Invasive Species Research

Science for Detection, Containment, and Control

Invasive species research within the U.S. Geological Survey’s (USGS) Ecosystems Mission Area (EMA) focuses 

on invasive organisms throughout the United States. USGS scientists work with partners in the Department of 

the Interior (DOI), other Federal, State and Territorial agencies, Tribes, industry, and agriculture to provide the 

information needed to help solve problems posed by these invaders. Key components of USGS invasive species 

science include the development of novel prevention, prediction, early detection, containment, and control tools.

USGS EMA Areas of Emphasis

• Preventing establishment and further spread of Asian carps in 

the Great Lakes, Upper Mississippi, and Ohio River Basins

• Control of sea lamprey (Petromyzon marinus) in the 

Great Lakes

• Support for brown treesnake (BTS, Boiga irregularis) 

control on Guam and regional Pacific Island biosecurity 

• Developing tools to address Rapid ʻOhiʻa Death (ROD, 

Ceratocystis lukuohia and huliohia) in Hawaii (an introduced chytrid fungus infecting ʻOhiʻa, a native Hawaiian 

tree species)

• Development of control and monitoring techniques for 

Burmese python (Python bivittatus), black and white tegu 

(Tupinambis merianae), and other pests in the Everglades 

and southern Florida

• Supporting management efforts related to invasive weeds 

such as salt cedar (Tamarix spp.), cheatgrass (Bromus 

tectorum), Russian olive (Elaeagnus angustifolia), leafy 

spurge (Euphorbia esula), brome (Bromus spp.), and 

buffelgrass (Cenchrus ciliaris)

• Assisting Federal, State and Tribal partners with response 

to zebra and quagga mussels (Dreissena polymorpha and 

D. bugensis) in the continental United States

• Providing nationwide reporting, monitoring, and tracking of 

all freshwater aquatic invasive species as part of a national 

early detection system

Invasive Species Facts

• Invasive species are alien species whose introduction does 

or is likely to cause economic or environmental harm, or 

harm to human health. 

• Invasive species adversely affect every State, Territory, and 

Tribe in the Nation, including urban centers and wilderness 

areas.

• Increased global travel and trade provide pathways for both 

intentional and unintentional introductions of invasive species. 

• Every year, harm caused by invasive species costs governments, industries, and private citizens substantial economic 

losses potentially reaching into the billions of dollars.

• The costs of battling invasive species impact farmers, 

ranchers, businesses, and all levels of government to control the economic, health, and environmental threats these 

invaders pose.

• Invasive species decrease agricultural production, compete with and predate on native plants and wildlife, impair 

critical water infrastructure, transmit disease to wildlife 

and humans, threaten commercial and native fisheries, and 

reduce hunting, fishing, and other recreational opportunities such as boating and swimming. 

U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2018–3080

April 2019
In Hawai’i, USGS scientists have developed a 

successful eDNA field method to detect the fungus 

that causes Rapid Ohi’a Death (ROD) in mature Ohi’a 

trees in collaboration with partners.

Buffelgrass is a nonnative perennial 

grass that is rapidly spreading across 

National Park Service (NPS) and 

adjacent lands in the Sonoran Desert 

in Arizona and California and can carry 

fire quickly across the landscape. USGS 

is working with the NPS and others on 

EDRR tools to detect invasive buffelgrass 

such as sensors aboard Unmanned 

Aerial Systems and high-resolution 

satellite imagery.

USGS EMA Advanced Tools and Technology

Genetics and Invasive Species Detection—Environmental 

deoxyribonucleic acid (eDNA), genetic material shed by organisms 

into the waters in which they live, has recently emerged as a 

powerful genetic tool for detecting invasive species and rare aquatic 

animals in lake or river water. USGS research has led to refinements 

of methods to improve detection sensitivity, understand how eDNA 

changes over time, and decrease time between sampling and results. 

For example, scientists have developed a portable eDNA detection 

kit for detecting bighead and silver carps that provides results in less 

than an hour and could be used to detect other species. The USGS 

also used eDNA sampling 

to detect invasive northern 

pike (Esox lucius) in several 

south-central Alaska lakes 

following eradication efforts, 

and to monitor potential 

range expansion of pythons 

and snakeheads in southern 

Florida. 

Nonindigenous 

Aquatic Species 

Database—The 

USGS Nonindigenous Aquatic Species (NAS) Program, 

created by Congress in 1990 to provide timely information 

to natural resource managers, maintains a database that 

helps managers monitor, record, and analyze sightings of 

nonindigenous aquatic plant and animal species throughout 

the United States. The NAS database is a clearinghouse of 

information for confirmed sightings of nonindigenous aquatic 

species throughout the Nation. The database assists managers 

by sending email risk alerts intended to support prompt early 

detection and rapid response efforts in the field when new 

species are detected in sites of concern. Flood and Storm 

Tracker (FaST) Maps, a new NAS database product, enable 

managers to predict potential spread of NAS associated with 

flooding and storm surge events. The database also provides 

species distribution maps, scientific publications, and other 

information products to support natural resource management.

Early Detection and Rapid Response (EDRR) Tool Development—

While invasive species prevention is the first line of defense, even the best prevention efforts will not stop all invaders. EDRR is a coordinated set of actions to detect 

and eradicate potential invasive species in a specific location before they spread 

and cause harm. In one example, the USGS provides scientific support to resource 

managers to aid in implementation of EDRR efforts, make informed management 

actions, and lead multiagency and partner rapid response efforts such as training 

relative to brown treesnake (BTS) rapid response. For this effort, the USGS developed a model for determining the amount of search and (or) trap effort required 

when responding to BTS rapid response efforts to meet the desired degree of certainty by resource managers that a population is not present in the area. 

USGS scientists developed tools to assist managers in 

predicting potential range expansions of invasive lionfish 

(Pterois volitans) following weather-related flooding such 

as hurricanes, and in producing maps indicating potential 

rapid response areas after a new location is invaded.
A brown treesnake crawls on some frangipangi blossoms in Guam, where significant 

quarantine efforts are implemented to prevent the introduction and establishment of 

this invasive snake elsewhere.

USGS has extensive capabilities that have led to development of the risk assessment tool, Fluvial Egg Drift Simulator, 

for bighead, silver, and grass carps to predict where Asian 

carps are likely to spawn and where eggs and larvae will 

likely be located after spawning.

Asian Carps—High-density populations of Asian carps [bighead, 

black, grass, and silver carps (Hypophthalmichthys nobilis, Mylopharyngodon piceus, Ctenopharyngodon idella and H. molitrix)] have 

caused a range of negative impacts to the Nation’s waterways. The 

USGS provides data, tools, and technologies to partners to keep these 

invasive fish out of the Great Lakes and other aquatic ecosystems, and 

to control them where they occur in the Ohio and Mississippi River 

Basins. Current field testing is being conducted on underwater sound 

technology and carbon dioxide levels in water as methods to deter 

Asian carps range expansion, and researchers are testing a specific 

toxicant to control populations in open-water systems. 

USGS EMA Research Examples

Invasive zebra mussels are now part of many 

of our Nation’s lakes and rivers, and USGS 

science and technical assistance is assisting 

in the control and prevention of further spread 

of these and other damaging mollusks.

USGS scientists conduct research on 

invasive Burmese pythons in Everglades 

National Park and other DOI lands in 

South Florida to aid in the management of 

these large, voracious constrictor snakes.

Burmese Pythons—Burmese pythons are large invasive snakes, which can 

exceed 18 feet and 150 pounds. USGS research on Burmese pythons has focused on 

methods for detection and control, predicting potential range of the species in the 

United States, understanding thermal tolerances, and conducting risk assessments of 

pythons and other giant constrictors. The USGS continues to conduct research to aid 

in the management of Burmese pythons in Everglades National Park, Big Cypress 

National Preserve, and other DOI lands in southern Florida. Recently, USGS scientists and partners documented that Burmese pythons have devastated the mammal 

communities in Everglades National Park and are known to have consumed several 

endangered species including Wood Storks (Mycteria americana) and Key Largo 

woodrats (Neotoma floridana smalli).

Zebra and Quagga Mussels—Invasive zebra and quagga mussels (collectively 

called dreissenid mussels) affect industrial and municipal infrastructure, recreational water 

use, and they severely alter aquatic ecosystems as they spread across North America. The 

USGS has been conducting dreissenid mussel control and rapid response in the Great 

Lakes and Upper Mississippi River Basins for several years including developing genetic 

tools for detecting and evaluating the application of molluscicides and assessing effects 

on nontarget species. In 2016 the first detection of dreissenid mussel larvae was documented in Montana resulting in strengthened Federal government efforts, in coordination 

with States and Tribes, to address invasive mussels in the Northern Rocky Mountains 

and Columbia River Basin. In support of this effort, the USGS evaluated genetic markers for early detection of 

dreissenid mussels and is 

working to improve eDNA 

sampling and analysis protocols, and early-detection 

monitoring plans.

Brown Treesnakes and Pacific Islands Biosecurity Research— The BTS is a threat to the economy and unique ecosystems of Guam, specifically to the biodiversity, economy, and human health of the Pacific region and 

beyond. The BTS was accidentally introduced to Guam in the late 1940s and 

has caused global or island-wide extinction of 9 of 13 native forest birds. This 

invader frequently short circuits power lines, causing costly power outages 

and is a significant biosecurity risk. The USGS has played an essential role in 

developing control techniques such as traps and barriers to manage this pest 

and leads the regional BTS Rapid Response Team to ensure effective EDRR to 

BTS sightings in new locations on the Pacific Islands. Scientists have also been 

applying lessons learned from working on the BTS to inform other biosecurity 

efforts regionally.
Photograph Credits

Tegu and zebra mussel images from ©iStock.com

All other images are U.S. Geological Survey

Contact Information

Cindy Tam, Invasive Species and Disease Program Coordinator ckolar@usgs.gov or 703-648-4023

Earl Campbell, Invasive Species Program Manager ewcampbell@usgs.gov or 703-648-5861

https://www.usgs.gov/ecosystems/invasive-species-program

Cheatgrass—Cheatgrass and other invasive grasses continue to expand into 

sagebrush ecosystems in western United States where they colonize burned areas 

before native plants can become established, providing more fuel for wildland fire. 

USGS scientists are assessing strategies to restore native vegetation to fight cheatgrass invasion and increase postfire resilience. These strategies include modeling 

postfire recovery times and developing fire management protocols that include 

alternatives to chemical and mechanical cheatgrass control methods and linking 

patterns of wildfire across the Great Basin with changing sage-grouse populations 

and climate.

Invasive cheatgrass turning red in the Squirrel Creek burn area, Medicine Bow 

National Forest, Wyoming. The USGS developed a map of the percentage of cheatgrass cover by early June each year which can help land managers plan fire 

operations and protective measures for development and crucial wildlife habitats.

In arid and semiarid regions of the western 

United States, much of the riparian vegetation is dominated by nonnative shrubs 

and trees such as salt cedar (tamarisk), 

which have replaced native vegetation in 

many areas over the past several decades. 

(Photograph from NPS)

Salt Cedar (Tamarisk)—The USGS is a leader in understanding the distribution 

and impact of invasive salt cedar, known as tamarisk, on riparian ecosystems in 

the Southwest including effects on plant communities, water loss, erosion, wildlife 

use and human recreational resources. Scientists are studying the effectiveness of 

biological control to reduce salt cedar populations, in collaboration with multiple 

partners to provide valuable information for resource managers tasked with 

decisions related to restoration of native plant communities and associated wildlife, 

and assessments of changes in water yield.

Sea lampreys feed on the blood and fluids of native fish, causing population declines in commercial and recreational species 

that are essential to the Great Lakes’ multibillion dollar per year fishery. USGS scientists registered with the U.S. Environmental 

Protection Agency the first vertebrate pheromone, which when applied can increase sea lamprey trap catch by 35 percent.

Sea 

Lamprey—

The parasitic sea lamprey invaded the Great Lakes 

in the mid-20th century, devastating valuable native 

fisheries and coastal economies. The USGS plays a 

central role in sea lamprey control research by working with the Great Lakes Fishery Commission, the 

U.S. Fish and Wildlife Service, other State, Federal, 

and Tribal agencies, and academic institutions to 

provide science on sea lamprey biology, ecology, and 

control technologies. Recently, the USGS developed 

a novel trap and electrical guidance array capable of 

removing 75 percent of invasive sea lamprey from a 

stream with minimal impacts to nontarget species and 

streamflow.

Black and White Tegu—(hereafter referred to as tegu) are large 

omnivorous lizards native to South America and are common in international pet trade. There are at least three established populations of 

tegus in southern Florida, all likely resulting from escaped or released 

pets. Tegus eat a variety of plants and animals but specialized in 

consuming eggs from bird and reptile nests. USGS scientists recently 

demonstrated that conditions suitable for tegu survival may exist 

across the southern one-third of the continental United States. USGS 

research on tegus includes developing and testing methods for detection and control, determining thermal tolerances, and assessing risks 

to the greater Everglades ecosystem.

USGS is working on development of tools for the detection and 

capture of invasive reptiles in Florida such as black and white 

tegu lizards (Salvator merianae).

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

https://doi.org/10.3133/fs20183080