Invasive Species

The invasive grass carp and black carp are artificially spawned to produce triploids, which means they have three sets of chromosomes and are sterile. WARC scientists invented an early ploidy prediction process for produced fry, and a post-mortem assessment method for carp caught either in the wild or sold and hauled live to other states.

The Asian tiger shrimp began appearing in commercial shrimp catches in 2006. They grow larger than native shrimp and are known to be fierce predators - so shrimpers and managers are concerned about the potential effects this species might have.

Welcome to the Nonindigenous Aquatic Species (NAS) information resource for the United States Geological Survey. Located at Gainesville, Florida, this site has been established as a central repository for spatially referenced biogeographic accounts of introduced aquatic species. The program provides scientific reports, online/realtime queries, spatial data sets, distribution maps, and general...

Invasive Asian carp are problematic for native species, and managers are implementing control measures without well-quantified detection limits or a means to assess the accuracy and precision of existing or future survey data for the fish. Environmental DNA - eDNA - is already used to detect the presence of invasive species, and can be used to identify locations to focus carp control efforts.

Traditional approaches to locating Burmese pythons - including visual searches and trapping - have resulted in low detection. Environmental DNA - or eDNA - is increasingly being used to detect the presence of non-native species, particularly when traditional methods may not be adequate.

Invasive Burmese pythons threaten the success of Everglades restoration efforts. To assist with management and population control decision making, USGS scientists are implementing genetic studies to identify potential new entry pathways and to help quantify the size of the breeding population.

Black carp have likely been present in the Mississippi River since the 1990s, but their current distribution and spread is not well understood. Genetics is helping to shed light on this species, including its diversity, the relatedness of wild and captive fish, and its introduction history.

Tegus are breeding, they have a diverse diet, and they are established in areas throughout South Florida. USGS is tracking this problematic reptile species to better understand their movements and habitat use to help managers prevent dispersal into new areas.

Nonindigenous - non-native - species threaten biodiversity, but the distribution of these species is not well-known. The Nonindigenous Aquatic Species (NAS) database tracks occurrence data on non-native aquatic plant and animal species throughout the United States, and provides the public with species profiles, distribution maps, and online/real-time queries for state/hydrologic basin- specific...

Current tools for detection of Burmese pythons in South Florida have resulted in low detection rates. Environmental DNA - eDNA - has shown to be effective at detecting these invasive snakes, and can help to determine range limits for the species, information that is critical for management and control efforts.

Telemetry tracking of captured pythons reveals movement patterns of the invasive Burmese python in the Greater Everglades, information that managers can use to prioritize python control efforts.

USGS scientists study the mechanisms of aquatic species invasions across the South Atlantic Landscape Conservation Cooperative (SALCC) with the help of the Nonindigenous Aquatic Species Database (NAS).