U.S. Department of the Interior

U.S. Geological Survey

Fact Sheet 2016-3063

September 2016

Printed on recycled paper

Use of an integrated pest management 

approach helps managers focus monitoring 

and control efforts. These multiple areas of 

research are interrelated.

Life

History

Ecosystems

Impacts

Detection

Tools

Control

Tools

USGS Science and Technology Help Managers 

Battle Invading Asian Carp

The U.S. Geological Survey (USGS) conducts Asian carp research 

focused on early detection, risk assessment, and development of control tools 

and strategies. The goals are to prevent the establishment of invasive Asian 

carp in the Great Lakes and to reduce their impacts in the Ohio River and 

Mississippi River Basins and elsewhere. Managers can use the information, 

tools, and strategies for early detection of Asian carp and to control them when 

their presence is first evident. New detection and control tools are designed 

to accommodate expansion to other invasive species and application in 

geographically diverse areas. 

This USGS focus complements goals of the Great Lakes Restoration 

Initiative (GLRI), a multi-agency collaboration started in 2010 to protect and 

restore the Great Lakes. As a member of the Asian Carp Regional Coordinating 

Committee, which guides Asian carp efforts, the USGS works closely with 

Federal and State agencies, Canada, and others to address high-priority Asian 

carp issues and provide science to inform management decisions. 

The USGS has gained extensive knowledge of Asian carp biology and life 

history over the past 30 years. That knowledge guides the design, development, 

and application of control strategies, 

and is essential for developing 

approaches in line with 

modern principles and 

practices of integrated 

pest management (IPM). 

IPM is a process used 

to solve pest problems 

while minimizing risks 

to people and 

the environment.

The USGS delivers high-quality data, technologies, and decision-support tools to help managers 

reduce existing populations and control the spread of Asian carp in the Nation’s waterways. 

What are Asian Carp?

The term “Asian carp” is used here to 

refer to four species of fish introduced 

into the United States in the 1960s 

and 1970s. Asian carp now have 

reproducing populations in waters 

of the United States. These species 

have similar life histories but differ in 

diet and distribution. Bighead carp 

and silver carp are filter feeders that 

remove plankton from the water and 

are established throughout much of 

the Mississippi River Basin. Grass carp 

specialize on eating submerged aquatic 

plants and are widely distributed in the 

United States, with growing numbers 

of reproducing populations, including 

in the Lake Erie watershed. Black carp 

consume freshwater mussels, snails, and 

other mollusks and have a limited but 

expanding range in the Mississippi River. 

Bighead carp

Bighead carp

Silver carp Grass carp Black carp
Figure 1. Conceptual schematic showing the Fluvial Egg Drift Simulator model and processes. (From Murphy and others, 2016.)

Turbulence Movement of eggs

Drives

suspension

Advection and dispersion

Growth

Spawning Hatching

Gas bladder

 inflation

x

z y

Flow

direction

of Asian carp using eDNA. The portable kit reduces the time 

between sample collection and results from days to less than 1 

hour for time-critical samples. Field testing indicates that lawenforcement officers without any prior experience can use the 

kit to detect the presence of a single, minnow-sized silver carp 

commingled with more than 10,000 fathead minnows in a large 

fish tank. Additional testing and accompanying directions and 

protocols for sample collection are being developed. Training and 

equipping law-enforcement officers with detection kits available 

through the GLRI is planned.

Risk Assessment

Scientists do risk 

assessments to estimate the 

likelihood a species may 

invade, spread, or cause 

economic or ecological 

damage; to identify 

ecosystems or habitats most 

likely to be invaded; and to 

estimate other risks associated with species’ invasions. Risk 

assessments are part of the IPM process and help managers focus 

monitoring and control efforts. The USGS has worked with the 

Government of Canada on a completed international bighead 

carp and silver carp risk assessment and is part of a partnership 

developing assessments for grass carp and black carp. The USGS 

also strives to inform and support decision-makers by producing 

easy-to-use decision tools based on risk-assessment results. 

Identification of Potential Spawning Sites

Understanding when Asian carp might be able to reproduce 

would inform monitoring and control efforts. Because not all 

habitats are suitable for reproduction, the USGS developed a 

computer model called Fluvial Egg Drift Simulator (FluEgg) 

to predict where river conditions would allow bighead, silver, 

and grass carp eggs and larval fish to survive until they find 

nursery habitat (fig. 1). FluEgg also can be used to assess risk 

of establishment of new spawning populations and to evaluate 

the effectiveness of control measures. It is applicable in areas 

where Asian carp are present and areas that have not yet been 

invaded. Identifying potential spawning areas may also provide 

opportunities for managers to disrupt spawning.

Early Detection

Early detection is a vital part of managing any invasive 

species. Detection of Asian carp is difficult because they avoid 

nets and other traditional capture gear, so they are hard to 

catch especially when populations are small. The USGS has 

contributed to the development and improvement of new genetic 

approaches to detect Asian carp at low abundances and identify 

initial invasions. 

Environmental DNA

Improvements in the technology to detect environmental 

DNA (eDNA) offer the potential to provide managers a 

“genetic toolbox” for detection and characterization of Asian 

carp occurrence. This technology involves detection of DNA 

in an environmental sample, such as lake or river water. USGS 

research has led to refinements to past methods to improve 

detection sensitivity, increase cost-effectiveness, and decrease 

time between sampling and results. Current research efforts are 

focused on evaluating the application of eDNA detection as a 

tool to detect fish movement, habitat use, and spawning, and to 

evaluate the effectiveness of management actions. The USGS 

also is developing methods to use eDNA to estimate Asian 

carp biomass and to characterize how eDNA changes with the 

passage of time once shed from a live fish. 

Portable eDNA Detection Device 

Working with industry, the U.S. Fish and Wildlife Service 

(USFWS), and state agencies, the USGS has tested and validated 

a commercially available kit for rapid detection 

Samples containing environmental DNA are processed in a laboratory.

Law enforcement processing eDNA samples.
Assessment of Food Availability in the Great Lakes

Understanding the potential impact of Asian carp in areas 

not yet invaded requires determining if adequate food resources 

are available. Using satellite imagery, USGS scientists have 

determined that there is enough food available for bighead carp 

and silver carp to survive if they reached Lake Erie. Green algae 

and blue-green algae on the surface of the lake are a preferred 

food source for these fish. The water temperatures and algal 

concentrations detected in Lake Erie from 2002 to 2011 show 

that bighead carp and silver carp could live and grow in this 

environment. If bighead carp and silver carp were to populate 

Lake Erie, they could damage native fish populations and have 

negative effects on the economy of the Great Lakes Region. 

Scientists also have begun to inventory and map aquatic 

vegetation in Lake Erie to better understand availability of food 

for grass carp.

Integrated Containment and Control

USGS scientists continue to develop and test containment 

and control tools and technologies to enhance the ability of 

agencies to manage Asian carp to minimize their influence 

and spread. The USGS also is 

investigating options for combined 

implementation of tools in an IPM 

context. A variety of control options, 

including hot water, ozone, and those 

mentioned below, have or are being 

explored, sometimes in creative 

combinations to address Asian 

carp issues.

Preventing Movement toward the 

Great Lakes

In collaboration with the U.S. 

Army Corps of Engineers (USACE), 

the USGS continues to collect 

hydraulic and water-quality data and 

conduct analyses to answer engineering questions and inform 

modeling efforts at Brandon Road Lock and Dam (BRLD) 

and other locations in the Illinois River and the Chicago Area 

Waterway System. Continuous flow and water-quality data 

contribute to designing Asian carp controls that are effective 

even when storms, lock operations, and other factors change 

water flow. The USGS and the USFWS also have conducted 

experiments in the Illinois Waterway to understand the potential 

for young Asian carp to move into areas not yet invaded, 

including beyond electric dispersal barriers. The USGS has 

measured and analyzed the hydrodynamics around the barges 

and provided the information to managers that are working on 

mitigation strategies. 

Carbon Dioxide 

The results of laboratory studies and other research in 

experimental ponds suggest that silver carp and bighead carp 

avoid areas with elevated concentrations of carbon dioxide gas 

(CO2

). This has led the USGS to explore the use of elevated CO2

to deter the further spread of Asian carp in certain areas, such as 

above locks and dams. For example, the USGS is evaluating the 

behavior of Asian carp in CO2 gradients in the field and testing 

methods to deliver CO2. Research results show elevated CO2 can 

be an effective deterrent for bighead carp and silver carp that 

could be integrated with multiple deterrents and barriers (for 

example, electric, sound, and CO2) to provide control 

and redundancy. 

Microparticles

The USGS is developing a targeted toxicant-delivery system 

in the form of a multilayered microparticle that is sized in the 

feeding range of bighead carp and silver carp but smaller than 

what most native fish feed on. The initial chemical incorporated 

into microparticles is Antimycin A, a U.S. Environmental 

Protection Agency (EPA)-registered fish toxicant, but the 

formulation of the particle can be modified to incorporate other 

potential fish-control chemicals. In laboratory studies, Asian carp 

consumed Antimycin A laden microparticles and died, but bluegill 

and largemouth bass did not. Initial studies to test Antimycin A 

laden microparticles in experimental ponds with algal attractants 

showed that microparticles killed a 

number of the silver carp and bighead 

carp in the pond without killing 

largemouth bass. Options for field 

experiments are now being explored. 

USGS researchers are adapting use 

of microparticles for other toxicants, 

bioactive compounds, and to target 

grass carp and other invasive species.

Algal Attractants

USGS scientists have discovered 

that Asian carp are strongly attracted 

to certain mixtures of algae and have 

been testing methods for using the 

attractants as lures to facilitate fish 

capture and removal. In expanded studies, algal compounds 

favored by Asian carp are being applied as an attractant through 

“feeding stations” deployed in conjunction with nets and traps. 

The attractants help draw Asian carp toward nets, traps, and other 

capture gear. The effectiveness of the gear for harvesting fish is 

then evaluated. Other studies involve the pairing of underwater 

sound with algal attractants to see how that combination affects 

Asian carp responsiveness to feeding stations, and testing the 

use of feeding stations for enhancing fish attraction during 

microparticle application.

Underwater Sound

The USGS is testing the use of underwater sounds to deter 

further spread of Asian carp. Working with the University of 

Minnesota, the USGS determined that bighead carp and silver 

carp react strongly to the broadband outboard-motor sound. 

Bighead carp and silver carp swam away from the recorded sound 

of a boat motor as many as 37 times in succession, whereas many 

USGS scientists measuring flow velocity in a lock channel.
Great Lakes

RESTORATION

Great Lakes

RESTORATION

RESTORATION

GREAT LAKES

RESTORATION

GREAT LAKES

RESTORATION

GREAT LAKES

ISSN 2327-6916 (print)

ISSN 2327-6932 (online)

http://dx.doi.org/10.3133/fs20163063

native fishes had little to no response. 

This suggests that sound may have some 

specificity for bighead carp and silver 

carp, and deter them from entering an 

area while allowing native fishes to 

move freely. Studies also are underway 

to evaluate the use of sound to move fish 

and improve capture and removal.

Making New Detection and Control Tools 

Available for Use 

As new tools are developed, 

managers need information about how 

the tools work, the information they 

provide, and how to use them. The 

USGS works with resource managers to 

better understand the Asian carp issues 

that managers want to address. The 

USGS also leads training sessions and 

workshops to meet managers’ needs and 

to introduce new tools, technologies, and 

scientific findings.

them where they now occur, including 

the Ohio River and Mississippi River 

Basins. Contributions by the USGS to 

inform integrated pest management are 

particularly important, especially the 

objective evaluation of tools for control. 

The USGS will continue this important 

research, coupled with education, 

synthesis, publication, and other forms 

of knowledge transfer that inform 

management solutions.

Reference Cited

Murphy, E.A., Garcia, Tatiana, Jackson, P.R., and 

Duncker, J.J., 2016, Simulation of hypothetical 

Asian carp egg and larvae development and 

transport in the Lockport, Brandon Road, 

Dresden Island, and Marseilles Pools of the 

Illinois Waterway by use of the fluvial egg drift 

simulator (FluEgg) model: U.S. Geological Survey 

Open-File Report 2016-1011, 19 p., http://dx.doi.

org/10.3133/ofr20161011.

Authors:

Cynthia S. Kolar and Sandra S. Morrison

Carp images used in banner: 

©Joseph R. Tomelleri. Used with permission.

All other photographs from USGS unless otherwise noted.

For more information:

Ecosystems Mission Area

http://www.usgs.gov/ecosystems/

http://www.usgs.gov/ask/

1-888-ASK-USGS (1-888-275-8747)

USGS Asian carp science – https://www2.usgs.

gov/ecosystems/invasive_species/midwest.html – 

http://cida.usgs.gov/glri/index.jsp#/Home/AsianCarp

Great Lakes Restoration Initiative – 

http://greatlakesrestoration.us

Asian Carp Regional Coordinating Committee – 

http://www.asiancarp.us

National Asian Carp Plan – 

http://anstaskforce.gov/Documents/Carps_

Management_Plan.pdf

1-888-ASK-USGS (1-888-275-8747)

Publishing support provided by the 

U.S. Geological Survey, 

Science Publishing Network,

Tacoma Publishing Service Center

Creating Barriers — Stopping Asian Carp at Brandon Road Lock and Dam

In the Great Lakes Mississippi River Interbasin Study, the U.S. Army Corps of 

Engineers (USACE) is assessing the viability of establishing a single point to control 

the one-way, upstream transfer of Asian carp and other aquatic nuisance species 

from the Mississippi River Basin into the Great Lakes Basin near the Brandon 

Road Lock and Dam (BRLD) located in Joliet, Illinois. The USGS is providing critical 

hydraulic data and analyses to help the USACE understand water flow and quality 

around the BRLD and inform barrier decisions, and to provide information for 

testing control tools.

Brandon Road Lock and Dam has been identified by the USACE as a downstream 

control point of the Chicago Area Waterway System for Asian carp and a number 

of other aquatic nuisance species. The topographic and geographic positioning 

of the site allows it to serve as a single point of passage for species able to move 

upstream toward the Great Lakes. (Photograph by U.S. Army Corps of Engineers, 

April 22, 2014.)

Compliance with environmental 

regulations is a major management 

consideration when applying chemical or 

biological control tools in any water body. 

To address environmental regulations, the 

USGS is collaborating with the USFWS 

and the EPA to develop the information 

needed to register chemical controls like 

CO2

 and Antimycin A laden microparticles 

with the EPA and State regulatory 

agencies. The USGS and USFWS also 

are working to identify species for testing 

to assess potential effects of chemical 

or biological controls on threatened and 

endangered species.

The Future

The negative effects of invasive 

Asian carp in North America already are 

far reaching and have real potential to 

expand and intensify. A wide variety of 

organizations are working to keep these 

invasive fish out of the Great Lakes and 

other aquatic ecosystems and control 

The USGS, in collaboration with the Great Lakes 

Restoration Initiative and Asian Carp Regional 

Coordinating Committee, provides science and 

technology to control the spread of Asian carp.

Design: William Gibbs