The Georgia Department of Natural Resources (DNR), Wildlife Resources Division (WRD) is concerned with non-native plants and fish in Georgia waterways. Both Lakes Oconee and Sinclair have non-native fish, and Lake Sinclair has at least one plant that could become invasive.

Across the United States, we are seeing a large number of non-native plants, fish, crustaceans and mollusks taking hold in waters where they do not belong. They are causing economic problems as costly attempts are introduced to remove them and they are in many cases replacing or diminishing native popilations.

Non-native plants like hydrilla and water hyacinth are cloging many waterways. Fish like the round goby, the sea lamprey and the common carp are replacing native populations of fish. Crustaceans like the rusty crawfish are competing with or replacing native crawfish populations, and the spiney water flea eats smaller zooplankton needed by native fishes.

Mollusks like the zebra mussel are not only replacing native mussel populations, they are causing damage to water intake structures by attaching to equipment. Zebra mussels are also disrupting the food chain in many waters by filtering large amounts of water and removing beneficial foods required by larvel and juvenile fish.

The only non-natives mentioned above that have caused considerable problems or have entered into Georgia waterways so far are hydrilla, water hyacinth and the sea lamprey. However, fish populations in Georgia waters have been changed and even seriously damaged in some cases by the introduction of non-native fish to its lakes and streams.  

Blue catfish are non-native to Lake Oconee and Sinclair and both lakes have established populations of those catfish. WRD suspects that blue catfish were illegally introduced into Lake Oconee and then made their way downstream through the Wallace Dam to Lake Sinclair.

Flathead catfish were also thought to have been illegally introduced into Lake Oconee where they have established a good population with several fish being caught that weighed more than 35 pounds. Flatheads are now showing up in Lake Sinclair. It is unknown at this point what the positive or negative impact the flatheads will have on both lakes.

WRD has confirmed non-native spotted bass in both lakes Oconee and Sinclair, and in Lake Oconee, anglers have reported blueback herring. Just like flathead catfish, blue catfish and spotted bass, if there are blueback herring in either lake, they were illegally introduced and if introduced they could potentially have devastating impacts on native populations.

One non-native fish species that has become a nuisance fish throughout the United States and can be found in both lakes Oconee and Sinclair is the European common carp. The common carp tends to reach an equilibrium level in lakes, and although a nuisance, the lakes are able to handle there populations without undue harm to the lake.

A vegetative species that could become invasive in Lake Sinclair is Lyngbya, blue – green algae that can form dense mats that often break free from the bottom and float to the surface. The algae occur in Sinclair in several places within the lake, most notably in the Beaverdam Creek area.

Another non-native species that is present in Sinclair is the Corbicula or Asiatic clam, a small clam about the size of a half dollar. Even though the Corbicula serves as a food source for fish species like catfish and shellcrackers, it competes with and displaces the larger native clam species that is found in the lake.

Georgia has had some serious negative impacts already from non-natives, and the state is likely going to face more problems in the not too distant future. The future of sunfish fishing in the Georgia mountain lakes is threatened since anglers illegally introduced blueback herring. Anglers who moved spotted bass from Lake Lanier to Lake Chatuge ruined Georgia’s best smallmouth fishery. Illegally introduced flathead catfish has decimated the popular redbreast sunfish in the Altamaha River.

Future problems in Georgia will surely occur as the zebra mussel continues its migration south and eventually into Georgia waters on boats or by individuals. The zebra mussel is now located in the waterways of Tennessee and Alabama, and it is only a matter of time before it will be in Georgia’s waterways.

Many of the nuisance and non-natives are referred to as hitchhikers. They attach themselves to boats that are then removed from one body of water and launched into another body of water. The zebra mussel was originally released into America’s water from the ballast of ships arriving from foreign countries.

Any observance of non-native species in lakes Oconee and Sinclair should be reported to the WRD. Report those incidences for Lake Oconee to (770) 918-6418 and for Lake Sinclair to (478) 825-6151.

Good fishing and see you next week.