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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.
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.
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, https:/www.fws.gov/fisheries/ANS/zebra-mussel-disposal.html)
Aesthetic Impacts are wide ranging and often seen with invasions by non-native species that become aquatic nuisances. This results in an inability for Kentuckians 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)
Some alternatives to release include:
Aquatic Nuisance Species Task Force USFWSInvasive Species USFWSNon-indigenous Aquatic Species USGSEDDMapS-Invasive Species MappingWestern Aquatic Invasive Species Resource CenterMore about KDFWR Nuisance Species Plans