Aquatic Nuisance Species (ANS)

​​​​General Information about Kentucky’s Aquatic Nuisance Species (ANS)

What are nuisance species?

 Nuisance species are non-native species (a.k.a. exotic, alien, or non-indigenous) that have moved outside their native range.  They threaten the natural function of native ecosystems or interfere with important commercial, agricultural and species or interfere with important commercial, agricultural, and recreational activities. Often, invasive species become "nuisances" due to their disruption of the environments where they are introduced.

• Zebra mussels (Dreissena polymorpha)
• Round goby (Neogobius melanostromus)
• Four species of invasive carp:  Invasive Carp Informatio​n
  
• Hydrilla (Hydrilla verticulata)
• curly-leaf pondweed (Potomogeton crispus)

Why do invasive species become “nuisances?”

Natural "checks and balances" such as predators, parasites, diseases, and competitors that otherwise control populations within their native ranges may not exist in areas where these organisms are introduced. This creates an environment where they can dominate and become "nuisances".  In addition, native species are not adapted to living with these introduced species and this can quickly upset the natural balance of an ecosystem and create cascading effects that lead to many negative impacts.

• Some aquatic nuisance species are so problematic that KDFWR has listed these species as prohibited in Kentucky (https://apps.legislature.ky.gov/law/kar/titles/301/001/122/). This means that these aquatic organisms are prohibited from being imported, bought, sold, or possessed in aquaria within Kentucky.
  
  
• U.S. Geological Survey maintains the national Nonindigenous Aquatic Species (https://nas.er.usg​s.gov​/). This database provides the user with options to search for aquatic nuisance species by state, species name, taxonomic group, location records, and species profiles.
  
  
• U.S. Fish and Wildlife Service maintains information on species in the form of Ecological Risk Screening Summaries (ERSS). ERSS reports provide a summary of species information to help inform readers about what is known about the potential for a species to be problematic (https://www.fws.gov/story/ecological-risk-screening-summaries). Key information contained in an ERSS is species environmental requirements, history of invasion, and documented impacts to the environment, economy, and/ or human health.
  

Aquatic Nuisance Species Impacts

Why should we make an effort to stop the spread of nuisance species?

Nuisance species have major biological, economical, and aesthetic impacts on Kentucky's natural resources.

Ecological Impacts include the degradation of native habitats and ecosystem function, reduced abundance of native species, and the loss of biodiversity (the community of unique organisms within specific habitats). Consider the invasive aquatic weed hydrilla. Hydrilla is a submerged plant that spreads rapidly while choking out native vegetation and altering the physical and chemical composition of the lakes and ponds where it is introduced. This can lead to reduced foraging habitat, alter the flow and mixing of the water column, and disrupt access for boating, fishing, swimming, and even block the withdraw of water for agricultural irrigation or power generation in many waterbodies.

Hydrilla dominates a previously balanced and diverse lake bottom in Kentucky. (Photo: KDFWR)

Economic Impacts can include increased costs to businesses and individuals due to interference with normal operations or infrastructure. In addition, tourism dollars are lost when recreational experiences such as hunting, hiking, fishing, swimming, and boating are no longer possible or pleasant. For example, invasive zebra mussels clog pipes, cover shoreline access, and encrust boat hulls and motors. Their impacts alone have cost the US billions of dollars in damage control. Most recently, zebra mussels were found in a popular aquarium and home décor product known as a moss ball. The threat of new introductions into US waters was so great that all sales and distribution of moss balls was effectively shut down and products were removed from shelves.

Invasive zebra mussels were found in a popular aquarium decoration, shutting down their sale and distribution in the US.  (Photo: USFWS).  For more information on zebra mussels being found on Marimo moss balls see (https://www.fws.gov/story/2021-03/invasive-zebra-mussels-found-moss-balls)

Aesthetic Impacts are wide ranging and often seen with invasions by non-native species that become aquatic nuisances. This results in an inability for Kentu​ckians to enjoy our natural heritage and pass along our favorite fishing, hunting, and recreational areas to future generations. Invasive carp such as silver and bighead carps can quickly colonize rivers through prolific reproduction and growth. This creates imbalances in the ecosystem and increases opportunities for the spread of disease as well as increasing the hazard that silver carp may pose to boaters and recreationalists with their unique jumping behavior. Follow the link for more on invasive carp impacts in Kentucky.

Dead Asian carp pile up below a dam after contracting Gas Bubble Disease. (Photo: Paul Rister)

Species Identification

What You Can Do

Anglers and Water Recreationists

• Clean your boat, anchor, and other items that may have been submerged in water. This is best done by rinsing your transportation sources and equipment thoroughly with a hard spray or HOT (120° F) water, like that found at a do-it-yourself carwash. 
  
  
• Drain equipment that may retain water before leaving a water access or shoreline property and allow equipment to dry thoroughly before using in another waterbody. 
  
  
• Use proper bait bucket practices. DO NOT DUMP leftover bait! DISPOSE of unwanted bait, including minnows, leeches, and worms, in the TRASH. Dumping of bait is a major pathway that allows nuisance species to spread between waterways. 
  
  
• If your dog goes swimming, wash your dog with clean water and brush its coat.
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Aquarium and Water Garden Owners

Some alternatives to release include:

• Give/trade with another aquarist, pond owner, or water gardener
• Donate to a local aquarium society, school, or aquatic business
• Seal aquatic plants in plastic bags and dispose in the trash
• Contact a veterinarian or pet retailer for guidance on humane disposal of animals
  

 Report a Suspected ANS

Laws and Regulations