Aquatic Nuisance Species (ANS) in Georgia

As is the case with many other states, Georgia has had a plethora of aquatic nuisance species introductions over the years. Though some of these introductions are the result of range expansions or climatic events (e.g. hurricanes, etc.), most of these introductions are result of man-induced activities. Many of these species have the potential to negatively impact native species. In an effort to properly respond to these introductions and formulate appropriate monitoring/management strategies, the Georgia Department of Natural Resources (GA DNR) oversees the management of and response to several aquatic nuisance species that occur in this state.

Moving live fish, aquatic plants, or mussels from one body of water to another can cause irreversible damage to the ecological balance of Georgia lakes, rivers and streams. Releasing unwanted aquarium species or other non-native species may not seem like a big deal, but it can have severe negative impacts on our local fish and fauna. DO NOT RELEASE NON-NATIVE ANIMALS! Should you need help in getting rid of them, contact your regional Georgia DNR Wildlife Resources Division Fisheries Office for assistance.

Stop Aquatic Hitchhikers LogoStop the spread of aquatic nuisance species. Non-native or introduced species can be an issue in Georgia, often presenting problems for many of our native fish and plant populations. You can help by:

  • REFRAIN from relocating fish or aquatic plants to areas in which they are not native

  • REMOVE any non-native species you catch while fishing

  • REPORT any non-native species you encounter while on the water to your local DNR office

  • REMEMBER to practice CLEAN, DRAIN and DRY after returning to the boat ramp

Giant Salvinia
Giant Salvinia

Report a Non-native Species

It is important that you report any non-native species you may encounter. The preferred method of reporting is to retain the species (preferably alive) in a secure container and contact your regional Georgia DNR Wildlife Resources Division Fisheries Office. Examples of species which should be retained and immediately reported are Northern Snakehead, Giant Salvinia, Zebra Mussel and Asian Carp.

Certain species may be reported online. In doing so, first make sure to take SEVERAL photos of the species, click on the species name below, fill out the subsequent form and submit it online. PLEASE MAKE SURE TO INCLUDE CONTACT INFORMATION (Your name, phone #, etc.) so that GA DNR staff may contact you to learn more about your capture. If you are uncertain about the species you have or the species is not found below, contact your regional Georgia DNR Wildlife Resources Division Fisheries Office.

Recent Discoveries

Zebra mussel in moss ball

In early March 2021, GADNR staff, along with wildlife agencies across the U.S., were issued a warning about aquarium moss balls that had been shipped nationwide to multiple pet stores and found to be contaminated with zebra mussels. Visits to multiple pet chain stores in Georgia confirmed the presence of zebra mussels in this and other products. Though a national recall for the products was done by PetCo and PetSmart, all pet store owners and operators are encouraged to check for this product, and if found, to immediately remove it and safely dispose of it. Consumers are urged to not purchase this product from stores or online. If you have purchased this item in February 2021, dispose of it properly and sanitize your tank(s). Detailed instructions for disposing of products and sanitizing aquariums can be found at Consumers may also contact their local WRD office ( for additional information on proper discarding techniques. Most importantly, DO NOT flush this product, or the mussels, down the toilet and DO NOT discard them outside. Zebra mussels pose a significant risk to our state, both economically and ecologically, thus it is critically important to pursue all preventative measures feasible so as to prevent the introduction of these invasives into the wild.

Biologist holding snakehead in net

In early October 2019, an angler captured a northern snakehead in a pond located on private property in Gwinnett County. This is the first time this fish has been confirmed in Georgia waters. It is unknown at this time why the species was released into the private pond from which it was captured, though potential reasons include: released by an aquarium owner who no longer desired the fish as a pet; released during a religious/spiritual event; released after being purchased from a live-fish food market; or released by an angler desiring to establish a new species to target in GA. Regardless, such man-induced releases are illegal and preventable, and such releases can have significant impacts on our native species. Thus, the GA DNR strongly encourages citizens DO NOT RELEASE non-native fish into environments from which they did not originate. Instead, retain the fish and contact your regional Georgia DNR Wildlife Resources Division Fisheries Office.

Have an Aquatic Pet You No Longer Want?

Aquarium pets are certainly enjoyable to have, and often bring happiness to those who own them. However, sometimes pet owners find themselves unable to care for these animals due to a variety of reasons. In such cases, the owners desire to rid themselves of their aquarium pet may result in the notion that taking the fish to a nearby pond, stream, river, lake, or other outside waterbody and releasing it is a good way to dispose of the animal. However, such actions can potentially have dramatically negative consequences on our native species in those waterbodies. Therefore, DO NOT RELEASE animals into a body of water from which they did not originate! Instead, you are encouraged to contact the pet store from where you purchased the animal and see if the animal may be returned to them. Otherwise, please contact your regional Georgia DNR Wildlife Resources Division Fisheries Office for assistance on how you can properly dispose of the animal(s).

Aquarium dumping illustration
Artwork by Jorah Mitchell

Examples in Our State

Snakeheads on ice
Northern Snakehead

Northern Snakehead

In October 2019, the first northern snakehead in GA was captured and reported by an angler in Gwinnett County. This is the first time this fish has been confirmed in Georgia waters. Native to China, Russia, and Korea, Northern snakeheads have been imported in several countries, including the USA, primarily for food purposes. An obligate air breather, the species can live out of water for hours and can travel short distances across land. As an apex predator, the species has the potential to have negative impacts on native species in areas where it is introduced. In Georgia, it is unlawful to import, transport, sell, transfer, or possess any species of snakehead fish without a valid wild animal license. If you suspect you have found a snakehead:

Read more about northern snakehead.

Colony of Giant Salvinia
Giant Salvinia

Giant Salvinia

Of all aquatic nuisance plants in Georgia, perhaps none poses a greater threat than giant salvinia (Salvinia molesta). This invasive plant is one of the world’s most noxious aquatic weeds and is notorious for dominating slow-moving or quiet freshwaters. Found in Georgia since 1999, it grows rapidly and forms free-floating colonies that create thick mats, which lead to oxygen depletion and absence of light for native vegetation. Sometimes confused with the native common salvinia, giant salvinia can be distinguished through examination of the stiff hairs on top of its leaf that branch into 4 parts which reconnect at the tip forming an “egg beater” appearance (leaf hairs on common salvinia do not reconnect). Infestations of this species can result in complete blockage of waterways, irrigation and power generation intakes. Control of the species can be achieved through multiple avenues: Biological (Salvinia weevil, Cyrotobagus salviniae); Mechanical Removal; Water Level Drawdown; and Chemical (herbicides). IF YOU SUSPECT YOU MAY HAVE GIANT SALVINIA IN YOUR WATERBODY, IMMEDIATELY contact your regional Georgia DNR Wildlife Resources Division Fisheries Office.

Learn more about giant salvinia.

Flathead catfish mouth
Flathead Catfish

Flathead Catfish

Native only to the Coosa River in Georgia, flathead catfish (Pylodictis olivaris) have decimated the popular redbreast sunfish and bullhead fisheries in the Altamaha River since their introduction in the mid-1970s. In the mid-1990s, the species was also illegally introduced into the Satilla River, a river known historically for its redbreast sunfish fishery. Flatheads pose a direct threat to these sunfish and many other native panfish. As such, GA DNR staff have dedicated significant time each year since 2007 to removing flathead catfish from the Satilla River in an effort to suppress the population and minimize its impacts on native fish populations.

Read more about the flathead catfish removal project.

Report a Flathead Catfish Button

Blue Catfish

Blue Catfish Illustration

One of the largest freshwater catfish species in North America, blue catfish (Ictalurus furcatus) are native in Georgia only to the Coosa River but have been introduced into several locales throughout the state. Several rivers (Ocmulgee, Oconee, Altamaha, and Satilla to name a few) are now home to the species, and concerns exist as to the potential impacts the species may have on native fish. Highly omnivorous, the species has been found to prey on non-native Asian clam (Corbiucula fluminea) in the Satilla River (and other rivers) while also feeding on a multitude of native fish. As part of the flathead removal project on the Satilla River, GADNR staff are removing non-native blue catfish as well.

Learn more about blue catfish.

Asian Swamp Eel

Asian swamp eel swimming

Having been found in multiple locations in Georgia but actually native to Asia, India, and China, the Asian swamp eel (Monopterus albus) is not a true eel. The species has a scaleless, elongated body with a tapering tail and blunt snout, unlike the native American eel (Anguilla rostrata) that has embedded scales; pectoral fins; and rayed dorsal, anal and caudal fins. The life cycle of the Asian swamp eel, which occurs entirely in freshwater, is quite interesting: all young are female at birth, with some changing into males as adults, though such males may transition back into females should female densities become low. Such strategies, along with the species ability to exists in a variety of habitats (shallow wetlands, stagnant waters, marshes, streams, rivers, ditches, canals, lakes, reservoirs, and shallow ponds); it’s tolerance of cold temperatures (can survive below freezing); and it’s tolerance of a wide range of water oxygen levels make it a very adaptable non-native species. The ecological impacts of Asian swamp eels remain relatively unknown, but the potential for the species to negatively impact native species through predation or competition is concerning.

Learn more about the Asian swamp eel.



Hydrilla (Hydrilla verticillata) is an aquatic plant species that is native to Eurasia and was believed to have been first introduced into the US in the 1960s. It is also known as Florida elodea, water thyme, water-thyme, and waterthyme. This plant is present in several Georgia waterbodies around the state. Research has recently been done to investigate potential links between hydrilla infestations and outbreaks of an often fatal disease that can affect birds. Most recently, a link to hydrilla has been suspected in bald eagle deaths in the Southeastern US.

Learn more about hydrilla.

Island Apple Snail
Island Apple Snail

Island Apple Snail

Island Apple Snail (Pomacea insularum) are originally native to South America. These exotic snails have been found in Georgia, California, Florida, North Carolina and Texas. The shells can be near baseball-sized (80 mm or over 3 inches). The large egg masses are laid on vegetation or trees and are bright pink or orange in color. Egg masses can be 2 to 3 inches long and may contain 200–600 eggs.

Learn more about the Island Apple Snail.

Report a Island Apple Snail Button

Aquarium Fish Species (Pacu, Tilapia, Oscar, Haplo, etc.)

Aquarium fishFish in aquarium

Over the years, several species of aquarium fish have been found in private and public waters in Georgia. These introductions typically occur as a result of aquarium owners who no longer wish to keep these pets decide to release such species into local waters. Unfortunately, these decisions can have dramatically negative impacts on native species populations. Consequently, we urge aquarium owners DO NOT RELEASE NON-NATIVE FISH/PETS that you no longer wish to keep or are able to keep. Instead, contact your regional Georgia DNR Wildlife Resources Division Fisheries Office for assistance on how to properly dispose of the animal(s). Should you encounter any of these fish while fishing in public or private waterbodies, contact your regional Georgia DNR Wildlife Resources Division Fisheries Office.

Report an Unknown Fish Button

Tiger shrimp
Tiger Shrimp

Tiger Shrimp

Native to Indo-Pacific, Asian, and Australian waters, Asian tiger shrimp (Penaeus monodon) are now found along the southeast and Gulf coasts of the United States, including Georgia. While small numbers of this non-native species have been reported in U.S. waters for over a decade, sightings have increased over the past few years. Tiger shrimp are one of the primary species raised in shrimp farms around the world and can grow to be three times the size of our native shrimp. Able to grow 2x or more the size of native white or brown shrimp, tiger shrimp are of concern due their potential to compete for food and habitat resources, prey on native shrimp, and potentially transmit disease to our native shrimp populations. In an effort to better track captures of tiger shrimp along Georgia’s coast, the GA DNR is requesting fishermen who capture any of the species to help provide some much needed data on such captures.

Get help in identifying tiger shrimp and for more information.

Report a Tiger Shrimp Button


Lionfish underwater

The northward expansion of the lionfish (Pterois miles) population in the past 2 decades since its first sighting in the Atlantic off the Florida coast in 1985 has undoubtedly created much angst amongst fishery managers. A notorious top-level predator, lionfish have been known and found to consume significant quantities of other reef fish, including prized grouper and snapper species. Such predation has been shown to negatively impact both the quantity and characterization of these and other fish sharing habitats with lionfish.

Read more about lionfish.

Report a Lionfish Button

Blueback Herring

Blueback herring drawing

An anadromous species native along much of the Atlantic coast, including Georgia, blueback herring (Alosa aestivalis) have been introduced in several inland waterbodies. Similar to alewife (Alosa pseudoharengus), blueback herring are dorsally blue and have 44–50 rakers on the lower limb of the 1st gill arch, while alewife have 39–41 and are green dorsally. A voracious consumer of zooplankton and fish eggs/fry, blueback herring have negatively impacted sunfish (bream), largemouth bass, white bass, walleye, and crappie populations in several of the Georgia mountain lakes where they have been illegally introduced.

Read more about blueback herring.

Alewife next to knife for scale


Native throughout much of the Atlantic coast north of Georgia, alewife (Alosa pseudoharengus) have been introduced in several inland waterbodies, including Lake Carters and Allatoona, Coosa River, and Savannah River. Similar to blueback herring (Alosa aestivalis), alewife are dorsally green and have 39–41 rakers on the lower limb of the 1st gill arch, while blueback herring have 44–50 and are blue dorsally. Like blueback herring, this voracious consumer of zooplankton can negatively impact and alter food webs, causing significant impact to native fish populations, including white bass populations.

Learn more about alewife.

Alabama Bass

Alabama Bass Illustration

Alabama bass (Micropterus henshalli), better known as Alabama spotted bass, were once considered a subspecies of spotted bass, but as of 2013 are recognized as a separate species more closely related to the red-eye basses. Native to the Coosa and Tallapoosa rivers in Georgia, the popularity of the species fast growth resulted in illegal introduction of the species throughout many other large waterbodies in Georgia, including Lake Lanier in the early 1970s. While the species has an ability to grow faster and larger than spotted bass, the species poses a significant concern in introduced areas and has proven to hybridize with every native species of black bass in the state except Suwannee bass. Such hybridization is problematic and compromises the genetic purity of native bass species like shoal, Chattahoochee, smallmouth, and largemouth bass. Not only have largemouth populations been affected by the species, but Georgia's best smallmouth bass fishery, Lake Chatuge, was lost to illegally-stocked Alabama bass. The only remaining smallmouth bass fishery, Lake Blue Ridge, is also threatened by Alabama bass competition.

While Alabama bass may be more aggressive and thus catchable for some fishermen, they are not native to much of Georgia and can have negative impacts on other fish species. Consequently, anglers should not relocate or introduce either of these species into new areas.

View more information on Alabama bass.

Spotted bass illustration
Spotted Bass

Spotted Bass

Spotted bass (Micropterus punctulatus), also known as Kentucky spotted bass, are native to the Mississippi River and Gulf drainages, including the Tennessee River and waters just inside the north Georgia border. While the species is not native to most of Georgia, it has been introduced into various waterbodies in Georgia in recent years. The negative implications of the fish in changing the dynamics of an ecosystem (lake, river) and affecting native bass populations through competition and cross-breeding present difficulties for fishery managers.

While spotted bass may seem desirable to some fishermen, they are not native to much of Georgia and can have negative impacts on other fish species. Consequently, anglers should not relocate or introduce the species into new areas.

Learn more about spotted bass.

Yellow Bass

Small yellow bass being held

Yellow bass (Morone mississipiens) are native to the Mississippi and Tennessee River drainages, including some waters in the upper northwest corner of Georgia. This smaller Morone species has been introduced into other locales in Georgia, including the Coosa (Etowah and Oostanaula rivers, Rocky Mountain PFA, and Carter’s Lake). In areas where it is not native, the species has the potential to compete with other more desirable game fish. Adult size is relatively small compared to other Morone species, making them less desirable to some anglers. There is no size or creel limit on yellow bass, and anglers are encouraged to harvest the species.

More information on yellow bass.

Help on identifying Morone species.

Oriental weather loach
Oriental weather loach

Oriental Weather Loach

While sampling for Altamaha shiners in early November 2020, University of Georgia researchers were surprised to find several specimens of an unknown species in McNutt Creek, a tributary to the Middle Oconee River near Athens. Close examination of the fish led them to identify the fish as Oriental weather loach (Misgurnus anguillicaudatus), a common aquarium species native to Eurasia and north Africa that is sometimes used as bait but one that had never been reported in Georgia. The discovery of Oriental weather loach is only Georgia’s latest instance of a non-native fish being introduced outside its native range. As a popular aquarium species, weather loaches likely may have been introduced by an aquarium owner who no longer wanted the fish, and it’s important to remind pet owners that such actions can have dramatic impacts. Aquarium owners and others who are considering getting rid of unwanted, non-native fish are strongly encouraged to contact the pet store where they bought it or call DNR for help. Remember, the choices we make and actions we take today may have an impact beyond tomorrow.

Other Invasive/Non-native Concerns in Georgia


Georgia trout populations are threatened by the following newly occurring invasive diseases:

  • Whirling Disease: First detected in the U.S. in 1958 and first documented in Georgia in 2021, this disease is found in more than 20 states, including in the Watauga River in North Carolina in 2015. Whirling disease can cause 90 percent or greater mortality of young rainbow trout and can have serious impacts to wild and hatchery trout populations. The disease is caused by the microscopic parasite Myxobolus cerebralis, which damages cartilage and skeletal tissue in trout causing diseased fish to swim in a "whirling" motion. While often fatal to juvenile trout, the disease is not known to affect humans or pets, and eating an infected fish is not known to cause any harmful effects. The disease is not harmful to humans. 
  • Didymo: This disease, also called rock snot, is a freshwater diatom that produces thick algae mats along stream bottoms. The mats can be so thick that they can alter stream habitats and make fishing difficult. Didymo can be spread easily from one water body to another. This microscopic algae was recently found in North Carolina for the first time and is a threat to Georgia streams and rivers. How to prevent the spread of Didymo.
  • Infectious Hematopoietic Necrosis Virus (IHNV): While IHNV had not previously been found in Georgia prior to its discovery in 2021, it has been documented in salmonids in the Pacific Northwest. The disease is caused by the Salmonid Novirhabdovirus and is passed through contact with urine, mucus, and other fluids. All species of trout are susceptible. The virus can cause high trout mortalities in hatchery systems and in the wild. There are no therapeutic treatments to eliminate the pathogen. Infected fish may exhibit lethargy, whirling behavior, darkened coloration, and swelling in the head and abdomen. The disease is not harmful to humans. 


The following parasites are known to potentially be problematic for various fish species in Georgia:

  • Gill lice: These lice, a parasitic crustacean that attach to the gills of trout, recently were found in trout in North Carolina. In high concentrations, these lice can impact respiration and the health and survival of the trout.
  • Achtheres: A parasitic copepod that infects the gills of freshwater fish, especially striped bass, and is easily visible when it matures and moves into the fish’s mouth and gill arches. First documented in Tennessee, the parasite has been observed in several Georgia lakes. Though currently not believed to cause direct mortality, it is believed to cause some fish stress and, along with other factors, could impact fish health. Read more information on Achtheres.

Examples Near Our State

Zebra Mussel

Zebra musselsNative to freshwaters in Eurasia, the zebra mussel (Dreissena polymorpha) was introduced in the Great Lakes in the mid-1980s, likely via ballast water. Since then, the species has been moving south, and is now found in Tennessee and Alabama. Though not currently known to have established populations in Georgia, the recent scare in 2021 near Lake Lanier and the nationwide recall of infected aquarium products reminds us that the potential for the species to find its way here is very real.

Distinguished by the striped pattern on its shell, zebra mussels are small in size (<2”) but potentially very large in impact. The species has the potential to cause significant ecological (adversely impact Georgia's native mussels, many of which are endangered) and economical (completely clog intakes for drinking water, power plants and outboard motors, costing millions of dollars in damage, control and abatement) impacts. Consequently, it is imperative boaters and other users visiting nearby areas having these invasive species take necessary precautions to prevent bringing them into Georgia. If you suspect you’ve found a zebra mussel, retain it and immediately contact your regional Georgia DNR Wildlife Resources Division Fisheries Office. Be sure to note where you found the specimen(s).

Learn more about zebra mussels.

Asian carp on sand
Asian Carp

Asian Carp

Imported to the U.S. in the 1970s as a means of controlling algal blooms in aquaculture ponds and wastewater treatment facilities, Asian Carp (both Bighead and Silver) are exotic fish species invading and causing harm to native fishes and mussels throughout the Mississippi River basin. A fast-growing filter feeder, the species can dominate a fish community; impact native species; alter water quality; harm important commercial and recreational fisheries; and create a significant safety hazard for boaters. As has been seen on many occasions, some species of Asian carp (e.g. Silver carp) have a tendency to jump when scared, thus creating a significant hazard to people operating boats, who may be injured by fish landing in their boat. Native to China and prized there for aquaculture, the species is now found as far south as the Tennessee River basin, which falls (in part) in north Georgia. Though the species has not been detected in Georgia waters yet, it’s close proximity is of serious concern. If you suspect you have captured an Asian carp, retain the fish and immediately contact your regional Georgia DNR Wildlife Resources Division Fisheries Office. Be sure to note the location of where you found the specimen(s).

More on Asian carp.

You Can Help Prevent the Movement of ANS


Georgia boaters and anglers can help prevent the movement of aquatic nuisance species through these simple actions:


  • CLEAN gear, watercraft, trailer, motor, and equipment. REMOVE visible aquatic plants, mussels, other animals, and mud before leaving any water access.
  • DRAIN water from gear, boat, bilge, motor and livewell by removing drain plug and opening all water draining devices away from the boat ramp. NEVER empty your bait bucket into Georgia waters.
  • DRY everything at least five (5) days before going to other waters and landings or SPRAY/RINSE recreation equipment with high pressure and/or hot water (120 degrees F/50 degrees C or higher).

Anglers Bank/Wading

  • CLEAN gear and recreation equipment. REMOVE visible aquatic plants, mussels, other animals, and mud before leaving any water access.
  • DRAIN water from gear and equipment, but NEVER empty your bait bucket into Georgia waters.
  • DRY everything at least five (5) days before going to other waters and landings or SPRAY/RINSE recreation equipment with high pressure and/or hot water (120 degrees F/50 degrees C or higher).

By taking these simple actions, you can help the Georgia Department of Natural Resources' Wildlife Resources Division protect Georgia's native aquatic resources and ensure good fishing for future generations.

For more information about aquatic nuisance species and ways that you can protect Georgia waters, visit the Stop Aquatic Hitchhikers program website or Facebook page. The Georgia Department of Natural Resources is a cooperating partner in this program.

Thank you for protecting your Georgia waters, your native fish and wildlife populations, and your excellent sport fishing opportunities across this state.

Georgia Efforts to Prevent Aquatic Nuisance Species

Georgia is working to educate and inform citizens of the threat of Aquatic Nuisance Species (ANS) and how we can best combat them in multiple ways. These include the development and implementation of management plans and projects; partnerships with other agencies; and ongoing education and outreach events.

Plans & Projects


Education & Outreach

Each year, GA DNR staff speak to hundreds of kids at various schools in our state. These events provide an excellent opportunity for students, teachers, and parents to hear about invasive species issues in our state, learn about many of our native species, and discover how they can help us in our efforts to prevent future introductions of non-native species. If you are interested in having someone speak to your school or civic group about native or non-native species in Georgia, please contact the GA DNR Fisheries office in Waycross at 912-285-6094.

Biologist in classroomHands-on biologist with crowdBiologist in classroom


Don't Move Fish Poster Freshwater Fish Poster Wanted ANS Poster
Don't Move Fish Poster Freshwater Fish Poster Wanted ANS Poster