Preventing an Invasion

Above: The Northern snakehead fish, native to Russia, China and Korea, has been found in Georgia waters. Inset: A close-up of the snakehead's mouth. Images provided by GADNR

By Melissa Cummings Communications and Outreach Specialist GADNR Wildlife Resources Division

WHAT ARE AQUATIC NUISANCE SPECIES?

Aquatic Nuisance Species (ANS) are organisms that disrupt the ecological stability of inland waters (rivers and lakes), estuarine or marine waters, and may also cause economic loss in areas where they are introduced. HOW DO THEY GET HERE?

ANS can arrive by several means, including: • Vessel: If a boater visits a body of water inhabited by an ANS (could be in your home state or further afield), and that plant or critter attaches to their boat (hull, motor, boat trailer, etc.) and the boat owner does not properly clean the vessel and trailer before it goes into a different water body – the species can potentially spread. • Negligent aquarium owners: When aquarium owners “dump” plants and fish into Georgia waters. • Illegal stockings: Anglers or others moving a species from one water body into another.

• Zebra mussel: Native to freshwaters in Eurasia, the zebra mussel 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. Distinguished by the striped pattern on its shell, zebra mussels are small in size (less than two inches) but potentially very large in impact, both ecological and economical. Damage could include adversely impacting Georgia's native mussels, many of which are endangered, and clogging intakes for drinking water, power plants and outboard motors, costing millions of dollars in damage, control and abatement. Georgia has had two close calls with this organism in 2021 – including finding them in moss balls sold in pet shops across the state and a boater discovering them on his vessel prior to launching in Lake Lanier (the boat had been purchased in Tennessee). As of this writing, zebra mussels have NOT been found in Georgia waters.

Zebra mussel size comparison.

• Giant Salvinia: This invasive plant (pictured right) 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, leading to oxygen depletion and absence of light for native vegetation. Infestations of this species can result in complete blockage of waterways, irrigation and power generation intakes.

• Snakeheads: In October 2019, the first northern snakehead in Georgia 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 into 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 negatively impact native species if introduced to their habitats. The introduction of ANS can affect Georgians on multiple levels. At the simplest, it may affect fishing in your favorite spot. If an ANS introduces a disease, hybridizes with native fish, or out-competes any native species found there, the ecological makeup of your pond changes, affecting your personal fishing experience. On a larger scale, ANS can cost millions in economic damage through potential harm to vessels and infrastructure (i.e. pipelines) and negatively affect local economies with the high cost of abatement and decline in recreational activities, such as boating. The presence of ANS can even change the ecological picture by devastating the overall health of water bodies and decimating native species.

ANS PREVENTION TIPS

• Never release live bait, aquarium fish, aquatic plants or mussels into Georgia waters, and properly dispose of bait. For more information on disposing of unwanted fish, plants, or other biota, contact a DNR fisheries office (georgiawildlife. com/about/contact). • Only GADNR staff is authorized to stock or move live fish or aquatic plants from one body of water to another.

• 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 and equipment, as well as from the 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 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).

MORE INFORMATION For more info, visit georgiawildlife.com/ans. Giant salvinia.