount of time, invasive species can create a biomass change. “What happens is the non-native species will suppress the population of our native species. The species that will take the biggest hit in the Ogeechee River, fishery-wise, is the redbreast sunfish. Most people are concerned about the redbreast sunfish. We anticipate as this population (Flathead catfish) expands, that there will be an impact on that fishery.”

The fins of the redbreast sunfish ― a prized game fish among anglers ― are clear to dusky orange, and there is a large mouth with the upper jaw extending under the front of the eye. The redbreast's diet is varied, according to the Florida Fish and Wildlife Conservation Commission. Their primary food source includes organisms such as bottom-dwelling insect larvae, snails, clams, shrimp, crayfish, and small fish.

The flathead catfish also pose a threat to bass and bullhead catfish, a sustenance fish to many communities along the Ogeechee.

Report invasive species to the Ogeechee Riverkeeper

“We certainly discourage the release of any non-native species,” said Fleming. “If you've got fish from your aquarium or fish from another river system, please don't release them into our native waters.”

Fleming said as far as a plan of action sampling and removing the non-native species is key.

“We're using electro fishing gear that we can set to shock catfish,” said Fleming. “When we set up an electrofishing unit to sample for catfish, what we’ve found in other river systems is that the fish actually become a little less susceptible to the electro fishing effort. If we sample more often they don't respond to the electrofishing very well. So it takes about a week for them to become susceptible again.”

Communications director for the Ogeechee Riverkeeper Meaghan Walsh Gerard said if an individual comes across a non-native species and are unable to catch it, they are encouraged to report it. 

“We encourage them to let us know the area and type of species,” said Gerard. “That way we can try to target that area as well. We have a hotline that people can call for anything whether it be pollution or if something is seen going into the water they can certainly include that. They can also include photos.”

To file a report with the Ogeechee Riverkeeper, contact Kris Howard, science and policy manager by email at kris@ogeecheeriverkeeper.org or by phone at 866-942-6222 ext.6

This reporting content is supported by a partnership with several funders and Journalism Funding Partners.

Erica Van Buren is the climate change reporter for The Augusta Chronicle, part of the USA TODAY Network. Connect with her at EVanBuren@gannett.com or on Twitter: @EricaVanBuren32