Management and Control Plan for 

 Bighead, Black, Grass, and Silver 

 Carps in the United States 

 Submitted to the Aquatic Nuisance Species Task Force 

 Prepared by the Asian Carp Working Group 

 October 2007

© Photo courtesy of Brian Johnson, 

 U.S. Army Corps of Engineers 

Bighead carp Silver carp 

Black carp Grass carp 
 2

Suggested citation for this document: 

Conover, G., R. Simmonds, and M. Whalen, editors. 2007. Management and control plan for 

bighead, black, grass, and silver carps in the United States. Asian Carp Working Group, 

Aquatic Nuisance Species Task Force, Washington, D.C. 223 pp. 

Cover sketches courtesy of Matthew Thomas, Kentucky Department of Fish and Wildlife 

Resources.
 i

ASIAN CARP WORKING GROUP MEMBERS 

Name Affiliation 

John Andersen The Nature Conservancy 

Mike Armstrong Arkansas Game and Fish Commission 

Jimmy Avery Mississippi State University 

Valerie Barko Missouri Department of Conservation 

Kim Bogenschutz Iowa Department of Natural Resources 

Joel Brammeier Lake Michigan Federation 

Beth Brownson Ontario Ministry of Natural Resources 

Sarah Calloway U.S. Forest Service 

Duane Chapman U.S. Geological Survey 

Matt Cochran FishPro/Cochran and Wilken, Inc. 

Mike Conlin Illinois Department of Natural Resources 

Greg Conover1

 U.S. Fish and Wildlife Service 

Mark Cornish U.S. Army Corps of Engineers 

Becky Cudmore Department of Fisheries and Oceans Canada 

John Dettmers Illinois Natural History Survey 

Carole Engle University of Arkansas at Pine Bluff 

Thad Finley Farm Cat Livehaulers 

Jeff Finley U.S. Fish and Wildlife Service 

Tom Flatt Indiana Department of Natural Resources 

Mike Freeze Keo Fish Farm 

Jim Garvey Southern Illinois University 

Chris Goddard Great Lakes Fishery Commission 

Mike Goehle U.S. Fish and Wildlife Service 

Joanne Grady U.S. Fish and Wildlife Service 

Bart Hawcroft Missouri Department of Agriculture 

Mike Hoff U.S. Fish and Wildlife Service 

Chris Horton B.A.S.S./ESPN 

Gary Jensen U.S. Department of Agriculture - Cooperative State Research, 

Education and Extension Service 

Anita Kelly Southern Illinois University 

Jack Kilgore U.S. Army Corps of Engineers 

Ron Kinnunen Michigan State University - Sea Grant 

Rob Klumb U.S. Fish and Wildlife Service 

Cindy Kolar U.S. Geological Survey 

 

1

 Chairman 
 ii

Name Affiliation 

Bill Mattes Great Lakes Indian Fish and Wildlife Commission 

Bill Mauck University of Missouri – Columbia 

Paula Moore Jones and Eaker Farms 

Tom Mosher Kansas Department of Wildlife and Parks 

Phil Moy University of Wisconsin - Sea Grant 

Elizabeth Murphy U.S. Environmental Protection Agency 

Marshal Myers Pet Industry Joint Advisory Council 

John Nickum Private Consultant, Aquatic Policy and Information Center 

International 

Leo Nico U.S. Geological Survey 

Mike Oetker U.S. Fish and Wildlife Service 

Tim Patronski U.S. Fish and Wildlife Service 

Mark Pegg University of Nebraska 

Jim Petty U.S. Geological Survey 

Bob Pitman U.S. Fish and Wildlife Service 

Andrew Plauck U.S. Fish and Wildlife Service 

Jerry Rasmussen Mississippi Interstate Cooperative Resource Association 

Bill Reeves Tennessee Wildlife Resources Agency 

Jay Rendall Minnesota Department of Natural Resources 

Mike Schaeffer Schaeffer Fish Market 

Steven Schainost Nebraska Game and Parks Commission 

Lynn Schlueter North Dakota Game and Fish Commission 

Hal Schramm U.S. Geological Survey 

Steve Shults Illinois Department of Natural Resources 

Rob Simmonds U.S. Fish and Wildlife Service 

Darlene Smith Department of Fisheries and Oceans Canada 

Andy Starostka U.S. Fish and Wildlife Service 

Nathan Stone University of Arkansas at Pine Bluff 

Kristin TePas Illinois Natural History Survey / Illinois - Indiana Sea Grant 

Dan Thomas Great Lakes Sport Fishing Council 

Jay Troxel U.S. Fish and Wildlife Service 

Hugh Warren Catfish Farmers of America 

Mike Welker U.S. Forest Service 

Paul Zajicek National Association of State Aquaculture Coordinators 
 iii

EDITORS 

Greg Conover, Asian Carp Working Group Chairman 

Assistant Project Leader 

U.S. Fish and Wildlife Service 

Carterville Fishery Resources Office 

9053 Route 148, Suite A 

Marion, Illinois 62959 

Phone: (618) 997-6869 

Fax: (618) 997-9185

greg_conover@fws.gov 

Rob Simmonds 

Project Leader 

U.S. Fish and Wildlife Service 

Carterville Fishery Resources Office 

9053 Route 148, Suite A 

Marion, IL 62959 

Phone: (618) 997-6869 

Fax: (618) 997-9185 

rob_simmonds@fws.gov 

Michelle Whalen 

Technical Writer 

U.S. Fish and Wildlife Service 

Migratory Birds and Habitat Programs 

911 NE 11th Ave. 

Portland, OR 97232 

Phone: (503) 231-2266 

Fax: (503) 231-2019 

michelle_whalen@fws.gov 
 iv

ACKNOWLEDGEMENTS 

I would like to thank all the members of the Asian Carp Working Group (Working Group) for their 

role in the collaborative development of this management and control plan. This document is 

the result of many dedicated individuals who invested numerous personal hours, including 

nights and weekends, to develop this plan. I am particularly grateful to those Working Group 

members who actively participated on drafting teams, developed a first draft of the plan for the 

remainder of the Working Group to build upon, participated in Working Group meetings, and 

assisted in revising and finalizing this document for the U.S. Fish and Wildlife Service Region 3 

Fisheries Program and the Aquatic Nuisance Species Task Force. Duane Chapman, Mike 

Goehle, Bill Mattes, Jay Rendall, and Hal Schramm provided a valuable contribution to the 

development of this plan in their voluntary roles as drafting team leaders. Mike Armstrong, 

Jimmy Avery, Duane Chapman, Carole Engle, Mike Goehle, Jo Grady, Rob Klumb, John 

Nickum, Steve Shults, Rob Simmonds, Jay Troxel, and Paul Zajicek were instrumental in 

revising the draft document based on guidance from the Working Group. Tom Mosher, John 

Nickum, Rob Simmonds, Michelle Whalen, and Paul Zajicek provided editorial reviews of this 

document. I would like to thank several colleagues that are not members of the Working Group 

but who contributed to the completion of this management and control plan, including Nate 

Caswell, Andrew Plauck, Shelley Simmonds, and Colby Wrasse. Mary Balogh, Sara Dolan, 

Mike Hoff, Tim Patronski, and Mike Stahl assisted in summarizing state regulations by providing 

data or developing GIS based maps. Andrew Mitchell, U.S. Department of Agriculture, though 

not an official member of the Working Group, provided valuable contributions throughout the 

development of this plan. Many other colleagues assisted in the development or review of 

specific materials or provided expertise through personal communications that are cited 

throughout the document. Susan Parks facilitated Working Group meetings and provided 

documentation for the completion of this plan. I would also like to thank Gerry Jackson and 

Everett Wilson for their participation in Working Group meetings and their guidance throughout 

this process. Kari Duncan, Mike Hoff, Mike Oetker, Rob Simmonds, and Erin Williams also 

provided guidance throughout this process for which I am grateful. 

 

Greg Conover Chair, Asian Carp Working Group
 v

EXECUTIVE SUMMARY 

There are many carps native to Asia, including seven that have been introduced to the United 

States. For the purposes of this document the term “Asian carps” refers to four species: black 

carp (Mylopharyngodon piceus), bighead carp (Hypophthalmichthys nobilis), grass carp 

(Ctenopharyngodon idella), and silver carp (H. molitrix). Feral bighead, grass, and silver carps 

have all established reproducing populations in several major rivers of the United States. To 

date, there have been at least 14 confirmed collections of adult black carp by commercial 

fishers in the United States and unconfirmed reports of adult black carp captured annually in the 

Mississippi River and its tributaries over the past 13 years (Nico 2007; Nico et al. 2005). There 

have been no collections of black carp eggs and larvae or observations of spawning (Nico et al. 

2005). 

The U.S. Fish and Wildlife Service (USFWS) requested and co-funded the completion of risk 

assessments by the U.S. Geological Survey (USGS) that analyzed the probability and 

consequences of a species becoming established in the United States. Using risk assessment 

methods described by the Risk Assessment and Management Committee (1996), the USGS 

concluded that the organism risk potentials for bighead, black, and silver carps are all high (i.e., 

an unacceptable risk; Kolar et al. 2007; Nico et al. 2005). A national risk assessment for grass 

carp has not been completed and state-level risk assessments may still be needed where grass 

carp have not been reported or where the species has not become established. 

The life history traits of Asian carps (e.g., reproductive capability, population densities, feeding 

habits, broad climate tolerance, mobility, and longevity) indicate that these four species have a 

high probability of causing ecological and economic effects where populations become 

established (Mandrak and Cudmore 2004; Kolar et al. 2007; Nico et al. 2005). In some 

locations of the Mississippi River Basin, such effects have occurred. Natural resources 

managers are concerned that Asian carps have the potential to cause extensive and irreversible 

changes to the aquatic environment, particularly those that have been extensively altered and 

are severely impacted by on-going physical and chemical stressors, thereby jeopardizing the 

long-term sustainability of native aquatic species, particularly to imperiled, threatened, and 

endangered species. The USFWS added all forms of live silver carp to the list of injurious 

wildlife under the Lacey Act, prohibiting their importation and interstate transport (except by 

permit), effective August 9, 2007. The USFWS has also been petitioned to add bighead and 

black carp as injurious wildlife under the Lacey Act and is evaluating these species to make 

determination recommendations. Confounding this situation is the fact that the bighead carp 

has been cultured and sold as a live food fish product since the early 1980s, grass carp have 

been stocked nationally by public and private entities since the mid 1970s as a biological control 

for aquatic weeds (grass carp are also cultured and sold as a live food fish product), and the 

black carp has been used since the early 1990s as a biological control for snail-borne parasites 

in commercial aquaculture production ponds. 

The USFWS recognized the complexity of the situation and that the potential magnitude of the 

problems were such that all stakeholders (i.e., private and public sector fisheries professionals, 

aquaculturists, aquatic ecologists, and the public) must be involved in the development of an 

appropriate management plan. With this kind of collaborative effort in mind, the USFWS and 

the Aquatic Nuisance Species Task Force organized an Asian Carp Working Group (Working 

Group) to develop a comprehensive national Asian carp management and control plan. This 

document represents the culmination of that effort.
 vi

The Working Group agreed that the desired endpoint of the plan is the extirpation of Asian carps 

in the wild, except for non-reproducing grass carp within planned locations [i.e., areas where 

nuisance aquatic vegetation can be controlled using planned introductions of sterile (triploid) fish 

contained within a designated area]. The Working Group was charged with developing a plan 

that first and foremost protects our Nation’s natural resources. The Working Group was also 

charged with developing solutions that would allow for a viable aquaculture industry when 

implemented. The Working Group agreed that identifying viable alternatives to black carp for 

snail control in aquaculture ponds is the highest research priority. Therefore, a framework for 

the responsible use of domestic stocks of Asian carps is described throughout this plan. It is in 

this context that the Working Group developed strategies and recommendations that address 

seven goals to protect the Nation’s natural resources. This collaborative process was highly 

successful and nearly all issues were resolved. The Working Group developed 48 strategies 

and 131 recommendations to manage and control Asian carps (Table I, page ix). 

Three issues were not resolved within the Working Group. In-depth discussions for these three 

unresolved issues are presented in Appendix 6.3 ‘Use of triploid black carp on aquaculture 

facilities’, Appendix 6.4 ‘Use of grass carp on aquaculture facilities and farm ponds in 

watersheds with self-sustaining populations of grass carp’, and Appendix 6.5 ‘Commercial, 

domestic transport of live farm-raised bighead and grass carps.’ Each appendix includes a 

synopsis of potential alternatives for the respective issues to highlight the principle ideas that 

have been discussed during the development of this plan. The potential alternatives are 

provided for consideration by natural resource management policy and decision makers, 

especially at the state level, where it is expected that most actions to address these issues will 

be made.

Implementation of the plan should begin immediately to prevent further introduction and to stop 

the spread of Asian carps into uninvaded waters throughout the United States. There is much 

to learn regarding management and control of Asian carps and new information should be 

readily assimilated into the management framework so that strategies and recommendations 

can be refined as plan implementation proceeds. Estimated cost for implementation over a 20 

year period is approximately $286 million. The amount of resources (e.g., staff, equipment, 

expertise, and funds) made available for plan implementation and how they are effectively 

integrated and efficiently used will largely determine the success of management and control 

efforts for Asian carps. 

Goal 1: Prevent accidental and deliberate unauthorized introductions of bighead, black, 

grass, and silver carps in the United States. Active control measures are needed to prevent 

introductions or range extensions; however, consideration must be given to the risks and 

costs/benefits to determine when actions are warranted. Strategies to manage 22 pathways for 

accidental or deliberate unauthorized introductions of Asian carps are presented within this plan. 

Working Group recommendations that address these potential pathways differ depending upon 

whether a particular species is absent, present without evidence of a reproducing population, or 

self-sustaining in the wild. Additional factors were considered for species in commercial trade 

(e.g. intended use). 

Goal 2: Contain and control the expansion of feral populations of bighead, black, grass, 

and silver carps in the United States. A long term, cooperative national effort between 

federal, state, tribal and private stakeholders is required to contain existing populations and 

prevent their spread. Such an effort will require a dedication of resources and manpower akin 

to those established for wildfire management and suppression or sea lamprey (Petromyzon 

marinus) control in the Great Lakes. Monitoring programs are paramount in the timely detection 
 vii

and effective utilization of Rapid Response Plans to prevent range expansions and eradicate 

new introductions. Due consideration should be given to the effects of containment actions on 

the long-term ecological sustainability of native aquatic resources. 

Goal 3: Extirpate, or reduce to levels of insignificant effect, feral populations of bighead, 

black, grass, and silver carps in the United States. Nine potential strategies to eradicate or 

reduce and maintain Asian carps at levels of insignificant effect were identified, however 

research is needed to develop and/or assess each. To increase effectiveness, multiple control 

strategies should be woven into an integrated management framework similar to the approach 

employed in the Great Lakes Sea Lamprey Control Program. Potential strategies for population 

reduction include: 1) enhancing commercial harvest through education, market research, gear 

development, and possibly financial incentives; 2) increasing recreational harvest; 3) physical 

removal by natural resources management agencies; 4)biological controls (e.g., diseases, 

parasites, or predators); 5) release of sterile Asian carps to reduce the reproductive success 

and size of a target population; 6) release of transgenic Asian carps (including “Daughterless 

Carp” and Trojan technologies) developed to reduce the size of a target population via spread of 

a deleterious gene; 7) application of pheromones to enhance harvest or interfere with 

reproduction, recruitment, or other behaviors; 8) habitat or hydrologic modification to favor 

native fishes over Asian carps or to facilitate harvest of Asian carps; and 9) use of piscicides. 

 

Goal 4: Minimize potential adverse effects of feral bighead, black, grass, and silver carps 

in the United States. The potential adverse effects of Asian carps are poorly understood, 

however reducing the abundance of feral populations is likely to benefit native species and 

systems. Once effects of feral Asian carps are accurately determined, it may be possible to 

further minimize their undesirable effects by direct remediation of the effect. It should be 

recognized that such efforts treat the symptoms of the problem rather than removing the 

causative agent. Nevertheless such strategies may be advisable if populations of key or 

threatened species are affected. In addition to mitigative actions that enhance native 

populations and their habitats, education of boaters and other recreationists is needed to 

minimize effects of silver carp. 

Goal 5: Provide information to the public, commercial entities, and government 

agencies to improve effective management and control of bighead, black, grass, and 

silver carps in the United States. An effective, nationally coordinated educational initiative 

is needed to: 1) identify specific needs for information and education; 2) identify the most 

effective approaches to reach and affect each group; 3) gather and validate the credibility of 

materials; 4) become both partners and leaders in planning, implementing, and evaluating 

education initiatives; and 5) identify gaps in knowledge or needs that can be addressed by 

applied or adaptive research. For greatest effectiveness, each component of an educational 

program should be developed in a stakeholder participatory process, monitored, evaluated, and 

adaptively managed. 

Goal 6: Conduct research to provide accurate and scientifically valid information 

necessary for the effective management and control of bighead, black, grass, and silver 

carps in the United States. A fundamental understanding of Asian carp biology and life history 

requirements underpins nearly all other areas of potential research to manage and control these 

species. Concurrent development of effective sampling gears and physical, chemical, or 

biological controls are required to reliably determine the relative abundance of Asian carp 

species and the potential for population reductions or eradication. The ecological and economic 

effects of past and potential introductions of Asian carps need to be verified and quantified to 

inform managers, stakeholders, and the general public of the importance in preventing further 
 viii

introductions. Research is needed to identify and evaluate economically and ecologically safe 

alternatives to Asian carps. Identifying viable alternatives to black carp for snail control in 

aquaculture ponds is the highest research priority identified by the Working Group. Research is 

also needed to find ways to ensure that any future use of Asian carps is low risk (i.e., low 

likelihood of escape and low consequence of escape). 

Goal 7: Effectively plan, implement, and evaluate management and control efforts for 

bighead, black, grass, and silver carps in the United States. Bighead, grass, and silver 

carps have established feral populations over a wide geographic range in the United States; 

therefore, a nationally coordinated approach is needed to successfully implement an effective 

integrated management plan. Implementation of an effective plan to address such a complex 

issue over such a wide geographic area will require a sophisticated management structure and 

significant funding. Efficient use of this funding will require that recommendations be 

strategically prioritized and properly sequenced. Formal institutional arrangements, including a 

process for conflict resolution, will also be required between partners to facilitate plan 

implementation. 
 ix

Table I. Summary of all Strategies and Recommendations, by Goal, developed by the Working 

Group for managing and controlling Asian carps in the United States. 

Goal 1: Prevent accidental and deliberate unauthorized introductions of bighead, black, 

grass, and silver carps in the United States. 

Strategies and Recommendations Species 

Strategy 3.1.1. Take actions to prevent the collection, transport, release, 

and improper disposal of Asian carps that may be intermixed with live wildharvested baitfish.

3.1.1.1. Assist states to develop, promulgate, and enforce regulations that manage 

the harvest, transport, import, trade, and release of live wild-harvested aquatic bait. 

Bighead, Black, 

Grass, Silver 

3.1.1.2. Explore the use of baitfish grown in monoculture, and certified to be diseasefree and uncontaminated by other aquatic species. Bighead, Black, 

Grass, Silver 

3.1.1.3. Develop and provide information to commercial and recreational baitfish 

harvesters that will help prevent accidental and deliberate unauthorized introductions 

of Asian carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.2. Take actions to prevent the stocking of diploid Asian carps 

into non-aquaculture waters for biological control.

3.1.2.1. Encourage states to develop regulations that prohibit the stocking of any 

diploid Asian carps into non-aquaculture waters for biological control. 

Bighead, Black, 

Grass, Silver 

3.1.2.2. Remove or contain diploid Asian carps that have been previously stocked into 

non-aquaculture waters for biological control. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.3. Take actions to prevent illegal sale, shipping, and stocking 

of diploid grass carp as triploid grass carp. 

3.1.3.1. Encourage states that allow the legal importation of grass carp to adopt 

consistent, uniform regulations that allow only certified triploid grass carp to be 

shipped or stocked. 

Grass 

3.1.3.2. Encourage states to conduct routine and random inspections of all live grass 

carp shipments within the state. 

Grass 

3.1.3.3. Encourage the USFWS to provide ploidy determination for states conducting 

inspections of grass carp shipments. 

Grass 

Strategy 3.1.4. Take actions to prevent the shipment of live black carp in 

grass carp shipments.

Strategy 3.1.5. Take actions to address stocking triploid Asian carps into 

non-aquaculture waters for biological control.

3.1.5.1. Encourage states to prohibit stocking triploid bighead, black, and silver carps 

for biological control in non-aquaculture waters. 

Bighead, Black, 

Silver 

3.1.5.2. Encourage states to allow stocking triploid grass carp for biological control in 

non-aquaculture waters only within watersheds where grass carp are already present 

in the wild.

Grass 
 x

Table I. Continued. 

Strategies and Recommendations Species

3.1.5.3. Remove or contain triploid Asian carps that have been previously stocked in 

non-aquaculture waters within watersheds where the fish are not currently selfsustaining in the wild. 

Bighead, Grass, 

Silver 

Strategy 3.1.6. Take actions to ensure that stocking triploid grass carp for 

biological control does not result in accidental or deliberate unauthorized 

introductions of diploid grass carp. 

3.1.6.1. The USFWS should seek an independent scientific review and evaluation of 

the Triploid Grass Carp Inspection and Certification Program. 

Grass 

3.1.6.2. Develop and provide information on the USFWS Triploid Grass Carp 

Inspection and Certification Program. 

Grass 

Strategy 3.1.7. Take actions to prevent the transport and release of Asian 

carps by commercial vessels and recreational watercraft.

3.1.7.1. Investigate fully the risks associated with ballast water transfers or other 

means of water transfer by commercial vessels and recreational watercraft. 

Bighead, Black, 

Grass, Silver 

3.1.7.2. Inform boaters, barge operators, and others of the risks of moving infested 

water and encourage voluntary actions to reduce this risk. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.8. Take actions to prevent the unintentional transport, release, 

or disposal of Asian carps by natural resources managers during 

management activities.

3.1.8.1. Natural resources managers should employ pathway management tools, 

such as Hazard Analysis and Critical Control Point planning in the review of Standard 

Operating Procedures, to prevent introductions of Asian carps through natural 

resources management related pathways. 

Bighead, Black, 

Grass, Silver 

3.1.8.2. Develop and provide information to natural resources managers and field 

staff that will help prevent unintentional introductions and spread of feral Asian carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.9. Take actions to prevent the illegal importation and prohibit 

the legal importation of live bighead, black, grass, and silver carps into the 

United States. 

3.1.9.1. Prohibit international importation of Asian carps under federal and state 

regulations, except for research purposes under a controlled permit. 

Bighead, Black, 

Grass, Silver 

3.1.9.2. Inform USFWS Law Enforcement Officers, other federal inspectors, and state 

conservation law enforcement officers about laws that apply to the import of live Asian 

carps, the importance of preventing the illegal import of Asian carps, and Asian carp 

identification. 

Bighead, Black, 

Grass, Silver 

3.1.9.3. Inform potential importers of applicable state and federal laws and associated 

risks with international shipments of live Asian carps. 

Bighead, Black, 

Grass, Silver 

3.1.9.4. Increase the numbers of trained USFWS Law Enforcement Officers and 

increase physical inspections of international shipments of live fish and eggs at 

designated or non-designated ports of entry. 

Bighead, Black, 

Grass, Silver 
 xi

Table I. Continued. 

Strategies and Recommendations Species 

Strategy 3.1.10. Take action to prevent the incidental inclusion of live 

Asian carps in international imports with other fishes. 

Strategy 3.1.11. Take actions to prevent the unintentional escape, release, 

or improper disposal of Asian carps from aquaculture facilities at poorly 

sited locations.

3.1.11.1. Urge the development and enforcement of state regulations that prohibit the 

production and use of Asian carps at poorly sited facilities. 

Bighead, Black, 

Grass, Silver 

3.1.11.2. Develop and provide information to Asian carp producers and growers that 

will help upgrade poorly sited facilities such that they are no longer high-risk to contain 

farm-raised Asian carps and prevent accidental introductions. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.12. Develop an active research initiative to identify alternatives 

to the use of Asian carps.

3.1.12.1. Form a coordinating research group that includes representatives from the 

aquaculture industry, the ethnic retail grocer industry, marketing scientists and 

developers, aquaculture scientists, and natural resources managers to focus research 

efforts on the highest priority alternatives to the use of Asian carps. 

Bighead, Black, 

Grass, Silver 

3.1.12.2. Develop an information module on economic and effective alternatives to 

replace the use of bighead and black carps on aquaculture facilities.

Bighead, Black 

Strategy 3.1.13. Take actions to prevent the incidental inclusion of Asian 

carps in aquaculture shipments of other farm-raised species to nonaquaculture waters.

3.1.13.1. Review Standard Operating Procedures and recommend Best Management 

Practices that include requirements for suppliers and purchasers to conduct 

inspections of fish prior to shipment and release. 

Bighead, Black, 

Grass 

3.1.13.2. Encourage states to develop regulations that allow for random inspections 

of live fish shipments into and within the state. 

Bighead, Black, 

Grass 

3.1.13.3. Prohibit the use of surface waters containing Asian carps from being used in 

aquaculture facilities unless effective treatment is in place with a monitoring program. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.14. Reduce potential risks of continued use of Asian carps on 

properly sited aquaculture facilities to the environment. 

3.1.14.1. Review Standard Operating Procedures and develop Best Management 

Practices for properly sited aquaculture facilities. 

Bighead, Black, 

Grass 

3.1.14.2. Encourage states to prohibit the use of grass carp on aquaculture facilities 

within watersheds where grass carp are not present in the wild. 

Grass 

3.1.14.3. Encourage states to restrict the use of grass carp to certified triploids only 

on aquaculture facilities within watersheds where grass carp are present but not 

reproducing. 

Grass 
 xii

Table I. Continued. 

Strategies and Recommendations Species 

3.1.14.4. Verify functional sterility of triploid bighead carp and develop a triploid 

certification program for bighead carp. 

Bighead 

3.1.14.5. Encourage states to prohibit the use of bighead carp on aquaculture 

facilities within watersheds where bighead carp are not self-sustaining in the wild. 

Bighead 

3.1.14.6. Encourage states to restrict the use of bighead carp on aquaculture facilities 

within watersheds with self-sustaining populations to certified triploids only. 

Bighead 

3.1.14.7. Encourage states to prohibit the use and production of silver carp on 

aquaculture facilities. 

Silver 

3.1.14.8. Encourage states to prohibit the use and production of diploid black carp on 

aquaculture facilities. 

Black 

Strategy 3.1.15. Take actions to prevent the live transport of wild-caught 

Asian carps and potential introduction through release, improper disposal, 

or escape.

3.1.15.1. Where legal for commercial or recreational fishers to possess Asian carps, 

encourage states to prohibit the possession of live wild-caught Asian carps. 

Bighead, Black, 

Grass, Silver 

3.1.15.2. Review Standard Operating Procedures and actions of commercial fishers 

to identify Best Management Practices that reduce risks of live transport and 

introduction. 

Bighead, Black, 

Grass, Silver 

3.1.15.3. Develop an information module and provide materials to commercial and 

recreational fishers and commercial live haulers that will help prevent accidental and 

deliberate unauthorized introductions of Asian carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.16. Take actions to prevent the release, escape, or improper 

disposal of domestic commercial shipments of live Asian carps.

3.1.16.1. Require informational labeling of truck and invoice for shipments of Asian 

carps to avoid improper handling and potential introduction of fish that may be 

involved in an accident (e.g., “Nonnative fish: Unauthorized release prohibited”). 

Bighead, Grass 

3.1.16.2. Review Standard Operating Procedures and develop Best Management 

Practices for fish haulers regarding containment and water transfer. 

Bighead, Grass 

3.1.16.3. Prohibit the use of water from natural water bodies for water exchange 

during transport. 

Bighead, Black, 

Grass 

3.1.16.4. Investigate improvements for containment methods on trucks carrying Asian 

carps. 

Bighead, Black, 

Grass 

3.1.16.5. Develop an information module and provide materials to commercial 

transporters of live farm-raised Asian carps that will help prevent accidental and 

deliberate unauthorized introductions. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.17. Reduce the potential risk to the environment from 

continued commercial, domestic transport of live farm-raised Asian carps. 
 xiii

Table I. Continued. 

Strategies and Recommendations Species 

Strategy 3.1.18. Take actions to prevent the accidental and deliberate 

unauthorized release of Asian carps by individuals. 

3.1.18.1. Encourage states to prohibit the sale, live transport, and unauthorized 

release of live Asian carps for non-commercial uses.

Bighead, Black, 

Grass, Silver 

3.1.18.2. Encourage states that allow sales of live Asian carps for human 

consumption to require retail grocers to kill the fish using prescribed humane methods, 

immediately upon sale. 

Bighead, Grass 

3.1.18.3. Use educational campaigns such as HabitattitudeTM to convey messages to 

the public that they should not release live Asian carps. 

Bighead, Black, 

Grass, Silver 

3.1.18.4. Develop an information module and provide materials to producers, 

growers, marketers, and foodfish consumers of live Asian carps that will help prevent 

accidental and deliberate unauthorized introductions. 

Bighead, Grass 

3.1.18.5. Promote the national Aquatic Nuisance Species Hotline and encourage the 

general public to report illegal possession or stocking of Asian carps and other activity 

that could effect an introduction or rapid response. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.19. Take actions to prevent the release, escape, or improper 

disposal of Asian carps by aquarium/hobby industry importers, 

wholesalers, and retailers.

3.1.19.1. Encourage states to prohibit the trade of Asian carps for aquaria and hobby 

purposes. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.20. Prevent the release, escape, or improper disposal of live 

Asian carps via education facilities and projects, including schools, public 

aquaria, and research facilities. 

3.1.20.1. Urge states to develop and enforce regulations to reduce risks associated 

with the possession and disposal of Asian carps for research and exhibition purposes.

Bighead, Grass 

3.1.20.2. Develop an information module and provide materials to the academic and 

research communities that will help prevent accidental and deliberate unauthorized 

introductions of Asian carps. 

Bighead, Black, 

Grass, Silver 

3.1.20.3. Encourage states to prohibit the trade of live Asian carps by commercial 

biological supply companies. 

Bighead, Black, 

Grass, Silver 

Strategy 3.1.21. Take action to prevent the transport and release of “adultsized” (non-baitfish) Asian carps by boaters, anglers, and bowfishers.

3.1.21.1. Develop an information module and provide materials to recreational fishers 

and boaters that will help prevent accidental and deliberate unauthorized introductions 

of Asian carps. 

Bighead, Black, 

Grass, Silver 
 xiv

Table I. Continued. 

Goal 2: Contain and control the expansion of feral populations of bighead, black, grass, 

and silver carps in the United States.

Strategies and Recommendations Species 

Strategy 3.2.1. Develop a national strategy and guidelines for sciencebased decision making concerning the need for continued and additional 

containment measures.

3.2.1.1. Develop a Decision Support System to assist natural resources managers in 

prioritizing specific locations for the construction, maintenance, monitoring, or removal 

of barriers to carp dispersal. 

Bighead, Black, 

Grass, Silver 

3.2.1.2. Evaluate the effectiveness afforded by alternative technical containment 

measures (i.e., physical and behavioral barriers). 

Bighead, Black, 

Grass, Silver 

3.2.1.3. Promote, support, and provide technical analysis and comment for the field 

testing of novel containment methods. 

Bighead, Black, 

Grass, Silver 

3.2.1.4. Anticipate and address consequences of specific containment actions on 

native biological communities.

Bighead, Black, 

Grass, Silver 

Strategy 3.2.2. Take immediate actions to prevent interbasin transfers and 

limit intrabasin movements of feral Asian carp populations. 

3.2.2.1. Develop and implement redundant barrier systems within the Chicago 

Sanitary and Ship Canal to limit the unrestricted access of Asian carps to Lake 

Michigan. 

Bighead, Silver 

3.2.2.2. Develop and implement reasonable and effective measures that prevent the 

spread of Asian carps via canals, water ways, or other water diversions between 

basins. 

Bighead, Black, 

Grass, Silver 

3.2.2.3. Construct and operate a Sound Projector Array-based acoustic bubble 

curtain fish deterrent at two locks and dams on the Upper Mississippi River to prevent 

the spread of Asian carps throughout the basin. 

Bighead, Silver 

3.2.2.4. Identify additional containment measures needed to limit intrabasin 

movements of feral populations of Asian carps within the Mississippi River and other 

basins where established. 

Bighead, Black, 

Grass, Silver 

Strategy 3.2.3. Minimize the range expansion and ecological effects of feral 

populations of Asian carps in conjunction with management actions to 

enhance aquatic environments for the sustainability of native biological 

communities.

3.2.3.1. The USFWS and other natural resources management agencies should 

provide technical assistance and biological information to the USACE and participate 

in collaborative planning of fish passage and habitat restoration projects. 

Bighead, Black, 

Grass, Silver 

3.2.3.2. Require federal and state agencies to consider the potential range expansion 

and ecological effects of Asian carps when designing or reviewing water control 

structure projects and permits. 

Bighead, Black, 

Grass, Silver 
 xv

Table I. Continued. 

Strategies and Recommendations Species 

Strategy 3.2.4. Forecast, detect, and rapidly respond to new feral Asian 

carp introductions and range expansions. 

3.2.4.1. Develop an early detection Decision Support System to: 1) identify high risk 

locations susceptible to introductions or range expansions of Asian carps, 2) identify 

watersheds of special concern, 3) prioritize specific locations for implementing 

comprehensive early detection monitoring programs. 

Bighead, Black, 

Grass, Silver 

3.2.4.2. Adopt and/or adapt a National Incident Management System to provide for 

national coordination and management of early detection and rapid response 

programs. 

Bighead, Black, 

Grass, Silver 

3.2.4.3. Develop and conduct routine early detection monitoring programs in locations 

where risk of introductions or range expansions of Asian carps exists. 

Bighead, Black, 

Grass, Silver 

3.2.4.4. Develop Rapid Response Plans that identify where rapid response actions 

can effectively eradicate Asian carps and how those actions will be carried out. 

Bighead, Black, 

Grass, Silver 

Strategy 3.2.5. Develop systems to identify the location of captive stocks 

of Asian carps and for the notification of appropriate agencies in the event 

of escapement.

3.2.5.1. Encourage states to identify the location of captive stocks of Asian carps and 

to develop a communication network for the reporting of escapees. 

Bighead, Black, 

Grass, Silver 

3.2.5.2. Create an information sharing system with early detection monitoring and 

rapid response project managers. 

Bighead, Black, 

Grass, Silver 

Strategy 3.2.6. Develop an information exchange network for agencies, 

organizations, and partners to communicate and share “real time” data to 

facilitate early detection and rapid response programs.

3.2.6.1. Develop a website and centralized databases to provide information on early 

detection and rapid response programs. 

Bighead, Black, 

Grass, Silver 

3.2.6.2. Develop a list-server to provide a forum for information exchange. Bighead, Black, 

Grass, Silver 

3.2.6.3. Utilize and support the Nonindigenous Aquatic Species Information Center for 

accurate and spatially referenced biogeographic information and the Nonindigenous 

Aquatic Species Alert System to track expansion. 

Bighead, Black, 

Grass, Silver 
 xvi

Table I. Continued. 

Goal 3: Extirpate, or reduce to levels of insignificant effect, feral populations of bighead, 

black, grass, and silver carps in the United States. 

Strategies and Recommendations Species 

Strategy 3.3.1. Determine life history characteristics and build population 

dynamics models of Asian carps in the Mississippi River Basin. 

3.3.1.1. Determine life history parameters of Asian carps in the Mississippi River 

Basin. 

Bighead, Black, 

Grass, Silver 

3.3.1.2. Create population, biomass, and recruitment models for Asian carps. Bighead, Grass, 

Silver 

Strategy 3.3.2. Increase the commercial harvest of Asian carps.

3.3.2.1. Evaluate gear and harvest method effectiveness, develop new gears if 

necessary, and provide information to commercial fishers. 

Bighead, Silver 

3.3.2.2. Increase the number of commercial fishers. Bighead, Silver 

3.3.2.3. Examine commercial fishing regulations and consider changes to increase 

harvest. 

Bighead, Silver 

3.3.2.4. Provide financial incentives to commercial fishers to increase harvest of 

Asian carps. 

Bighead, Silver 

3.3.2.5. Develop new markets for Asian carps. Bighead, Grass, 

Silver 

3.3.2.6. Determine contaminant concentrations in edible portions of feral Asian carps. Bighead, Grass, 

Silver 

Strategy 3.3.3. Increase recreational harvest of Asian carps. 

3.3.3.1. Examine recreational harvest regulations to eliminate barriers to recreational 

harvest of Asian carps. 

Bighead, Grass, 

Silver 

3.3.3.2. Inform recreational fishers about Asian carp harvest and preparation 

methods. 

Bighead, Grass, 

Silver 

Strategy 3.3.4. Physical removal by natural resources management 

agencies.

3.3.4.1. Biologists should physically remove Asian carps collected as a result of 

management actions or research. 

Bighead, Black, 

Grass, Silver 

Strategy 3.3.5. Consider stocking sterile Asian carp or monosex tetraploids 

to inhibit reproduction and recruitment of feral fish.

3.3.5.1. Examine the potential efficacy of introduction of monosex tetraploid fish as a 

control method. 

Bighead, Silver 

Strategy 3.3.6. Research and apply transgenic manipulations (e.g., 

“Daughterless carp” and “Trojan gene” technologies). 
 xvii

Table I. Continued. 

Strategies and Recommendations Species 

3.3.6.1. Adapt “daughterless carp” genetic technology to Asian carps. Bighead, Silver 

Strategy 3.3.7. Develop and apply pheromone baits to control Asian carps. 

3.3.7.1. Sex pheromone research should continue with the goal of production and 

application of field-applicable technologies.

Bighead, Silver 

3.3.7.2. Investigate aggregation pheromones for juvenile Asian carps. Bighead, Silver 

Strategy 3.3.8. Develop and apply habitat and hydrological manipulations 

that favor native species over Asian carps or that might be useful in 

harvest enhancement. 

3.3.8.1. Provide technical assistance and biological information to the USACE and 

participate in collaborative planning of habitat improvement projects (e.g., Navigation 

and Ecosystem Sustainability Program, Missouri River Mitigation Project, and other 

authorities). 

Bighead, Silver 

Strategy 3.3.9. Investigate the sensitivity of Asian carps to piscicides, and 

examine the feasibility of chemical Asian carp control in specific habitats. 

3.3.9.1. Determine effectiveness of registered piscicides to control Asian carps. Bighead, Black, 

Grass, Silver 

3.3.9.2. Identify conditions where rotenone or antimycin could be used to control 

populations of Asian carps. 

Bighead, Black, 

Grass, Silver 

3.3.9.3. Determine potential of other chemicals to control Asian carps. Bighead, Black, 

Grass, Silver 

3.3.9.4. Determine feasibility and applicability of piscicide bait deployment to control 

black and grass carps. 

Black, Grass 

3.3.9.5. Determine registration needs, if any, for the use of piscicides to control Asian 

carps, and ensure that piscicides are available for appropriate uses. 

Bighead, Black, 

Grass, Silver 

Strategy 3.3.10. Reduce populations of Asian carps through the 

introduction of biological controls such as disease agents, parasites, or 

predators.

3.3.10.1. Develop information on the factors that determine the efficacy of native 

predator enhancement to control Asian carps. 

Bighead, Silver 

 
 xviii

Table I. Continued. 

Goal 4: Minimize potential adverse effects of feral bighead, black, grass, and silver carps 

in the United States. 

Strategies and Recommendations Species 

Strategy 3.4.1. Enhance organisms adversely affected by Asian carps.

3.4.1.1. Monitor populations of species most likely to be affected by Asian carps. Bighead, Black, 

Grass, Silver 

3.4.1.2. Restore or supplement numbers of native species through direct release (i.e., 

stocking). 

Bighead, Black, 

Grass, Silver 

3.4.1.3. Protect or restore native species through methods other than stocking. Bighead, Black, 

Grass, Silver 

Strategy 3.4.2. Minimize damage to waterway users that results from silver 

carp.

3.4.2.1. Inform and train boaters to avoid damage from jumping silver carp. Silver 

Goal 5: Provide information to the public, commercial entities, and government 

agencies to improve effective management and control of bighead, black, grass, and 

silver carps in the United States. 

Strategies and Recommendations Species 

Strategy 3.5.1. Understand the specific information needs and the most 

effective approaches to reach and affect desired results with each key 

audience.

3.5.1.1. Engage potential key audiences in the development of a comprehensive 

education and outreach program. 

Bighead, Black, 

Grass, Silver 

Strategy 3.5.2. Prepare science-based materials based on key audience 

needs that can be used to develop curricula for effective education and 

outreach programs.

3.5.2.1. Develop an information module that defines and describes Asian carps, 

efforts to contain and reduce feral populations, and sources from which to learn more 

about these fishes. 

Bighead, Black, 

Grass, Silver 

3.5.2.2. Develop an information module on the United States’ Asian carp industry, 

size, scope, economics, and current farming practices. 

Bighead, Black, 

Grass, Silver 

3.5.2.3. Develop an information module on potential effects of Asian carps and 

reasons to contain and reduce their feral populations. 

Bighead, Black, 

Grass, Silver 

3.5.2.4. Develop an information module on the identification of all life stages of Asian 

carps. 

Bighead, Black, 

Grass, Silver 

3.5.2.5. Develop an information module on why and how to report sightings of Asian 

carps. 

Bighead, Black, 

Grass, Silver 
 xix

Table I. Continued. 

Strategies and Recommendations Species 

3.5.2.6. Develop an information module on Hazard Analysis and Critical Control Point 

planning procedures. 

Bighead, Black, 

Grass, Silver 

3.5.2.7. Develop an information module on the construction and maintenance of 

effective spillway barriers to reduce the risk of escape of Asian carps from private 

impoundments. 

Bighead, Black, 

Grass 

3.5.2.8. Develop an information module to provide general information about 

regulations related to Asian carps. 

Bighead, Black, 

Grass, Silver 

Goal 6: Conduct research to provide accurate and scientifically valid information 

necessary for the effective management and control of bighead, black, grass, and silver 

carps in the United States. 

Strategies and Recommendations Species 

Strategy 3.6.1. Develop effective sampling gears and monitoring methods 

for all life stages of Asian carps in both standing and flowing water 

environments. 

3.6.1.1. Develop and evaluate effective methods for sampling feral populations of 

Asian carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.6.2. Assemble information about the distribution, biology, life 

history, and population dynamics of bighead, black, grass, and silver 

carps.

3.6.2.1. Describe current and temporal changes in distribution to better understand 

the invasion and colonization process. 

Bighead, Black, 

Silver 

3.6.2.2. Describe movements and distribution of Asian carps in waters of the United 

States (e.g., habitat preference, habitat selection, and habitats used).

Bighead, Black, 

Grass, Silver 

3.6.2.3. Describe diets, evaluate food selection and availability, estimate food 

consumption, and assess feeding interactions (i.e., predation and competition) with 

native biota (trophic ecology). 

Bighead, Black, 

Grass, Silver 

3.6.2.4. Assess ecologically important aspects of physiology and behavior such as 

environmental tolerances, endocrine functions, and sensory capabilities. 

Bighead, Black, 

Grass, Silver 

3.6.2.5. Estimate key population variables such as mortality, emigration and 

immigration, growth rates, fecundity, and stock-recruitment relations for population 

modeling. 

Bighead, Black, 

Grass, Silver 

Strategy 3.6.3. Develop effective methods to contain feral Asian carp 

populations and prevent their further spread. 

3.6.3.1. Develop effective physical and behavioral barriers for controlling the 

movement of Asian carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.6.4. Develop an integrated management strategy to extirpate or 

reduce abundances of feral Asian carps. 
 xx

Table I. Continued. 

Strategies and Recommendations Species 

3.6.4.1. Develop and evaluate effective attractants and repellents. Bighead, Silver 

3.6.4.2. Evaluate existing piscicides and, if necessary, develop new piscicides that 

are selective for Asian carps. 

Bighead, Black, 

Silver 

3.6.4.3. Evaluate the potential for physical removal of feral Asian carps to control their 

abundance in public waters. 

Bighead, Black, 

Grass, Silver 

Strategy 3.6.5. Determine the demonstrated and probable ecological and 

economic effects of Asian carps in the United States and determine the 

degree to which these effects are negative.

3.6.5.1. Assess the ecological effects of bighead, black, and silver carps on individual 

aquatic species and aquatic ecosystems. 

Bighead, Black, 

Silver 

3.6.5.2. Document the actual ecological effects of bighead, black, grass, and silver 

carps. 

Bighead, Black, 

Silver 

3.6.5.3. Conduct analyses of economic effects of feral bighead, black, and silver 

carps. 

Bighead, Black, 

Grass, Silver 

Strategy 3.6.6. Develop economically viable and environmentally safe 

alternatives to the uses of farm-raised Asian carps.

3.6.6.1. Evaluate ecologically safe and economically viable alternatives to black carp 

for snail control. 

Black 

3.6.6.2. Characterize ethnic markets for live fish and for fresh fish on ice. Determine 

consumer preferences for various attributes including size, product form, and price. 

Bighead, Black, 

Grass, Silver 

3.6.6.3. Evaluate the economic feasibility of growing and selling triploid bighead and 

grass carps for the live and fresh-on-ice markets. 

Bighead, Grass 

Goal 7: Effectively plan, implement, and evaluate management and control efforts for 

bighead, black, grass, and silver carps in the United States. 

Strategies and Recommendations Species 

Strategy 3.7.1. Develop an implementation program that effectively 

coordinates, oversees, and drives implementation efforts.

3.7.1.1. The Aquatic Nuisance Species Task Force should create a committee 

composed of key partners and stakeholders with needed expertise to oversee the 

implementation of this plan. 

Bighead, Black, 

Grass, Silver 

3.7.1.2. Develop institutional arrangements that formalize the roles and 

responsibilities of partner agencies and organizations in plan implementation. 

Bighead, Black, 

Grass, Silver 

3.7.1.3. Integrate, sequence, and prioritize recommendations from among all sections 

of this plan. 

Bighead, Black, 

Grass, Silver 
 xxi

Table I. Continued. 

Strategies and Recommendations Species 

3.7.1.4. Seek “new” funds from various sources to implement this plan. Bighead, Black, 

Grass, Silver 

3.7.1.5. Develop criteria and/or performance measures to evaluate the effectiveness 

of management and control efforts. 

Bighead, Black, 

Grass, Silver 

3.7.1.6. Develop an adaptive management framework that allows the flexibility to 

readily change and adapt management strategies as knowledge is gained and 

techniques are refined or developed. 

Bighead, Black, 

Grass, Silver 

3.7.1.7. Develop an effective strategy for communication and coordination among 

those implementing recommendations for management and control of Asian carps. 

Bighead, Black, 

Grass, Silver 
 xxii

TABLE OF CONTENTS 

ASIAN CARP WORKING GROUP MEMBERS ............................................................................ i

ACKNOWLEDGEMENTS ........................................................................................................... iv

EXECUTIVE SUMMARY.............................................................................................................. v

TABLE OF CONTENTS ............................................................................................................xxii

CHAPTER 1. INTRODUCTION ...................................................................................................1

1.1. Background ..................................................................................................................1

1.2. Goals...... ...................................................................................................................6 

CHAPTER 2. SPECIES OVERVIEWS ........................................................................................8

2.1. Bighead carp ................................................................................................................8 

2.2. Black carp...................................................................................................................14 

2.3. Grass carp..................................................................................................................20 

2.4. Silver carp...................................................................................................................29 

CHAPTER 3. MANAGEMENT AND CONTROL OF ASIAN CARPS .......................................34

Goal 3.1. Prevent accidental and deliberate unauthorized introductions of bighead, 

black, grass, and silver carps in the United States..................................34

Strategy 3.1.1. Take actions to prevent the collection, transport, release, and 

improper disposal of Asian carps that may be intermixed with 

live wild-harvested baitfish..............................................................36 

Strategy 3.1.2. Take actions to prevent the stocking of diploid Asian carps into 

non-aquaculture waters for biological control. ................................38 

Strategy 3.1.3. Take actions to prevent illegal sale, shipping, and stocking of 

diploid grass carp as triploid grass carp..........................................40 

Strategy 3.1.4. Take actions to prevent the shipment of live black carp in grass 

carp shipments. ..............................................................................41 

Strategy 3.1.5. Take actions to address stocking triploid Asian carps into nonaquaculture waters for biological control.........................................42 

Strategy 3.1.6. Take actions to ensure that stocking of triploid grass carp for 

biological control does not result in accidental or deliberate 

unauthorized introductions of diploid grass carp.............................42 

Strategy 3.1.7. Take actions to prevent the transport and release of Asian carps 

by commercial vessels and recreational watercraft. .......................44 

Strategy 3.1.8. Take actions to prevent the unintentional transport, release, or 

disposal of Asian carps by natural resources managers during 

management activities. ...................................................................45 
 xxiii

Strategy 3.1.9. Take actions to prevent the illegal importation and prohibit the 

legal importation of live bighead, black, grass, and silver carps 

into the United States. ....................................................................46 

Strategy 3.1.10. Take actions to prevent the incidental inclusion of live Asian 

carps in international imports of other fishes. ..............................48 

Strategy 3.1.11. Take actions to prevent the unintentional escape, release, or 

improper disposal of Asian carps from aquaculture facilities at 

poorly sited locations. ..................................................................49 

Strategy 3.1.12. Develop an active research initiative to identify alternatives to 

the use of Asian carps. ................................................................50 

Strategy 3.1.13. Take actions to prevent the incidental inclusion of Asian carps in 

aquaculture shipments of other farm-raised species to nonaquaculture waters.......................................................................51 

Strategy 3.1.14. Reduce potential risks of continued use of Asian carps on 

properly sited aquaculture facilities to the environment...............52 

Strategy 3.1.15. Take actions to prevent the live transport of wild-caught Asian 

carps and potential introduction through release, improper 

disposal, or escape......................................................................58 

Strategy 3.1.16. Take actions to prevent the release, escape, or improper 

disposal of domestic commercial shipments of live Asian 

carps. ...........................................................................................60 

Strategy 3.1.17. Reduce the potential risk to the environment from continued 

commercial, domestic transport of live farm-raised Asian 

carps. ...........................................................................................61 

Strategy 3.1.18. Take actions to prevent the accidental and deliberate 

unauthorized release of Asian carps by individuals.....................63 

Strategy 3.1.19. Take actions to prevent the release, escape, or improper 

disposal of Asian carps by aquarium/hobby industry importers, 

wholesalers, and retailers. ...........................................................65 

Strategy 3.1.20. Prevent the release, escape, or improper disposal of live Asian 

carps via education facilities and projects, including schools, 

public aquaria, and research facilities..........................................66 

Strategy 3.1.21. Take actions to prevent the transport and release of "adultsized" (non-baitfish) Asian carps by boaters, anglers, and 

bowfishers....................................................................................67 

Goal 3.2. Contain and control the expansion of feral populations of bighead, black, 

grass, and silver carps in the United States. ...........................................68

Strategy 3.2.1. Develop a national strategy and guidelines for science-based 

decision making concerning the need for continued and 

additional containment measures...................................................68 

Strategy 3.2.2. Take immediate actions to prevent interbasin transfers and limit 

intrabasin movements of feral Asian carp populations. ..................70 
 xxiv

Strategy 3.2.3. Minimize the range expansion and ecological effects of feral 

populations of Asian carps in conjunction with management 

actions to enhance aquatic environments for the sustainability of 

native biological communities. ........................................................73 

Strategy 3.2.4. Forecast, detect, and rapidly respond to new feral Asian carp 

introductions and range expansions. ..............................................75 

Strategy 3.2.5. Develop systems to identify the location of captive stocks of Asian 

carps and for the notification of appropriate agencies in the 

event of escapement.. ....................................................................77 

Strategy 3.2.6. Develop an information exchange network for agencies, 

organizations, and partners to communicate and share "real 

time" data to facilitate early detection and rapid response 

programs.........................................................................................78 

Goal 3.3. Extirpate, or reduce to levels of insignificant effect, feral populations of 

bighead, black, grass, and silver carps in the United States.. .................80

Strategy 3.3.1. Determine life history characteristics and build population 

dynamics models of Asian carps in the Mississippi River Basin.....80 

Strategy 3.3.2. Increase the commercial harvest of Asian carps. .............................81 

Strategy 3.3.3. Increase recreational harvest of Asian carps....................................84 

Strategy 3.3.4. Physical removal by natural resources management agencies........86 

Strategy 3.3.5. Consider stocking sterile Asian carp or monosex tetraploids to 

inhibit reproduction and recruitment of feral fish.............................86 

Strategy 3.3.6. Research and apply transgenic manipulations (e.g., 

"Daughterless carp" and "Trojan gene" technologies). ...................87 

Strategy 3.3.7. Develop and apply pheromone baits to control Asian carps.............88 

Strategy 3.3.8. Develop and apply habitat and hydrological manipulations that 

favor native species over Asian carps or that might be useful in 

harvest enhancement. ....................................................................89 

Strategy 3.3.9. Investigate the sensitivity of Asian carps to piscicides, and 

examine the feasibility of chemical Asian carp control in specific 

habitats. ..........................................................................................90 

Strategy 3.3.10. Reduce populations of Asian carps through the introduction of 

biological controls such as disease agents, parasites, or 

predators.........................................................................................91 

Goal 3.4. Minimize potential adverse effects of feral bighead, black, grass, and silver 

carps in the United States........................................................................93

Strategy 3.4.1. Enhance organisms adversely affected by Asian carps. ..................93 

Strategy 3.4.2. Minimize damage to waterway users that result from silver carp. ....94 

Goal 3.5. Provide information to the public, commercial entities, and government 

agencies to improve effective management and control of 

bighead, black, grass, and silver carps in the United States. ............96
 xxv

Strategy 3.5.1. Understand the specific information needs and the most effective 

approaches to reach and affect desired results with each key 

audience. ........................................................................................96 

Strategy 3.5.2. Prepare science-based materials based on key audience needs 

that can be used to develop curricula for effective education and 

outreach programs........................................................................100 

Goal 3.6. Conduct research to provide accurate and scientifically valid information 

necessary for the effective management and control of bighead, 

black, grass, and silver carps in the United States................................104

Strategy 3.6.1. Develop effective sampling gears and monitoring methods for 

all life stages of Asian carps in both standing and flowing 

water environments. .....................................................................105 

Strategy 3.6.2. Assemble information about the distribution, biology, life history, 

and population dynamics of bighead, black, grass, and silver 

carps .............................................................................................106 

Strategy 3.6.3. Develop effective methods to contain feral Asian carp 

populations and prevent their further spread ................................108 

Strategy 3.6.4. Develop an integrated management strategy to extirpate or 

reduce abundances of feral Asian carps.......................................108 

Strategy 3.6.5. Determine the demonstrated and probable ecological and 

economic effects of Asian carps in the United States and 

determine the degree to which these effects are negative. ..........109 

Strategy 3.6.6. Develop ecologically safe and economically viable alternatives 

to the uses of farm-raised Asian carps. ........................................112 

Goal 3.7. Effectively plan, implement, and evaluate management and control efforts 

for bighead, black, grass and silver carps in the United States.............114

Strategy 3.7.1. Develop an implementation program that effectively 

coordinates, oversees, and drives implementation efforts............115 

CHAPTER 4. TABLE OF RECOMMENDATIONS..................................................................119

CHAPTER 5. LITERATURE CITED ........................................................................................139

CHAPTER 6. APPENDICES ...................................................................................................160

Appendix 6.1. Summary of State Regulations Pertaining to Asian Carps .......................160 

Appendix 6.2. Asian Carp Working Group Drafting Team Members...............................170

Appendix 6.3. Unresolved Issue: Use of Triploid Black Carp on Aquaculture 

Facilities..................................................................................................172 

Appendix 6.4. Unresolved Issue: Use of Grass Carp on Aquaculture Facilities and 

Farm Ponds in Watersheds with Self-Sustaining Populations of 

Grass Carp .............................................................................................177

Appendix 6.5. Unresolved Issue: Commercial, Domestic Transport of Live FarmRaised Bighead and Grass Carps .........................................................181
 xxvi

Appendix 6.6. Summary of the Asian Carp Working Group Decisions for Developing 

Recommendations to Prevent Unauthorized Introductions of Asian 

Carps (Nashville, Tennessee, August 22-25, 2005)..............................186 

Appendix 6.7. Overview of Physical and Behavioral Barriers..........................................192 

Appendix 6.8. Additional Information on the Chicago Sanitary and Ship Canal..............199 

Appendix 6.9. Additional Information on Acoustic Dispersal Barriers..............................201 

Appendix 6.10. Additional Considerations for the Enhancement of Commercial 

Harvest of Asian Carps..........................................................................204 

Appendix 6.11. Additional Information on "Daughterless Carp" Technology...................209 

Appendix 6.12. Additional Considerations Regarding the Development and 

Application of Habitat and Hydrological Manipulations to Control 

Feral Asian Carps.................................................................................211 

Appendix 6.13. Additional Consideration Regarding the Use of Piscicides to Control 

Feral Asian Carps..................................................................................213 

Appendix 6.14. Additional Considerations Regarding the Use of Biological Controls 

to Reduce the Abundance of Feral Asian Carps ...................................215 

Appendix 6.15. Additional Education and Outreach Recommendations .........................217 

Appendix 6.16. Additional Research Recommendations ................................................221 
 1

CHAPTER 1. INTRODUCTION 

1.1. Background 

Freshwater aquatic animals have been identified as the most threatened group of species in the 

United States (Master et al. 1998). “One-third of the Nation’s freshwater fish species are 

threatened or endangered, 72 percent of freshwater mussels are imperiled, and the number of 

threatened and endangered species has tripled in the last 20 years” (USFWS 2002). Nonnative 

species are second only to habitat loss as a leading threat to native biodiversity in the United 

States (Wilcove et al. 1998). Aquatic systems are especially vulnerable, and invasions in these 

ecosystems are especially difficult to contain and reverse (FAO 1996). 

Unintentional aquatic species introductions can have harmful, even catastrophic, environmental 

consequences (Courtenay and Stauffer 1984; Great Lakes Commission 1992; Fuller et al. 

1999). Often, nonnative species cause a combination of economic, environmental, and health 

threats (National Invasive Species Council 2001; Lodge et al. 2006). In the Great Lakes alone, 

approximately 160 nonnative aquatic organisms have become established since the 1800s 

(Ricciardi 2001). Many of these species, including sea lamprey (Petromyzon marinus) and 

zebra mussels (Dreissena polymorpha), have had substantial economic and ecological effects 

(Great Lakes Commission 1992). 

The increased understanding and concern over nonnative species are evidenced also in the 

aquaculture community. The National Aquaculture Association, an aquaculture industry trade 

association, recognizes the importance of environmental issues. The Association’s web site 

(http://www.nationalaquaculture.org) includes pages addressing environmental stewardship 

issues related to water use, discharges from facilities, and nonnative animal introductions. 

Statements recognizing the facts that introductions, either intentional or unintentional, can cause 

significant harm are also included (National Aquaculture Association 2004). 

The Aquatic Nuisance Species Task Force (ANS Task Force) is an intergovernmental entity 

established under the Non-indigenous Aquatic Nuisance Prevention and Control Act of 1990 

(Act, 16 U.S.C. 4701-4741). The ANS Task Force is co-chaired by the U.S. Fish and Wildlife 

Service (USFWS) and the National Oceanic and Atmospheric Administration (NOAA) and is 

responsible for coordination of national efforts to prevent the introduction and spread of aquatic 

nuisance species. The ANS Task Force may develop national control programs for aquatic 

nuisance species. Key challenges that require urgent action include prevention, detection, 

eradication, and control, and the coordination of these efforts at all levels of government (Lodge 

et al. 2006). The ANS Task Force determined that Asian carps are nuisance species that 

warrant active control by natural resources management agencies. To that end, the ANS Task 

Force requested that the USFWS develop a national management and control plan for Asian 

carps to guide the ANS Task Force and other interested parties in managing Asian carps 

already present in the United States and to prevent the introduction and spread of these fishes 

to new areas. 

There are many carps native to Asia, including seven that have been introduced to the United 

States; however, the common usage of the term “Asian carps” in the United States has come to 

include four carps. These are the grass carp (Ctenopharyngodon idella), black carp 

(Mylopharyngodon piceus), bighead carp (Hypophthalmichthys nobilis), and silver carp (H. 

molitrix). For the purposes of this document, the term “Asian carps” will be defined as these 
 2

four species. Summaries of each of the four species of Asian carps including overviews of 

biology, introduction into the United States, present distribution and abundance, present uses, 

and potential adverse effects are presented in Chapter 2. This document does not consider 

common carp (Cyprinus carpio; introduced in the late 1800s) or goldfish (Carassius auratus;

introduced in the 1600s) which are carps originating in Asia1

, and are established in North 

America, or the crucian carp (Carassius carassius), which has been introduced but is apparently 

extirpated. This document also does not consider other carps native to Asia that could be 

introduced into the United States, such as the largescale silver carp (H. harmandi) and mud 

carp (Cirrhinus molitorella). 

Introductions of Asian carps into waters of the United States are the result of combinations of 

direct stockings by or authorized by various agencies, unauthorized stockings by private 

individuals, and unintentional escapes from university research facilities, federal and state 

agency facilities, and private aquaculture operations. Bighead, grass, and silver carps have all 

established reproducing populations in the United States. Adult black carp have been collected 

in the Mississippi River Basin, however there have been no collections of eggs and larvae or 

observations of spawning (Nico et al. 2005). Asian carps have the potential to disperse widely 

in open systems, potentially affecting waters beyond where the original introduction occurred. 

Due to the widespread distribution and migratory nature of Asian carps, coordination among the 

states will be vitally important for implementing management and control strategies. State 

agencies must look beyond their borders and work together to be most effective when 

developing approaches and regulations to manage and control Asian carps. State-by-state 

programs will be less effective with these species.

This plan focuses primarily on actions that can be taken to prevent the introduction and spread 

of Asian carps. Some states prohibit or restrict the possession or use of certain species of 

Asian carps (Appendix 6.1). In addition, the USFWS has been petitioned to list live bighead, 

black, and silver carps as injurious wildlife under the federal Lacey Act. The USFWS added all 

forms of live silver carp to the list of injurious wildlife under the Lacey Act, prohibiting their 

importation and interstate transport (except by permit), effective August 9, 2007. The USFWS is 

evaluating bighead and black carps to make determination recommendations for these species. 

An injurious wildlife designation prohibits the importation and interstate transportation of the 

species, including offspring and eggs, without a permit issued by the USFWS; permits may be 

granted for bona fide scientific, medical, educational, or zoological purposes. Regulation of 

intrastate use, possession, etc. is the responsibility of the States. Regardless of decisions 

made at the Federal level, state coordination and cooperation will be most effective to manage 

and control these interjurisdictional species. The failure of only one or two states to address the 

most important management needs will likely lead to overall failure in controlling the expansion 

of the species’ range. 

The altered conditions of river ecosystems in the interior United States have likely affected the 

ability of native fishes to compete with Asian carps in these waters. The dynamic habitats in 

which native large river fishes and aquatic communities evolved have been altered by man. 

Most of the Mississippi River Basin has been modified for commercial navigation, flood control, 

and other human uses. The Upper Mississippi River-Illinois Waterway System and floodplain 

 

1 The native range of common carp is disputed, but is often reported as being of Eurasian origin (Page 

and Burr 1991; Balon 1995). Balon (1995) found that common carp evolved in the Caspian Sea, then 

migrated naturally to the Black and Aral Seas, east to eastern mainland Asia and west as far as the 

Danube River.
 3

ecosystem was described by the U.S. Army Corps of Engineers (USACE) Environmental Effect 

Statement (USACE 2004) as follows: 

“Prior to widespread European settlement of the region, the Upper Mississippi 

River System was a diverse landscape of tallgrass prairie, wetlands, savannas, 

and forests. Logging, agriculture, and urban development over the past 150 

years have resulted in the present floodplain landscape that is more than 80 

percent developed. Millions of acres of wetland drainage, thousands of miles of 

field tiles, road ditches, channelized streams, and urban storm water sewers 

accelerate runoff to the main stem rivers. The modern hydrologic regime is 

highly modified, with increased frequency and amplitude of changes in river 

discharge. Management to facilitate barge transport has occurred since the 

1820’s, and today a system of 43 locks, 37 dams and thousands of river channel 

training structures, including wing dams and revetments, and dredging maintain a 

permanent three meter deep channel for barge traffic. The modern basin 

landscape delivers large amounts of sediment, nutrients, and contaminants to the 

river. Since impoundment, sediment accumulation and littoral (i.e., wind and 

wave) processes in the navigation pools have greatly altered aquatic habitats.” 

The fish fauna of these rivers have undergone rapid change in response to habitat alterations 

(Pflieger 1997). For example, prior to these changes in habitat, native large river fishes such as 

paddlefish (Polyodon spathula) and sturgeons (Acipenser and Scaphyrhynchus spp.) traveled 

great distances to spawn over submerged gravel bars where their adhesive fertilized eggs are 

deposited and incubated (Russell 1986; Pflieger 1997). With the eventual dredging, 

straightening, and damming of the Mississippi River for navigation and flood control, most gravel 

bars required for spawning and incubation were removed. Other species such as speckled 

chub (Macrhybopsis aestivalis), sicklefin chub (M. meeki), and sturgeon chubs (M. gelida) are 

specialized for life in open, sandy or gravelly sections of the river channel and have nearly 

disappeared in some river reaches (Pflieger 1997). Dams block migrations of many species 

including paddlefish, Alabama shad (Alosa alabamae), and skipjack herring (Alosa 

chrysochloris). As a result the skipjack herring is nearly extirpated from Wisconsin, along with 

the ebony shell (Fusconaia ebena) and elephant ear (Elliptio crassidens), both state 

endangered mussels for which the skipjack herring is the sole host (Wisconsin Department of 

Natural Resources 2004). 

While native, large river fishes such as the paddlefish have struggled in this disturbed system, 

introduced bighead, grass, and silver carps have become established and thrive in the altered 

habitats of the Mississippi River Basin. The floodplain system provides varied biophysical 

conditions for successful spawning, egg incubation, nursery and overwintering areas, and 

plentiful macrophytes, planktonic, detrital or molluskan food resources for Asian carps 

(Cudmore and Mandrak 2004; Kolar et al. 2007; Nico et al. 2005). In addition, these fishes have 

been introduced within 1,800 km of the mainstem Mississippi River Basin that is free flowing 

from St. Louis, Missouri to New Orleans, Louisiana. This allows for relatively unimpeded 

movement of Asian carps from the mouth of the Mississippi River to the Missouri and Ohio 

rivers. Within the impounded reaches of these large rivers, there is sufficient passage through 

some locks and dams as well as sufficient distance, flow, and suitable temperatures to support 

egg incubation during the period of late May to late September (Nico et al. 2005). 

In addition to the ability of introduced Asian carps to disperse throughout the Mississippi River 

and connected waterways, the plan identifies 22 potential pathways of introduction related to the 

movement of Asian carps through human actions. Each of these pathways could lead to 
 4

additional introductions. Examples of such pathways include the transport and release of 

baitfishes caught in the wild; stocking Asian carps in private or public waters for biological 

control; the production, live transport, and live sales of Asian carps in seafood markets; live 

transport and intentional spread of Asian carps by commercial fishers; movement of Asian carps 

in ballast waters and live wells; and intentional releases of Asian carps by consumers, 

hobbyists, and animal rights activists (Higbee and Glassner-Shwayder 2004; Kolar et al. 2007). 

Based on experiences with other nuisance species, natural resources management agencies, 

fishery and aquaculture scientists, and associated industries are concerned about the potential 

ecological and economic effects posed by feral populations of Asian carps. The life history traits 

of Asian carps (e.g., reproductive capability, population densities, feeding habits, broad climate 

tolerance, mobility, and longevity) indicate that these four species have a high probability of 

causing ecological and economic effects where populations become established (Mandrak and 

Cudmore 2004; Kolar et al. 2007; Nico et al. 2005). Environmental and economic impacts 

(damage and control costs) of aquatic nuisance species in the Great Lakes Basin alone were 

estimated at nearly $5.7 billion per year in 2005; approximately $4.5 billion of which is 

associated with fishery losses (i.e., reduced populations of important commercial and sport 

fishes; Pimentel 2005). Millions of dollars are spent each year on integrated, long-term control 

efforts such as the Sea Lamprey Control Program. Without sea lamprey control, it would be 

impossible to restore many of the Great Lakes’ native fish species. Invasive sea lamprey 

populations in the Great Lakes are managed through an extensive program administered by the 

Great Lakes Fishery Commission under authority of the 1954 Convention on Great Lakes 

Fisheries. The Great Lakes Fishery Commission (2006) and USFWS financial documents 

reported the costs for sea lamprey control, assessment, and research exceeded $21 million in 

2006. Nuisance species have the potential to cause extensive and irreversible changes to the 

environment (USEPA 2005; Lodge et al. 2006), thereby jeopardizing the long-term sustainability 

and use of existing resources, particularly imperiled, threatened, and endangered species. 

Although concerns over feral populations of Asian carps in large river systems and their 

tributaries are most often noted, these fishes can survive and potentially affect interior small 

order streams and lakes. Fishing, hunting, boating, and other wildlife-associated recreation may 

be adversely affected by feral populations of bighead and silver carps (Kolar et al. 2007). The 

decline of native fishes important as sport and food species would adversely affect recreational 

angling and other industries that benefit from sport fishing, such as tourism (Kolar et al. 2007). 

The USFWS estimated that nationwide freshwater fishing expenditures by 28.4 million anglers 

totaled $21.3 billion in 2001 (U.S. Department of the Interior et al. 2002). 

Confounding the Asian carp issue is the fact that three of the four species (bighead, black, and 

grass carps) have commercial applications and are in trade in the United States. The bighead 

carp has been cultured and sold as a live food fish product since the early 1980s, grass carp 

have been stocked nationally by public and private entities since the mid 1970s as a biological 

control for nuisance aquatic weeds, (grass carp are also cultured and sold as a live food fish 

product), and the black carp has been used since the early 1990s as a biological control for 

snail-borne parasites in commercial aquaculture production ponds. Silver carp, although 

cultured on a limited basis in the past, are not presently cultured in the United States, mostly 

because of their jumping habits and poor handling qualities during production, harvest, and 

transport (Kolar et al. 2007). However, there is some interest within the aquaculture industry in 

producing silver carp on a commercial scale in the future, especially as part of Partitioned 

Aquaculture Systems (personal communication, Robert Glennon, J. M. Malone and Sons Inc.). 

The National Aquaculture Development Act, signed into law in 1980, stated that it is “in the 

national interest, and it is the national policy, to encourage the development of aquaculture in 
 5

the United States.” This act indicated that the principal responsibility for the development of 

aquaculture lies with the private sector, but also assigned responsibility to the U.S. Department 

of Agriculture (USDA), U.S. Department of Commerce, and U.S. Department of Interior (16 

U.S.C. 2801-2810; Public Law 96-362). This policy and the subsequent responsibilities remain 

in force. 

The majority of private aquaculture facilities in the United States are classified as small 

businesses by the Small Business Administration (93% of baitfish farms, 84% of catfish farms, 

and 88% of foodfish businesses other than catfish and trout farms; USDA 1999). Much of the 

aquaculture in the United States occurs in impoverished rural areas such as parts of the 

Mississippi Delta region. The channel catfish (Ictalurus punctatus) industry was responsible, 

directly and indirectly, for 48% of the employment in Chicot County, Arkansas. This included 

$22 million in tax revenue and a total economic effect of over $384 million (Kaliba and Engle 

2004). The 2002 Census of Agriculture reported that aquaculture of all organisms in the United 

States grew from a $45 million industry in 1974 to a $1.13 billion industry in 2002 (USDA 2004). 

This economic activity multiplies into a total economic effect of over $7.6 billion in the United 

States when feed mills, supply companies, processors, labor expenditures, and tax revenue are 

included. Both natural resource conservation and the aquaculture industry must be considered 

in the development of management and control plans for Asian carps. 

As a first step in addressing Asian carp issues, the USFWS hosted an Asian Carp Workshop in 

St. Louis, Missouri, during April 2000. The purpose of that workshop was to initiate the process 

of gathering input for the development of a Mississippi River Basin Asian carp management and 

control plan. The goal of the workshop was to review the status, distribution, biology, 

ecological, and economic benefits and effects of Asian carps, and to identify management and 

control alternatives that may reduce or mitigate adverse effects (USFWS 2000). In 2002, the 

ANS Task Force requested the USFWS develop a national management and control plan for 

Asian carps. In early 2004, the USFWS and ANS Task Force organized an Asian Carp Working 

Group (Working Group) with broad and diverse representation from partners and stakeholders 

to participate in the collaborative development of the national management and control plan. 

Asian carp and nuisance species management specialists representing federal, state, tribal, and 

Canadian natural resources management agencies, and experts from universities and research 

facilities, aquaculturists and their trade association representatives, and non-governmental 

organizations are members of the Working Group. (See pages i-ii for a list of Working Group 

members and affiliations.) 

In May 2004, the USFWS hosted an initial Working Group meeting in Columbia, Missouri, that 

built upon the Workshop held in 2000. The purpose of the meeting was to begin a collaborative 

process to develop an integrated, national management and control plan for Asian carps. 

Breakout sessions conducted during the meeting focused discussions on the issues of 

preventing spread, detection and monitoring, population control and abatement, and research 

and information exchange. Working Group members were invited to participate on drafting 

teams (Appendix 6.2) to develop the strategies, initiatives, and actions identified during the 

meeting into an integrated national management and control plan. In August 2005, Working 

Group members met in Nashville, Tennessee, to review and discuss a first draft of the 

management and control plan. 

This collaborative process was highly successful and nearly all issues were resolved. The 

Working Group developed 48 strategies and 131 recommendations to manage and control 

Asian carps (presented in Chapter 3). However, three issues were not resolved within the 

Working Group. In-depth discussions for these three issues are presented in Appendix 6.3
 6

‘Unresolved issue: Use of triploid black carp on aquaculture facilities’, Appendix 6.4 ‘Unresolved 

issue: Use of grass carp on aquaculture facilities and farm ponds in watersheds with selfsustaining populations of grass carp’, and Appendix 6.5 ‘Unresolved issue: Commercial, 

domestic transport of live farm-raised bighead and grass carps’.

The complexity of developing strategies to manage and control these four different species on a 

national scale prevents a progressive approach and presentation of recommendations in this 

plan. The Working Group has identified an extensive set of strategies and recommendations to 

address various aspects of prevention, control, and management. Concurrent actions to 

prevent introductions and spread, and to reduce or eradicate feral populations are required to 

successfully manage and control Asian carps. Comprehensive approaches to prevent 

introductions of all aquatic nuisance species through integrated vector management (Ruiz and 

Carlton 2003) would greatly improve efforts to prevent intentional and unintentional introductions 

of Asian carps. No single control technique (i.e., no “silver bullet”) is available to eradicate 

Asian carps once they become established. Instead, effective long-term control will require the 

development of various innovative methods integrated into a single program (i.e., integrated 

pest management), similar to the integrated approach developed for sea lamprey control in the 

Great Lakes. 

For implementation of this plan to successfully prevent further introduction and spread, and to 

reduce or eradicate feral populations, coordination of management and control actions is 

paramount. A coordination structure and consortium for Asian carp management must be 

organized early in the process of implementing this plan. Strategy 3.7.1 identifies several 

recommendations to develop an implementation program that effectively coordinates, oversees, 

and drives implementation efforts. Action to establish this implementation program, which will 

integrate, sequence, and prioritize the 136 recommendations in this plan, should begin at once. 

1.2. Goals 

The Working Group agreed that the desired endpoint of the plan is the extirpation of Asian carps 

in the wild, except for non-reproducing grass carp within planned locations [i.e., areas where 

nuisance aquatic vegetation can be controlled using planned introductions of sterile (triploid) fish 

contained within a designated area]. The Working Group recognizes that there are few 

examples of an aquatic nuisance species being completely eliminated once it has become 

established, even in closed systems. However, such an endpoint is warranted in the 

development of long-term plans to manage and control these fishes. It is necessary to explore 

and identify what is needed to reach this endpoint rather than to resolve altogether that it is not 

attainable. 

The Working Group was charged with developing a plan that first and foremost protects our 

Nation’s natural resources. The Working Group was also charged with developing solutions 

that would allow for a viable aquaculture industry when implemented. Therefore, a framework 

for the responsible use of domestic stocks of Asian carps is described throughout this plan. It is 

in this context that the Working Group developed strategies and recommendations that address 

seven goals to protect the Nation’s natural resources. The Strategies and Recommendations 

developed by the Working Group to accomplish each of the following seven goals are discussed 

in detail in Chapter 3 and are summarized in Chapter 4 (Table 4.1, page 120) with a subjective 

estimate of the cost to independently implement each action. 
 7

1. Prevent accidental and deliberate unauthorized introductions of bighead, black, grass, and 

silver carps in the United States. 

2. Contain and control the expansion of feral populations of bighead, black, grass, and silver 

carps in the United States. 

3. Extirpate, or reduce to levels of insignificant effect, feral populations of bighead, black, grass, 

and silver carps in the United States. 

4. Minimize potential adverse effects of feral bighead, black, grass, and silver carps in the 

United States. 

5. Provide information to the public, commercial industries, and government agencies to 

improve effective management and control of bighead, black, grass, and silver carps in 

the United States. 

6. Conduct research to provide accurate and scientifically valid information necessary for the 

effective management and control of bighead, black, grass, and silver carps in the United 

States. 

7. Effectively plan, implement, and evaluate the management and control of bighead, black, 

grass, and silver carps in the United States. 
 8

CHAPTER 2. SPECIES OVERVIEWS 

This chapter presents an overview of the biology, introduction into the United States, present 

distribution and abundance, present uses, and potential adverse effects of each of the four 

species of Asian carps. The action plan for managing and controlling Asian carps is presented 

in Chapter 3. 

2.1. Bighead Carp 

2.1.1 Biology 

The bighead carp (Figure 2.1.1) is large, deepbodied, and can grow to lengths of 1.5 m and 

weights of 40 kg (Laird and Page 1996). It has a 

very large head, a large toothless mouth, and 

eyes located far forward and low on the head 

well below the axis of the body (Lin 1991). 

Coloration of the body is dark gray above and 

cream-colored below with dark gray to black 

irregular blotches on the back and sides (Kolar et 

al. 2007). 

Bighead carp are native to eastern China’s large lowland rivers, preferring temperatures 

between 4-26o

C. The species is known to school and occupy the upper to middle layers of the 

water column. They are extremely hardy and can readily adapt to many temperate freshwater 

environments. Juvenile bighead carp have been reported in low-velocity and off-channel 

habitats in the Missouri, Mississippi, Wabash, and lower Ohio rivers (Kolar et al. 2007). 

The bighead carp feeds in benthic, mid-water, and surface environments; feeding primarily on 

zooplankton, but also consuming large quantities of blue-green algae, aquatic insects (adults 

and larvae), and detritus (Robison and Buchanan 1988). Gill rakers are long, comb-like and 

close-set, allowing it to strain planktonic organisms from the water for food. Bighead carp lack a 

true stomach which requires them to feed almost continuously (Henderson 1976). 

Female bighead carp reach sexual maturity at three years of age with a body weight of 7-10 kg, 

while males can reach sexual maturity in two years with a body weight of 5-8 kg; however, this 

varies significantly with changing environmental conditions (Huet 1970; Kolar et al. 2007). 

Spawning activity is associated with high spring flows (Verigin et al. 1978), and spawning areas 

have high water velocity (0.6-2.3 m/s), turbid water, and water temperature in the range of 18-

30°C (Kolar et al. 2007). Bighead carp produce eggs that are semi-buoyant and require current 

to keep them from sinking to the bottom (Soin and Sukhanova 1972; Pflieger 1997). 

Floodplains associated with rising water levels provide nursery areas for larvae and juvenile 

forms (Huet 1970). Fecundity increases with age and body weight and is directly related to 

growth rate (Verigin et al. 1990). Vinogradov et al. (1966) found that first-time spawners 

average 288,000 eggs, while Sukhanova (1966) and Jennings (1988) documented egg 

production to range from 478,000-1,100,000, respectively. 

Figure 2.1.1. Bighead carp. Photo courtesy of 

USFWS, Carterville Fishery Resources Office.
 9

2.1.2. Introduction to the United States 

Bighead carp were first imported into the United States in 1973 by a private fish farmer in 

Arkansas (personal communication, Andrew Mitchell, USDA) as a potential biological control 

agent to improve water quality and increase fish production in culture ponds (Nico and Fuller 

2005). Universities and state agencies conducted research on bighead carp for a number of 

years. Bighead carp have been stocked for research purposes in Arkansas (Jennings 1988), 

Alabama (Pretto 1976; Dunseth 1977; Cremer and Smitherman 1980), Illinois (Buck et al. 

1978a, 1978b, 1981), South Carolina (Wilson et al. 1984), Texas (Bettoli et al. 1985; McBride 

1997), and Colorado (Lieberman 1996). Henderson and Wert (1976), in a document prepared 

for the U.S. Environmental Protection Agency (USEPA), stated that “aquaculture wastewater 

alternatives appear to be economically attractive regardless of the market for products if water 

quality goals are met.” Henderson (1978) stocked bighead carp in an existing lagoon treatment 

system in Arkansas in 1975-1976 to evaluate the effect of the fishes on water quality and the 

potential for using this nutrient source for fish production. In a follow-up study, Henderson 

(1979) reported results from a project funded by the USEPA that involved stocking six treatment 

lagoons of the Benton Services Center treatment plant in Benton, Arkansas. In a later paper, 

Freeze and Henderson (1982) refer to four stocking sites in Arkansas (specific locations not 

identified) in addition to the location of state and private hatcheries with bighead carp. With few 

regulations in place to restrict the sale or possession of bighead carp and with culture 

information and technical support supplied by the USFWS, fish farmers in Alabama, Arkansas, 

Mississippi, Missouri, and Oklahoma acquired fish from research facilities and imports, 

propagated bighead carp as food fish, and began marketing them to ethnic live fish markets. 

After concerns about introductions into open waters were raised, regulations were mandated to 

restrict stocking of the species in Arkansas waters, and the control of accidental introductions 

was investigated (Freeze and Henderson 1982). 

Bighead carp first began to appear in open public waters (e.g., the Ohio and Mississippi rivers) 

in the early 1980’s (Freeze and Henderson 1982; Carter 1983), with the first documented 

evidence of natural reproduction in the Missouri River in 1989 (Pflieger 1997; Kolar et al. 2007). 

Since their introduction, nearly every state in the Mississippi River Basin and several states 

outside the basin, have reported bighead carp in their waters. The reproducing populations 

currently in the Mississippi River Basin could be the result of escape from one or more sources, 

including: research, state agency, university, and private aquaculture facilities, and illegal 

introductions (Dill and Cordone 1997; Pigg et al. 1997). 

2.1.3. Present Distribution and Abundance in the United States 

Bighead carp have now been recorded from within or along the borders of at least 23 states 

(Figure 2.1.2) and are self-sustaining within the Mississippi, Missouri, Ohio, and Tennessee 

river basins (Kolar et al. 2007; Nico and Fuller 2005; Schofield et al. 2005). In October 1999 a 

fish kill was reported in shallow backwaters on the Upper Mississippi River National Wildlife 

Refuge near St. Louis that consisted of 97% Asian carps (mostly bighead and silver carps). 

Among fishes killed, only four native species were found and these were represented by one 

individual each (personal communication, Chuck Surprenant, USFWS). Adult bighead carp 

have also been reported to concentrate in large numbers below dams on many Midwestern 

rivers (Iowa to Indiana; MICRA 1999) and juveniles are known to invade small tributaries, 

particularly areas below spillways (Kolar et al. 2007). The catch rates of bighead carp in the 

Mississippi and Illinois rivers between 1993 and 2004 during standardized sampling by the Long 

Term Resources Monitoring Program, an element of the USACE Environmental Management 

Program, peaked between 2000 and 2002 (USGS 2007). 
 10

Figure 2.1.2. Distribution of bighead carp in the United States as reported in the Nonindigenous Aquatic 

Species database at the U.S. Geological Survey (USGS). Map reproduced from http://nas.er.usgs.gov/.

Live bighead carp have been imported to several states outside of the Mississippi River Basin. 

The USGS Nonindigenous Aquatic Species database (http://nas.er.usgs.gov) includes reported 

collections of bighead carp in Arizona (Specimen ID #237385), California (Specimen ID 

#29757), and Florida (Specimen ID #31508 and #31970). Five bighead carp have been 

collected in western Lake Erie between 1995 and 2003 (Mandrak and Cudmore 2004; Nico and 

Fuller 2005). 

It is difficult to describe accurately the potential distribution of bighead carp in the United States; 

however most of the United States lies within the preferred latitudes of bighead carp (Figure 

2.1.3). Based on an examination of the present distribution of established and introduced 

populations around the world, Kolar et al. (2007) conclude that bighead carp have the potential 

to become established in large rivers in much of the continental United States. Life history traits 

of bighead carp suggest they are well adapted to large river systems such as those of the 

central United States. Limiting factors to range expansions of reproducing populations are most 

likely access to rivers with moderate to swift current of a length at least 100 km to fulfill 

spawning requirements, fairly high ionic concentrations for successful egg incubation, and 

successful recruitment of larvae and juveniles (Kolar et al. 2007). 
 11

Figure 2.1.3. The latitudinal range of bighead carp projected across North America. The native range 

of bighead carp in eastern Asia extends from approximately 24o N to 43o N; other reports from 21o N to 

47o

 N include introduced populations (Kolar et al. 2007). Map modified from www.theodora.com/maps.

2.1.4. Present Uses within the United States 

Some researchers have reported that bighead carp, especially in combination with silver carp, 

may improve the quality of pond water by continually removing plankton, especially blue-green 

algae, thereby stabilizing plankton and lessening the probability of die-offs in production ponds 

(Kolar et al. 2007; Schofield et al. 2005). Studies have yielded conflicting results (Kolar et al. 

2007) and Stickney (1996) concluded that more studies would be needed to confirm that 

bighead carp improve water quality in culture ponds. Stone et al. (2000) stated that changes in 

the plankton community brought about by bighead carp do not necessarily result in improved 

water quality or reduced off-flavor in water. In addition to water quality control, bighead carp are 

used in polyculture with channel catfish in the United States (Kolar et al. 2007) and sold for 

human consumption at the end of the production cycle, providing supplemental income for 

catfish producers. The greatest efficiencies were reportedly achieved when catfish and bighead 

carp were grown separately with nutrient rich water from catfish ponds used as a source of feed 

for bighead carp (Griffin 1993). 

Bighead carp raised for human consumption are primarily sold through the livehaul market as a 

live product (Engle 1998a, 1998b) and can be an important source of revenue for fish farmers 

during times of low catfish prices (Stone et al. 2000; DFO 2005). The estimated net benefit of 

stocking bighead carp with catfish ranged from $1,628 to $2,743 annually from a 15-acre pond, 

or $108-$183/acre (Engle 1998a; Engle and Brown 1998). Jensen (1998) estimated net profit 

from bighead carp raised in catfish ponds at $5,560 for a 15-acre pond, or $371/acre. 

Extrapolating this estimated annual net profit to the estimated 5,100 acres of bighead carp 

polycultured with channel catfish (Stone et al. 2000) would yield $550,800 - $1,892,100. 

Bighead carp market prices fluctuate widely and raising bighead carp alone is unlikely to be 

profitable at current prices (Engle 1998b). 

Most live bighead carp produced in the United States are sold from small specialty food markets 

to consumers of various Asian cultures in major North American cities (Figure 2.1.4; Stone et 
 12

al. 2000). The current market for live bighead carp in the United States is limited and easily 

saturated (Stone et al. 2000). “The typical consumer will buy only enough fish for the current 

day’s meal and will pay top dollar only for live fish” (Stone et al. 2000). In states where 

consumers can purchase live bighead, the price per pound is relatively higher than for dead 

bighead (Stone et al. 2000), indicating a distinct consumer preference for the live product. 

Bighead carp that die in retail markets are sold at about 20% of the live price (Stone et al. 

2000). Specialized live haulers transport live fish from fish farms to wholesalers who warehouse 

the fish and distribute live bighead carp to individual fish markets by smaller trucks (Figure 

2.1.5; Stone et al. 2000). Marketing as a live product for ethnic markets in Canada began in 

1981 (DFO 2005). 

Figure 2.1.4. Specialty food market in New York 

City. Photo courtesy of David Heikes, University of 

Arkansas at Pine Bluff.

Many governments restrict or prohibit the possession and/or sales of live Asian carps. Ontario 

amended its provincial Fish and Wildlife Conservation Act to restrict the purchase and sale of 

live bighead, black, grass and silver carps effective May 2004 (personal communication, Beth 

Brownson, Ontario Ministry of Natural Resources). Ontario also amended its Fisheries 

Regulations to restrict live possession of Asian carps effective August 31, 2005 (Canada 

Gazette 2005). Illinois put new Administrative Rules into effect May 1, 2005, listing bighead, 

black, and silver carps as Injurious Species, thereby prohibiting the live sales of these fishes 

within the state (Illinois Administrative Code, Title 17, Chapter 1, Part 805). New York State 

passed emergency regulations prohibiting import and live sales of bighead, black, and silver 

carps with the exception that live bighead carp may be sold in New York City, however the fish 

must be killed by the seller before the purchaser takes possession (New York Conservation 

Rules and Regulations, Title 6, Chapter 1, Part 180). The State of California prohibits the sale 

of live bighead carp requiring out-of-state live haulers to kill bighead carp prior to entering the 

state (personal communication, Bob Hulbrock, California Department of Game and Fish). In the 

absence of live bighead carp, consumers in California have accepted “freshly dead” products. 

Bighead carp have also been used experimentally in the United States to manage water quality 

in sewage treatment lagoons, manure lagoons, and reservoirs. Henderson (1983) 

recommended the use of bighead and silver carps to reduce municipal sewage treatment plant 

operational costs and treatment pond size. Early research in this capacity indicated that facility 

design greatly determined the overall effect of bighead carp on water quality. Due to their 

feeding preferences, bighead carp are more effective at feeding on zooplankton than on algae 

(Kolar et al. 2007). 

Figure 2.1.5. Delivery of live bighead carp from 

a wholesaler to a specialty food market in New 

York City. Photo courtesy of David Heikes, 

University of Arkansas at Pine Bluff. 
 13

Commercial enterprises are attempting to develop products and establish markets for wild 

harvested bighead carp. Commercial harvest of bighead carp is increasing in parts of the 

Mississippi River Basin. Bighead carp had the highest biomass (3,653 kg, 39%) of fish caught 

commercially from the Missouri River in Iowa during 2003 (Iowa Department of Natural 

Resources 2003). The combined annual commercial harvest of bighead and silver carps from 

the Mississippi and Illinois rivers within Illinois increased from less than 600 kg per year 

between 1988 and 1992 to over 50,000 kg per year since 1997 (Chick and Pegg 2001). The 

reported combined commercial harvest of these fishes in 2003 was nearly 60,000 kg from the 

Mississippi River alone and exceeded 338,000 kg in the Illinois River (Maher 2005). 

2.1.5. Potential Adverse Effects 

Although direct species interactions are not understood fully and competition is difficult to 

document in large and dynamic river systems (Kolar et al. 2007), the potential of increasing 

populations of bighead carp to affect native species at all life stages is a concern. Bighead carp 

are believed to affect many native species adversely because they feed on plankton, the 

primary food source for mussels, larval fish, and several adult fishes (Laird and Page 1996; 

Fuller et al. 1999). Sampson (2005) found dietary overlap between bighead carp with gizzard 

shad (Dorosoma cepedianum) and bigmouth buffalo (Ictiobus cyprinellus) in the Illinois and 

Mississippi rivers. Schrank et al. (2003) demonstrated dietary overlap between age-0 bighead 

carp and age-0 paddlefish in mesocosms. Bighead carp have the potential to influence large 

crustacean zooplankton negatively and to alter food web interactions, thereby potentially 

affecting other native aquatic organisms (Kohler et al. 2005; Sampson 2005). Field studies to 

investigate a decline in planktivorous species in areas with abundant bighead carp populations 

are lacking.

The spread of bighead carp may be adversely affecting the existing commercial fishery in parts 

of the Mississippi River Basin (Maher 2005). There is not yet a large market for bighead carp in 

the United States, but in some locations this species has become a substantial portion of the 

commercial catch (Iowa Department of Natural Resources 2003; Maher 2005; personal 

communication, Vince Travnichek, Missouri Department of Conservation). Commercial fishers 

on the Illinois River reported a 124% increase in the harvest of bighead and silver carps 

(reported together) and a 35% decrease in buffalo harvest during 2002. Unless economically 

viable markets develop, the establishment of large self-sustaining populations of bighead carp in 

the United States may compromise commercial fishing. 

Feral bighead carp have been reported from rivers of the United States since the 1980’s 

(Freeze and Henderson 1982; Carter 1983) and are no longer a risk of introducing nonnative 

pathogens within their current range. However, additional importation of bighead carp into the 

United States could introduce nonnative pathogens with unknown potential consequences. 

Scientists have found the Asian tapeworm (Bothriocephalus acheilognathi) in bighead carp 

stocks in China and the former USSR (Kolar et al. 2007). Asian carps, along with common carp 

and many native fishes, are known vectors of Asian tapeworm and hence should be inspected 

for this parasite if Asian carp are to be stocked into a body of water where the parasite is not 

known to be present. Infected fish should not be stocked into uninfected water bodies. 

A recently completed environmental risk assessment, using methods described by the Risk 

Assessment and Management Committee (1996), concluded that the overall organism risk 

potential associated with bighead carp is high (Kolar et al. 2007). The organism risk potential is 

based on the probability of bighead carp becoming established and the consequences of 

bighead carp establishment. The finding of high organism risk potential indicates that bighead 
 14

carp are an organism of major concern and present an unacceptable level of risk. The 

probability of bighead carp establishment if released (high) was determined using the following 

factors: probability of being within the pathway, probability of the surviving transit, probability of 

successfully colonizing and maintaining a population where introduced, and probability of 

spread beyond the colonized area. The consequence of bighead carp establishment (medium 

to high) was determined using the following factors: estimation of economic effect if established, 

estimation of environmental effect if established, and estimation of effect from social and/or 

political influences. 

2.2. BLACK CARP 

2.2.1. Biology 

The black carp (Figure 2.2.1) is large, elongated, 

laterally compressed and can exceed 1.8 m and 

70 kg (Nico et al. 2005). It has a pointed head 

with a flattened anterior portion and a small 

toothless mouth (Lin 1991). The body of the 

black carp is covered with large cycloid scales; 

coloration of the body varies from brown to black 

and grading to a bluish-grey or nearly white belly. The fins are darker than the body and most 

often described as black or brownish-black with lighter hues at the base (Lin 1991; Nico et al. 

2005). 

Black carp are native to the Pacific drainages of eastern Asia between 22 and 51°N latitudes. 

Its range extends from the Pearl River Basin in China north to the Amur River and its major 

tributaries of China and far eastern Russia, including possibly the Red River of northern Viet 

Nam (Frimodt 1995; Nico et al. 2005). Throughout its native range the black carp inhabits 

lowland lakes and rivers, mostly at altitudes less than 200 meters above sea level (Li and Fang 

1990). The climate of this range varies from subtropical to cold (FAO 1983; Nico et al. 2005). 

Black carp have been reported to tolerate dissolved oxygen concentrations as low as 2 ppm. 

Optimal feeding temperatures for black carp range from 25-30°C; feeding ceases at 

temperatures < 3°C. Temperatures less than 0.5°C or above 40°C are lethal (Lin 1991). 

Recently-hatched black carp fry feed primarily on zooplankton. At 26+ days after hatching (3.1-

33 cm), the pharyngeal teeth have fully formed and the fish begin feeding on a larger variety of 

benthos, insect larvae, and organic detritus (Liu et al. 1990; Lin 1991). Adult black carp feed 

primarily on mollusks, using their molar like pharyngeal teeth to crush the shells. The species of 

mollusks consumed varies with geography, fish size, and mouth gape, but usually include 

gastropods and bivalves (Nico et al. 2005). 

Black carp mature from 6-11 years, depending on latitude, diet, and habitat. Males typically 

mature a year earlier than females. Females average 1 m and 15 kg at maturity while males 

average 88 cm and 10 kg (Lin 1991; Nico and Williams 1996). Spawning occurs in rivers with 

water velocities of 0.8-1.8 m/s and water temperatures of 17-30o

C (Nico et al. 2005). Increased 

water flow and temperatures trigger an upstream spawning migration in spring and early 

summer (Nico et al. 2005). Lin (1991) reported fecundity of females weighing 13.3 kg and 34 kg 

to be 74.6 and 99 eggs per gram of body weight (about 1.3-3.4 million eggs), respectively. 

Figure 2.2.1. Black carp. Photo courtesy of 

James Candrl, USGS.
 15

Black carp eggs are non-adhesive, semi-buoyant, and drift with water currents. Eggs range in 

size from 4-7 mm diameter and hatch 24 to 35 hours post fertilization, depending on water 

temperature (Nico et al. 2005). The eggs and larvae are carried into floodplain lakes, smaller 

streams, and channels with little or no current. These areas serve as nursery areas for larval 

and juvenile fish. If the drift of eggs and larvae occurs during falling river levels, then the larvae 

migrate actively to their feeding areas after absorbing the yolk sac (Nico et al. 2005). 

2.2.2. Introduction to the United States 

Black carp were first imported into the United States in 1973 by a private fish farmer in Arkansas 

as part of a “mixed shipment of Chinese carps.” These initial specimens were trusted into the 

possession of the Arkansas Game and Fish Commission for evaluation, were never 

successfully spawned, and were eventually destroyed (personal communication, Mike Freeze, 

Keo Fish Farm). Black carp were imported into the United States on several occasions during 

the 1980’s by private fish farmers as a potential food fish and again during the 1990s as a 

potential biological control for snail-borne parasites in aquaculture ponds (personal 

communication, Andrew Mitchell, USDA). By the early 1990’s four private fish farms were 

producing triploid black carp for use as biological control agents. However, controversy over the 

black carp has restricted its use in research and management. 

The presence of some black carp in natural waters indicates that they have escaped from 

research facilities or private aquaculture facilities. It has been reported that black carp escaped 

into the Osage River (a tributary to the Missouri River) when high water flooded hatchery ponds 

at an aquaculture facility in Missouri during April 1994 (Nico 2007; Nico et al. 2005). Although 

an estimated 30 black carp were reported as escaped to the Missouri Department of 

Conservation by an employee of the fish farm (Missouri Department of Conservation 

memorandum from C. Fuller to K. Richards, dated 13 April 1994), the owner of the fish farm 

states that no black carp have escaped from ponds on his facility (personal communication, Jim 

Kahrs, Osage Catfisheries, Inc.). 

2.2.3. Present Distribution and Abundance in the United States 

Agencies, research institutes, or individuals in 11 states have possessed live black carp, 

received shipments of live black carp, or both, at one time or another. These include Arkansas, 

Florida, Illinois, Iowa, Louisiana, Mississippi, Missouri, North Carolina, Oklahoma, Texas, and 

Wisconsin (Nico et al. 2005). Nico et al. (2005) stated “The total numbers of black carp in the 

United States at any one time is uncertain. During the 1990s, it was reported that the number 

being held by fish farmers and other entities in a few southern states totaled well over 400,000 

individuals, including triploids and diploids (M. Freeze, memo to B. Collins, U.S. Department of 

Agriculture, Stuttgart, Arkansas). At that time, there were four privately owned aquaculture 

facilities, located in Arkansas and Missouri, and each reportedly held more than 100,000 diploid 

and triploid black carp.” 

Less is known about the distribution and abundance of feral black carp in the United States. To 

date, there have been no adequate field surveys conducted to determine the distribution and 

abundance of black carp in the Mississippi River Basin or studies conducted for the expressed 

purpose of identifying spawning grounds or for targeting capture of larval black carp in the wild. 

During 2003 and 2004, following testing of gear in ponds with known numbers of black carp, 

Schramm and Basler (2005) employed AC electrofishing gear to sample selected waterways “in 

proximity to open-pond aquaculture facilities known or expected to use black carp” in Arkansas, 

Louisiana, and Mississippi. No black carp were captured. The researchers concluded that the 
 16

absence of black carp in their samples “suggests black carp are absent or present in low 

densities” in these waterways. 

Relatively few fishery biologists and commercial fishers in the Mississippi River basin are 

experienced in fishing appropriate gear and habitat (e.g., large hoop nets placed in deep water) 

for catching black carp. However, some commercial fishers operating in the Mississippi River 

and its tributaries have been capturing black carp in the wild since the early 1990s and black 

carp captures have reportedly been an annual event in portions of the lower Mississippi Basin 

for more than a decade (Nico 2007; Nico et al. 2005; personal communication, Leo Nico, 

USGS). Most of the fish captured were not retained, however at least 14 of the wild-caught 

black carp specimens were examined by experts and their identifications verified (Table 2.2.1; 

Figure 2.2.2; Nico 2007; Nico et al. 2005; personal communication, Leo Nico, USGS; personal 

communication, Mark McElroy, Louisiana Department of Wildlife and Fisheries). 

Figure 2.2.2. Distribution of black carp in the United States as reported in the Nonindigenous Aquatic 

Species database at the U.S. Geological Survey (USGS). Map reproduced from http://nas.er.usgs.gov/.
 17

Table 2.2.1. A partial listing of wild-caught black carp taken in the Mississippi River Basin by 

commercial fishers and whose identities have been verified by experts (Nico 2007; Nico et al. 

2005; personal communication, Leo Nico, USGS; personal communication, Mark McElroy, 

Louisiana Department of Wildlife and Fisheries). 

Collection Date River Location Total 

Length 

(mm) 

Age (Years)1

 Ploidy 

26 March 2003 Mississippi Illinois, Horseshoe Lake, 

Alexander County 

783 4 (scale) Triploid 

19 April 2004 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

1,110 8 (otolith) Diploid 

6 May 2004 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

904 6 (pectoral 

spine) 

Diploid 

2 June 2004 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

 

10 June 2004 Mississippi Illinois, below Lock and Dam 

24 at river mile 273.4 

755 

13 August 2004 Atchafalaya Louisiana, at Simmesport 1,135 Diploid 

5 April 2005 White Arkansas, river mile 129 

14 May 2005 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

 5 (pectoral 

spine) 

Diploid 

22 March 2006 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

996 Diploid 

28 April 2006 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

995 4 (pectoral 

spine) 

Diploid 

27 June 2006 Red Louisiana, near confluence of 

Red and Atchafalaya rivers 

1027 5 (pectoral 

spine) 

Diploid 

10 May 2007 Red Louisiana, at Simmesport 1117 6 (pectoral 

spine) 

May 2007 Red Louisiana 

May 2007 Mississippi Louisiana 

 

1

 Structure used to estimate age indicated in parentheses. 
 18

It is difficult to predict the potential distribution of black carp in the United States; however most 

of the United States lies within the preferred latitudes of black carp (Figure 2.2.3) and there are 

an abundance of large rivers well suited for black carp. There have been no collections of eggs 

and larvae or observations of spawning (Nico et al. 2005). However there have been no studies 

directed at the collection and identification of black carp eggs or larvae, and, since black carp 

spawning does not normally take place near the water surface (Nico et al. 2005), direct 

observation of spawning fish would be unlikely. Although there has been no documented 

natural reproduction, the continued capture of reproductively viable (i.e., diploid) adult black 

carp has increased concerns that feral black carp are reproducing in the wild and may establish 

self-sustaining populations (Nico et al. 2005). 

Figure 2.2.3. The latitudinal range of black carp projected across North America. The native range of 

black carp in eastern Asia extends from approximately 22o N to 51o N (Nico et al. 2005). Map modified 

from www.theodora.com/maps.

2.2.4. Present Uses within the United States 

In their native China, black carp are an important food fish, with culture of black carp dating 

back at least 1000 years (Nico et al. 2005). Black carp are considered one of the most 

desirable food fish in China and fish farmers in the United States anticipated that sales of the 

fish would be high in ethnic markets. However, to date there is neither demand for black carp in 

fish markets in the United States nor any commercial production of this fish for the live food 

market. 

Currently black carp are used on aquaculture facilities as biological control agents for snails, 

which serve as intermediate hosts for several fish parasites that can kill juvenile fish and render 

fish flesh unmarketable (see Strategy 3.1.14 and Appendix 6.3). 

The ANS Task Force was asked to consider black carp as a control agent for zebra mussels 

over a decade ago, and it strongly rejected such a use (personal communication, Dean 

Wilkinson, NOAA). Black carp have been reported to consume zebra mussels, but it is unlikely 

that black carp are able to break apart clumps or rafts of zebra mussels (Nico et al. 2005). It is 

also not known whether black carp will select zebra mussels preferentially over native mollusks. 
 19

Current knowledge of the species suggests that black carp would not be effective in controlling 

zebra mussel populations (Nico et al. 2005). 

2.2.5. Potential Adverse Effects 

Black carp feed primarily on mussels and snails, collectively the most imperiled aquatic 

organisms in the United States; nearly 70 percent of North American mussels are listed as 

extinct, endangered, threatened, or of special concern (Johnson and Butler 1999; USFWS 

2005). Mollusk populations have been reduced greatly by poor water quality, pollution, habitat 

degradation, commercial harvest, and nonnative species introductions [e.g., Asiatic clams 

(Corbicula fluminea) and zebra mussels] (Johnson and Butler 1999). Black carp could add 

substantially to the problem (Nico et al. 2005). The effects of these fish are likely to be 

proportional to their abundance in the wild. Introduced individuals or a reproducing population 

of black carp in open waters of the United States could pose a serious threat to many of the 

remaining populations of threatened and endangered mollusks (Nico et al. 2005), however there 

is a vast difference between the long-term effects of introduced individuals and a reproducing 

population of these fish. Black carp could consume many imperiled native mussels. Nico et al. 

(2005) concluded that all size classes of 12 (85%) of the 14 federally endangered unionid 

species in Midwestern rivers are within the gape limits of a 2 m long black carp. Because there 

are no known native molluskivores with a similar combination of size, morphology, and diet, the 

black carp could potentially fill a niche in North American rivers currently unoccupied and 

consequently alter food webs substantially (Nico et al. 2005). 

Although direct species interactions are not fully understood, established populations of black 

carp could compete with native fishes that feed on small mollusks. Freshwater drum 

(Aplodinotus grunniens), redear sunfish (Lepomis microlophus), several ictalurid catfishes, and 

several redhorse species (Moxostoma spp.) may be affected (Nico et al. 2005). In addition, 

larval and juvenile black carp consume plankton, insect larvae, and detritus (Lin 1991) and 

potentially could compete for food with native larval and juvenile fishes if these resources are 

limited. 

Additional importation of black carp into the United States could introduce nonnative pathogens 

with unknown potential consequences. Nico and Williams (1996) concluded that until black carp 

are evaluated as a pathway for disease, no additional stocks of black carp should be imported 

without additional precautions. Scientists have found the Asian tapeworm in stocks of black 

carp in the former USSR (Nico et al. 2005). Asian carps, along with common carp and many 

native fishes, are known vectors of Asian tapeworm and hence should be inspected for this 

parasite if Asian carp are to be stocked into a body of water where the parasite is not known to 

be present. Infected fish should not be stocked into uninfected water bodies. 

A recently completed environmental risk assessment, using methods described by the Risk 

Assessment and Management Committee (1996), concluded that the overall organism risk 

potential associated with black carp is high (Nico et al. 2005). The organism risk potential is 

based on the probability of black carp becoming established and the consequences of black 

carp establishment. The finding of high organism risk potential indicates that black carp are an 

organism of major concern that compels mitigation. The probability of black carp establishment 

if released (high) was determined using the following factors: probability of being within the 

pathway, probability of surviving in transit, probability of successfully colonizing and maintaining 

a population where introduced, and probability of spread beyond the colonized area. The 

consequence of black carp establishment (high) was determined using the following factors: 
 20

estimation of economic effect if established, estimation of environmental effect if established, 

and estimation of effect from social and/or political influences. 

2.3. GRASS CARP 

2.3.1. Biology 

The grass carp (Figure 2.3.1) is large, elongated, 

laterally compressed, and can grow to lengths of 

1.6 m and weights of 37 kg (Pflieger 1997; 

Bowman 1998). The head is slightly flattened, 

with moderately small eyes centered on the side 

of the head. The body is covered with large 

cycloid scales. Coloration of the body varies 

from blackish or olive-brown, grading to brassy or silvery-white on the sides and belly. Scale 

pockets on the back and sides are outlined by dusky pigment, giving a crosshatched effect 

(Pflieger 1997). 

Grass carp are native to the large rivers of eastern Asia. Its native range extends from southern 

Russia to northern Vietnam and from coastal waters inland. The grass carp is a sub-tropical to 

temperate species found between 25-65°N latitudes (Lee et. al. 1980; Shireman and Smith 

1983; Froese and Pauly 2001). The grass carp is most commonly reported to inhabit lower and 

middle reaches of rivers. Grass carp prefer large, slow flowing water bodies with available 

vegetation. Grass carp can tolerate water temperatures between 0-38°C, but prefer 

temperatures of 10-26°C. The species can withstand dissolved oxygen concentrations as low 

as 0.5 ppm and salinities to 10 ppt (Froese and Pauly 2001) 

Grass carp possess comb-like pharyngeal teeth that are used to grind vegetation. Adult grass 

carp prefer a diet of submerged plants with soft leaves (Bain et al. 1990; Pine and Anderson 

1991) and will consume filamentous algae and firmer macrophytes [e.g., Eurasian milfoil 

(Myriophyllum spicatum)] when preferred forage has been exhausted (Opuszynski and 

Shireman 1995). In the absence of aquatic vegetation, grass carp have been reported to 

consume organic detritus, insects, small fish, earthworms, and other invertebrates (Laird and 

Page 1996; Froese and Pauly 2001). Grass carp can consume up to 40% of their body weight 

per day in aquatic vegetation (Laird and Page 1996). 

Grass carp grow rapidly before the onset of maturity, reaching 1 kg by age one and growing 2-3 

kg per year in temperate climates and 4.5 kg/year in tropical climates (Shireman and Smith 

1983). Age at maturity ranges from 2-10 years (50-86 cm) and is largely a function of water 

temperature and diet (Cudmore and Mandrak 2004). Males generally mature one year earlier 

than females. Spawning activity is associated with high spring flows, and spawning areas have 

high water velocity, turbid water, and a temperature in the range of 15-30°C (Cudmore and 

Mandrak 2004). Grass carp spawn primarily in the main river channel in the upper part of the 

water column over rapids or sand bars during times of turbulent water currents ranging from 0.6 

to 1.5 m/s (Shireman and Smith 1983). Fecundity is directly proportional to length, weight, and 

age, averaging 500,000 eggs for a 5 kg female (Shireman and Smith 1983; Chilton and 

Muoneke 1992). 

Grass carp eggs are non-adhesive and semi-buoyant, requiring flowing water for incubation 

(Cudmore and Mandrak 2004). Eggs can become dispersed widely from the spawning site and 

Figure 2.3.1. Grass carp. Picture courtesy of 

Duane Chapman, USGS. 
 21

have reportedly traveled downstream as far as 180 km (Fedorenko and Fraiser 1978). 

Successful reproduction requires long stretches of warm, flowing water for egg incubation and 

suitable backwater habitats for larval development (Verigin et al. 1978). Floodplains associated 

with rising water levels provide nursery habitat areas for larvae and juvenile forms. Larval grass 

carp initially feed on rotifers and protozoans, switching to larger cladocerans and insect larvae 

at 11-15 days post-hatch (Fedorenko and Fraser 1978; Opuszynski and Shireman 1995). Three 

weeks post-hatch, grass carp begin feeding on filamentous algae and macrophytes. By the age 

of 1 to 1.5 months grass carp feed exclusively on macrophytes (Opuszynski and Shireman 

1995). 

2.3.2. Introduction to the United States 

Grass carp were brought into the United States 

in 1963 through a joint action of the United 

Nations Food and Agriculture Organization, the 

USFWS, and Auburn University to evaluate 

their use as a biological control for aquatic 

vegetation (Avault 1965; Stevenson 1964; 

Pflieger 1978; Leslie et al. 1996; Mitchell and 

Kelly 2006). The original fish were housed at 

the USFWS Fish Farming Experiment Station 

in Stuttgart, Arkansas (Figure 2.3.2) and 

Auburn University, Alabama (Avault 1965; 

Stevenson 1964; Pflieger 1978; Leslie et al. 

1996; Mitchell and Kelly 2006). These stocks 

reached sexual maturity in 1966 and were 

spawned at both facilities (Mitchell and Kelly 

2006). Some of the offspring produced by the 

USFWS in Stuttgart, Arkansas are thought to 

have escaped in 1966 and newly hatched 

grass carp fry were observed passing through 

screens on rearing troughs in 1970 (Mitchell 

and Kelly 2006). 

The Arkansas Game and Fish Commission stocked Lake Greenlee, a topographically isolated 

lake near Brinkley, Arkansas, in 1969 and 1970 (Leslie et al. 1996; Mitchell and Kelly 2006). In 

1971, the Arkansas Game and Fish Commission produced 1 million grass carp fry and stocked 

the first reservoir open to a stream system, Lake Conway, and began providing out-of-state 

researchers with fish (Guillory and Gasaway 1978). By 1972 grass carp had been shipped to at 

least 16 states (Guillory and Gasaway 1978) and the Director of the USFWS Fish Farming 

Experiment Station (K.E. Sneed) reported that grass carp had been introduced into 40 states 

(Pflieger 1978). By 1975, the Arkansas Game and Fish Commission had stocked 380,000 

grass carp in more than 100 lakes throughout the state (Guillory and Gasaway 1978; Pflieger 

1978). 

Feral grass carp were collected in 1970 in the White River, Arkansas and in the Illinois portion of 

the Mississippi River in 1971 (Mitchell and Kelly 2006). Age determination indicated the fish 

were from the 1966 year class and most likely had escaped from the USFWS facility in 

Stuttgart, Arkansas (Mitchell and Kelly 2006). By 1974 feral grass carp from the 1971 year 

class began to appear with great frequency in the Mississippi River (Pflieger 1978). Other free 

Figure 2.3.2. A picture of the first grass carp 

shipment to the United States arriving at the U.S. 

Fish and Wildlife Service laboratory at Stuttgart, 

Arkansas, on November 16, 1963 (Photo copied 

from Stevenson 1964).
 22

ranging or escaped grass carp appeared in rivers of Alabama, Florida, Georgia, and Mississippi 

(Mitchell and Kelly 2006). 

Realizing the effectiveness of grass carp for controlling nuisance aquatic vegetation, private fish 

hatcheries began marketing grass carp in 1972 (Mitchell and Kelly 2006). The first grass carp 

marketed by private fish hatcheries were received from the Arkansas Game and Fish 

Commission in 1972; additional imports of grass carp did not occur until the late 1970s or early 

1980s (personal communication, Andrew Mitchell, USDA). By 1973 grass carp, marketed as 

white amur, were being sold to private pond owners via trade magazines for aquatic vegetation 

control. Few regulations existed to restrict the distribution of grass carp. 

By the late 1970s a growing controversy had developed regarding the grass carp’s potential to 

reproduce in river systems in the United States and many states banned the importation of 

diploid grass carp (Leslie et al. 1996). Private hatcheries, attempting to create an 

environmentally safe grass carp, began developing hybrid, sterile, and mono-sex stocks of 

grass carp (Leslie et al. 1996). 

In 1983 a private fish hatchery in Arkansas produced the first triploid grass carp on a 

commercially viable scale (Malone 1984), pioneered the Coulter Counter for blood testing 

individual fish to ensure 100% triploid stocks, and initiated USFWS involvement in ploidy 

inspection and verification (Mitchell and Kelly 2006). In 1985 the USFWS established a triploid 

grass carp ploidy inspection program that opened the way to ship certified triploid grass carp 

around the country (http://www.fws.gov/warmsprings/FishHealth/frgrscrp.html; Griffin 1991). 

Triploid grass carp sales have grown to more than 400,000 fish per year with more than 30 

states receiving USFWS certified triploid grass carp through 2004 (Mitchell and Kelly 2006). 

From 2002-2004, more than 1.3 million triploid grass carp were shipped with USFWS 

certification to more than 20 states for aquatic vegetation control (Mitchell and Kelly 2006). 

2.3.3. Present Distribution and Abundance in the United States 

Grass carp have been widely distributed throughout the United States. Grass carp are currently 

reported in every state except Alaska, Rhode Island, Maine, Vermont, and Montana (Figure 

2.3.3) primarily because they are deliberately stocked by various natural resources 

management agencies and private pond owners as a cost-effective biological control for certain 

nuisance aquatic plants, and due to their use in research projects, escape from aquaculture 

facilities, and dispersal from introduced sites (Fuller et al. 1999). Grass carp are considered 

established in Arkansas, Kentucky, Illinois, Louisiana, Missouri, Mississippi, Oklahoma, 

Tennessee, and Texas (Courtenay 1993; Elder and Murphy 1997; Nico et al. 2006; personal 

communication, Jeff Boxrucker, Oklahoma Department of Wildlife Conservation). Selfsustaining populations of grass carp are established within or along the borders of at least nine 

states, reproducing in rivers such as the Mississippi, Missouri, Ohio, and Trinity and some 

tributaries (Elder and Murphy 1997; Schofield et al. 2005; Nico et al. 2006). Grass carp have 

also been reported in Lakes Michigan, Erie, Huron, and Ontario (Cudmore and Mandrak 2004; 

USGS 2006). 

2.3.4. Present Uses within the United States 

Diploid (i.e., fertile) and triploid (i.e., sterile) grass carp continue to be used as an effective 

biological control for vegetation in lakes and ponds (Cassani 1996). Hoyer et al. (2005) 

concluded “it is clear that if there was some cost-effective and selective method of removing 

grass carp from a lake system before complete eradication of submersed aquatic vegetation 

was accomplished then triploid grass carp would be an excellent method of hydrilla (Hydrilla 
 23

verticillata) control for large and small lakes.” Although desired results are often hard to 

achieve, biological control is often preferred to chemical or mechanical control. At least three 

biotypes of hydrilla in 20 water bodies throughout central Florida have developed a resistance to 

the herbicide fluridone (Michel et al. 2004; Hoyer et al. 2005). A hydrilla management workshop 

to summarize management, control, and research options and recommendations was funded by 

Florida LAKEWATCH in response to spreading fluridone resistance (Hoyer et al. 2005). As a 

result of the workshop, the Florida Department of Environmental Protection, Bureau of Invasive 

Plant Management, is funding a triploid grass carp risk analysis to determine whether these fish 

can be effectively managed in open waters. The use of triploid grass carp may expand over 

time in response to spreading resistance of hydrilla to fluridone. 

Figure 2.3.3. Distribution of grass carp in the United States as reported in the Nonindigenous Aquatic 

Species database at the U.S. Geological Survey (USGS). Map reproduced from http://nas.er.usgs.gov/. 

State natural resources management agencies, working with the USFWS, have used triploid 

grass carp for aquatic vegetation control, particularly in those states with the most severe 

aquatic vegetation problems. Many state fishery management agencies (34) offer some type of 

guidance for stocking grass carp, with 23 states specifying a stocking rate and whether triploid 

or diploid fish are allowed (Dauwalter and Jackson 2005). Grass carp are also used widely for 

vegetation control by private aquaculture facilities; approximately 42% of catfish production 

facilities use grass carp for vegetation control (APHIS 2003). A substantial trade in the species 

exists for use in commercial aquaculture facilities, private ponds and lakes, public ponds and 

lakes, and municipal irrigation projects. Triploid grass carp sales have grown to more than 

400,000 fish per year with more than 30 states receiving USFWS certified triploid grass carp 

through 2004 (Mitchell and Kelly 2006). Millions of dollars are spent on aquatic vegetation 
 24

management in the United States annually (Greenfield et al. 2004). While many control 

measures exist, the use of grass carp is the least expensive, costing $45 to $125 per acre 

(Greenfield et al. 2004).

Grass carp are also polycultured with catfish for human consumption, and similar to bighead 

carp, are sold from small specialty food markets to consumers of various Asian cultures in major 

North American cities (Stone et al. 2000). Grass carp are more in demand by consumers, sell 

for a higher price than bighead carp (Stone et al. 2000), and livehaulers view grass carp as 

more profitable than bighead carp (Engle 1998b). However, grass carp are commonly stocked 

in catfish ponds at 10 to 30 fish per acre compared to bighead carp that are stocked at 125 to 

300 per acre (Engle 1998a). 

Triploid grass carp can be considered sterile for management purposes (Nico et al. 2005). 

Triploid female grass carp have greatly reduced ovaries and are functionally sterile (Thorgaard 

and Allen 1987; Benfey 1999; Devlin and Nagahama 2002). In contrast, Doroshov (1986) and 

Mager (1993) determined that triploid male grass carp undergo complete spermatogenesis, 

however, they produce very low numbers of viable sperm. For grass carp, cytological studies 

have demonstrated only about 60 viable spermatids for every billion cells, and that even with 

artificial insemination using normal eggs from diploid females, no viable larvae were produced 

(Allen et al. 1986; Allen and Wattendorf 1987; Van Eenennaam et al. 1990). The risk of triploid 

grass carp successfully reproducing is only realized in populations where triploid males can 

spawn with diploid females, and is very low (Allen et al. 1986; Doroshov 1986; Mager 1993). 

The Grass Carp Ad Hoc Panel concluded that “triploids proposed for introduction are 

considered functionally sterile and even when triploids are mated with diploids the offspring do 

not develop or do not survive” (Chesapeake Bay Program 1994). Nico et al. (2001) indicated 

that they were not aware of any research documenting reversion among grass carp or other 

triploid fish. The induction of triploidy is less than 100% effective, requiring all fish to be 

individually tested for ploidy determination and diploid fish removed. The effectiveness of 

triploidy is, therefore, dependent upon the quality and integrity of the inspection and certification 

processes to screen fish prior to shipping or stocking. 

Thirty-eight states authorize triploid grass carp stocking for biological control of nuisance aquatic 

vegetation and ten states allow diploids to be stocked, however twelve states (and the District of 

Columbia) either prohibit possession or do not issue permits to authorize the use of grass carp 

in their waters (Table 2.3.1; Dauwalter and Jackson 2005; personal communication, Jill 

Popham, USFWS). Twenty-nine states restrict the stocking of grass carp to triploids only and 

all but Tennessee require triploid grass carp to be certified. 

Alabama, Arkansas, Illinois, Iowa, Kansas, Mississippi, Missouri, Nebraska, and Oklahoma 

allow private fish farmers to possess diploid brood stock for the production of diploid or triploid 

grass carp. Indiana, Florida, Georgia, and Kentucky allow private fish farmers to possess 

diploid broodstock for the production of triploid grass carp for sale (all diploid offspring produced 

must be destroyed upon blood testing). California allows the Imperial Irrigation District to 

maintain diploid grass carp broodstock for the production of triploids for use in California. 

Culture of diploid grass carp as food fish is permitted in Alabama, Arkansas, Iowa, Kansas, 

Mississippi, Missouri, Nebraska, and Oklahoma (personal communication, Robert Glennon, J. 

M. Malone and Sons Inc.). 

In 1996 grass carp represented 8% of the total commercial harvest from the Mississippi and 

Missouri Rivers (Nico et al. 2006). Grass carp had the fourth highest biomass (1,139 kg, 12%) 
 25

Table 2.3.1. Summary of state grass carp importation regulations (current January 2006). 

Information provided by the USFWS Triploid Grass Carp Inspection and Certification Program. 

 

1

 States marked with a “Yes” require triploid certification. Some of these states require USFWS 

certification while others accept USFWS certification or an alternate triploid certification. 2

 Colorado only allows diploids in the eastern half of the state. 

3

 Georgia requires USFWS certification for fish shipped from Arkansas and Indiana producers. 

State Diploid Grass 

Carp 

Triploid Grass 

carp 

Grass Carp 

Banned 

Triploid 

Certification 

Required 1

 

Alabama Yes Yes No No

Alaska No No Yes No

Arizona No Yes No Yes 

Arkansas Yes Yes No No

California No Yes No Yes

Colorado Yes 2 Yes No Yes

Connecticut No Yes No Yes

Delaware No Yes No Yes

Florida No Yes No Yes

Georgia No Yes No Yes 3 

Hawaii Yes Yes No No

Idaho No Yes No Yes

Illinois No Yes No Yes

Indiana No Yes No Yes

Iowa Yes Yes No No

Kansas Yes Yes No No

Kentucky No Yes No Yes
 26

Table 2.3.1. Continued. 

State Diploid 

Grass Carp 

Triploid Grass 

Carp 

Grass Carp 

Banned 

Triploid 

Certification 

Required 1 

Louisiana No Yes No Yes

Maine No No Yes No

Maryland No No No No

Massachusetts No No Yes No

Michigan No No Yes 4 No

Minnesota No No Yes No

Mississippi Yes Yes No No

Missouri Yes Yes No No

Montana No No Yes No

Nebraska Yes Yes No No

Nevada No Yes No Yes 

New Hampshire No No Yes No

New Jersey No Yes No Yes

New Mexico No Yes No Yes

New York No Yes No Yes

North Carolina No Yes No Yes

North Dakota No No Yes No

Ohio No Yes No Yes 

 

1

 States marked with a “Yes” require triploid certification. Some of these states require USFWS 

certification while others accept USFWS certification or an alternate triploid certification. 4 Michigan bans grass carp, but allows eggs to be imported for research purposes. 
 27

Table 2.3.1. Continued. 

State Diploid 

Grass Carp 

Triploid Grass 

Carp 

Grass Carp 

Banned 

Triploid 

Certification 

Required 1 

Oklahoma Yes Yes No No 

Oregon No Yes No Yes

Pennsylvania No Yes No Yes

Rhode Island No No Yes No

South Carolina No Yes No Yes 5

South Dakota No Yes No Yes 

Tennessee No Yes No No

Texas No Yes No Yes

Utah No Yes No Yes

Vermont No No Yes No

Virginia No Yes No Yes

Washington No Yes No Yes

Washington 

D.C. No No Yes No

West Virginia No Yes No Yes 

Wisconsin No No Yes No

Wyoming No Yes No Yes 

 

1

 States marked with a “Yes” require triploid certification. Some of these states require USFWS 

certification while others accept USFWS certification or an alternate triploid certification. 5

 South Carolina conducts its own inspection of all triploid grass carp shipments entering the state. 
 28

of fish commercially caught from the Missouri River in Iowa during 2003 (Iowa Department of 

Natural Resources 2003). Grass carp offer limited opportunities for recreational fishing; 

however the fish is popular with some fly fisherman. Some states (such as Florida) require the 

immediate release of grass carp caught in public waters. 

2.3.5. Potential Adverse Effects 

Grass carp are stocked to alter “undesirable” habitats by consuming nuisance aquatic 

vegetation. However, Hoyer et al. (2005) concluded that there is “little hard evidence that 

submersed aquatic plant control can be achieved with low density stocking of grass carp while 

maintaining some submersed aquatic vegetation.” Grass carp are long-lived, are often 

overstocked, and can result in unintended effects in both target and non-target locations 

(Cassani 1996). High densities of grass carp have the potential to alter habitats significantly 

and affect native communities adversely through interspecific competition with invertebrates and 

other fishes; decrease refugia for aquatic organisms; modify preferred fish habitats; increase 

nutrient enrichment and eutrophication of lakes; disrupt food webs and trophic structure; and 

spread nonnative parasites and diseases (Nico et al. 2006). Given favorable conditions, diploid 

grass carp may reproduce and create a self-sustaining population, while the effects of triploid 

grass carp are limited to the life spans of the individual fish. Grass carp have been reported to 

consume all available aquatic vegetation in some lakes (Froese and Pauly 2001). Grass carp 

are also known to consume terrestrial vegetation (Kilgen and Smitherman1971; Terrell and Fox 

1974) by digging into banks and uprooting riparian vegetation (personal communication, Duane 

Chapman, USGS). This method of feeding damages banks and may cause erosion. Grass 

carp have been associated with increased turbidity and alkalinity and reduced dissolved oxygen 

as a result of their feeding behavior and removal of macrophytes (Lembi et al. 1978; Mitzner 

1978; Leslie et al. 1983). Competition for vegetation has been documented to decrease 

abundances of snails and cause significant declines in crayfish populations (Fedorenko and 

Fraiser 1978; Chilton and Muoneke 1992). The removal of macrophytes can directly degrade 

habitat for those fishes which depend upon aquatic vegetation for all or part of their life cycle, 

such as northern pike (Esox lucius) and largemouth bass (Micropterus salmoides) (Taylor et al 

1984; Chilton and Muoneke 1992). Although reports describing the effects on overall standing 

crops of fish in ponds stocked with grass carp are conflicting, the standing crop of bluegill 

(Lepomis macrochirus) was found to be significantly lower in ponds where grass carp were 

introduced (Forester and Lawrence 1978). 

 

Feral grass carp have been reported from rivers of the United States since 1970 (Mitchell and 

Kelly 2006) and are no longer a risk of introducing nonnative pathogens within their current 

range. However, additional importation of grass carp into the United States could introduce 

nonnative pathogens with unknown potential consequences. Grass carp are known to host the 

Asian tapeworm, a cestode parasite thought to be initially introduced into the United States with 

imported grass carp (Hoffman and Schubert 1984; McCann et al. 1996; Hoole et al. 2001) or 

common carp. The parasite has been documented in grass carp on fish farms in the United 

States (American Fisheries Society 2004). Grass carp are highly migratory, transported across 

watersheds, and widely stocked; factors that make this fish a concern for the further dispersal of 

the Asian tapeworm in waters of the United States. Asian carps, along with common carp and 

many native fishes, are known vectors of Asian tapeworm and hence should be inspected for 

this parasite if Asian carp are to be stocked into a body of water where the parasite is not known 

to be present. Infected fish should not be stocked into uninfected water bodies. 
 29

A national risk assessment for grass carp has not been completed and state-level risk 

assessments may still be needed where grass carp have not been reported or where the 

species has not become established. 

2.4. SILVER CARP 

2.4.1. Biology 

The silver carp (Figure 2.4.1) is large, deep-bodied, 

and can grow to lengths of 1 m and weights of 27 

kg. It has a moderately large and broad head 

encompassing just less than 1/3 of its body size, a 

toothless upturned lower jaw, and eyes located 

below the axis of the body (Lin 1991; Pflieger 

1997). Coloration of the body is generally silver on 

the sides with a slate grey head and dorsal surface, 

and the belly is white (Lin 1991; Pflieger 1997). 

Silver carp are native to several major Pacific drainages in eastern Asia (Fuller et al. 1999) and 

prefer standing or slow flowing water of impoundments or river backwaters ranging in 

temperature from 6-28o

C. A very active, schooling species (Mukhamedova 1977; Kolar et al. 

2007), silver carp are well known for their habit of leaping out of the water when disturbed 

(Skelton 1993). Adult silver carp in the lower Missouri River usually use low velocity areas 

behind wing dikes, especially areas > 3 m deep, and during the winter, occupied depths 

between 1-5 m deep (unpublished data, Duane Chapman, USGS). Thousands of individuals 

have also been observed in some off-channel areas of the Mississippi River (unpublished data, 

Nate Caswell, USFWS). There are indications that silver carp can live in slightly brackish water 

(FAO 1972; Kolar et al. 2007). 

Silver carp very efficiently strain suspended material from the water with highly specialized gill 

rakers that are fused into sponge-like porous plates (Robison and Buchanan 1988). They feed 

primarily on phytoplankton, but also feed on zooplankton, invertebrates, detritus, and bacteria, 

especially when phytoplankton abundance is low (Burke et al. 1986; Kolar et al. 2007). Silver 

carp lack a true stomach which requires them to feed almost continuously (Henderson 1976). 

Female silver carp reach sexual maturity at three to four years of age with a body weight of 7-14 

kg, while males can reach maturity in two years with a body weight of 5-13 kg, however, this can 

change significantly with environmental conditions. Spawning activity is associated with high 

spring flows, and spawning areas have high water velocity, turbid water, and a temperature in 

the range of 18-30o

C; optimal water temperature for spawning is 22-28°C (Lin 1991). Silver 

carp produce eggs that are semi-buoyant and require current to prevent the eggs from sinking 

to the bottom. Floodplains associated with rising water levels provide nursery habitat areas for 

larvae and juvenile forms (Lin 1991; Froese and Pauly 2001; Kolar et al. 2007). Egg production 

per females varies with location and body size, ranging from 50,000 to 5,000,000 (Singh 1989; 

Kamilov and Salikhov 1996; Froese and Pauly 2001). 

2.4.2. Introduction to the United States 

Silver carp were first brought into the United States in 1973 by a private fish farmer in Arkansas 

(Freeze and Henderson 1982) as a potential biological control agent to improve water quality in 

municipal sewage treatment lagoons and aquaculture ponds and as a food fish (Froese and 

Pauly 2001). The initial specimens were trusted into the possession of the Arkansas Game and 

Figure 2.4.1. Silver carp. Picture courtesy of 

USFWS, Carterville Fishery Resources Office. 
 30

Fish Commission for evaluation (personal communication, Mike Freeze, Keo Fish Farm). By 

1974-1975, silver carp were being evaluated by the Arkansas Game and Fish Commission, 

Auburn University, and the Illinois Natural History Survey for use in municipal sewage treatment 

lagoons, commercial fish production ponds, and swine manure lagoons, respectively. 

Henderson (1983) recommended the use of bighead and silver carps to reduce municipal 

sewage treatment plant operational costs and treatment pond size. At one time, six federal, 

state, and private facilities in Arkansas raised silver carp and four municipal sewage lagoons 

had been stocked with silver carp. The Arkansas Game and Fish Commission stocked 400 

adult silver carp into Mallard Lake in 1983 for a phytoplankton control experiment. This same 

lake was drained and treated with rotenone the next year during planned renovation. Some of 

these silver carp may have entered the St. Francis River which drains into the Mississippi River 

(personal communication, Don Brader, Arkansas Game and Fish Commission). 

The reproducing populations of silver carp currently in the Mississippi River Basin could be the 

result of escape from one or more sources, including: research facilities, municipal facilities, 

universities, state hatcheries, and private fish farms. By 1981, feral silver carp were recorded in 

seven locations in Arkansas (Robison and Buchanan 1988), including the White, Arkansas, and 

Mississippi rivers. Since their introduction, silver carp have been reported in nearly every state 

in the Mississippi River Basin and several states outside the basin. The first reported natural 

reproduction of silver carp in the United States was from a ditch near Horseshoe Lake, 

Alexander County, Illinois during 1995 (Pflieger 1997). 

2.4.3. Present Distribution and Abundance in the United States 

Silver carp have now been recorded from within or along the borders of at least 16 states 

(Figure 2.4.2) and are self-sustaining within the Mississippi, Missouri and Ohio River drainages 

(Kolar et al. 2007; Schofield et al. 2005). Established populations of reproducing and overwintering silver carp have been confirmed in 10 states (Nico 2005). Live silver carp have been 

imported to several states outside of the Mississippi River Basin (e.g., Alabama, Florida, North 

Carolina, and California). 

The silver carp appears to be adapting very well to the temperate climates of the United States. 

It continues to colonize in a northward direction and is spreading rapidly throughout the 

Mississippi River Basin. Large numbers of fish and substantial natural reproduction have been 

documented in off-channel and backwater habitats (MICRA 1999; unpublished data, Nate 

Caswell, USFWS). The catch rates of silver carp in the Mississippi and Illinois rivers between 

1993 and 2004 during standardized sampling by the Long Term Resources Monitoring Program, 

an element of the USACE Environmental Management Program, have continually increased 

and were highest during 2004 (USGS 2007). 

It is difficult to predict the potential distribution of silver carp in the United States; however most 

of the United States lies within the preferred latitudes of bighead carp (Figure 2.4.3). Based on 

an examination of the present distribution of established and introduced populations around the 

world, Kolar et al. (2007) conclude that silver carp have the potential to become established in 

much of the continental United States. Life history traits of silver carp suggest they are well 

adapted to large river systems such as those of the central United States. Limiting factors to 

range expansions of reproducing populations are most likely access to rivers with moderate to 

swift current of a length at least 100 km to fulfill spawning requirements, fairly high ionic 

concentrations for successful egg incubation, and successful recruitment of larvae and juveniles 

(Kolar et al. 2007). 
 31

Figure 2.4.2. Distribution of silver carp in the United States as reported in the Nonindigenous Aquatic 

Species database at the U.S. Geological Survey (USGS). Map reproduced from http://nas.er.usgs.gov/. 

Figure 2.4.3. The latitudinal range of silver carp projected across North America. The native range of 

silver carp in eastern Asia extends from approximately 21o

 N to 54o N (Kolar et al. 2007). Map modified 

from www.theodora.com/maps. 
 32

2.4.4. Present Uses within the United States 

Silver carp are not presently being cultured in the United States, and have only occasionally 

been cultured in the last 20 years (Kolar et al. 2007). While some believe silver carp have 

potential as a food fish within the United States (Laird and Page 1996), silver carp are not 

cultured, largely because of their jumping habits and poor handling qualities during production, 

harvest, and transport (Kolar et al. 2007). 

Henderson (1983) recommended the use of bighead and silver carps to reduce municipal 

sewage treatment plant operational costs and treatment pond size. Due to their ability to 

efficiently filter suspended material from water, silver carp have been stocked intentionally in 

some states to improve water quality in lakes, aquaculture ponds, and wastewater systems 

(Henderson 1978, 1979; Burke et al. 1986; Lieberman 1996; Kolar et al. 2007). Silver carp are 

no longer raised or stocked as biological control agents to improve water quality in the United 

States (personal communication, Mike Freeze, Keo Fish Farms). However, there is some 

interest within the aquaculture industry in potentially producing silver carp on a commercial 

scale in the future, especially as part of Partitioned Aquaculture Systems (personal 

communication, Robert Glennon, J. M. Malone and Sons Inc.). All forms of live silver carp were 

added to the list of injurious wildlife under the Lacey Act, prohibiting their importation and 

interstate transport (except by permit), effective August 9, 2007. 

Commercial harvest of silver carp is increasing in parts of the Mississippi River Basin. The 

combined annual commercial harvest of bighead and silver carps from the Mississippi and 

Illinois rivers within Illinois increased from less than 600 kg per year between 1988 and 1992 to 

in excess of 50,000 kg per year since 1997 (Chick and Pegg 2001). The reported combined 

commercial harvest of these fishes in 2003 was nearly 60,000 kg from the Mississippi River 

alone and exceeded 338,000 kg in the Illinois River (Maher 2005). Wild-caught silver carp are 

occasionally encountered in live fish markets (Kolar et al. 2007). There are on-going efforts by 

commercial enterprises to develop products and establish markets for wild-harvested silver 

carp. 

2.4.5. Potential Adverse Effects 

Although direct species interactions are not fully understood and competition is difficult to 

document in large and dynamic river systems (Kolar et al. 2007), the potential of increasing 

populations of silver carp to affect native species at all life stages is a concern. Silver carp are 

believed to affect many native species adversely because they feed on plankton, the primary 

food source for mussels, larval fish, and several adult fishes (Laird and Page 1996; Fuller et al. 

1999). Sampson (2005) found dietary overlap between silver carp with gizzard shad and 

bigmouth buffalo in the Illinois and Mississippi rivers. Silver carp have the potential to influence 

large crustacean zooplankton negatively and to alter food web interactions, thereby potentially 

affecting other native aquatic organisms (Kohler et al. 2005; Sampson 2005). Field studies to 

investigate a decline in planktivorous species in areas with abundant silver carp populations are 

lacking. 

Feral silver carp have been reported from rivers of the United States since 1981 (Robinson and 

Buchanan 1988) and are no longer a risk of introducing nonnative pathogens within their current 

range. However, additional importation of silver carp into the United States could introduce 

nonnative pathogens with unknown potential consequences. Scientists have found the Asian 

tapeworm in silver carp stocks in the former USSR and Philippines (Kolar et al. 2007). Asian 

carps, along with common carp and many native fishes, are known vectors of Asian tapeworm 

and hence should be inspected for this parasite if Asian carp are to be stocked into a body of 
 33

water where the parasite is not known to be present. Infected fish should not be stocked into 

uninfected water bodies. 

The spread of silver carp may be adversely affecting the existing commercial fishery in parts of 

the Mississippi River Basin (Maher 2005). There is not yet a large market for silver carp in the 

United States, but in some locations this species is becoming a more substantial portion of the 

commercial catch (Iowa Department of Natural Resources 2003; Maher 2005; personal 

communication, Vince Travnichek, Missouri Department of Conservation). Commercial fishers 

on the Illinois River reported a 124% increase in the harvest of bighead and silver carps 

(reported as combined harvest) and a 35% decrease in buffalo harvest during 2002. Unless 

economically viable markets develop, the establishment of large self-sustaining populations of 

silver carp in the United States may compromise commercial fishing. 

Silver carp pose a threat to human safety due to their jumping behavior when startled (Figure 

2.4.4). These “flying carp” as some have called them (Skelton 1993; Pflieger 1997) have 

caused numerous personal injuries and property damage to recreational boaters and fishers 

(Kolar et al. 2007). 

A recently completed environmental risk assessment, completed using methods described by 

the Risk Assessment and Management Committee (1996), concluded that the overall organism 

risk potential associated with silver carp was high (Kolar et al. 2007). The organism risk 

potential is based on the probability of silver carp becoming established and the consequences 

of silver carp establishment. The finding of high organism risk potential indicates that silver carp 

are an organism of major concern and present an unacceptable level of risk. The probability of 

silver carp establishment if released (high) was determined using the following factors: 

probability of being within the pathway, probability of surviving transit, probability of successfully 

colonizing and maintaining a population where introduced, and probability of spread beyond the 

colonized area. The consequence of silver carp establishment (medium to high) was 

determined using the following factors: estimation of economic effect if established, estimation 

of environmental effect if established, and estimation of effect from social and/or political 

influences. 

Figure 2.4.4. Silver carp jumping below the Peoria Lock and Dam on the Illinois River. Picture courtesy 

of Mike Smith, Illinois River Biological Station, Illinois Natural History Survey.
 34

CHAPTER 3. MANAGEMENT AND CONTROL OF 

ASIAN CARPS 

Strategies and recommendations developed by the Working Group to accomplish each of the 

seven goals presented in Section 1.2 are discussed in detail within this chapter. A summary 

table listing each of the recommendations is presented in Chapter 4 (Table 4.1, page 120). 

Goal 3.1. Prevent accidental and deliberate unauthorized 

introductions of bighead, black, grass, and silver 

carps in the United States. 

Feral and domestic stocks of Asian carps can be a source of fish for accidental or deliberate 

unauthorized introductions, and represent a continued risk for spread and range expansion. 

Currently, self-sustaining populations of bighead, grass, and silver carps are primarily confined 

to the Mississippi River and its major tributaries (e.g., Illinois, Missouri, and Ohio rivers). 

Preventing introductions into waters where these fishes do not already exist is of utmost 

importance throughout the remainder of the United States (e.g., Great Lakes and Columbia 

River basins). Efforts to prevent introductions are warranted to prevent potential adverse 

ecological and economic effects and are generally more cost-effective than attempting to 

manage and control a species once it has been introduced. Active control measures are 

needed to prevent introduction or range extension, however consideration must be given to the 

risks and costs/benefits to determine when actions are warranted. 

To protect the Nation’s natural resources, but also allow for a viable aquaculture industry when 

implemented, a framework for the responsible use of domestic stocks of Asian carps is 

described. Bighead, black, and grass carps have unique beneficial uses for pond aquaculturists 

and are in commercial trade. Efforts are warranted to develop improved methods for the safe 

use of these species with the potential for minimal risk to the environment and to derive 

ecologically safe and economically viable alternatives to their uses.

Prevention recommendations have been developed using a variety of factors considered by the 

Working Group (Appendix 6.6). Differences in the biology and use of these various species 

dictate that each species be addressed individually. Prevention recommendations differ 

depending upon whether a particular species is absent, present without evidence of a 

reproducing population, or self-sustaining in the wild. For species in commercial trade, 

additional factors were considered in developing recommendations, including their intended use 

(i.e., stocking for biological control or sales to live food markets). 

Twenty-two pathways are discussed in this section, with strategies and recommendations 

following each pathway. Risk levels for each pathway were developed by the prevention 

section drafting team based on both the likelihood for an introduction to occur and the potential 

for adverse ecological and/or economic effects (Table 3.1.1). Pathways and risk levels were 

proposed based on the opinion of the prevention section drafting team. Although the full 

Working Group agreed with all 22 pathways, there is agreement with only 6 of the 22 pathway 

risk levels proposed by the prevention section drafting team. There is broad agreement that 1) 

activities related to wild-caught baitfish, 2) domestic live transport and distribution of wild-caught 

Asian carps, 3) poorly sited aquaculture facilities with Asian carps, and 4) stocking of diploid 
 35

Table 3.1.1. Twenty-two pathways identified by the Working Group are grouped according to 

risk levels proposed by the Prevention drafting team.1

 Pathways within the different risk levels 

are ordered alphabetically and not by relative risk. The six pathways with broad agreement 

from the full Working Group are indicated in the right column.2

 

Prevention Drafting Team’s Proposed Highest Risk Pathways Working Group 

Agreement 

Accidental and deliberate unauthorized releases by individuals 

Activities related to wild-caught baitfish Highest 

Domestic live transport and distribution of wild-caught fish Highest 

Illegal distribution and sales of diploid grass carp as triploid fish 

Importation into the United States3 

Poorly sited aquaculture facilities with Asian carps Highest 

Stocking of diploid Asian carps into non-aquaculture waters Highest 

Unintentional live transport “in water” by commercial vessels and recreational 

watercraft 

Unintentional live transport and distribution by natural resources management 

agencies 

Prevention Drafting Team’s Proposed Moderate Risk Pathways Working Group 

Agreement 

Aquarium/hobby industry 

Commercial, domestic transport of live farm-raised Asian carps 

Incidental inclusion of Asian carps in aquaculture shipments of other farm-raised 

species to non-aquaculture waters 

Research and educational facilities and projects 

Unintentional shipment of black carp in diploid or untested triploid grass carp 

stockings 

Moderate 

Prevention Drafting Team’s Proposed Lowest Risk Pathways Working Group 

Agreement

Incidental inclusion and potential release of Asian carps in farm raised baitfish 

Incidental inclusion of Asian carps in domestic shipments of catfish to fish farms 

Incidental inclusion of Asian carps in domestic shipments of food fishes 

Incidental inclusion of Asian carps in international imports of other fishes 

Intentional release of live, “adult-size” (non-baitfish) Asian carps by boaters, 

anglers, and bow fishers 

Low 

Properly sited aquaculture facilities 

Stocking of triploid Asian carps into non-aquaculture waters for biological control 

 

1 Risk levels were proposed by the Prevention Drafting Team based on both the likelihood for an 

introduction to occur and the potential for adverse ecological and/or economic effects. 2

 Consensus on pathway risk levels will be addressed early in implementation. 3 Importation “for commercial use” was proposed separately as a moderate risk pathway. 
 36

Asian carps in non-aquaculture waters are among the highest risk pathways for introduction. 

There is also broad agreement that the unintentional shipment of black carp in diploid or 

untested triploid grass carp stockings is a moderate risk, while the intentional release of live, 

“adult-size” (non-baitfish) Asian carps by boaters, anglers, and bow fishers presents a low risk 

of introductions. 

Such risks are important factors in the prioritization of recommended actions to address specific 

pathways and prevent unauthorized introductions. To attain consensus in the pathway risk 

rankings, a formal process could be used early in the implementation phase when 

recommendations among all sections of the plan are integrated, sequenced, and prioritized 

(Recommendation 3.7.1.3). 

The pathways are presented by the following subject headings: 1) wild-caught baitfish; 2) 

stocking for biological control in non-aquaculture waters; 3) boats, barges and ships; 4) natural 

resources management actions; 5) importation into the United States; 6) aquaculture; 7) live 

transport; 8) accidental and deliberate unauthorized releases by individuals, 9) aquarium / 

hobby industry, 10) research and educational institutions; and 11) recreational boaters and 

fishers. 

1) WILD-CAUGHT BAITFISH

PATHWAY: Activities related to wild-caught baitfish

The transport and release of wild-caught baitfish by anglers and commercial dealers represents 

one of the highest risk pathways for introduction of Asian carps because live fish can easily be 

released into new waters. To the untrained eye, juvenile bighead and silver carps can be 

difficult to distinguish from some species of native baitfish (e.g., gizzard shad). These species 

have been documented in high abundances in some locations throughout the Mississippi River 

Basin (e.g., tailwaters and backwaters). Because of their abundance and natural behavior, 

juvenile bighead and silver carps may be collected with, or in place of, native bait fish. Although 

less likely to be collected than bighead and silver carps, juvenile grass carp may be collected 

with wild-harvested native baitfish. Dumping or releasing unwanted, unused live baitfish is a 

pathway of concern for any aquatic nuisance species. Effective information programs, 

regulations, and enforcement are all essential components for controlling this pathway. 

Strategy 3.1.1. Take actions to prevent the collection, transport, release, and improper 

disposal of Asian carps that may be intermixed with live wild-harvested baitfish. 

Recommendation 3.1.1.1. Assist states to develop, promulgate, and enforce 

regulations that manage the harvest, transport, import, trade, and release of live 

wild-harvested aquatic bait. 

Dumping or releasing unused live baitfish is a common practice among anglers. Eggs, 

larvae, and juvenile Asian carps can be transferred rapidly and easily between 

watersheds or upstream over dams when intermixed with wild-harvested baitfish. A 

single commercial baitfish dealer potentially can ship baitfish contaminated with Asian 

carps to locations in multiple states. 

Some states allow baitfish collected from the wild to be held in private holding ponds. In 

Michigan, anytime fish are held in this manner for commercial purposes the business is 
 37

required to be licensed as an aquaculture facility. Once these fish are placed in a 

holding pond they become the private property of the aquaculturists and are then 

considered “farm raised” and not wild caught. Most of the non-resident licensed minnow 

wholesalers supplying Michigan are aquaculture facilities that ship a combination of wild 

caught and “farm raised” minnows. Wild caught baitfish held in holding ponds and later 

distributed as “farm raised” minnows present similar risks as wild caught baitfish. 

State regulations are needed to ensure that baitfish harvest, transport, release, and 

disposal does not expand existing populations or establish new populations of Asian 

carps or other nonnative biota. To prevent the unintentional introduction of Asian carps 

or other nonnative biota, states should employee a suite of regulations that: 

• Require exporters and importers of live baitfish to implement Hazard Analysis 

and Critical Control Point planning (http://haccp-nrm.org/) for all shipments of live 

baitfish. 

• Limit the transport and importation of live baitfish to specific approved species by 

developing a list of bait species approved for importation (i.e., “Clean List”). 

• Require all shipments of live baitfish within their state to be certified as containing 

no nonnative or aquatic nuisance species. 

• Require proper disposal of all unwanted live bait. 

• Prohibit the release of live baitfish into waters. 

• Address the waters used to transport baitfish to prevent the transport of Asian 

carp eggs, larvae, and other nonnative biota. 

States may also want to consider stricter regulations, however certain regulations may 

be more difficult to enforce. Development of appropriate regulations should be 

coordinated with respective law enforcement personnel. Potential regulations might 

include but are not limited to: 

• Prohibit the possession and/or transport of live wild-caught Asian carps. 

• Restrict the use of wild-caught live baitfish by anglers to the immediate 

waterbody where collected. 

• Prohibit the transport of wild-caught baitfish contaminated with Asian carps or 

collected from waters known or suspected of having any species of Asian carp. 

Information awareness campaigns to change commercial and recreational baitfish 

harvester ethics and law enforcement will be needed to support regulations. 

Recommendation 3.1.1.2. Explore the use of baitfish grown in monoculture, and 

certified to be disease-free and uncontaminated by other aquatic species. 

Baitfish grown in monoculture, and certified disease-free and uncontaminated by other 

aquatic species may provide states with an alternative to the risks associated with wild 

baitfish harvest and transfer. Natural resources management agencies and 

aquaculturists should work together to explore the feasibility of producing, certifying, and 

shipping monocultured baitfishes as alternatives to wild-harvested baitfish. 

Recommendation 3.1.1.3. Develop and provide information to commercial and 

recreational baitfish harvesters that will help prevent accidental and deliberate 

unauthorized introductions of Asian carps. 
 38

An information module and educational materials are needed to assist commercial and 

recreational baitfish-harvesters in reducing the risk of accidental and deliberate 

unauthorized introductions of Asian carps. Commercial and recreational baitfish 

harvesters should be engaged to ensure that their specific education and outreach 

needs, and how to most effectively meet these needs, are understood. 

Currently, training in Hazard Analysis and Critical Control Point planning specific to 

aquatic nuisance species is provided by both the National Sea Grant College Program 

(Gunderson and Kinnunen 2004) and the USFWS (http://haccp-nrm.org/) for 

implementation by the baitfish community, natural resources management agencies, the 

aquaculture industry, researchers, and enforcement officers. The training could be 

adapted more specifically for baitfish harvesters in watersheds with Asian carps. 

Various WATCH cards, fact sheets, and posters are also available for baitfish 

harvesters. Information materials could be made available with both commercial and 

sport licenses, at bait shops, marinas, and boat ramps. 

2) STOCKING ASIAN CARPS FOR BIOLOGICAL CONTROL IN NONAQUACULTURE WATERS

Note: For the purposes of this plan, the Working Group divided waters into two categories: 

aquaculture and non-aquaculture waters. Aquaculture waters include those bodies of water that 

are part of a commercial aquaculture facility, while non-aquaculture waters are inclusive of all 

other waters, including natural and man-made waters, and open and closed systems. 

While bighead, grass, and silver carps have been stocked for biological control in the past, only 

grass carp are currently stocked for biological control in “non-aquaculture” waters. 

PATHWAY: Stocking of diploid Asian carps into non-aquaculture waters for biological 

control 

The stocking of diploid Asian carps into non-aquaculture waters for biological control is among 

the highest risk pathways for introducing these fishes into new waters. Because diploid and 

triploid Asian carps are referred to throughout this chapter a brief explanation of these terms is 

provided here. In the diploid (2n) state, the natural condition for Asian carps, a double set of 

chromosomes occurs in each cell. Diploid Asian carps have the potential to spawn and 

establish reproducing populations in the wild. Techniques have been developed to manipulate 

chromosome sets and develop triploid (3n) individuals with three sets of chromosomes in each 

cell for the purpose of producing sterile fish. Triploids are morphologically indistinguishable 

from diploids (Thorgaard and Allen 1987). Induced triploidy leads to varying degrees of sterility 

in some fish species (Kapuscinski and Patronski 2005) meaning that triploid of some species 

may successfully reproduce in the wild. Triploid grass carp are functionally sterile and can be 

considered sterile for management purposes (Allen et al. 1986; Allen and Wattendorf 1987; 

Thorgaard and Allen 1987; Van Eenennaam et al. 1990; Benfey 1999; Devlin and Nagahama 

2002; Nico et al. 2005). Techniques to produce triploid bighead, black, and silver carps have 

been developed; however the functional sterility of these fishes needs to be rigorously evaluated 

through peer-reviewed research. 

Strategy 3.1.2. Take actions to prevent the stocking of diploid Asian carps into nonaquaculture waters for biological control. 
 39

Bighead and silver carps were stocked in sewage treatment lagoons and natural waters by state 

and federal agencies in the 1970s, but have not been stocked for biological control in recent 

decades. Black carp have never been stocked in natural waters for biological control in the 

United States. Ten states allow stocking diploid grass carp for biological control of nuisance 

aquatic vegetation (Table 2.3.1, page 25; Dauwalter and Jackson 2005; personal 

communication, Jill Popham, USFWS). 

Recommendation 3.1.2.1. Encourage states to develop regulations that prohibit 

the stocking of any diploid Asian carps into non-aquaculture waters for biological 

control. 

Diploid Asian carps should not be stocked as biological controls in any open waters and 

regulations to prohibit future stockings of bighead, black, grass, and silver carps are 

warranted. Scientific information on the effects of reproducing grass carp populations in 

the Mississippi River Basin can be assembled and distributed to state natural resource 

agencies in those states which still permit stocking diploid grass carp, to provide those 

agencies with data that would assist in decision-making relative to sales and use of the 

diploid fish. Continued stocking of diploid Asian carps is counterproductive to efforts to 

contain and reduce feral populations. However, triploid grass carp are more expensive 

than diploids and therefore regulations that prohibit stocking diploid grass carp will 

create a higher cost for consumers, including state natural resources management 

agencies and private pond owners. This may be especially true for some limited 

resource landowners who use grass carp to manage aquatic vegetation in recreational 

or farm ponds. However, triploid grass carp remain a relatively low-cost alternative 

compared to other methods of aquatic vegetation control (i.e., chemical or mechanical). 

Recommendation 3.1.2.2. Remove or contain diploid Asian carps that have been 

previously stocked into non-aquaculture waters for biological control. 

Encourage states to identify where diploid Asian carps have been previously stocked in 

non-aquaculture waters for biological control. States should evaluate the risk of existing 

diploid Asian carps introducing or expanding feral populations and determine if 

measures to contain or remove fish are warranted. Where warranted, containment 

and/or control measures should be implemented. 

PATHWAY: Illegal distribution and sales of diploid grass carp as triploid fish 

Triploid grass carp are more expensive to produce and are sold at approximately 2-3 times the 

price of diploid fish (personal communication, Mike Freeze, Keo Fish Farm). Most states that 

require triploid grass carp for biological control are only able to inspect a small percentage of 

grass carp shipments within the state. Recent law enforcement cases support the concern that 

diploid grass carp have been sold fraudulently as triploid fish and stocked into open waters. 

Some states employ measures such as the USFWS Triploid Grass Carp Certification and 

Inspection Program (http://www.fws.gov/warmsprings/FishHealth/frgrscrp.html) for assurances 

that shipments of triploid grass carp do not contain diploid fish. Many states attempt to prevent 

the introduction and establishment of diploid grass carp within their borders, while others do not 

take effective measures to enforce regulations. Reasons for less than effective enforcement 

include 1) insufficient numbers of law enforcement personnel; 2) lack of access to the 

expensive, sophisticated equipment required to determine ploidy; or 3) diploid grass carp are 
 40

regarded with low concern because diploid populations are already widespread in many 

watersheds in the United States. 

The economic incentive for people to fraudulently sell diploid grass carp as triploids, 

accompanied by a frequent lack of enforcement, perpetuate the potential for unauthorized 

introductions of diploid grass carp. 

Strategy 3.1.3. Take actions to prevent illegal sale, shipping, and stocking of diploid 

grass carp as triploid grass carp. 

Recommendation 3.1.3.1. Encourage states that allow the legal importation of 

grass carp to adopt consistent, uniform regulations that allow only certified 

triploid grass carp to be shipped or stocked. 

Consistent regulations requiring shipment and stocking of certified triploid grass carp 

only, combined with state enforcement, could eliminate most of the sources of fraudulent 

sales. Possession of diploid grass carp can be prohibited or restricted through permits 

to licensed or authorized triploid grass carp producers. In the absence of markets for 

diploid fish, the majority of distributors, wholesalers, and retailers will not have a need to 

possess, or be tempted to fraudulently sell, diploid grass carp. 

States should work together, possibly through the Association of Fish and Wildlife 

Agencies, to ensure that unauthorized stockings of diploid grass carp are effectively 

prevented. Diploids that escape into the wild in one state may migrate to a state that is 

effectively preventing or controlling the establishment of feral populations within or along 

its borders. 

Recommendation 3.1.3.2. Encourage states to conduct routine and random 

inspections of all live grass carp shipments within the state. 

Shipments of live grass carp frequently enter or move within many states. All states 

should be encouraged to develop and enforce regulations regarding sales, shipping, and 

stocking grass carp. Natural resources management agencies should require the 

inspection of shipments of live grass carp (and other Asian carps) to enforce and 

encourage compliance with existing or new regulations. 

Live fishes are a commodity, and inspections will require carefully planned and executed 

procedures to prevent the loss of capital. Liability should not prevent the inspection of 

shipments, but should promote the use of good judgment, and development and testing 

of efficient inspection procedures to prevent delays and loss of product. 

Recommendation 3.1.3.3. Encourage the USFWS to provide ploidy determination 

for states conducting inspections of grass carp shipments. 

The USFWS Triploid Grass Carp Inspection and Certification Program does not have an 

enforcement component and is dependent upon states to inspect shipments and enforce 

state regulations regarding importation of the species. However, many states do not 

have the equipment or expertise to determine ploidy of fish in inspected shipments and 

may need assistance to provide for enforcement of regulations. 

The USFWS should consider providing regional assistance to states, perhaps through 

National Fish Technology or Fish Health Centers. The USFWS currently has the 
 41

expertise and equipment to determine grass carp ploidy in some Regions and the 

capability for development in all Regions. The USFWS was authorized by Congress 

(Public Law 104-40; November 1, 1995) to “charge reasonable fees for expenses to the 

federal government for triploid grass carp certification inspections." Triploid grass carp 

producers who choose to participate in the Triploid Grass Carp Inspection and 

Certification Program are charged fees based on the numbers of fish inspected, plus 

travel costs for the inspector. Contingent upon demonstration of economic feasibility, it 

is recommended to build additional fees into the Triploid Grass Carp Inspection and 

Certification Program to reimburse the USFWS for ploidy determination as part of 

random state inspections of interstate shipments of certified triploid grass carp. 

PATHWAY: Unintentional shipment of black carp in diploid or untested triploid grass 

carp stockings 

The Working Group agreed that the unintentional shipment of black carp in diploid or untested 

triploid grass carp stockings represents a moderate risk for the introduction of black carp into 

new waters. Black and grass carps are similar in appearance, especially when the fish are 

small. Although black carp are produced legally at a very limited number of facilities, it is 

common for facilities that produce black carp to also produce grass carp. 

When produced and sold in large numbers, the possibility does exist for some mixing of black 

and grass carps. The extent of such occurrence is unknown. Release of black carp in a 

shipment of grass carp is a high-risk to the environment given that stocking often occurs in 

public waters. Black carp contained in the shipment and subsequently released would 

constitute a range expansion of feral populations of this species. The shipment and stocking of 

diploid grass carp and uncertified triploid grass carp present the greatest opportunity for 

unintentional stockings of black carp. Diploid and uncertified triploid grass carps are handled in 

bulk at harvest and individual black carp intermixed with these fish could go undetected. The 

unintentional stocking of black carp in a shipment of certified triploid grass carp is much less 

likely given that each fish is individually screened for ploidy. The nuclear diameters of blood 

cells from triploids of both black and grass carps and of diploids of both species are essentially 

the same according to flow cytometer data and coulter counter data (personal communication, 

Mike Freeze, Keo Fish Farm). A black carp would thus have to be misidentified by screeners as 

a grass carp and be a triploid individual for it to be included in the lot of triploid grass carp. 

Although the production of black and grass carps at the same facility provides a pathway for the 

unintentional introduction of black carp, the pathway can be managed to reduce this risk. 

Strategy 3.1.4. Take actions to prevent the shipment of live black carp in grass carp 

shipments. 

This strategy is addressed by Recommendation 3.1.3.1: Encourage states that allow the legal 

importation of grass carp to adopt consistent regulations that allow only certified triploid grass 

carp to be shipped or stocked. 

PATHWAY: Stocking triploid Asian carps into non-aquaculture waters for biological 

control 

Grass carp can cause secondary effects on biological communities as a consequence of 

vegetation changes (Bain 1996). The use of triploid grass carp is not without ecological risks, 

although those risks are greatly reduced compared to using diploid grass carp. Thirty-eight 
 42

states authorize triploid grass carp stocking for biological control of nuisance aquatic vegetation 

and ten allow diploids, however twelve states (and the District of Columbia) either prohibit 

possession or do not issue permits to authorize the use of grass carp in their waters (Table 

2.3.1, page 25; Dauwalter and Jackson 2005; personal communication, Jill Popham, USFWS). 

Grass carp are migratory and have the potential to affect non-target waters long distances from 

their place of introduction into open systems. Inconsistent state regulations can result in 

unintended consequences in states that share connected waters. 

As previously discussed in Strategy 3.1.2, bighead and silver carps were stocked in nonaquaculture waters for biological control during the 1970’s. Actions are warranted to address 

past and future stocking of all Asian carps in non-aquaculture waters for biological control. 

Strategy 3.1.5. Take actions to address stocking triploid Asian carps into nonaquaculture waters for biological control. 

Recommendation 3.1.5.1. Encourage states to prohibit stocking triploid bighead, 

black, and silver carps for biological control in non-aquaculture waters. 

Bighead, black, and silver carps are not currently stocked into non-aquaculture waters 

for biological control and states should develop regulations to prohibit future stocking. 

Recommendation 3.1.5.2. Encourage states to allow stocking triploid grass carp 

for biological control in non-aquaculture waters only within watersheds where 

grass carp are already present in the wild. 

Stocking triploid grass carp should be prohibited in watersheds where grass carp are not 

present in the wild to prevent introductions into currently uninvaded waters. In 

watersheds where grass carp are present, states should restrict stocking grass carp for 

biological control in non-aquaculture waters to certified triploids only to limit potential 

range expansion of reproducing populations. Implementing this recommendation may 

adversely effect some limited-resource landowners who might otherwise use grass carp 

to manage aquatic vegetation in recreational or farm ponds. Implementation of this 

recommendation may also encourage greater use of chemical herbicides. 

Recommendation 3.1.5.3. Remove or contain triploid Asian carps that have been 

previously stocked in non-aquaculture waters within watersheds where the fish 

are not currently self-sustaining in the wild. 

Encourage states to identify waters where triploid Asian carps have been stocked in 

non-aquaculture waters, but within watersheds where the fish are not currently selfsustaining in the wild. States should evaluate the risk of triploid Asian carps escaping 

from stocked waters and determine if measures to contain or remove the fish are 

warranted. Implementation of this recommendation may have the same adverse effects 

as those identified for Recommendation 3.1.5.2. 

Strategy 3.1.6. Take actions to ensure that stocking triploid grass carp for biological 

control does not result in accidental or deliberate unauthorized introductions of diploid 

grass carp. 
 43

Recommendation 3.1.6.1. The USFWS should seek an independent scientific 

review and evaluation of the Triploid Grass Carp Inspection and Certification 

Program. 

An “overwhelming support from state conservation and fish and game agencies from 

about 20 states” in the 1990s resulted in Congress passing the Triploid Grass Carp 

Certification Act of 1995 (Mitchell and Kelly 2006). Twenty-seven states currently rely on 

the USFWS Triploid Grass Carp Inspection and Certification Program (Program) to 

prevent accidental or deliberate unauthorized stockings of diploid grass carp as triploids 

(Table 2.3.1, page 25; personal communication, Jill Popham, USFWS). Throughout this 

plan, the Working Group recommends the planned use of triploid grass carp within 

watersheds where grass carp are present in the wild. The effective use of triploids to 

prevent self-sustaining populations from becoming established is dependent upon the 

effectiveness of inspection programs to identify and remove diploid fish. 

The USFWS and triploid grass carp inspectors have worked together to develop 

reasonable and effective standards for the Program. An independent scientific review is 

warranted to evaluate the effectiveness of this widely used Program and to recommend 

reasonable actions that would improve the integrity, efficiency, and effectiveness of the 

Program. The USFWS should request an independent scientific review of the Program 

from the American Fisheries Society and the United States Aquaculture Society or other 

appropriate groups. Recognized experts in triploidy induction and reproductive 

physiology of grass carp should be included on the review team. Producers and natural 

resources managers alike favor a program of high integrity and effectiveness that 

provides reliable assurances to the receiving states. 

Recommendation 3.1.6.2. Develop and provide information on the USFWS 

Triploid Grass Carp Inspection and Certification Program. 

An information module should be developed on the Program, its operation, and its 

effectiveness at protecting our natural resources. The primary audiences for this module 

are natural resources managers, fish farmers, and the general public. The module 

should include a presentation on the Program that can be delivered to natural resources 

managers at regional and professional society meetings. In addition, state natural 

resources management agencies should be actively involved in meetings of producers 

and inspectors. Fish farmers and the public often ask why triploid grass carp are either 

recommended or required for biological control as their cost is much greater than 

diploids. This is especially true throughout portions of the Mississippi River Basin where 

feral grass carp have established reproducing populations in numerous rivers.

An effective module will increase participation and understanding of the need, benefits, 

and limitations of the Program among the public and natural resources management 

agencies. An improved understanding by consumers should result in increased support 

and compliance with efforts to prevent introductions of diploid grass carp. Eliminating 

the source of fertile grass carp that may escape into the wild is an important step toward 

the control of feral populations. 

The standards for the Program are available on the Internet at 

http://www.fws.gov/warmsprings/FishHealth/frgrscrp.html. This web site could be 

expanded to provide additional information developed as part of the Program 

informational module. 
 44

The USFWS should be the lead agency to develop this module, with participation and 

assistance from triploid grass carp producers. Development of this module should be 

coordinated by USFWS employees that participate in the Program. 

3) BOATS, BARGES, AND SHIPS

PATHWAY: Unintentional live transport “in water” by commercial vessels and 

recreational watercraft 

Boats, barges, dredges, and ships are potential vectors for the distribution and expansion of 

aquatic nuisance species. Commercial vessels and recreational watercraft certainly can 

transport and release planktonic organisms, nuisance plants, and macroinvertebrates; however, 

their potential for the transport and release of viable Asian carp eggs or larvae is uncertain. 

More than 25,000 miles of navigable rivers and canals, of which 12,000 miles are operated and 

maintained by the federal government as commercial waterways, provide access between 

numerous interconnected watersheds in 41 states (Tennessee-Tombigbee Waterway 

Development Authority 1999). Vessels and watercraft, using the Inland Waterway System, are 

a potential pathway for expanding the distribution and range of feral Asian carps. It is uncertain 

if viable Asian carp eggs and larvae could be unintentionally transported beyond dispersal 

barriers (Recommendation 3.2.2.3) by vessels or watercraft. Research is needed to fully 

understand the potential for vessels and watercraft to transport viable Asian carp eggs and 

larvae to new waters, including waters upstream of dispersal barriers. 

Strategy 3.1.7. Take actions to prevent the transport and release of Asian carps by 

commercial vessels and recreational watercraft. 

Recommendation 3.1.7.1. Investigate fully the risks associated with ballast water 

transfers or other means of water transfer by commercial vessels and recreational 

watercraft. 

This potential threat warrants immediate actions to understand the full risk potential that 

boats, barges, dredges, and ships pose as a vector for expanding feral populations of 

Asian carps. Bilge, seep, and live well waters are generally taken on in one location and 

pumped out or released in another, potentially miles or watersheds away. If viable eggs 

and larvae can be transported and released through bilge, seep, or live well waters, this 

pathway has the potential to disperse Asian carps throughout the Inland Waterway 

System and all waterways in the United States. The transfer of water by commercial 

and recreational vessels must be researched and understood to recommend 

management actions to address this potential pathway. The risk of introducing Asian 

carps or other nonnative organisms, and the potential pragmatic solutions to prevent this 

potential pathway will likely differ between commercial vessels and recreational 

watercraft. 

Recommendation 3.1.7.2. Inform boaters, barge operators, and others of the risks 

of moving infested water and encourage voluntary actions to reduce this risk. 

Informing commercial and recreational vessel operators of the risks of moving infested 

water is warranted to encourage voluntary actions that reduce the risk of unintentional 

transfers and introductions. Continue to seek partners for, and spread the message of, 
 45

the national “Stop Aquatic Hitchhikers!” campaign. Programs of the 100th Meridian 

Initiative, which is intended to prevent the westward spread of aquatic nuisance species, 

are applicable to preventing the unintentional spread of Asian carps and provide model 

programs for other parts of the United States. 

4) NATURAL RESOURCES MANAGEMENT ACTIONS

PATHWAY: Unintentional live transport and distribution by natural resources 

management agencies 

Natural resources management agencies routinely sample aquatic organisms and their habitats, 

and implement management actions to sustain ecosystems. The nature of the biologist’s job 

involves working in the ecosystem, which presents risks to species and their habitats. Among 

these risks is the potential for management actions to provide a pathway of introduction to 

aquatic nuisance species, including Asian carps. Natural resources management actions are 

considered a likely pathway because of the frequency with which biologists and technicians 

come into contact with Asian carps and the potential for biologists to travel throughout and 

among different waters in a short period of time. The potential to transfer eggs and larvae 

unintentionally in residual waters, and to misidentify juvenile fish, is a risk that natural resources 

managers must recognize and work to prevent. 

Strategy 3.1.8. Take actions to prevent the unintentional transport, release, or disposal 

of Asian carps by natural resources managers during management activities. 

Recommendation 3.1.8.1. Natural resources managers should employ pathway 

management tools, such as Hazard Analysis and Critical Control Point planning in 

the review of Standard Operating Procedures, to prevent introductions of Asian 

carps through natural resources management related pathways. 

Natural resources managers should review Standard Operating Procedures and adapt 

pathway management tools where necessary to reduce the risk of unintentionally 

transferring Asian carps, and other aquatic nuisance species. Hazard Analysis and 

Critical Control Point planning is a pathway management tool adopted by natural 

resources management agencies to identify risks of aquatic nuisance species 

introductions and to implement procedures that prevent the unintentional spread of 

species. 

Recommendation 3.1.8.2. Develop and provide information to natural resources 

managers and field staff that will help prevent unintentional introductions and 

spread of feral Asian carps. 

An information module and outreach products to help reduce the risk of accidental or 

deliberate unauthorized introductions by natural resources managers is needed. These 

groups can include state, federal, international, and tribal agencies, private (nongovernmental) organizations, and businesses. Natural resources managers, particularly 

field biologists and technicians, must be adequately trained in the identification of all 

species and life stages of Asian carps, as well as, Hazard Analysis Critical Control Point 

planning. 
 46

Natural resources managers must seek and share current information on the distribution 

of feral Asian carp populations. Mechanisms for information exchange must be 

identified, developed, and utilized. Natural resources managers should be informed 

about Asian carps and other aquatic nuisance species in the locations where work is 

being conducted. Informed and trained natural resources managers not only reduce the 

risk of unintentional introductions, but are effective sentinels for early detection. 

Hazard Analysis Critical Control Point planning is currently implemented by the USFWS 

at many national fish hatcheries and fisheries management assistance field offices with 

training offered nationally to all natural resources management agencies (http://haccpnrm.org/). This training could be used more specifically for technicians and biologists in 

watersheds with Asian carps as a long-term solution to preventing unintentional release. 

Opportunities to participate in these training programs are currently available and should 

be utilized immediately. Field biologists and technicians should receive copies of 

WATCH cards and fact sheets, and participate in Asian carp presentations. 

5) IMPORTATION INTO THE UNITED STATES

PATHWAY: Importation into the United States 

There have been only a limited number of legal importations of Asian carps for commercial 

aquaculture use in the United States (personal communication, Mike Freeze, Keo Fish Farm). 

Currently, there are fertile stocks of bighead, grass, and silver carps available from the wild and 

bighead, black, and grass carp broodstock are available from a few commercial hatcheries. 

Illegal imports are of concern because of the risk that appropriate safeguards to avoid 

accidental or deliberate unauthorized introductions will not be used. In addition to illegal 

imports, legal importations to facilities outside of the established ranges of Asian carps in the 

wild present risks of introduction or range expansion. 

Live Asian carp may also be imported for purposes other than commercial aquaculture including 

such uses as human consumption, deliberate unauthorized stocking or release, and collection 

by aquarium or water garden hobbyists. The Internet and mail service makes it easy to buy, 

sell, and even import live fish, including Asian carps. Importers, through the Internet, catalog, 

and other means, may be unaware of laws and problems associated with Asian carps, and may 

present unique issues or problems for prevention actions. Small shipments of Asian carps may 

be more difficult to detect, and Internet sellers may be more difficult to inform and regulate. The 

extent of such imports is unknown, but the potential distribution and release of live Asian carps 

threatens all watersheds in the United States. 

The USFWS has been petitioned to list the bighead, black, and silver carps as injurious wildlife 

under the Federal Lacey Act and is evaluating these species to make determination 

recommendations. The results of these potential injurious wildlife listings would affect federal 

regulations pertaining to international import of these fishes, including the offspring and eggs of 

these species. The USFWS added all forms of live silver carp to the list of injurious wildlife 

under the Lacey Act, prohibiting their importation and interstate transport (except by permit), 

effective August 9, 2007.

Strategy 3.1.9. Take actions to prevent the illegal importation and prohibit the legal 

importation of live bighead, black, grass, and silver carps into the United States. 
 47

Recommendation 3.1.9.1. Prohibit international importation of Asian carps under 

federal and state regulations, except for research purposes under a controlled 

permit. 

Imports of live fish and eggs into the United States must be declared to the United 

States Customs and Border Protection (USCBP) Agency, USFWS, or other federal 

agency. State regulations and permits for the importation of Asian carps will reinforce 

federal regulations and help ensure that appropriate safeguards against release into the 

wild are in place. 

 

All states should be urged to maintain or develop state regulations that prevent future 

importation of all Asian carps, except for research purposes. Any importation for 

research purposes should be allowed only under permits to institutions that have been 

specifically designed and constructed to confine the fish and prevent the accidental 

escape of all life stages. States, USFWS, and other federal agencies should work 

collaboratively in preventing the import of state prohibited species. 

Prohibiting the international importation of Asian carps will not have an adverse effect on 

aquaculture related businesses since domestic stocks of these fishes are readily 

available. The aquarium and hobby trades are potential importers of Asian carps; 

however, Asian carps rarely are found in the aquarium trade and, thus, there should be 

no adverse effects to the pet industry. 

Recommendation 3.1.9.2. Inform USFWS Law Enforcement Officers, other federal 

inspectors, and state conservation law enforcement officers about laws that apply 

to the import of live Asian carps, the importance of preventing the illegal import of 

Asian carps, and Asian carp identification. 

An information awareness campaign is needed to alert USFWS Officers, other federal 

inspectors, and state conservation law enforcement officers that Asian carps are 

nuisance species and regulations may apply to their importation. Further, federal 

inspectors and state and federal officers should establish regular dialogue and work in 

partnerships to prevent illegal imports of Asian carps. It will be necessary to develop 

and maintain current information that lists which Asian carps are legal or illegal to import 

into individual states, and applicable federal laws. 

Recommendation 3.1.9.3. Inform potential importers of applicable state and 

federal laws and associated risks with international shipments of live Asian carps. 

An information module and outreach materials are needed to alert importers to the fact 

that Asian carps are nuisance species, regulations may apply to their importation, and of 

the potential adverse effects of imported fish to wild and/or captive fishes. Fish 

importers should be engaged to ensure that their specific education and outreach needs, 

and how to most effectively meet these needs, are understood. Implementing this 

recommendation will enable agencies to deter importers from legally or illegally 

importing Asian carps. It will be necessary to develop and maintain current information 

that lists which Asian carps are legal or illegal in individual states, and applicable federal 

laws. 
 48

Recommendation 3.1.9.4. Increase the numbers of trained USFWS Law 

Enforcement Officers and increase physical inspections of international 

shipments of live fish and eggs at designated or non-designated ports of entry. 

All imports of live fish should be physically screened by trained USFWS Officers to 

ensure that only the species declared are shipped. An increase in the number of trained 

USFWS Officers is warranted due to the number of live fish imports into the United 

States. At a minimum, increased random physical inspections and screenings for exact 

matches to declared contents should be conducted. If Asian carps or other aquatic 

nuisance species are detected in a shipment but are not declared or are prohibited, the 

shipment should be denied entry into the United States. State regulations banning the 

importation of Asian carps would also help USFWS Officers to seize shipments 

containing Asian carps in violation of a receiving state’s laws.

PATHWAY: Incidental inclusion of Asian carps in international imports of other fishes 

Millions of live fish are imported annually into the United States for both commercial and noncommercial uses. Imported shipments of live fish and eggs into the United States must be 

declared to the USCBP, USFWS, or other federal agency and inspected at a designated port of 

entry by a USFWS Officer, except under special permit. However, most inspections focus on 

import paperwork only and do not include a physical inspection of the package. Declared 

shipments must indicate the scientific names, country of origin, and quantity for each species in 

the shipment. Limited physical inspections primarily screen for humane shipment of live fish, 

and for threatened and endangered species or injurious wildlife. Physical inspections of all 

imports are needed to verify the contents of shipments with paper work declarations. 

Each shipment of live fish into the United States provides an opportunity for non-target species, 

including Asian carps and other aquatic nuisance species, to enter the country. Actions are 

warranted to provide some level of Quality Assurance and Quality Control that importations do 

not contain non-target species. 

Strategy 3.1.10. Take action to prevent the incidental inclusion of live Asian carps in 

international imports with other fishes. 

This pathway is addressed by Recommendations 3.1.9.1, 3.1.9.2, 3.1.9.3, and 3.1.9.4. 

6) AQUACULTURE

PATHWAY: Poorly sited aquaculture facilities with Asian carps 

The Working Group defined poorly sited, high risk, aquaculture facilities as those with ponds 

that are 1) connected to or dependent on open, natural bodies of water or 2) subject to flooding. 

There is a high-risk that Asian carps will escape from poorly sited facilities to the wild due to the 

lack of adequate safeguards to prevent escape, the volume of water flowing from the production 

unit, or because production units are prone to flooding. 

Aquaculture, the controlled cultivation of aquatic organisms, is a form of agriculture in which 

aquatic plants and animals are raised for a variety of uses. Farmers, whether of fish, livestock, 

or row crops, have a vested interest in keeping their livestock (both aquatic and terrestrial) 

under control on their farm and preventing their escape to the wild. One way that fish could 
 49

escape from a fish farm or hatchery is by swimming in a stream of water that discharges from 

the farm and enters an open, natural waterway. This assumes that there is a connection 

between the point of discharge from a pond and the open body of water. A second way that fish 

could escape is during severe flood events. 

Most commercial pond aquaculture facilities have incorporated advances in water quality 

management which have demonstrated that water exchange is not an effective way to maintain 

water quality in earthen ponds; aerators are more effective in maintaining oxygen levels and are 

more economical (Boyd 1990). Many types of efficient aeration devices are used on fish farms 

today and pond fish farmers do not exchange water as a regular means to manage water 

quality. 

Many states have regulations that affect the siting of aquaculture facilities to prevent escape of 

farmed animals and minimize effluent discharge. Loss of fish stocks directly reduces farm 

revenue and is an incentive for businesses to minimize losses. Losses from a poorly sited 

facility can lead to new or expanded populations in the wild. 

Strategy 3.1.11. Take actions to prevent the unintentional escape, release, or improper 

disposal of Asian carps from aquaculture facilities at poorly sited locations. 

Recommendation 3.1.11.1. Urge the development and enforcement of state 

regulations that prohibit the production and use of Asian carps at poorly sited 

facilities. 

As previously defined, poorly sited facilities are those with connections to open waters or 

subject to flooding. States should prohibit the future stocking of Asian carps on any 

poorly sited facility. Regulations should define acceptable parameters, including sitespecific conditions such as: 1) protection from flooding available either by the system of 

containment levees along river systems, pond levee elevations, or not locating facilities 

in a flood plain; 2) frequency and volume of discharges; and 3) controls to prevent 

escapes. By reducing the number of poorly sited facilities, the potential for additional 

escapes to the wild will be reduced. Poorly sited facilities that are able to upgrade within 

acceptable parameters would no longer be considered a high-risk facility and states may 

choose to permit the use Asian carps within other provisions of the plan. 

Recommendation 3.1.11.2. Develop and provide information to Asian carp 

producers and growers that will help upgrade poorly sited facilities such that they 

are no longer high-risk to contain farm-raised Asian carps and prevent accidental 

introductions.

Work with Asian carp producers and growers to understand their operational activities 

and practices and identify information needs that will result in a reduced risk of 

accidental and deliberate unauthorized releases from these facilities. This audience 

should include both hatcheries used for distribution and those that culture Asian carps 

for commercial purposes. Information should assist poorly sited facilities upgrade, if 

possible, such that they are no longer high-risk and are able to produce Asian carps 

within other provisions of the plan. 

Several relevant activities have been or currently are being implemented. University and 

aquaculture Cooperative Extension educators, trade publications, trade associations, 

and the media have alerted growers on how their activities have been perceived. Some 
 50

university and aquaculture Cooperative Extension service educators and trade 

associations have provided information to improve production practices (e.g., 

http://aquanic.org). States within the Mississippi River Basin regulate the culture, 

possession, or sale of nonnative species and require aquaculture facilities to acquire 

nonnative species permits and specific farm design, operation, and management 

practices to reduce nonnative species risks and occurrences (Environmental Law 

Institute 2002). 

A major obstacle for this recommendation is effective communication between growers, 

natural resources managers, and educators. The challenge arises from the diversity of 

locations, various fish raised, different management practices, and other factors. It is 

essential that growers be identified and included in the collaborative process. 

Strategy 3.1.12. Develop an active research initiative to identify alternatives to the use of 

Asian carps. 

Recommendation 3.1.12.1. Form a coordinating research group that includes 

representatives from the aquaculture industry, the ethnic retail grocer industry, 

marketing scientists and developers, aquaculture scientists, and natural 

resources managers to focus research efforts on the highest priority alternatives 

to the use of Asian carps. 

Natural resources management agencies and aquaculture scientists should work with 

the aquaculture industry and marketing scientists to find environmentally safe 

alternatives to the use of Asian carps by the aquaculture industry. A focused 

multidisciplinary research effort will accelerate progress towards the identification of 

economically feasible alternatives. Identifying sources of funding and coordinating 

research efforts will contribute to more rapid implementation of research programs. The 

coordinating group will play a key role in advancing research goals and initiatives. 

Recommendation 3.1.12.2. Develop an information module on economic and 

effective alternatives to replace the use of bighead and black carps on 

aquaculture facilities. 

 

The Working Group indicated that identifying viable alternatives to black carp for snail 

control in aquaculture ponds is the highest research priority. The module should first be 

intended to identify the need for alternatives and the need for stakeholders to work 

together to identify alternatives. Once research identifies viable alternatives, the 

information module should be modified to encourage use of the identified alternatives. 

PATHWAY: Incidental inclusion of Asian carps in aquaculture shipments of other farmraised species to non-aquaculture waters 

Catfish and other species are sold live for use in non-aquaculture waters. If Asian carps are 

present in the aquaculture ponds from which the catfish and other species are harvested, it is 

possible to transport them to fishing ponds and lakes. Erdman (1984) reported that two silver 

carp were apparently stocked into golf course ponds as fingerlings mixed with grass carp. 

Other species have been accidentally introduced into new waters via public and private 

stockings (Simpson and Wallace 1982; Zuckerman and Behnke 1986). However, any Asian 

carps that might be present tend to be much larger than the other fish and are removed from the 

net prior to loading out fish. Size differences make the Asian carps relatively easy to detect, 
 51

and removing them is a standard practice. In-pond grading technology is also available to 

replace hand sorting on farms. 

In addition to the following strategy, this pathway is further addressed by Strategy 3.1.12.

Strategy 3.1.13. Take actions to prevent the incidental inclusion of Asian carps in 

aquaculture shipments of other farm-raised species to non-aquaculture waters. 

Recommendation 3.1.13.1. Review Standard Operating Procedures and 

recommend Best Management Practices that include requirements for suppliers 

and purchasers to conduct inspections of fish prior to shipment and release. 

A review of Standard Operating Procedures on farms that ship fish to non-aquaculture 

waters would provide a basis for determining whether there are areas for which Best 

Management Practices would be useful. Any development of Best Management 

Practices should occur through a participatory process with growers, live-haulers, 

university researchers, extension personnel, natural resources management agencies, 

and the appropriate industry associations to ensure maximum compliance. Purchasers 

of fish should directly communicate with suppliers about their expectations and needs. 

When possible, purchasers should visit farms and better understand management 

practices on their supplier’s farm. Purchasers of fish for stocking, including natural 

resources management agencies and non-governmental organizations, should be 

encouraged to screen or inspect shipments prior to release. Any inspection process 

developed should consider issues related to implementation that may result in lengthy 

delays and losses of fish. 

Recommendation 3.1.13.2. Encourage states to develop regulations that allow for 

random inspections of live fish shipments into and within the state. 

Anecdotal information suggests that Asian carps may have been introduced incidentally 

in shipments of other fish stocked into fishing lakes. In the absence of state inspections 

during shipment or stocking, it is difficult to know if this has occurred. Anecdotal 

information and common sense are often all that is available to identify a stock 

contamination problem. Random inspections of live fish shipments into and within the 

state would provide a basis for determining if any problems exist. Live fishes are a 

commodity, and inspections will require carefully planned and executed procedures to 

prevent the loss of capital. Any inspection process developed should consider liability 

for damages to shipments if the inspection process results in lengthy delays or losses of 

fish. However, liability should not prevent the inspection of shipments, but should 

promote the use of good judgment and development and testing of efficient inspection 

procedures to prevent delays and loss of product. 

Recommendation 3.1.13.3. Prohibit the use of surface waters containing Asian 

carps from being used in aquaculture facilities unless effective treatment is in 

place with a monitoring program. 

Some older culture facilities were constructed based on surface water supplies. If the 

surface water comes from waters with reproducing populations of Asian carps, it is very 

likely that the culture waters could include Asian carp larvae and fry. If the facility is a 

state or federal hatchery used for stocking programs, or a commercial hatchery selling 

fish for stocking into fishing ponds and lakes, the Asian carp fry or larvae could be 
 52

inadvertently included and result in unintentional stocking of new waters. Regulating 

agencies should prohibit aquaculture facilities from using surface waters that contain 

Asian carps, or require effective water treatment and water monitoring programs to 

prevent the transfer of Asian carps to other waters.

PATHWAY: Properly sited aquaculture facilities 

The Working Group categorized aquaculture facilities that are not 1) connected to or dependent 

on open, natural bodies of water or 2) subject to flooding (i.e., poorly sited) as “properly” sited. 

The Working Group did not specifically define properly sited aquaculture facilities, recognizing 

that most states have regulations that affect the siting of aquaculture facilities. These 

regulations were developed to prevent escape of farmed animals, and in some cases minimize 

effluent discharge. Properly sited facilities conform to these regulations and have adopted sitespecific practices required to maintain control over their stocks of fish. These include selecting 

sites that are protected from flooding either by the system of containment levees along river 

systems, by pond levee elevations, or by not being located in a floodplain. 

Most properly sited commercial aquaculture ponds are constructed on land previously used for 

crops such as cotton or soybeans. Groundwater is the principal water source used. Wells are 

the preferred source because well water avoids disease problems, the majority of variable water 

quality conditions, and the potential for contaminants associated with many surface waters. 

Most pond facilities generally discharge water fewer than 30 days per year and are therefore not 

considered Concentrated Aquatic Animal Production facilities (i.e., point sources of pollution) 

subject to the National Pollutant Discharges Elimination System permit system 

(http://www.epa.gov/fedrgstr/EPA-WATER/2004/August/Day-23/w15530.htm). Catfish foodfish 

ponds are usually not drained for periods of 7-10 or more years since it is not economical to do 

so and the earthen ponds themselves function as a very effective waste treatment system. 

Engle and Valderrama (2002) estimated that 17-28% of the cost of raising catfish foodfish is a 

result of the natural waste treatment function of earthen ponds. When drained, pond effluents 

typically flow through systems of drainage ditches, including many that are ephemeral, before 

reaching natural waters. 

In addition to the following strategy, this pathway is further addressed by Strategy 3.1.13.

Strategy 3.1.14. Reduce potential risks of continued use of Asian carps on properly sited 

aquaculture facilities to the environment. 

UNRESOLVED ISSUE: Use of triploid black carp on aquaculture facilities.

The Working Group was not able to reach consensus on recommendations regarding 

the use of triploid black carp on aquaculture facilities. Working Group members agreed 

that the desired endpoint is to have no black carp in use on aquaculture facilities (or in 

the wild), but did not agree on how long it should take to reach this endpoint. The 

Working Group also agrees that because black carp are not yet established in the wild, 

research to identify feasible alternatives to black carp for snail control is the highest 

priority research need and that all stakeholders should be actively pursuing alternatives 

to black carp. 

Many members of the Working Group support an approach that discourages the use of 

all black carp, but until feasible alternatives are proven and available for snail control, 

certified triploid black carp (100% inspected/retested) would be permitted with 
 53

appropriate controls for containment. The use of triploid black carp would require 

research to verify the functional sterility of black carp, a triploid inspection and 

certification program for black carp, and adequate and redundant controls for 

containment (see 3.1.14.1). Concurrent research for feasible alternatives to black carp 

for snail control is needed. However, there was disagreement on where triploid black 

carp should be permitted. Some members agreed that the limited use of triploid black 

carp should be restricted to the states and locations where black carp are currently 

produced or stocked (i.e., Arkansas, Mississippi, Missouri, and North Carolina), while 

others desire that triploid black carp should remain an option to any aquaculture facility 

that encounters the need for snail control. There was also disagreement on how long 

triploid black carp should be allowed in the absence of feasible alternatives. 

Other members of the Working Group oppose even limited use of triploid black carp 

because six black carp have been collected (many more unconfirmed reports) from the 

Mississippi River Basin and because of the potential effects of introduced individuals or 

reproducing populations of black carp on imperiled native mussels. These members 

support an approach that prohibits the use of all black carp and the immediate 

application of all available resources to developing a solution to the problem of snail 

control, as opposed to validating a tool (i.e., triploid black carp) that is a risk to imperiled 

mussels. To prevent the black carp from becoming established in rivers of the United 

States, temporary subsidies to farmers for losses due to inadequate snail control may be 

warranted. 

A detailed discussion on this unresolved issue and several potential alternatives 

regarding the use of triploid black carp on aquaculture facilities, along with some of the 

positive and negative aspects of each alternative, are presented in Appendix 6.3 for 

consideration by natural resources management policy and decision makers. 

UNRESOLVED ISSUE: Use of grass carp on aquaculture facilities in watersheds 

with self-sustaining populations of grass carp.

The Working Group was not able to reach consensus on recommendations regarding 

the use of grass carp on aquaculture facilities in watersheds with self-sustaining 

populations of grass carp. 

Some Working Group members support an approach consistent with recommendations 

addressing the use of grass carp on aquaculture facilities in watersheds where grass 

carp are absent or present but not reproducing. These members believe that the 

introduction of additional fish with reproductive potential exacerbates and directly 

conflicts with efforts to control feral populations. Therefore, at a minimum, states should 

encourage the use of triploid grass carp in watersheds with self-sustaining populations of 

grass carp. 

Other members support the use of diploid grass carp in watersheds with self-sustaining 

populations of grass carp and do not believe that states should encourage or require the 

use of triploid grass carp on aquaculture facilities. The effect of requiring triploid rather 

than diploid fish will be felt by consumers (public and private) that are currently allowed 

to purchase diploid grass carp for vegetation control, and could have a substantial 

economic burden on some private aquaculturists who use large numbers of these fish. 

The majority of commercial aquaculture facilities are not connected directly to open 
 54

waterways and the additional costs will only prevent the addition of a relatively few fish 

with reproductive potential to an already established population. 

A detailed discussion on this unresolved issue and two potential alternatives regarding 

the use of grass carp on aquaculture facilities in watersheds with self-sustaining 

populations of grass carp are presented in Appendix 6.4 for consideration by natural 

resources management policy and decision makers. 

Recommendation 3.1.14.1. Review Standard Operating Procedures and develop 

Best Management Practices for properly sited aquaculture facilities. 

Employ a stakeholder participatory process, led by university Cooperative Extension 

specialists, Sea Grant specialists, scientists associated with Regional Aquaculture 

Centers, and others, with expertise in aquaculture to develop a document that describes 

current Standard Operating Procedures for properly sited aquaculture facilities. The 

document should describe the appropriate use of redundant containment measures to 

prevent escapes of farm-raised carps. In the event areas for improvement are identified, 

industry associations will be encouraged to work with this group of scientists to develop 

Best Management Practices to address any issues. This document would also serve to 

educate those unfamiliar with current Standard Operating Procedures on commercial 

aquaculture farms with Asian carps. 

Recommendation 3.1.14.2. Encourage states to prohibit the use of grass carp on 

aquaculture facilities within watersheds where grass carp are not present in the 

wild. 

To prevent introductions and range expansion of grass carp in the wild, states should 

prohibit the use of grass carp on aquaculture facilities within watersheds where grass 

carp are absent. If a state allows the use of grass carp within a watershed where grass 

carp are not present in the wild despite the recommendation to prohibit their use, then 

only certified triploids should be permitted with appropriate controls for containment 

(Recommendation 3.1.14.1). 

Recommendation 3.1.14.3. Encourage states to restrict the use of grass carp to 

certified triploids only on aquaculture facilities within watersheds where grass 

carp are present but not reproducing. 

If a state allows the use of grass carp within watersheds where grass carp are present in 

the wild, then only certified triploids should be permitted with adequate and redundant 

controls to prevent escape. If a state allows the use of diploid grass carp, diploid grass 

carp should only be permitted with adequate and redundant controls to prevent escape 

(Recommendation 3.1.14.1). 

Scientists associated with Regional Aquaculture Centers, university Cooperative 

Extension scientists, and Sea Grant Extension scientists should be encouraged to 

initiate educational programs to encourage aquaculture facilities to use only certified 

triploid grass carp in all aquaculture applications. This initiative will provide a redundant 

measure to the risk of escape from properly sited aquaculture facilities. 

Recommendation 3.1.14.4. Verify functional sterility of triploid bighead carp and 

develop a triploid certification program for bighead carp. 
 55

“Triploid bighead (apparently sterile) have been produced and could be raised for 

market, although a limited study showed that they grow more slowly than normal 

(diploid) fish” (Stone et al. 2000). Commercial fish farmers have produced triploid 

bighead carp using techniques similar to those used to produce triploid grass carp 

(personal communication, Mike Freeze, Keo Fish Farm); however, the functional sterility 

of these fish has not been evaluated. If triploid bighead carp are proven functionally 

sterile, a triploid certification program would provide a mechanism to test individual fish 

for assurances that diploids will not be shipped. However, bighead carp fingerlings are 

sensitive to handling and cannot be kept out of pond water (i.e., held without food) for 

more than two days, making blood testing every bighead fingerling sold for foodfish 

production difficult and expensive (personal communication, Robert Glennon, J.M. 

Malone and Sons Inc.). Research is also needed to determine if triploid bighead carp 

are an economically viable substitute for diploids. If proven economically viable, sterile 

bighead carp would be a reasonable alternative to diploids for their continued use on 

properly sited aquaculture facilities within watersheds where bighead carp are currently 

self-sustaining. 

Recommendation 3.1.14.5. Encourage states to prohibit the use of bighead carp 

on aquaculture facilities within watersheds where bighead carp are not selfsustaining in the wild. 

 

To prevent introductions and range expansion of bighead carp in the wild, states should 

prohibit the use of bighead carp on aquaculture facilities within watersheds where 

bighead carp are not self-sustaining in the wild. If a state allows the use of bighead carp 

despite the recommendation to prohibit their use, then only certified triploids should be 

permitted with adequate and redundant controls to prevent escape (Recommendation 

3.1.14.1). The recommendation to allow certified triploid bighead carp is dependent 

upon research to determine that triploid bighead carp are functionally sterile and the 

implementation of a triploid inspection and certification program (Recommendation 

3.1.14.5). 

Recommendation 3.1.14.6. Encourage states to restrict the use of bighead carp 

on aquaculture facilities within watersheds with self-sustaining populations to 

certified triploids only. 

States that allow the use of bighead carp on aquaculture facilities within watersheds 

where bighead carp are self-sustaining in the wild should encourage the use of only 

certified triploids. If a state allows the use of diploid bighead carp despite the 

recommendation to use only triploids, diploid bighead carp should only be permitted with 

adequate and redundant controls to prevent escape (Recommendation 3.1.14.1). 

If research shows that triploid bighead carp production is both biologically and 

economically feasible, scientists associated with Regional Aquaculture Centers, 

university Cooperative Extension scientists, and Sea Grant Extension scientists should 

be encouraged to initiate educational programs to encourage aquaculture facilities to 

use only certified triploid bighead carp in all aquaculture applications. This initiative will 

provide a redundant measure to the risk of escape from properly sited aquaculture 

facilities. 
 56

Recommendation 3.1.14.7. Encourage states to prohibit the use and production of 

silver carp on aquaculture facilities. 

Silver carp are not in commercial production, and regulations are warranted to prohibit 

their future use in commercial production. 

Recommendation 3.1.14.8. Encourage states to prohibit the use and production of 

diploid black carp on aquaculture facilities. 

State regulations to prohibit the use of diploid black carp are warranted. Black carp are 

not yet considered established within the United States. Black carp have the potential to 

survive almost anywhere in the United States where there is suitable habitat and food 

resources (Nico et al. 2005). Adult black carp have been collected from the wild; 

however, natural reproduction has not been documented through the collections of eggs 

and larvae or observations of spawning (Nico et al. 2005). Black carp have similar 

spawning requirements to grass carp and other Asian carps (Nico et al. 2005). Given 

that bighead, grass, and silver carps have established self-sustaining populations in 

large river within the Mississippi River Basin, it is reasonable to expect that feral black 

carp would be able to spawn successfully in these same large rivers and potentially 

establish self-sustaining populations (Nico et al. 2005). 

PATHWAY: Incidental inclusion and potential release of Asian carps in farm raised 

baitfish 

This pathway addresses baitfish that are produced on aquaculture facilities and not wild-caught 

baitfish held in holding ponds and later sold as “farm raised” minnows (see Strategy 3.1.1). 

Bighead carps generally are not stocked in baitfish ponds, but black and grass carps are 

stocked in fathead minnow (Pimephales promelas) ponds for vegetation and snail control to 

prevent infestations of yellow grub. Yellow grub infestations in fathead minnow ponds have 

been reported to cause up to 80% mortality of fathead minnows (Mitchell 1995). Asian carps 

are not stocked in golden shiner (Notemigonus crysoleucas) or goldfish ponds because these 

fishes have delicate scales and are easily damaged by the larger Asian carps when harvested. 

In fathead minnow ponds in which black carp are stocked, the black carp are much larger and 

easily removed from nets if present during harvest. Because baitfish go through several days of 

intensive vat grading in sheds prior to sale, any black or grass carps present with fathead 

minnows should be identified and removed. 

This pathway is directly addressed by the suite of recommendations identified under Strategy 

3.1.1 and indirectly addressed by Strategy 3.1.12. The Working Group did not identify 

additional Strategies or Recommendations specific to this pathway. 

PATHWAY: Incidental inclusion of Asian carps in domestic shipments of food fishes 

Black and grass carps are stocked into foodfish ponds with channel catfish, hybrid striped bass, 

and largemouth bass; and bighead carp are sometimes stocked with channel catfish. Hybrid 

striped bass normally are packaged individually for sale; therefore, any incidentally included 

Asian carps should be removed during this process. Largemouth bass are often live-hauled to 

market; therefore, there is some risk of including Asian carps in these shipments. The primary 

foodfish industry in the United States is channel catfish. Bighead carp are co-cultured on some 

farms with channel catfish, and black carp are stocked in channel catfish foodfish ponds for 
 57

snail control to prevent infestations of the nonnative trematode (Bolbophorus spp.). Channel 

catfish raised as foodfish generally are sold to processing plants, most of which are located 

close to the production facilities. Processing plants must be permitted for discharge of wastes, 

and for this reason are not located near open bodies of water. 

Black carp have no foodfish markets and must be removed from nets by hand when harvesting 

catfish, resulting in extra labor and additional costs (Venable et al. 2000; personal 

communication, Anita Kelly, Southern Illinois University). Black carp are very susceptible to 

catfish harvesting operations and seine crews must be diligent in returning black carp to the 

pond (Avery et al. 2004). However, due to the high growth rates of Asian carps, it is generally 

quite easy to distinguish these fish from the catfish due to their much larger size and different 

appearance. Because farmers are docked (reduction in price of fish) for non-target fish, there is 

an incentive for farmers to remove Asian carps before delivery to a processor. Asian carps that 

do arrive at a processing plant are electrocuted and sold dead to a rendering plant along with 

the rest of the waste products from processing. 

This pathway is addressed by Strategy 3.1.12. The Working Group did not identify additional 

Strategies or Recommendations specific to this pathway. 

PATHWAY: Incidental inclusion of Asian carps in domestic shipments of catfish to fish 

farms 

The Working Group considered the potential for Asian carps to be included incidentally in 

domestic shipments of catfish to other fish farms. The primary case would be that of catfish 

stockers (intermediate size ranging from 60-180 pounds/1000 fish) sold by one farm to another. 

These sales occur infrequently and, thus, are not part of the routine practices of catfish 

production. Some black and grass carps may be stocked into catfish fingerling ponds. Bighead 

carp are stocked in catfish foodfish grow-out ponds, not stocker or fingerling ponds. It is 

possible for black or grass carps to be loaded unintentionally onto a truck for delivery to another 

catfish farm. Black carp are very susceptible to catfish harvesting operations and seine crews 

must be diligent in returning black carp to the pond (Avery et al. 2004). The grower has an 

incentive to retain the black and grass carps in their ponds because if they are loaded out, the 

grower would lose the aquatic vegetation and snail control provided by these species and would 

incur additional expense for replacement. The much larger size of the Asian carps makes it 

relatively easy to remove them from a net of catfish stockers during the loading process. 

However, additional labor is required to remove black carp when harvesting catfish, which 

results in extra labor and additional costs to the farm (Venable et al. 2000; personal 

communication, Anita Kelly, Southern Illinois University). 

This pathway is addressed by Strategy 3.1.12. The Working Group did not identify additional 

Strategies or Recommendations specific to this pathway. 

7) LIVE TRANSPORT 

PATHWAY: Domestic live transport and distribution of wild-caught fish 

The Working Group agreed that the domestic live transport and distribution of wild-caught Asian 

carps is one of the highest risk pathways for introducing these fish into new waters. 
 58

Commercial fishers have an important role in the control and management of established 

populations of Asian carps (e.g., early detection and population control). However, commercial 

fishers also represent a potential pathway of accidental, or even deliberate unauthorized 

introductions. Commercial fishers in many locations throughout the Mississippi River Basin 

report high incidental catches of Asian carps, and a few commercial fishers who have access to 

markets target Asian carps (personal communication, Rob Maher, Illinois Department of Natural 

Resources). It is in the commercial fisher’s financial interest to find markets for as much of a 

day’s catch as possible, whether target or non-target fish. Asian carps harvested by commercial 

fishers are likely to be diploid fish. Transportation of these non-target fish to markets also 

entails a high risk of introduction into additional drainages and some risk of disease agent 

transfer. The potential clearly exists for commercial fishers to act as a vector of introduction if 

steps are not taken to ensure safe transport and handling of their catch. Regulations regarding 

the transport and sale of live wild-caught Asian carps are needed. 

Although commercial fishers typically receive relatively low prices for Asian carps, higher prices 

can be obtained by selling them live in ethnic seafood markets. Ethnic seafood markets with a 

demand for live Asian carps are usually located in large cities (e.g., New York), requiring 

commercial fishers to transport their live catch away from the river of capture and often into 

watersheds without established populations of these fishes. In 2004, three live bighead carp 

that fell from a commercial fisher’s boat were found along a state highway in Illinois (personal 

communication, Dan Sallee, Illinois Department of Natural Resources). In similar 

circumstances, fish may drop into waters along the highway or fall from a bridge into waters 

below. Passengers in other vehicles may stop to move fish to nearby waters; attempting with 

the best of intentions to rescue the fish, but potentially creating detrimental results. A vehicle 

accident could also provide a large-scale introduction into a waterway without an established 

population of Asian carps. The water used to transport live Asian carps also presents a threat 

of transferring Asian carp eggs or larvae (and other aquatic nuisance species) into new 

watersheds. 

Strategy 3.1.15. Take actions to prevent the live transport of wild-caught Asian carps and 

potential introduction through release, improper disposal, or escape. 

Recommendation 3.1.15.1. Where legal for commercial or recreational fishers to 

possess Asian carps, encourage states to prohibit the possession of live wildcaught Asian carps. 

Encourage states to require all commercially- or recreationally-harvested Asian carps to 

be killed at the time of capture to prevent their live transport and potential introduction 

into new locations. States should prohibit the transport of live wild-caught Asian carps 

by commercial live haulers. Regulations are warranted to prevent the transport and 

distribution of live Asian carps away from the immediate waters in which the fish are 

collected. Even under closely managed transport, the distribution of live, primarily 

diploid, Asian carps into watersheds without established populations represents a 

substantial risk to the environment. 

Recommendation 3.1.15.2. Review Standard Operating Procedures and actions of 

commercial fishers to identify Best Management Practices that reduce risks of live 

transport and introduction. 

Natural resources management agencies should work directly with commercial fishers to 

review or establish Standard Operating Procedures involving wild-caught fish. Best 
 59

Management Practices that reduce risks of introductions from live transport should be 

developed, shared, and enforced throughout the industry. Trained managers should 

employ a Hazard Analysis and Critical Control Point planning approach to identify critical 

procedures, and work with commercial fishers to find solutions that minimize risks. 

Recommendation 3.1.15.3. Develop an information module and provide materials 

to commercial and recreational fishers and commercial live haulers that will help 

prevent accidental and deliberate unauthorized introductions of Asian carps. 

State natural resources management agencies license and regulate commercial and 

recreational fishers and should implement programs to directly communicate with the 

target audience and provide information on regulations regarding Asian carps and the 

reason that they exist. A number of informational materials have already been 

developed that convey information about Asian carps. Commercial and recreational 

fishers and commercial live haulers should be engaged to ensure that their specific 

education and outreach needs, and how to most effectively meet these needs, are 

understood. Interactions with the target audience and delivery of applicable existing 

information should begin immediately. Education and outreach will require a long-term 

sustained effort. 

PATHWAY: Commercial, domestic transport of live farm-raised Asian carps 

Bighead, black, and grass carps are traded commercially in the United States. The live 

transport of Asian carps to markets throughout the United States and into Canada is cause for 

concern because each shipment of live fish within a watershed without feral Asian carps creates 

the opportunity for introduction and establishment in new waters. Silver carp are not traded 

commercially in the United States and interstate transport of all forms of live silver carp are 

prohibited under the Lacey Act. 

The primary market for bighead carp is a live product sold in Asian ethnic markets in major cities 

in the United States and Canada. Bighead carp are transported live on specialized fish hauling 

trucks equipped with oxygen, a series of tanks, and generally on an 18-wheeled transport truck 

(Figure 3.1.1). The fish are off-loaded in wholesaler/distributor warehouses in the cities and 

then transported by smaller trucks to individual grocery stores for sales (Figure 3.1.2). Grass 

carp are transported in a similar manner, but are sold primarily for aquatic vegetation control, 

with some sales in the foodfish market. Black carp are sold for snail control for fish ponds in 

southern states. They are transported from hatcheries to fish ponds for stocking. 

Asian carps can escape during commercial, domestic transport due to an accident or other 

human error. In nearly 25 years of livehauling, there has been only a single known report of an 

accident involving a truck while hauling live Asian carps. A tractor-trailer hauling 12,000 pounds 

of live bighead carp from Arkansas to an Asian fish food market in New York in 1996 overturned 

on Interstate 81 in Virginia (personal communication, Gary Martel, Virginia Department of Game 

and Inland Fisheries). The Fire Rescue Crew salvaged some fish by placing them in a local 

farm pond and requested permission to stock others into South Holston Lake. Although the 

likelihood of an introduction via this pathway is small, the risk to the environment is high in 

watersheds without established populations of these species. 

In addition to the following strategies, this pathway is also addressed by Strategy 3.1.12. 
 60

Figure 3.1.1. Commercial hauling truck used to 

transport live bighead and grass carps from 

production facilities to food markets in the United 

States. Photo courtesy of David Heikes, University 

of Arkansas at Pine Bluff.

Strategy 3.1.16. Take actions to prevent the release, escape, or improper disposal of 

domestic commercial shipments of live Asian carps. 

Recommendation 3.1.16.1. Require informational labeling of truck and invoice for 

shipments of Asian carps to avoid improper handling and potential introduction of 

fish that may be involved in an accident (e.g., “Nonnative fish: Unauthorized 

release prohibited”). 

Labels on trucks hauling Asian carps and on the invoices would alert emergency 

personnel (e.g., police, fire, and rescue) and the public to the nature of the cargo. 

Labeling programs should be established in coordination with the Institute of Hazard 

Materials Management, which publishes a handbook of codes for labeling cargoes and 

appropriate responses in case of spills. Such labeling may help avoid unauthorized 

human-mediated introduction of fish as occurred in the previously discussed incident. 

Labels must be supported by information programs so that highway patrol and 

emergency personnel know what to do. 

Recommendation 3.1.16.2. Review Standard Operating Procedures and develop 

Best Management Practices for fish haulers regarding containment and water 

transfer. 

A review of Standard Operating Procedures of livehaulers who transport Asian carps 

would provide a basis for determining operational areas for which Best Management 

Practices would be useful. Development of Best Management Practices should occur 

through a participatory process with the appropriate industry associations, university 

Cooperative Extension Service specialists, Sea Grant specialists, personnel associated 

with Regional Aquaculture Centers, and others, to ensure maximum compliance. 

Recommendation 3.1.16.3. Prohibit the use of water from natural water bodies for 

water exchange during transport. 

Livehaulers primarily use well water for transport and water exchange, if needed en 

route. However, the use of a natural water body for water exchange could introduce 

Figure 3.1.2. Warehouse delivery truck ready to 

unload live bighead at a fish market in New York 

City. Photo courtesy of David Heikes, University of 

Arkansas at Pine Bluff.
 61

Asian carps into new locations and is suspected to be the source of bighead carp in 

South Holston Lake, Virginia (personal communication, Gary Martel, Virginia Department 

of Game and Inland Fisheries). Regulations are warranted that prohibit the exchange of 

water with wild sources while enroute to market to prevent introductions via this 

pathway. 

Recommendation 3.1.16.4. Investigate improvements for containment methods on 

trucks carrying Asian carps. 

Research into the possibility of improving the latch systems on livehauling trucks 

potentially could result in modifications that would prevent the lids of tanks from opening 

during an accident. Such modifications in the design would require thorough testing and 

evaluation, including field trials, to determine its feasibility both from a practical and an 

economic perspective. 

Recommendation 3.1.16.5. Develop an information module and provide materials 

to commercial transporters of live farm-raised Asian carps that will help prevent 

accidental and deliberate unauthorized introductions. 

Little information is available concerning factors that may contribute to accidental release 

or escape during transport. Stakeholders representing a cross section of interests 

should work directly with commercial transporters of live Asian carps to review and 

understand their Standard Operating Procedures, as well as, their specific education and 

outreach needs. Meeting these needs will result in a reduced risk of escape during 

transport. Transporters are not limited to commercial livehaulers, and may also include 

fish farmers, wholesalers, live haulers, fish retailers, consumers, and researchers. 

University aquaculture Cooperative Extension educators, trade publications, trade 

associations and the media have informed some transporters about the potential risks 

associated with their business. Some university aquaculture Cooperative Extension 

educators and trade associations have also provided information to improve 

transportation practices. 

Strategy 3.1.17. Reduce the potential risk to the environment from continued 

commercial, domestic transport of live farm-raised Asian carps. 

The following recommendation addresses only bighead and grass carps. If Recommendation 

3.1.14.8 (‘Encourage states to prohibit the use and production of silver carp on aquaculture 

facilities’) is adopted there will be no need to take further actions to prohibit commercial, 

domestic transport of live farm-raised silver carp. Likewise, the Working Group did not develop 

recommendations addressing the commercial, domestic transport of live farm-raised black carp, 

pending decisions on the unresolved issue ‘use of triploid black carp on aquaculture facilities’ 

(Strategy 3.1.14). The transport of live farm-raised black carps currently is limited to 

movements within and between a very small number of states (i.e., Arkansas, Missouri, 

Mississippi, and North Carolina) as a biological control agent for nuisance snails (personal 

communication, Mike Freeze, Keo Fish Farm). 

 
 62

UNRESOLVED ISSUE: Commercial, domestic transport of live farm-raised bighead 

and grass carps. 

The Working Group was not able to reach consensus on recommendations regarding all 

aspects of commercial, domestic transport of live farm-raised bighead and grass carps. 

Working Group members agreed that any commercial transport of live fish should be 

conducted with adequate controls to minimize escapes (Strategy 3.1.16) and with the 

requirement that all fish are killed at the point of sale, with the exception of authorized 

stockings of grass carp to control nuisance aquatic vegetation. As with other pathways, 

recommendations to address live transport were considered based on whether or not 

bighead and grass carps are absent, present without evidence of natural reproduction, 

or are self-sustaining in the wild. 

Watersheds where bighead and/or grass carps are self-sustaining in the wild:

Working Group members agreed that commercial live transport of bighead and grass 

carps is acceptable within watersheds where these species are self-sustaining in the 

wild. However, the Working Group did not agree on whether or not live transport within 

these watersheds should be limited to certified triploid fish only or if diploid fish should be 

permitted. 

Watersheds where bighead and/or grass carps are absent or are not self-sustaining in 

the wild:

Some Working Group members suggested that to prevent introductions or range 

expansions of these species, commercial live transport should be prohibited within any 

watershed where bighead and grass carps are not self-sustaining. Some members 

support prohibiting commercial live transport where the fish are completely absent in the 

wild, but allowing certified triploids to be live-hauled within watersheds where the fish are 

present but not self-sustaining. Other members support commercial live transport of 

certified triploids within watersheds where the fish are completely absent in the wild. 

Some members suggested that the commercial live transport of diploid bighead and 

grass carps should be permitted within any watershed. 

A detailed discussion on this unresolved issue and several potential alternatives 

regarding the commercial transport of live bighead and grass carps, along with some of 

the positive and negative aspects of each alternative, are presented in Appendix 6.5 for 

consideration by natural resources management policy and decision makers. 

8) ACCIDENTAL AND DELIBERATE UNAUTHORIZED RELEASES BY 

INDIVIDUALS

PATHWAY: Accidental and deliberate unauthorized release by individuals 

There are several potential sources of accidental and deliberate unauthorized release, escape, 

or improper disposal of Asian carps into open waters of the United States. One pathway is 

cultural, ceremonial, or symbolic releases related to special events. It has been a long tradition 

in some Southeast Asian cultures to release fish as a way to recognize very special events 

(e.g., birth of child, funerals, or New Year celebrations; personal communication, Josee Chung, 

Minnesota Department of Natural Resources). There are most likely two levels of this practice 

in the United States. One is the release of small, easy to obtain fish, from pet or bait stores, into 

small ponds at temples for ceremonial reasons. This does not appear to be a likely pathway for 
 63

Asian carp introductions. A second pathway is catching and subsequently releasing wild-caught 

fish. It is a cultural practice among some religious groups to release fish as a symbolic token. 

This generally occurs with wild-caught fish and not with fish purchased live at a fish market. 

However, fish markets could provide a source for live Asian carps in locations where they are 

not present in the wild. While releases are usually done infrequently by an individual or 

individual family (every 5-15 years; personal communication, Josee Chung, Minnesota 

Department of Natural Resources), the cumulative effect of many individual actions over time 

elevates the risks associated with this pathway. 

Another potential pathway is the retail sale of live Asian carps as food fish. Many retail grocers 

within ethnic communities have specialized market sales of live Asian carps. Consumers within 

these markets prefer to purchase live Asian carps rather than dead or even freshly killed fish 

(Kerr et al. 2005). The sale of live fish within these markets has created considerable concern 

over potential unauthorized introduction; enough concern that some large cities have 

promulgated local laws that require Asian carps sold live by a retail grocer to be slaughtered 

upon sale (Higbee and Glassner-Shwayder 2004). California does not allow most species of 

live Asian carps within its borders and all fish market sales are limited to dead product. Any of 

these fish that are transported live to the state line must be killed before entering the state 

(personal communication, Bob Hulbrock, California Department of Game and Fish). 

Release and/or improper disposal of aquaria or hobby fish are additional pathways for the 

unauthorized introduction of Asian carps and other nonnative fishes (see www.habitatitude.net/). 

Although uncommon in the aquarium/hobby industry, bighead carp have been advertised for 

sale by hobbyists on the Internet (e.g., www.aquabid.com). Internet trade by aquaria owners 

and hobbyists is a possible, but unlikely pathway for the introduction of Asian carps. However 

this pathway provides for the potential introduction of Asian carps anywhere in the United 

States. The extent of this pathway is unknown. 

Strategy 3.1.18. Take actions to prevent the accidental and deliberate unauthorized 

release of Asian carps by individuals. 

Recommendation 3.1.18.1. Encourage states to prohibit the sale, live transport, 

and unauthorized release of live Asian carps for non-commercial uses. 

States should be urged to develop specific regulations that prohibit sales of live Asian 

carps, live transport, and unauthorized release by private individuals. Regulations are 

needed to address sales by private individuals, especially via the Internet. 

Recommendation 3.1.18.2. Encourage states that allow sales of live Asian carps 

for human consumption to require retail grocers to kill the fish using prescribed 

humane methods, immediately upon sale. 

Live fish must not be permitted out of the possession of the retailer. Retail grocer 

associations should be involved in discussions related to the most effective means of 

preventing escape of live fish. 

Recommendation 3.1.18.3. Use educational campaigns such as HabitattitudeTM to 

convey messages to the public that they should not release live Asian carps. 

Information may be as powerful as regulations in the effective control of this pathway. 

Effective informational programs directed at the appropriate audiences are needed. 
 64

Information awareness campaigns that focus on segments of the public most likely to 

transport live Asian carps and accidentally or deliberately release fish should be 

developed immediately. 

Recommendation 3.1.18.4. Develop an information module and provide materials 

to producers, growers, marketers, and foodfish consumers of live Asian carps 

that will help prevent accidental and deliberate unauthorized introductions. 

Stakeholders representing a cross section of interests should work directly with 

producers, growers, marketers, and foodfish consumers of live Asian carps to 

understand their operational functions and specific education and outreach needs, as 

well as how to most effectively meet these needs to result in a reduced risk of accidental 

and deliberate unauthorized releases by these groups. A better understanding of 

cultural and religious practices that may result in the release of live Asian carps is 

needed. 

Developing a complete functional list of producers, growers, marketers, and foodfish 

consumers of live Asian carps is not feasible because of the diversity of groups and 

operations. Identifying effective outreach methods to improve operational practices or 

behaviors to reduce the risks of accidental and deliberate unauthorized introductions of 

Asian carps will be challenging. Language differences may require the need for both 

verbal and written translations. Sea Grant Programs on the east coast have developed 

foreign language materials dealing with the release of fish intended for human 

consumption. 

Recommendation 3.1.18.5. Promote the national Aquatic Nuisance Species 

Hotline and encourage the general public to report illegal possession or stocking 

of Asian carps and other activity that could affect an introduction or rapid 

response. 

The general public can have an active role in helping to prevent accidental or deliberate 

unauthorized introductions of Asian carps. The USFWS sponsors a national Aquatic 

Nuisance Species Hotline (877-STOP- ANS). The hotline can be used to report 

sightings of new or unusual species of plants, animals, or other organisms. The hotline 

should be actively promoted to the general public as a tool for reporting possession, 

stocking, or other activity that could effect an introduction of Asian carps or other aquatic 

nuisance species. Reports that prevent an introduction or lead to rapid response actions 

should be publicized. States may want to consider developing programs of incentives to 

encourage the general public to be aware of aquatic nuisance species issues and to 

take action to prevent their introduction. 

9) AQUARIUM / HOBBY INDUSTRY

PATHWAY: Aquarium/hobby industry 

Millions of live fishes are imported, sold, and shipped throughout the United States for the 

aquarium and hobby industry each year. The Working Group recognized aquarium hobbyists, 

backyard pond owners, and water gardeners as the end consumers for the aquarium and hobby 

industry. Release, escape, and improper disposal of Asian carps by various consumers are 
 65

addressed under “accidental and deliberate unauthorized releases by individuals”. This 

pathway specifically addresses the commercial suppliers of aquarium/hobby industry fishes. 

Various species of carp dominate world finfish aquaculture, representing more than 90% of all 

finfish aquaculture harvests (Shivappa et al. 2004), however there is little or no current interest 

for Asian carps within the aquarium/hobby industry. Koi and goldfish are both nonnative 

Cyprinids important to the United States ornamental fish industry (Shivappa et al. 2004), but are 

not included in the collective term of “Asian carps” in this document. Asian carps generally are 

not used within the aquarium hobby industry and are, therefore, considered a possible, but 

unlikely pathway. 

Fish sold in the aquarium/hobby industry originate from farms in the United States or are 

imported from international suppliers. The volume of live fish in trade in the aquarium/hobby 

industry poses a risk of introduction. Inclusion of Asian carps with aquarium and hobby fish, 

including Koi carp, is considered unlikely. Aquaria fish are typically sorted, held, and sold by 

species; therefore, mixing of species is not economical and measures are taken to avoid mixing 

species in shipments. Even if co-mingled in shipments, wholesalers and retailers hold fish in 

closed systems that are subject to effluent discharge regulations and to inspection by the 

USFWS. Larger Asian carps should be easily distinguished by size during sorting or holding. 

Individual Koi carp can have a potential market value of tens of thousands of dollars (Shivappa 

et al. 2004) and are typically hand selected, tank sorted, and held in higher water quality 

conditions (personal communication, Marshal Myers, Pet Industry Joint Advisory Council). 

Mixing of Asian carps in shipments of Koi carp is, therefore, unlikely. 

Strategy 3.1.19. Take actions to prevent the release, escape, or improper disposal of 

Asian carps by aquarium/hobby industry importers, wholesalers, and retailers. 

Recommendation 3.1.19.1. Encourage states to prohibit the trade of Asian carps 

for aquaria and hobby purposes. 

Currently there is no known trade of Asian carps in the aquarium/hobby industry. State 

regulations that prohibit the import and trade of Asian carps for aquaria and hobby 

purposes are needed to prevent such trade from occurring in the future. This 

recommendation should have no adverse effects on the aquarium/hobby industry and is 

an effective, proactive control for a potential pathway of introduction. 

10) RESEARCH AND EDUCATIONAL FACILITIES

PATHWAY: Research and educational facilities and projects 

Three separate levels of educational and research facilities were identified within this pathway. 

Research projects by government or university researchers; less formal educational projects at 

high schools, junior highs, or elementary schools; and routine operations of public aquaria are 

all potential sources for accidental or deliberate unauthorized releases, escapes, and improper 

disposal of Asian carps. 

Unplanned introductions from government and university level projects and public aquaria are 

possible, but unlikely. Typically those participating in these projects establish and follow 

protocols for research projects that include methods for appropriate disposal (e.g., animal care 

and handling protocols). The Guidelines for the Use of Fishes in Research provides “a structure 
 66

that ensures appropriate attention to valid experimental design and procedures” for general use 

by researchers in the United States (Nickum et al. 2004). An ANS Task Force Research 

Committee will review and update a research protocol that provides guidance for federally 

funded research involving aquatic nuisance species. Federally funded research must meet 

National Environmental Policy Act requirements and this is part of all intramural federal research 

programs as well. 

Lower level education and research projects are also a potential pathway for unauthorized 

introductions of Asian carps. This is because facilities may not have adequate containment and 

students and teachers may not be aware of protocols, permit requirements, or other precautions 

to avoid actions that could lead to introductions of Asian carps into new waters. Often, students 

are enthusiastic about helping science by conducting simple science projects with nuisance 

species that are in the news. It is not unreasonable to expect that students will try to obtain 

nuisance species such as Asian carps for school projects. If they obtain these fishes, it is 

probable that some students will not want to euthanize the fish, but will make plans to release 

them. Although commercial biological supply companies are not known to currently provide live 

Asian carps for education or research project, they remain a potential source of these fishes for 

students. 

Strategy 3.1.20. Prevent the release, escape, or improper disposal of live Asian carps via 

education facilities and projects, including schools, public aquaria, and research 

facilities. 

Recommendation 3.1.20.1. Urge states to develop and enforce regulations to 

reduce risks associated with the possession and disposal of Asian carps for 

research and exhibition purposes. 

Encourage states to develop regulations restricting the possession and disposal of Asian 

carps for research and exhibition purposes. Research and exhibition facilities should be 

required to provide reasonable and effective protocols to prevent the release, escape, or 

improper disposal of Asian carps. The possession of live Asian carps by research and 

exhibition facilities should only be permitted after effective protocols have been 

established and reviewed. 

Recommendation 3.1.20.2. Develop an information module and provide materials 

to the academic and research communities that will help prevent accidental and 

deliberate unauthorized introductions of Asian carps. 

Stakeholders representing a cross section of interests should work directly with the 

academia and research communities to understand their operational functions and 

specific education and outreach needs, as well as how to most effectively meet these 

needs to result in a reduced risk of accidental and deliberate unauthorized releases by 

this group. 

Recommendation 3.1.20.3. Encourage states to prohibit the trade of live Asian 

carps by commercial biological supply companies. 

Currently there is no known trade of Asian carps by commercial biological supply 

companies. State regulations that prohibit the import and trade of Asian carps by 

commercial biological supply companies are needed to prevent such trade from 

occurring in the future. This recommendation should have no adverse effects on the 
 67

biological supply industry and is an effective, proactive control for a potential pathway of 

introduction. 

11) RECREATIONAL BOATERS AND FISHERS

PATHWAY: Intentional release of live, “adult-sized” (non-baitfish) Asian carps by 

boaters, anglers, and bow fishers 

The Working Group agreed that the release of live, “adult-sized” Asian carps by boaters, 

anglers, and bow fishers is a low risk pathway. Boaters are unlikely to come into contact with 

bighead, black, or grass carps. Silver carp will jump into boats creating a potential pathway of 

introduction that should be addressed. However, boaters are not likely to possess large 

numbers of silver carp or transfer these fish to different waters. Bowfishers capture many Asian 

carps, but any fish in the possession of a bowfisher are likely to have been captured after being 

speared by an arrow. There seems little risk of bowfishers transferring live Asian carps between 

waters. Recreational anglers are likely to catch an occasional bighead or silver carp. Grass 

carp are targeted by some recreational fishers. Recreational anglers are not likely to possess 

large numbers of Asian carps, but do present a potential pathway that should be addressed. 

Strategy 3.1.21. Take action to prevent the transport and release of “adult-sized” (nonbaitfish) Asian carps by boaters, anglers, and bowfishers. 

Recommendation 3.1.21.1. Develop an information module and provide materials 

to recreational fishers and boaters that will help prevent accidental and deliberate 

unauthorized introductions of Asian carps. 

An information module and outreach materials are needed to reduce the risk of 

accidental or deliberate unauthorized releases of Asian carps by recreational fishers and 

boaters. It is critical that these groups understand how and why to help prevent 

introductions. Stakeholders representing a cross section of interests should work 

directly with the recreational fishers and boaters to understand their specific education 

and outreach needs, and how to most effectively meet these needs to reduce risk of 

accidental and deliberate unauthorized releases by these groups. 

Numerous Asian carp outreach events of a general nature occur regularly across the 

geographical range of established Asian carp populations in the United States. Current 

outreach activities include WATCH cards and poster displays. Messages targeting 

recreational boaters and fishers should be included in state and federal boating and 

fishing materials and websites. Information about Asian carps should be included in the 

Stop Aquatic Hitchhikers! Campaign, materials posted at tackle shops, boat ramps, and 

marinas; and included in outdoor publications and television programs. 

 
 68

Goal 3.2. Contain and control the expansion of feral 

populations of bighead, black, grass, and silver 

carps in the United States. 

Feral bighead, black, silver, and grass carps are spreading by larval dispersion and/or migration 

throughout the Mississippi River Basin and threaten to expand to additional watersheds via 

interbasin connections (e.g., canals and waterways) and human-mediated spread. To prevent 

their expansion into waters where they do not exist, a long term, dedicated, and cooperative 

effort by federal, state, tribal and private partners is required to create or maintain dispersal 

barriers and to develop forecasting, detection, and rapid response capabilities to control or 

eradicate new populations. Targeted reductions in the abundance of feral Asian carp 

populations (Goal 3.3), especially at the periphery of the range and near dispersal barriers, will 

improve efforts to contain and control the expansion of feral Asian carps by lowering the chance 

that these fish will invade or establish in new areas. Containment and control capabilities exist 

in a limited number of local jurisdictions (e.g., Chicago Sanitary and Ship Canal), but have not 

been widely developed on a national scale. Nationally coordinated capabilities and actions are 

likely to require a dedication of resources and manpower akin to those established for wildfire 

management and suppression.

Strategy 3.2.1. Develop a national strategy and guidelines for science-based decision 

making concerning the need for continued and additional containment measures. 

The rapidly growing and expanding populations of bighead and silver carps are forcing federal 

and state agencies to develop both immediate and long-term strategies for containing these 

fishes and for limiting their distribution. Decisions to undertake specific containment actions 

should be science-based. In addition, a long-term strategic, rather than an opportunistic, 

approach should be used to contain feral Asian carps. Due consideration should be given to the 

effects of containment actions on the long-term ecological sustainability of native aquatic 

resources. 

Recommendation 3.2.1.1. Develop a Decision Support System to assist natural 

resources managers in prioritizing specific locations for the construction, 

maintenance, monitoring, or removal of barriers to carp dispersal. 

A Decision Support System based on computer models developed using reliable data is 

the best approach to synthesize the available information and allow for informed 

decision making. Specifically, a Decision Support System would be used to 

• describe and understand the current distribution of feral carps 

• estimate the future rate of spread, establishment, and consequences of Asian 

carps in the absence of actions to contain feral populations 

• estimate the effects of limiting the distribution and connectivity to habitats of 

native species as a result of implementing containment actions 

• evaluate the effectiveness and need for existing dispersal barriers 

• estimate the dispersal of Asian carps and effects on native communities upon 

removal or bypass of existing barriers (i.e., fish passage) 

• identify high risk areas and waters of special concern 

• prioritize specific locations for the construction, maintenance, monitoring, or 

removal of barriers to Asian carp dispersal. 
 69

The Decision Support System should be a collaborative project with national 

participation in the design of the tool, analysis of the data, and development of 

recommendations. 

The Decision Support System will provide the scientific basis to develop a national 

strategy for actions to contain feral populations. Natural resources management 

agencies will more effectively contain Asian carps, use limited resources, and obtain 

new funds by working together under a national strategy. The timeframe for developing 

a Decision Support System is dependant upon factors such as research capabilities, 

agency collaboration, and funding. Depending upon the funding and staffing committed 

to the completion of the project, a fully functional Decision Support System could take 

from one to several years to develop. However, containment measures are needed now

to be most effective; therefore, a preliminary model based on the expert opinions of a 

diverse group of scientist and managers should be developed and implemented as soon 

as possible. Models based on expert opinion have proven to be highly functional in 

many other situations. Never-the-less a complete Decision Support System is warranted 

and will provide a more accurate and predictable basis for sound decision making in the 

future and would set up a management framework for other aquatic nuisance species 

introductions. It is reasonable to expect that management questions involving actions to 

construct, maintain, monitor, or remove water control structures, or other potential 

barriers to Asian carp dispersal, will need to be addressed well beyond the timeframe 

required to develop a Decision Support System. In addition, many of the Geographic 

Information System coverages that are needed for the Asian carp Decision Support 

System could be used to evaluate and address introductions of new aquatic nuisance 

species in the future. 

Recommendation 3.2.1.2. Evaluate the effectiveness afforded by alternative 

technical containment measures (i.e., physical and behavioral barriers). 

Potential barrier and deterrent systems that may limit the movement and establishment 

of Asian carps are summarized in Appendix 6.7. There are two barrier and deterrent 

classifications presented; behavioral and physical. Behavioral guidance technologies 

include methods that cause migrating fish to avoid, or move away from, specific areas 

through sensory stimulation (Coutant 2001). The purpose is to discourage fish from 

entering a particular area and to make it desirable and possible for them to move 

elsewhere. Examples include strobe lights, air bubble curtains, acoustic deterrents, 

electrical disbursal barriers, hydrodynamic louver screens, and combination systems that 

may use two or more systems to provide a more effective barrier or deterrent. Physical 

barriers have been used in numerous locations to prevent fish movement through the 

use of rotating drum screens, traveling screens, floating curtains, vertical drops (existing 

and constructed), and velocity barriers. 

The available data on the effectiveness of deterrents for Asian carps should be 

compiled, their biological and practical effectiveness on Asian carps and native fishes 

analyzed, and the circumstances under which each deterrent is most effective 

evaluated. Field tests should be conducted for barriers that are deemed likely to be 

effective. Further research is needed to explore other innovative methods as 

alternatives to effectively contain feral Asian carp populations (Recommendation 

3.6.3.1). 
 70

Recommendation 3.2.1.3. Promote, support, and provide technical analysis and 

comment for the field testing of novel containment methods. 

Effective containment is an immediate need that will require a long term commitment of 

personnel, equipment and funding. Publication of this national management and control 

plan and on-going research and development efforts should yield innovative methods to 

contain Asian carp range expansion. Field testing should begin immediately to test and 

refine technologies while the Decision Support System is being developed. Preference 

should be given to technologies that may be selective and allow native fishes to pass 

while deterring passage of Asian carps. Personnel, equipment, and funds must be 

made available to field test ideas, promote technology transfer, select appropriate 

riverine sites, and develop and monitor performance measures. 

Recommendation 3.2.1.4. Anticipate and address consequences of specific 

containment actions on native biological communities.

 

Natural resources managers must consider the entirety of effects that may be brought 

about by specific containment actions. In addition to the intended effects on Asian 

carps, planning, design, and evaluation of containment measures must anticipate and 

address the probable consequences to native communities. Planners must do their best 

to determine if the costs of containment actions are too great for the future sustainability 

and health of native aquatic resources before projects are implemented. Containment 

actions implemented without due consideration of the consequences to native 

communities may do more harm than good. Barriers may be used as temporary 

measures that can be removed in the future; however the establishment of Asian carps 

in new waters is likely to be permanent and have irreversible effects on native 

communities. Information on native aquatic communities and habitats should be 

included in the development of decision support tools, and assist the formation of a 

national strategy to identify and prioritize needed containment measures (Strategy 

3.2.1). 

Strategy 3.2.2. Take immediate actions to prevent interbasin transfers and limit 

intrabasin movements of feral Asian carp populations. 

Once an aquatic nuisance species becomes established it can be very difficult and costly to 

manage and potentially impossible to eliminate (Kolar et al. 2007; USEPA 2005). The best 

protection for native aquatic ecosystems is to minimize the distribution of feral Asian carp 

populations and prevent their access to additional waters. Because existing feral Asian carps 

populations are dispersing and will not wait to be contained, implementation of this strategy is 

urgent and immediate actions are warranted to prevent the expansion of feral Asian carp 

populations throughout the Mississippi River Basin and into new watersheds. Navigation locks 

and dam systems have slowed but not stopped the upriver migration of these fishes. Canals 

and waterways have been constructed throughout the country to facilitate the transfer of waters, 

people, and commodities between basins. These same interbasin connections now threaten to 

facilitate the dispersal and range expansion of Asian carps. 

Recommendation 3.2.2.1. Develop and implement redundant barrier systems 

within the Chicago Sanitary and Ship Canal to limit the unrestricted access of 

Asian carps to Lake Michigan. 

Natural resources managers are concerned about the potential introduction of Asian 

carps into the Great Lakes. Bighead and silver carps have been collected from the 
 71

Illinois River within 50 miles of Lake Michigan. The Chicago Sanitary and Ship Canal 

(Appendix 6.8), is the primary key to stopping large numbers of these nuisance fishes 

from dispersing into Lake Michigan and the other Great Lakes. An initial dispersal 

barrier (Barrier I) was constructed on the Chicago Sanitary and Ship Canal near 

Romeoville, Illinois, as a demonstration project. The barrier, activated in April of 2002 

with an expected service life of three to five years, is close to the end of its design life; 

three electrodes are exhibiting wear resulting in decreased effectiveness (University of 

Wisconsin Sea Grant Institute 2006b). It is intended to deter fish movements in the 

canal by repelling them with electroshock. The electric charge (2-3 volts per second per 

in3

) is not considered lethal or even injurious to humans, mammals, or fish. The 

manufacturer (Smith-Root Inc, Vancouver, Washington) estimates the barrier’s efficiency 

in the mid 80% range (Moy 1997), and has stated a need for two or three more such 

barriers downstream to gain 100% efficiency. Cost of the structure was approximately 

$2.2 million (USEPA 2006). There is interest in maintaining Barrier I as part of an overall 

barrier project. Continued operation of Barrier I will require the installation of new, 

heavier electrodes at an estimated cost of $5.5 million (University of Wisconsin Sea 

Grant Institute 2006a). 

Construction of a second, larger, and more powerful barrier (Barrier II) is being 

completed in two phases. Design of this barrier incorporated results of research 

conducted with bighead and silver carps in a laboratory setting. The barrier will be more 

effective on small fish and will have dual arrays to prevent passage of large fish in 

association with barge traffic. The first half of Barrier II (IIA) was completed in April 2006 

but can only be operated short term (a matter of weeks) until safety issues are fully 

addressed. However, Barrier IIA can be operated on an emergency basis if Barrier I 

were to fail. Insufficient funds remain to complete construction of the second portion of 

Barrier II (IIB). The USACE has requested an additional $8.5 million to complete Barrier 

II and to operate Barrier I (University of Wisconsin Sea Grant Institute 2006b). 

Without federal legislation, responsibility for operation and maintenance of Barrier II will 

be transferred to the State of Illinois once construction of both phases is complete. The 

cost for full operation and maintenance of Barrier II is estimated at $450,000 per year 

($37,500 per month; personal communication, Steve Shults, Illinois Department of 

Natural Resources). Legislation has been introduced (Water Resource Development 

Act of 2007, H.R. 1495; Barrier Project Consolidation and Construction Act of 2007, 

S.336.IS; and Great Lakes Asian Carp Barrier Act, H.R.553.IH) that would (1) fund 

improvements to Barrier I to make it “permanent”, (2) provide full federal funding for the 

construction, operation, and maintenance of Barrier II, and (3) reimburse the eight Great 

Lakes states that contributed the non-federal funds for construction of Barrier II. 

In addition to the Chicago and Sanitary Ship Canal electrical barriers, the feasibility of 

additional electrical barriers for construction within the Des Plaines River needs to be 

investigated. Other technologies such as the creation of a 3-5 mile anaerobic zone in 

the canal should be investigated, as should the construction of a physical dam or levee 

to separate the two ecosystems. 

The Proceedings of an Aquatic Invasive Species Summit hosted in Chicago during 2003 

(City of Chicago and USFWS 2003) identified three general approaches for preventing 

the exchange of aquatic invasive species between the Mississippi River and Great 

Lakes basins. These approaches include 1) investigate and evaluate hydrologic 

separation of the two basins; 2) pursue additional control and prevention technologies; 
 72

and 3) procure broad-based political support and federal funding for developing and 

implementing solutions. The recommendations from the Chicago Summit should be 

considered during the planning, development, and implementation of water resources 

projects in the Chicago area. 

Recommendation 3.2.2.2. Develop and implement reasonable and effective 

measures that prevent the spread of Asian carps via canals, water ways, or other 

water diversions between basins. 

Canals and waterways have been constructed throughout the country to connect basins 

and facilitate the transfer of waters, people, and commodities between basins. Actions 

are needed to close open hydrologic connections in non-commercial canals with 

physical barriers or control structures and investigate the feasibility and effectiveness of 

alternative barriers in canals and waterways with commercial navigation. In addition to 

the Chicago Sanitary and Ship Canal, the Great Lakes Regional Collaboration Aquatic 

Invasives Species Strategy Team Action Plan (USEPA 2005) identifies the Ohio canals 

and waterways system as priority interbasin connections that must be addressed to 

prevent the spread of Asian carps into the Great Lakes. Particular attention should be 

directed to the Ohio and Erie and Miami and Erie canals. The potential for spread of 

Asian carps from the Ohio River Basin into the Great Lakes via these routes is 

significant. Efforts to improve recreational access must consider effective means to 

prevent the spread of Asian carps. 

Efforts are needed to identify locations where intermittent flood-related connections 

occur between watersheds and take reasonable and effective actions to prevent the 

transfer of Asian carps and other aquatic nuisance species via these connections. This 

is particularly important where natural waterways may parallel canals, as occurs in the 

Chicago region. The Des Plaines River and Deep Run Creek parallel the Chicago 

Sanitary and Ship Canal for several miles. To ensure the effectiveness of the existing 

electric barrier, flood-related connections between these waterways must be eliminated. 

Water resources development and other projects have been constructed that transfer 

waters between basins and warrant careful evaluation for their potential to expand the 

range of Asian carps and other aquatic nuisance species. Water transfer projects within 

the range of feral Asian carp populations can expand feral populations if viable eggs, 

larvae, or fish are transferred in project waters. Existing canals, water ways, and water 

transfer projects should be evaluated for their potential to transfer Asian carps and other 

aquatic nuisance species. Reasonable and effective measures should be implemented 

to reduce associated risks. Similar consideration should also be made for all future 

water transfer projects to provide reasonable and effective assurances that these 

projects will not expand feral populations of Asian carps or other aquatic nuisance 

species. 

Recommendation 3.2.2.3. Construct and operate a Sound Projector Array-based 

acoustic bubble curtain fish deterrent at two locks and dams on the Upper 

Mississippi River to prevent the spread of Asian carps throughout the basin. 

Fish deterrents should be constructed and activated quickly to limit the range expansion 

of Asian carps in the Upper Mississippi River Basin. A study, funded by the states of 

Minnesota and Wisconsin and the USFWS, was conducted by a consulting firm to 

evaluate the feasibility of installing existing and new technologies for “stopping the 
 73

northward movement” of Asian carps in the Upper Mississippi River (FishPro 2004). The 

study’s final report ranked sound projector array-based, acoustic bubble curtains 

downstream of locks and dams as the most feasible and potentially most effective 

barrier to slow the spread of feral populations of Asian carps from their existing ranges. 

(See Appendix 6.9 for an overview of acoustic technology.) 

The USACE is authorized to construct and maintain locks and dams in the Upper 

Mississippi River and Illinois Waterway. If authorized, and funded, the USACE would 

lead the project to design, plan, and install these fish deterrents as a demonstration 

project. The recommended technologies have not been tested in rivers the size of the 

Mississippi River. Demonstration projects are operated for relatively short periods of 

time (less than 3-years) to test new technologies. Once they are tested, they are 

decommissioned. Additional authorization and appropriation would be required to install, 

operate and maintain permanent deterrent systems. Responsibility for operation and 

maintenance of these systems could fall upon other federal agencies or on the nonfederal project sponsor. 

Recommendation 3.2.2.4. Identify additional containment measures needed to 

limit intrabasin movements of feral populations of Asian carps within the 

Mississippi River and other basins where established.

The best protection to native ecosystems is to prevent the establishment of Asian carps. 

In those waters with populations, containment can prevent or slow their distribution 

throughout a system. 

Using available information, natural resources managers should determine current 

distributions of Asian carps within their jurisdictions, and predict where expansion is 

likely to continue in the absence of actions to contain them. Natural resources 

management agencies should also identify waters of special concern, for example 

• waters containing populations of endangered and threatened mollusks that may 

be threatened by feral populations of black carp; 

• waters with unusual or sensitive biodiversity that would be affected by feral 

populations of Asian carps; and 

• waters of economic importance would be affected by reduced stocks of sport fish 

and the presence of silver carp. 

Natural resources managers must weigh the economic costs of individual actions 

against the anticipated economic and ecological benefits. 

As discussed in Strategy 3.2.1, natural resources managers should work together to 

develop and operate within a national strategy to address the containment of feral 

populations where appropriate. Partner agencies should begin working together 

immediately to pool information and resources to effectively address this issue. 

Strategy 3.2.3. Minimize the range expansion and ecological effects of feral populations 

of Asian carps in conjunction with management actions to enhance aquatic 

environments for the sustainability of native biological communities. 

Natural resources management agencies and institutions are investing millions of dollars and 

thousands of hours enhancing aquatic environments to sustain native communities. Restoring 

habitat connectivity, has come under question because of the continual invasion of aquatic 

nuisance species, especially Asian carps. Expanding the range or increasing the abundance of 
 74

Asian carp populations can be unintended effects of these actions. Natural resources 

managers must weigh the benefits that habitat enhancements will have on Asian carps and 

other nonnative organisms, as well as to the native communities that they are intended to help 

sustain. In the end, natural resources managers must decide if the native biological 

communities are more sustainable with or without specific projects to enhance the aquatic 

environment. 

Recommendation 3.2.3.1. The USFWS and other natural resources management 

agencies should provide technical assistance and biological information to the 

USACE and participate in collaborative planning of fish passage and habitat 

restoration projects. 

The USACE plans to construct fish passageways at the following locations by 2020 as 

part of the Navigation and Ecosystem Sustainability Program: 

• Lock and Dam 26 at Alton, Illinois 

• Lock and Dam 22 near Saverton, Missouri 

• Lock and Dam 8 at Guttenberg, Iowa 

• Lock and Dam 4 near Wabasha, Minnesota. 

The USACE will also complete engineering and design for fish passage at Lock and 

Dam 19 at Keokuk, Iowa by 2020. Evaluations of fish passage alternatives must 

consider potential benefits to Asian carps and other nonnative species (i.e., range 

expansion), as well as adverse effects on the sustainability of native aquatic 

communities and habitats.

The USACE is developing these projects in collaboration with federal and state natural 

resources management agencies under an adaptive management framework. Under 

the authority of the Fish and Wildlife Coordination Act, the USFWS will continue to 

provide technical assistance and coordination to the USACE as their funding permits. 

Asian carps are being considered in the planning of these fishways. Sites were selected 

where substantial numbers of Asian carps have been documented in the commercial 

harvest for over 10 years (Pools 26, 22, and 19), or are above the leading edge of the 

Asian carp infestation (Pools 8 and 4). In cooperation with the USFWS and state 

agencies, the USACE is currently developing fish passage alternatives for Lock and 

Dams 22 and 26. 

Recommendation 3.2.3.2. Require federal and state agencies to consider the 

potential range expansion and ecological effects of Asian carps when designing 

or reviewing water control structure projects and permits. 

Numerous government agencies are involved with projects affecting water control 

structures in both navigable and non-navigable waters. Many of these are falling into 

states of nonuse and/or disrepair, creating an impetus for removal. Natural resources 

managers commonly pursue opportunities to: 

• remediate the ecological effects of barriers to aquatic ecosystems via dam 

removal or notching, 

• construct fishways that bypass the barrier, 

• construct boulder ramps and stair steps to the head of a dam, 

• eliminate perched culverts, and 

• re-install low-water crossings that impede fish passage. 
 75

These actions can greatly aid the expansion of feral populations of Asian carps, even in 

low order streams. All agencies involved in water control structure projects should 

develop policies that require the potential range expansion and ecological effects of 

Asian carps, and other nonnative species, as functional considerations when designing 

or reviewing water control structures and permits. 

Federal agencies such as the USACE, USFWS, and U.S. Forest Service (USFS) should 

take lead roles to enact such policies. Asian carp interdiction should be an on-going, 

long term commitment by these agencies. Those knowledgeable of Asian carps should 

be sought by and assist these agencies during water control structure permit reviews 

and project design. 

Strategy 3.2.4. Forecast, detect, and rapidly respond to new feral Asian carp 

introductions and range expansions. 

Persistent, active measures are needed to control the expansion of feral populations of Asian 

carps. Natural resources managers must accurately determine the current distribution of feral 

populations and anticipate where range expansions or introductions are likely to occur. A 

limited risk evaluation is currently underway for bighead, black, and silver carps in Pacific 

Northwest waters. Preliminary information indicates significant portions of the Columbia River 

Basin are at risk for introductions based on pathway opportunities and habitat conditions 

(personal communication, Paul Heimowitz, USFWS). 

Effective monitoring programs are paramount in the timely detection and effective utilization of 

Rapid Response Plans to prevent range expansions and eradicate new introductions. Rapid 

Response Plans typically take considerable time to develop. Thus, they should be developed 

well in advance of their anticipated need. The Illinois Dispersal Barrier Advisory Panel and rapid 

response program could serve as a model for the proactive development of an Asian Carp 

Rapid Response Plan. 

Recommendation 3.2.4.1. Develop an early detection Decision Support System to: 

1) identify high risk locations susceptible to introductions or range expansions of 

Asian carps, 2) identify watersheds of special concern, 3) prioritize specific 

locations for implementing comprehensive early detection monitoring programs. 

An early detection Decision Support System is needed to effectively identify where Asian 

carp populations are most likely to expand and are likely to be most damaging. This 

Decision Support System will allow managers to focus monitoring or detection efforts in 

areas of greatest need and concern. It will effectively prioritize locations for 

establishment of early detection programs to reduce the risk that range expansion might 

occur undetected and allow for rapid response measures to be enacted. An effective 

prioritization scheme can help management authorities to effectively direct limited 

resources to critical areas. 

A Decision Support System coordinator is essential to operate a clearinghouse to 

communicate with state and local agencies. 

Research is needed to understand 1) which water bodies and watersheds are at high 

risk for Asian carps’ range expansion, 2) which water bodies and watersheds are most 

amenable to rapid response, and 3) whether alternatives to rapid response may reduce 

the threat of introductions or range expansions. 
 76

Recommendation 3.2.4.2. Adopt and/or adapt a National Incident Management 

System to provide for national coordination and management of early detection 

and rapid response programs. 

Managing emergency actions after detection of Asian carps, such as rapid response and 

eradication, may be complex, confusing, and inefficient, because multiple agencies at 

the federal, state, and local levels will be trying to rapidly react within dynamic aquatic 

ecosystems. The single standard Incident Management System was developed in the 

United States almost 30 years ago to respond to wildland fires 

(http://www.nifc.gov/fireinfo/ics_disc.html). Incident Management System has become 

the benchmark standard for multi-agency emergency management and coordination, 

and provides an on-scene structure of management-level positions suitable for 

managing any incident. It is flexible, comprehensible, and logical; it has been adapted 

for hazmat, oil spill, riots, and extreme weather (hurricanes, flooding, earthquakes, etc.) 

events. Implementing a national Asian carp or aquatic nuisance species Incident 

Management System will require a concerted and sustained effort by a lead federal 

agency, consultation and coordination with state natural resources management 

agencies, multi-agency agreements, unified training, and dedicated funding. A National 

Incident Management System would benefit from the designation of a single federal 

agency as the primary agency responsible for the management and control of nuisance 

species. 

Recommendation 3.2.4.3. Develop and conduct routine early detection monitoring 

programs in locations where risk of introductions or range expansions of Asian 

carps exists. 

Early detection is a key component in the control of feral Asian carp populations. 

Sampling methods and protocols effective for detecting new introductions or range 

expansions of Asian carps are critically needed (3.6.2.1). Together, early detection and 

rapid response can prevent expanding feral populations or new introductions of Asian 

carps from becoming established in new locations. Effective early detection will trigger 

rapid response plans in sufficient time for responders to prevent range expansion. 

Coordinated early detection programs should be developed based on the highest priority 

areas identified by the early detection Decision Support System (Recommendation 

3.2.4.1). Early detection programs in interjurisdictional waters or in locations that could 

affect multiple governances should be part of a national strategy to contain Asian carps 

(Recommendation 3.2.4.2). In many situations multi-agency efforts will be needed to 

optimize available resources and effectively implement early detection monitoring 

programs. Multi-agency programs will inherently require additional time for agency 

coordination and planning. 

Research is needed to develop effective and efficient sampling techniques for all life 

stages of Asian carps in a variety of habitats to provide for effective early detection 

monitoring and evaluation of rapid response efforts. 

Recommendation 3.2.4.4. Develop Rapid Response Plans that identify where 

rapid response actions can effectively eradicate Asian carps and how those 

actions will be carried out. 
 77

Rapid response is not likely to effectively stop the advancement of Asian carps in all 

situations, therefore, guidelines must be established to identify when rapid response 

actions are warranted and feasible. A rapid response action will require preparation and 

consideration of factors including threshold for action (i.e., number of fish to warrant a 

response action), necessary permits/licenses, responding and lead agency, and action 

plan for implementation. 

Rapid response actions may be feasible in a relatively small subset of locations because 

of constraints imposed by 1) the biology of the organism, 2) the physics of the water 

body in question, and 3) politics or other factors that would make an area unfishable or 

untreatable with a rapid response technique. A Rapid Response Plan will identify when 

and where rapid response actions are feasible and most effective. 

To be most effective, guidelines for implementation must be established in advance of 

the need. This will require agreement among agencies on clear guidance on the 

following: what level of detection will trigger a rapid response, what response techniques 

will be applied for each situation, what permits are required, what personnel and 

equipment are required, and who will respond. All protocols, permits, staff, equipment, 

and funding must be in place and on standby prior to the need for it. 

“The National Environmental Policy Act requires federal agencies to integrate 

environmental values into their decision making processes by considering the 

environmental effects of their proposed actions and reasonable alternatives to those 

actions” (USEPA 2005). To meet this requirement, federal agencies prepare a detailed 

statement known as an Environmental Impact Statement, a very time consuming 

process. To be effective, Rapid Response Plan by definition must be rapid. For the 

timely implementation of a Rapid Response Plan, the USFWS should seek a categorical 

exclusion for Rapid Response Actions. Categorical exclusions are "a category of actions 

which do not individually or cumulatively have a significant effect on the human 

environment . . . and for which, therefore, neither an environmental assessment nor an 

environmental effect statement is required" (40 CFR 1508.4; Council of Environmental 

Quality 1978). Additional methods to get accelerated environmental review should be 

concurrently explored. 

Local community coordination and involvement is vital. Local stakeholders must be 

involved in rapid response planning so that their support for a rapid response action is 

solid. Lack of stakeholder support could derail rapid response. Involvement could 

include town meetings, press releases, fact sheets, and experts to answer stakeholder 

questions about why a rapid response may be needed and what the benefits to the local 

community might be. 

Strategy 3.2.5. Develop systems to identify the location of captive stocks of Asian carps 

and for the notification of appropriate agencies in the event of escapement.

State laws and regulations govern possession, culture, and sale of native and nonnative fishes. 

Each state has developed laws, rules, and policies relative to nonnative species. States should 

establish systems to identify the location of captive stocks of Asian carps within their jurisdiction. 

States that do not prohibit Asian carps may or may not require a nonnative species license 

and/or reporting. Licensing and reporting can be valuable tools to allow states to track 

nonnative species within their jurisdiction. To achieve basin-wide reporting, states are 

encouraged to develop a license and reporting system and coordinate their regulatory efforts 

regionally, and nationally. At a minimum, states should require the reporting of escaped Asian 
 78

carps. A central coordination mechanism is needed so information is rapidly and widely 

available and to initiate a rapid response. Existing infrastructure such as the USGS 

Nonindigenous Aquatic Species Alert System (http://nas.er.usgs.gov/AlertSystem/default.asp) 

and USFWS sponsored national Aquatic Nuisance Species Hotline (1-877-STOP-ANS) may 

prove sufficient mechanisms, or starting points, if utilized fully. 

Recommendation 3.2.5.1. Encourage states to identify the location of captive 

stocks of Asian carps and to develop a communication network for the reporting 

of escapees. 

States should establish systems to identify the location of captive stocks of Asian carps 

at both private and public facilities within their jurisdiction. States should be encouraged 

to require the reporting of escaped Asian carps, particularly in waters where feral Asian 

carps are not established. A communication network with regulatory agencies, private 

aquaculture, and public facilities possessing Asian carps should be developed for the 

reporting of escapees. Information awareness campaigns should be implemented to 

create awareness about the need to contain Asian carps, as well as how and why to 

report escaped fish. Reporting programs for escaped Asian carps should be linked to 

rapid response assessment programs and in such cases should be mandatory. 

Management agencies that regulate the possession of Asian carps should collaborate, 

potentially under the auspices of the ANS Task Force Regional Panels. 

Recommendation 3.2.5.2. Create an information sharing system with early 

detection monitoring and rapid response project managers. 

Coordination among natural resources management agencies responsible for regulating 

the possession of Asian carps, conducting early detection monitoring, and implementing 

rapid response programs will be aided by tools such as the USGS Nonindigenous 

Aquatic Species Alert System and the USFWS sponsored national Aquatic Nuisance 

Species Hotline that facilitate communication and information exchange. States that 

require escapee reports should post them to a central information exchange 

Strategy 3.2.6. Develop an information exchange network for agencies, organizations, 

and partners to communicate and share “real time” data to facilitate early detection and 

rapid response programs.

The size and scope of the Mississippi Basin poses an extreme challenge to those organizations 

and individuals coordinating nonnative species management programs. Currently, information 

sharing is handled by the ANS Task Force through the Mississippi River Basin Panel on Aquatic 

Nuisance Species. The panel has a website 

(http://wwwaux.cerc.usgs.gov/MICRA/MRB%20Panel%20on%20ANS.htm) and a ListServe 

which members can use to post messages and reports. The Panel currently includes 

membership from interested federal agencies, Mississippi River Basin states, and numerous 

stakeholders including the National Association of State Aquaculture Coordinators, Catfish 

Farmers of America, the Pet Industry Joint Advisory Council, B.A.S.S., and the Nature 

Conservancy. As the Panel continues to evolve, it could become a clearinghouse for 

information via automated or managed electronic exchanges. 

Recommendation 3.2.6.1. Develop a website and centralized databases to provide 

information on early detection and rapid response programs. 
 79

Information exchange of real time data can be provided quickly and efficiently to 

agencies, organizations, and partners through a centralized database housed on a 

website dedicated to early detection and rapid response programs. 

Recommendation 3.2.6.2. Develop a list-server to provide a forum for information 

exchange. 

Information exchange can be provided quickly and efficiently through a list-server, where 

agencies, organizations, and partners can post questions to their peers and gather 

additional information about solutions being implemented by others. 

Recommendation 3.2.6.3. Utilize and support the Nonindigenous Aquatic Species 

Information Center for accurate and spatially referenced biogeographic 

information and the Nonindigenous Aquatic Species Alert System to track 

expansion. 

The Nonindigenous Aquatic Species Information Center (http://nas.er.usgs.gov) provides 

spatially referenced biogeographic information (scientific reports, online/real-time 

queries, spatial data sets, regional contact lists, and general information) which can be 

accessed by agencies, organizations, and partners via the Internet. Natural resources 

management agencies should adapt Standard Operating Procedures for supplying 

timely information to the Nonindigenous Aquatic Species Alert System to maximize its 

accuracy and utility as a real-time tool to track the expansion of Asian carps. 
 80

Goal 3.3. Extirpate, or reduce to levels of insignificant effect, 

feral populations of bighead, black, grass, and 

silver carps in the United States. 

Every effort should be put forth to prevent introductions and range expansions into new waters. 

Experiences controlling populations of other aquatic nuisance species introduced into the United 

States have proven difficult (e.g., sea lamprey, zebra mussels, and common carp) and indicate 

that extirpating or reducing feral populations of Asian carps to levels of insignificant effect will at 

best be challenging, expensive, and will require a long-term, dedicated effort. Controlling a new 

introduction or range expansion is not an acceptable alternative to prevention (Goal 3.1) and 

containment (Goal 3.2), however once a population is established, control measures should be 

done in concert with aggressive prevention and containment actions. 

Extirpating or reducing feral populations of Asian carps is consistent with management efforts to 

promote ecosystems based on assemblages of native species. The effects of Asian carps on 

native ecosystems are likely to be proportional to their abundance; therefore, reducing the 

numbers of Asian carps should ameliorate potential adverse effects within these locations, and 

lower the chance that these fishes will spread to new areas. Potential strategies for population 

reduction include: 1) enhancing commercial harvest through education, market research, gear 

development, and possibly financial incentives; 2) increasing recreational harvest; 3) physical 

removal by natural resources management agencies; 4) biological controls (e.g., diseases, 

parasites, or predators); 5) release of sterile Asian carps; 6) release of transgenic Asian carps 

(including Daughterless Carp and Trojan technologies) developed to reduce the size of a target 

population via spread of a deleterious gene; 7) application of pheromones to enhance harvest or 

interfere with reproduction or recruitment; 8) habitat or hydrologic modification to favor native 

fishes over Asian carps or to facilitate harvest of Asian carps; and 9) use of piscicides. 

Considerable research is necessary to further explore the efficacy of many of these potential 

strategies. 

To increase effectiveness, these potential strategies should be woven into an integrated 

management framework. Integrated management is a strategy used by farmers and 

environmental managers to plan and implement actions that maximize control of the target 

species while minimizing damage to the environment, including native plants and animals (Hart 

et al. 2000). The integrated management philosophy takes a holistic approach and uses a 

logical sequence of events to develop a plan that employs the best management options and 

control tools to restrict, reduce, and maintain the target species at levels of insignificant impact, 

while minimizing danger to the environment, human health, and the economy (Hart et al. 2000). 

Integrated management strategies that have worked well in agricultural and urban settings can 

be used to manage aquatic nuisance species that threaten native ecosystems (Hart et al. 2000). 

The Great Lakes Fishery Commission has implemented an integrated management approach 

within the sea lamprey control program (Great Lakes Fishery Commission 1992). An integrated 

management philosophy is warranted and should be employed in the identification of methods 

to eradicate or reduce and maintain populations of feral Asian carps at levels of insignificant 

effect to native aquatic ecosystems. 

Strategy 3.3.1. Determine life history characteristics and build population dynamics 

models of Asian carps in the Mississippi River Basin. 
 81

Development of scientifically sound and cost-effective sampling methods is essential to 

adequately monitor the distribution and abundance of Asian carps (Recommendation 3.6.2.1). 

Models of the populations and biomass of Asian carps must be developed and supplied with the 

required data. This will require substantial effort and commitment of resources, but these 

models are critical to determine whether biological, chemical, and physical efforts to reduce feral 

Asian carp populations are justifiable and likely to be successful. Substantial advancements 

have been made in Australia in the modeling of common carp populations to predict efficacies of 

different control efforts (Brown 2005). Asian carp population models for the Mississippi River 

Basin should adopt and adapt useful parts of these prior efforts. 

Recommendation 3.3.1.1. Determine life history parameters of Asian carps in the 

Mississippi River Basin. 

Understanding the success of Asian carps in establishing populations in new areas is 

essential to controlling their populations. While there may be similarities between the 

Mississippi River Basin and the native ranges of Asian carps, their interactions with an 

area of the world in which they did not evolve must be understood. Life history 

characteristics that need to be identified in the Mississippi River Basin include habitat 

and hydrology preferences for spawning cues, fecundity rates, and larval fish rearing; 

food preferences; growth rates; recruitment rates and life expectancy. This activity is 

critical to several strategies in this plan. 

Recommendation 3.3.1.2. Create population, biomass, and recruitment models for 

Asian carps 

Life history information can be used to create models of Asian carp populations in 

regions of the Mississippi River Basin. Priority should be given to modeling bighead and 

silver carps in regions where they are most abundant. Models should first attempt to 

predict the effects of harvest on available biomass and population of Asian carps. 

Understanding the available quantity of Asian carps for harvest is necessary before large 

amounts of money will be invested by private interests. Later models might be created 

that would be geared toward estimating the efficacy of other control methodologies. 

The Illinois Department of Natural Resources is currently financing a study to estimate 

biomass of Asian carps in the Illinois River that could be available for commercial 

harvest. These data will be used for stock-recruit modeling to concentrate commercial 

harvest efforts at a segment of the population whose removal could most effectively 

reduce the total population (personal communication, Steve Shults, Illinois Department 

of Natural Resources). 

The USFWS, Illinois Natural History Survey, and University of Nebraska-Lincoln are 

developing stock-recruit models for bighead and silver carps in portions of the Illinois 

and Mississippi Rivers (unpublished data, Michael Hoff, USFWS). Provisional results of 

the models imply that control of stock size can significantly reduce recruitment and total 

population size. 

Strategy 3.3.2. Increase the commercial harvest of Asian carps. 

Large biomasses of Asian carps are available and are harvested commercially in portions of the 

Mississippi River Basin (Maher 2002, 2005; FishPro 2004; personal communication, Jody 

David, Louisiana Department of Wildlife and Fisheries; personal communication, Brian 
 82

Canaday, Missouri Department of Conservation). Commercial fishers report high catch rates of 

bighead and silver carps in some locations of the Mississippi River Basin, suggesting that 

harvest to regulate the abundance of these fishes in the United States may be a practical 

alternative. In their native China, wild populations of Asian carps are often considered overharvested (Yi et al. 1988). Preliminary modeling of the bighead carp population in portions of 

the Illinois (LaGrange Pool) and Mississippi (Pool 26) rivers indicates that controlling adult stock 

size (not to exceed 0.05 adults/unit of fishing effort) will reduce recruitment and adult abundance 

over the long term (Hoff et al. In press). More research in this vein is needed. 

Promoting an increased commercial harvest is not without risks (Appendix 6.10). Because of 

potential undesirable consequences, decisions have been made not to allow the commercial 

harvest of other aquatic nuisance species (e.g., sea lamprey in the Great Lakes and the 

Chinese mitten crab (Eriocheir sinensis) in California). However, harvest enhancement is the 

only method likely to result in substantial lowering of Asian carp populations over the near term. 

Likewise, over the long term enhanced harvest is likely to be an important component of an 

integrated management approach to extirpate or reduce and maintain populations of Asian 

carps at levels of insignificant effect. It is the opinion of this Working Group that harvest 

enhancement should be a primary tool in the control of Asian carps. Natural resources 

managers need to continue to weigh the advantages and disadvantages of enhancing the 

harvest of Asian carps as information on the potential (and limitations) of this strategy becomes 

available. 

Federal and state agencies should promote commercial harvest of Asian carps. This requires 

development of markets for the harvested fish and, in the short or medium term, may require 

incentives for harvesters (Appendix 6.10). Harvest enhancement should be focused on bighead 

and silver carps because they are the most abundant of the Asian carps in the system (Barko et 

al. 2005), and because the less abundant grass carp already fetches a reasonably high price 

(Maher 2002, 2005). Harvest or market enhancement specifically for black carp is not likely to 

be productive because of the extremely low abundance of black carp in the wild in the United 

States. 

Recommendation 3.3.2.1. Evaluate gear and harvest method effectiveness, 

develop new gears if necessary, and provide information to commercial fishers. 

Determine harvest methods that are effective in habitats where Asian carps are 

abundant. If habitats that are heavily used by Asian carps are not fishable with 

traditionally used gears, investigate non–traditional gears and if necessary provide 

education to commercial fishers. Some of the methods developed under 

Recommendation 3.3.1.1 to assess carp populations may be useful for increasing 

harvest by commercial fishers. Federal, state, or university agencies should determine 

the methods used by the most successful commercial fishers and transfer this 

information to other fishers and between basins. 

Recommendation 3.3.2.2. Increase the number of commercial fishers. 

Commercial fishing in the Mississippi River Basin is a very small industry with few and a 

decreasing number of full-time experienced fishers (unpublished data, Rob Maher, 

Illinois Department of Natural Resources). Economic returns are low and fishing is a 

secondary source of income to most commercial fishers. If the value of landed Asian 

carps were to increase substantially, the number of fishers would be expected to 

increase and fishers could be expected to fish more. Nevertheless, there may be some 

lag time between the generation of a market and an increase in the number of 
 83

experienced fishers. Training and financial incentives might be provided directly to 

fishers by government agencies. Perhaps a more likely way to achieve this result would 

be the training, hiring, or contracting of fishers by processors and marketers. 

Recommendation 3.3.2.3. Examine commercial fishing regulations and consider 

changes to increase harvest. 

State agencies should examine commercial fishing regulations and consider changes to 

increase harvest of Asian carps, such as listing them as acceptable commercial species. 

The cost of licenses and other fees paid by commercial fishers should be examined to 

determine if modifications might encourage the harvest of Asian carps. One possibility 

might be to allow commercial harvest in areas that are currently off-limits to commercial 

fishing. However, prior to any regulation changes, the potential adverse effects on 

native species must be considered carefully. If necessary, gear types and seasons 

could be regulated in special areas to minimize adverse effects from opening new areas 

to commercial fishing. If the overall intensity of commercial fishing increases because of 

the advent of markets for Asian carps, it may be necessary to introduce regulations (for 

example, mesh size restrictions) that will minimize by-catch mortality of native species. 

Transportation of live wild-caught Asian carps should be prohibited except by permitted 

state and federal agencies or researchers. 

Recommendation 3.3.2.4. Provide financial incentives to commercial fishers to 

increase harvest of Asian carps. 

Increasing the economic return from fishing for Asian carps should increase harvest. 

This might be accomplished through subsidies, low interest loans, bounties, or contract 

fisheries (Appendix 6.10). However, the economics of the fishing industry in the 

Mississippi River Basin are not fully understood. 

Recommendation 3.3.2.5. Develop new markets for Asian carps. 

Federal or state agencies may need to provide low-interest loans or other fiscal 

inducements to speed the development of new markets for Asian carps (Appendix 6.10). 

New products must be developed and test-marketed. Development of new products and 

markets might be done by private industry without federal or state inducements, but 

these activities will proceed faster if beginning risks and expenses are mediated by 

government entities. Markets for Asian carps in the United States are currently few and 

limited to primarily ethnic markets, where live fish are preferred but dead fish are also 

sold. Private enterprise has already recognized the abundant population of Asian carps 

as a low-cost protein source, and several entities are investigating possible new outlets 

for these fish. Because these are start-up businesses, they are high-risk endeavors and 

may require large capital investments. However, development of markets for Asian 

carps will enhance the value of landed fish and provide impetus for increased 

commercial fishing effort. Markets for commercially harvested Asian carps should be 

based on a dead product and marketing of live wild-caught Asian carps should be 

prohibited (see Recommendation 3.1.16.1). 

State agencies are encouraging and working with private entities to investigate 

marketing of Asian carps. For example, the Missouri Department of Conservation has 

met with private corporations that have an interest in oils of bighead and silver carps, 

which are high in “good” cholesterol (Steffens et al. 1992) for the health food market and 
 84

in marketing Asian carps for pet food (personal communication, Brian Canaday, Missouri 

Department of Conservation). Dr. Lynn Hannaman of Louisiana State University is 

developing an inexpensive device that will more efficiently chop large carps into 

manageable pieces for use as crab and crawfish bait. Private businesses are testing 

new products and markets, but for proprietary reasons it is difficult to determine the 

status of these efforts. The Illinois Department of Commerce and Economic Opportunity 

awarded a grant to the City of Havana, Illinois, to assist in a feasibility study for various 

fish products processed from Asian carps. 

Recommendation 3.3.2.6. Determine contaminant concentrations in edible 

portions of feral Asian carps. 

Contaminant concentrations in the flesh of Asian carps must be determined. Business 

interests will likely not invest capital to develop markets for the fish without knowing the 

risk posed by contaminants. 

Contaminant concentrations generally are higher in fishes that are high on the food web, 

benthic, slow-growing, and long-lived (Schmitt et al. 1999). Bighead, silver, and grass 

carps grow quickly, feed low on the food chain, and are not primarily benthic (Kolar et al. 

2007), therefore they may not have high contaminant concentrations compared to other 

fishes in the same system. Nevertheless, there is substantial chemical contamination of 

some of the rivers inhabited by Asian carps. A preliminary study on contaminants in 

bighead and silver carps collected in the Illinois River and the middle Mississippi River 

has been completed recently (Rogowski et al. 2005). By their methods, none of the fish 

exceeded any advisory concentration for polychlorinated biphenyls (PCBs) or chlordane, 

and mean values for mercury fell well below the most conservative advisory 

concentration bracket. These data are encouraging, but further work is recommended. 

In areas where Asian carps may be found to contain high contaminant levels, some of 

the alternative market uses listed in Recommendation 3.3.2.5 may be appropriate. 

The Illinois Department of Natural Resources is funding further studies of contaminant 

concentrations in the flesh of bighead and silver carps in Illinois (personal 

communication, Steve Shults, Illinois Department of Natural Resources). The USGS will 

begin similar studies on fish collected from the lower and middle Missouri River in 2005 

(personal communication, Carl Orazio, USGS). 

Strategy 3.3.3. Increase recreational harvest of Asian carps. 

Commercial harvest of Asian carps is likely to be more important than recreational harvest for 

the foreseeable future. Bighead and silver carps are primarily filter feeders and grass carps 

primarily herbivores (Kolar et al. 2007). Thus, they are difficult to take on hook and line, which 

impedes recreational harvest, although some are taken by rod and reel fishers, both on baits 

and by snagging. Asian carps are often targeted by bowfishers (Figure 3.3.1) who often take 

hundreds of pounds of Asian carps from a single boat in a day. The surface feeding behavior of 

bighead carp (Figure 3.3.2; Kolar et al. 2007) makes them susceptible to bowfishers. However, 

bowfishing is unlikely to have a substantial effect on the population of Asian carps because of 

the limited number of bowfishers. A limited recreational fishery for Asian carps exists when and 

where snagging is legal, but this fishery is not likely to remove the large numbers of fish 

required for population control. Methods for taking Asian carps with baits have been developed 

in Europe and Asia (Barth 2004), but North American anglers do not generally target Asian 

carps and have not yet embraced these techniques. 
 85

 

Figure 3.3.1. Bowfishers can take large numbers 

of bighead carp. This catch represents one 

outing by four fishers; the total weight of the fish 

was estimated between two and three thousand 

pounds. Picture courtesy of Bowfishing 

Association of Iowa.

Nevertheless, additional harvest may be achieved by encouraging the use of Asian carps by 

recreational fishers. Asian carps are large, meaty fishes that are consumed avidly by 

consumers from Asian cultures, here and overseas. The flesh of Asian carps is considered by 

some to be high quality (Michaelson 1999; Stone et al. 2000; Chapman 2004). Although Asian 

carps have intramuscular bones that render the flesh undesirable to many North American 

recreational fishers, information on how to prepare the fish in ways that make the fish more 

acceptable is available (Chapman 2004). Harvest enhancement may be accomplished by 

angler education and by modification of regulations that might in some way hamper Asian carp 

harvest (e.g. harvest limits for non-game fishes). 

Although in the short term enhancement of recreational harvest is not likely to cause a 

substantial decrease in the population of Asian carps, there is potential that over the long term 

harvest may become considerable. Costs of these efforts are low and benefits to the public 

accrue from the potential for decreased Asian carp populations and from the benefits of 

capturing and consuming the fish. 

Recommendation 3.3.3.1. Examine recreational harvest regulations to eliminate 

barriers to recreational harvest of Asian carps. 

States should examine their recreational harvest regulations in relation to patterns of 

Asian carp harvest. For example, the State of Missouri removed a limit of 20 non-game 

fish per day (Missouri Wildlife Code, 3 CSR 10-6.550). Illinois will soon add Asian carps 

to the list of species legal for snagging and bowfishing (personal communication, Steve 

Shults, Illinois Department of Natural Resources). Bowfishing at night is illegal in some 

states, yet bowfishing of Asian carps is especially productive at night (personal 

communication, Ron Cannon, Bowfishing Association of America). If regulatory changes 

can increase recreational harvest of Asian carps without endangering native species, 

then this may result in a low-cost harvest enhancement. 

Recommendation 3.3.3.2. Inform recreational fishers about Asian carp harvest 

and preparation methods. 

Figure 3.3.2. Surface feeding behavior of 

bighead carp. Picture courtesy of Bowfishing 

Association of Iowa. 
 86

Provide information to recreational fishers on how to catch Asian carps and the culinary 

attributes of these fish. This could be enhanced by encouraging tournament-type events 

to increase recreational harvest. Establishing partnerships with chapters of the 

American Culinary Federation would encourage development of Asian carp recipes. A 

potential negative effect of this strategy is the possibility that some may eventually view 

these fishes as a beneficial species. Educational information for the public should 

include information on the positive environmental benefits of removing and consuming 

these species. 

Stakeholders representing a cross section of interests should work with partners to 

develop appropriate outreach products for recreational fishers to encourage Asian carp 

harvest, cleaning, preparation and consumption. Angling and bowfishing for Asian carps 

should be promoted, including angling techniques, equipment, baits, and tournaments 

throughout the geographic distribution of feral Asian carps. 

The Missouri Department of Conservation and the Illinois Department of Natural 

Resources have published articles describing techniques for catching and preparing 

Asian carps in their outreach publications (Perea 2002; Chapman 2004). The Native 

Fish Conservancy, together with bowfishing organizations and Bass Pro Shops, is 

organizing an Asian carp cook-off in central Missouri (personal communication, Robert 

Rice, Native Fish Conservancy). 

Strategy 3.3.4. Physical removal by natural resources management agencies. 

Natural resources management agencies, universities, and others regularly sample aquatic 

organisms and their habitats. Asian carps are collected as both targeted and non-targeted 

catch during fisheries surveys, silver carp frequently jump and land in work boats, and specific 

actions may be implemented to target Asian carps for removal from distinct locations. 

Recommendation 3.3.4.1. Biologists should physically remove Asian carps 

collected as a result of management actions or research. 

Natural resources management agencies, universities, and others should review policies 

and protocols regarding the collection and release of aquatic nuisance species. In most 

situations it is highly undesirable to release live Asian carps and other aquatic nuisance 

species back to the wild following capture, with the exception of certain research projects 

which require the release of live individuals for study results. Protocols are warranted for 

the constructive use or humane destruction and appropriate disposal of aquatic nuisance 

species collected as a result of management actions or research. 

Strategy 3.3.5. Consider stocking sterile Asian carp or monosex tetraploids to inhibit 

reproduction and recruitment of feral fish. 

The introduction of sterile males has been effective in the control of some species of insects 

(Meyer and Simpson 1994). Preliminary evidence of effective sea lamprey control in the Great 

Lakes through the release of sterile male lamprey (Twohey et al. 2003) suggests that releasing 

sterile fish may hold promise in the control of other nonnative fishes; however, little research 

has been conducted on this topic (Kapuscinski and Patronski 2005). 

 

Research is needed to explore the potential for release of sterile Asian carps as a control 

method (Kapuscinski and Patronski 2005), and is not currently recommended by the Working 
 87

Group. The reduction of a target species via the release of sterile fish requires achieving a high 

rate of sterile to fertile males (Kapuscinski and Patronski 2005). The presence of large numbers 

of sterile male Asian carps may only marginally interfere with spawning, even if the sterile males 

behave like fertile males. Because female Asian carps are attended during spawning by several 

males (Chang 1966, Jennings 1988), if only one of the attending males is fertile, fertilization of 

the eggs is likely. 

An alternative to the release of sterile males is the release of sex reversed, monosex, tetraploid 

(4n) males. Sex reversed, tetraploid males would interfere with the normal reproduction cycle of 

wild fish by fertilizing normal haploid (1N) wild eggs with diploid (2N) sperm thereby resulting in 

the production of only triploid (3N) sterile fish that can not continue to contribute gametes back 

into the wild population. Stocking of sex reversed, tetraploids males over an extended period 

could result in a substantial reduction of biomass of the targeted Asian carp species. 

This strategy requires further research into the development of tetraploid fish, confirmation that 

it leads to sterile triploid progeny, and modeling of the required stocking rate of tetraploid male 

fish. If the technology for tetraploid grass carp production is improved so that large numbers of 

viable tetraploid fish are available, then it would be prudent to produce models to determine if 

stocking sex-reversed Asian carps constitutes a viable control method. 

Recommendation 3.3.5.1. Examine the potential efficacy of introduction of 

monosex tetraploid fish as a control method. 

Private industry and academic institutions are likely to continue to work towards the 

development of viable tetraploid stocks of Asian carps to be used in the production of 

triploid fish (personal communication, Mike Freeze, Keo Fish Farms). If those efforts are 

successful, then the stocking of monosex tetraploid fish to control feral populations 

should be investigated and would require modeling to assess efficacy. 

Strategy 3.3.6. Research and apply transgenic manipulations (e.g., “Daughterless carp” 

and “Trojan gene” technologies). 

Genetic modifications (i.e., transfer of novel genetic constructs into the fish genome) that result 

in “transgenic” fish expressing a novel trait may be useful in controlling nonnative fish 

populations (Kapuscinski and Patronski 2005). The release of transgenic Asian carps bearing a 

deleterious gene would disrupt part of the fishes’ life cycle or biology. “Trojan gene” technology 

involves a transgenic fish with a novel construct that simultaneously confers one advantage, 

such as a mating advantage, that drives the transgene into the target population and one 

disadvantage, such as reduced offspring viability, that triggers a decline in the target population 

(Kapuscinski and Patronski 2005). Purposely releasing a transgenic fish expressing a 

deleterious gene for control of a nonnative fish is a relatively new idea and much research is still 

required. Kapuscinski and Patronski (2005) discuss 6 deleterious gene spread strategies 

(including strengths, weaknesses, and other considerations) for the control of nonnative fishes. 

One promising strategy involves spreading a transgene designed to alter a target population’s 

sex ratio. “Daughterless Carp” technology involves the use of a genetic modification to develop 

an all-male strain of fish. When these fish breed with “normal” fish of the same species, all the 

offspring are male. This trait is carried through subsequent generations until reproduction 

declines, or is finally eliminated, because of a lack of females in the population. A more detailed 

discussion of this technology is presented in Appendix 6.11. This technology could be an 
 88

elegant solution to any nuisance fish problem, but the technology is in its infancy and success is 

not ensured. 

Although no immediate actions toward development of daughterless Asian carps are 

recommended, this does not mean that the potential importance of this control technique is low. 

This strategy is perhaps the only strategy yet identified that might eventually extirpate Asian 

carps from the wild in the United States. However, this strategy requires an extremely long-term 

outlook, and the timing of actions and expenditures should be prudently paced. Depending on 

the rate of advancement of this technology, it is possible that efforts directed at Asian carps 

could begin within three to five years. 

Recommendation 3.3.6.1. Adapt “daughterless carp” genetic technology to Asian 

carps. 

Advancements in the research and implementation of daughterless carp technology 

should be monitored closely. When and if successes in population control of common 

carp are evident or seem likely, then efforts to adapt this technology to bighead, grass, 

and silver carps should be undertaken as a high priority. This will require research to 

understand sex determination in Asian carps. 

On-going research on daughterless common carp is underway in Australia 

(Commonwealth Scientific and Industrial Research Organization Marine Laboratories in 

Hobart, under the direction of Ron Thresher). Scientists transferred an aromatase 

blocker gene into zebrafish (Brachydanio rerio) and showed that significantly more 

males were produced than females. Laboratory studies are now concentrated on finding 

the best way to ensure the modified gene is passed on to offspring and developing a 

carp-specific modified gene. 

Strategy 3.3.7. Develop and apply pheromone baits to control Asian carps. 

Pheromones are odors or mixtures of odorous substances released by an individual that evoke 

a behavioral response in conspecifics or closely related species, requiring no prior experience 

or learning (Sorensen and Stacey 2004). The use of migratory and sex pheromones to control 

sea lampreys in the Great Lakes is currently under investigation (Li et al. 2003; Sorensen and 

Stacey 2004) and is in the field trial stage (personal communication, Gavin Christie, Great 

Lakes Fishery Commission). The use of pheromones has been proposed as a potential means 

for controlling other nuisance fishes such as common carp (Maniak et al. 2000; Sorensen and 

Stacey 2004). Sex or aggregation pheromones have potential for use as attractants or baits 

that can be used to enhance the capture of Asian carps. Pheromones have been implicated in 

the aggregation of juvenile common carp (Sisler 2005), but this research has not yet been 

performed with bighead, black, grass, or silver carps. If pheromones play a part in the observed 

long-distance spawning migrations of Asian carps or in the aggregation of the large schools of 

juveniles or adults, then Asian carp pheromones may eventually become useful management 

tools. 

Research in pheromone attractants has a high chance of producing positive results. However, 

this technology will require years of development before it is useful in the field. Use of this 

technology will likely require artificial synthesis of pheromones and release of those chemicals 

into the environment. Pheromones are natural chemicals that are unlikely to have adverse 

environmental effects, but permits must nevertheless be obtained and legal hurdles overcome. 
 89

It will be necessary to work closely with the USEPA to achieve the appropriate approvals. The 

use of pheromones in the control of sea lampreys should be an appropriate legal model. 

When pheromones are developed that may have field application, they will need to either be 

extracted from harvested Asian carps or synthesized in large quantities and then tested in the 

field. One difference between Asian carp and sea lamprey control with pheromones is that the 

Asian carps are a potentially marketable resource. This may make a difference in how and by 

whom the pheromones are applied. The most sensible approach may be to have commercial 

fishers use the chemicals instead of state or federal natural resources managers, or possibly 

managers and commercial fishers may work together. 

Recommendation 3.3.7.1. Sex pheromone research should continue with the goal 

of production and application of field-applicable technologies. 

Developing pheromone technologies for the control of Asian carps is a high priority. The 

USEPA and state agencies with similar mandates should work closely with researchers 

and those that would eventually apply the pheromones for removal operations so that 

the proper approvals can be obtained. 

 

The use of bighead and silver carp pheromones is currently being assessed by Edward 

Little at the USGS Columbia Environmental Research Center in Columbia, Missouri. To 

date, these studies have focused on the use of alarm pheromones. Alarm pheromones 

may be most useful as deterrents or to deny the use of certain zones to bighead and 

silver carps, but they will have limited application in population control. Dr. Little is now 

beginning research on sex pheromones of bighead and silver carps. 

Recommendation 3.3.7.2. Investigate aggregation pheromones for juvenile Asian 

carps. 

The existence and potential uses of aggregation pheromones for juvenile Asian carps 

should be investigated. If such pheromones exist, they would constitute useful bait for 

the capture of small carps before they mature. Evidence for the existence of 

aggregation pheromones for juvenile common carp has been shown (Sisler 2005), but 

this has not been investigated in Asian carps. 

Strategy 3.3.8. Develop and apply habitat and hydrological manipulations that favor 

native species over Asian carps or that might be useful in harvest enhancement. 

The manipulation of habitat has many potential uses to control Asian carps (Appendix 6.12). 

Most such applications and their potential adverse consequences are not fully understood. 

Nevertheless, agencies in control of public lands and waterways should strive to understand the 

effects of land and water use and habitat manipulations on Asian carps and native fishes and 

changes should be made where appropriate. 

Habitat manipulations to control Asian carps have the potential of undesired effects. For 

example, habitat conditions that favor native species may be similar to those preferred by Asian 

carps. Some native fishes will be adversely affected by migration barriers. The desirable and 

undesirable effects of habitat manipulations must be weighed before any such actions are 

taken, and the effects of habitat manipulation should be monitored to ensure that they are 

producing the desired results. A better understanding of the life history of Asian carps in the 
 90

United States, as outlined in Recommendation 3.3.1.1, is critical to devising most habitat 

manipulation strategies. 

Recommendation 3.3.8.1. Provide technical assistance and biological information 

to the USACE and participate in collaborative planning of habitat improvement 

projects (e.g., Navigation and Ecosystem Sustainability Program, Missouri River 

Mitigation Project, and other authorities). 

The USACE is involved in multimillion dollar habitat and species restoration projects in 

the Mississippi and Missouri river basins. The USFWS and state conservation agencies 

should participate throughout the preparation of these plans, under authority of the Fish 

and Wildlife Coordination Act, to develop habitats that are more beneficial for native 

species than for Asian carps. Specifically, containment and control of the expansion of 

feral Asian carp populations should be a critical issue in the development of USACE 

plans for mitigation of adverse effects of proposed navigation improvements. Those 

involved in mitigation activities should evaluate and monitor mitigation projects and 

large-scale habitat manipulations for effects on Asian carp populations. Habitat and 

hydrological manipulations that can be economically and efficiently used to control Asian 

carps or to enhance the ability of fishers to remove Asian carps should be investigated, 

and used where appropriate. The adverse effects of such habitat modifications on 

native species should also be evaluated and monitored. Adaptive management should 

be used in further applications of habitat manipulations for control of Asian carps. 

Strategy 3.3.9. Investigate the sensitivity of Asian carps to piscicides, and examine the 

feasibility of chemical Asian carp control in specific habitats. 

Piscicides have been applied to ponds, lakes, streams, and rivers to control nuisance fishes for 

decades (Dawson and Kolar 2003). The toxicity of many chemicals to bighead, grass, and 

silver carps has been examined (13 chemicals, 34 studies for bighead carp; 75 chemicals, 233 

studies for grass carp; 21 chemicals, 83 studies for silver carp; Pesticide Action Network 2005). 

Rotenone and antimycin are the only registered piscicides available to potentially control Asian 

carps in the United States without considerable additional expense. Rotenone and antimycin 

are both labeled for use in lakes and running waters (i.e., streams and rivers). The American 

Fisheries Society has published a manual for the use of rotenone in fisheries management 

(Finlayson et al. 2000). Research is needed to further investigate the effectiveness of 

registered piscicides to control Asian carps, evaluate their potential use in the control of feral 

populations, and to determine the potential of other chemicals to control Asian carps. 

Additional considerations in the use of piscicides to control feral Asian carps are presented in 

Appendix 6.13. 

Recommendation 3.3.9.1. Determine effectiveness of registered piscicides to 

control Asian carps. 

State, federal or university researchers should determine contact time required to kill 

bighead, black, grass, and silver carps using rotenone and antimycin under a variety of 

environmental conditions. The toxicity of rotenone and antimycin to black carp must be 

determined. 

Recommendation 3.3.9.2. Identify conditions where rotenone or antimycin could 

be used to control populations of Asian carps. 
 91

The feasibility of using rotenone or antimycin to target Asian carps in backwaters or 

intermittently connected wetlands should be examined. Treatment plans should be 

developed where warranted. Other areas with concentrations of juvenile Asian carps 

might also be identified where rotenone might be a useful tool. 

Recommendation 3.3.9.3. Determine potential of other chemicals to control Asian 

carps. 

Asian carps may be susceptible to chemicals not currently approved for piscicide use in 

the United States. A review of chemicals used in other countries to control fish 

populations has been completed (Dawson and Kolar 2003). Laboratory studies to 

determine toxicity rates, effectiveness on Asian carps, and effects on native species 

should be conducted for identified potential chemicals. Development of new piscicides 

is expensive; registration costs alone can exceed $5 million dollars (Dawson and Kolar 

2003). If effective chemicals are identified, formulations and application methods will 

need to be developed and environmental and human safety will need to be thoroughly 

investigated. 

Recommendation 3.3.9.4. Determine feasibility and applicability of piscicide bait 

deployment to control black and grass carps. 

In specific areas where black or grass carps are especially problematic, control using 

piscicide baits should be attempted. This will require research to develop and test baits 

specific for black or grass carps, and determine deployment methods that have limited 

affects on non-target organisms. 

Recommendation 3.3.9.5. Determine registration needs, if any, for the use of 

piscicides to control Asian carps, and ensure that piscicides are available for 

appropriate uses. 

The use of piscicides to control Asian carps may require unusual applications or new 

formulations (e.g., black carp bait). Changes to piscicide registrations may take time 

and be expensive. Federal dollars should be allocated, if necessary, to provide for any 

necessary registration changes. 

Strategy 3.3.10. Reduce populations of Asian carps through the introduction of 

biological controls such as disease agents, parasites, or predators. 

The use of biological controls is not recommended at this time as a strategy for controlling feral 

population of Asian carps. The introduction of nonnative biological controls such as disease 

agents, parasites, or predators to reduce or eliminate Asian carps is not likely to be fruitful and it 

is not recommended. There are no known diseases or parasites that are likely to effectively 

control Asian carps that are completely specific to Asian carps (Kolar et al. 2007). It is also 

unlikely that any predator could be found that would prey only on Asian carps. 

Stocking native predators (or otherwise enhancing their abundance) might reduce the 

recruitment of Asian carps, however little information is available on the susceptibility of Asian 

carps to native piscivores. The enhancement of native predators could result in unintended 

effects to native prey fishes that are already stressed and is not recommended until the potential 

effects of such actions are better understood. 
 92

Basic research on the early life history and ecology of feral Asian carps (Recommendation 

3.3.1.1) and diet studies of native piscivores are critical needs that will provide insights and the 

ability to form testable hypotheses regarding control of Asian carps using native predators. The 

enhancement of native predators to control feral Asian carps should be pursued only after 

necessary research has been completed and with caution to prevent unintended effects to 

native prey fishes. Predator enhancement applications are likely to be limited by the number of 

appropriate locations. 

Additional considerations for the use of disease agents, parasites, or predators as biological 

controls for feral Asian carps are provided in Appendix 6.14. 

Recommendation 3.3.10.1. Develop information on the factors that determine the 

efficacy of native predator enhancement to control Asian carps. 

The Department of the Interior and other natural resources management agencies 

should fund research into predator-prey relationships that affect Asian carps. Before 

beginning any artificial enhancement of predator densities or changes to species 

assemblages, the effects of enhancement must be well understood to avoid undesirable 

consequences or activities that are not cost-effective. This information is required for the 

biological control of Asian carps, assessing the risk of Asian carp establishment in new 

environments, and providing insights into habitat modifications that would make Asian 

carps more susceptible to native piscivores. An example might be in floodplain scours 

or backwaters inhabited by many juvenile Asian carps where predators are not abundant 

(perhaps limited by recruitment or physical access). Basic research on the early life 

history and ecology of feral Asian carps (Recommendation 3.3.1.1) and diet studies of 

native piscivores are critical needs that will provide insights and the ability to form 

testable hypotheses regarding control of Asian carps using native predators. 

States and federal agencies should determine locations and timing where predator 

enhancement would be beneficial and cost-effective, and implement predator 

enhancement through stocking or other appropriate methods (predator harvest 

restrictions, habitat manipulations) only after adequate research has been completed to 

accurately understand predator-prey interactions and to predict results of such 

management actions on a case-by-case basis. 
 93

Goal 3.4. Minimize potential adverse effects of feral bighead, 

black, grass, and silver carps in the United States. 

The adverse effects of Asian carps are poorly understood, however reducing the abundance of 

feral populations is likely to benefit native species and systems. Additionally, once effects are 

accurately determined, it may be possible to further minimize the undesirable effects of Asian 

carps by direct remediation of the effect. For example, if native fish populations are adversely 

affected, it may be possible to ameliorate these effects through direct stocking or other methods 

of population enhancement. It should be recognized that such efforts treat the symptoms of the 

problem rather than removing the causative agent, nevertheless such strategies may be 

advisable if the populations of key or threatened species are affected. 

Undesirable effects of Asian carps that have been established can be mediated in ways other 

than reducing their populations. The jumping behavior of silver carp constitutes a new and 

serious threat to boaters and other recreationists. Severe personal injuries and damage to 

boats and equipment have occurred. Precautions can be taken to ameliorate this threat, but 

because this danger is new, many boaters are not aware of the threat and do not understand 

what precautions to take. Information programs to alert boaters and recreationists are required. 

Strategy 3.4.1. Enhance organisms adversely affected by Asian carps. 

Specific long-term effects of Asian carps on native species are largely unknown. Undesired 

effects to some populations such as reduced numbers or even extirpation are possible, and may 

be mitigated directly. Potential actions to minimize these possible adverse effects include: 

enhancing critical habitats and ecosystem functions, removing animals from the wild to serve as 

captive broodstock, stocking individuals cultured at hatcheries, and physically protecting species 

such as mollusks from black carp by using enclosures. Populations of species most likely to be 

affected should be routinely monitored. 

Recommendation 3.4.1.1. Monitor populations of species most likely to be 

affected by Asian carps. 

Monitor populations of sensitive native species to determine actual and potential 

reductions in their abundance when they are in the presence of Asian carps, and 

determine whether or not there is a need for proactive management actions to prevent 

further decline or extirpation. 

Recommendation 3.4.1.2. Restore or supplement numbers of native species 

through direct release (i.e., stocking). 

If populations of fish or other organisms are reduced or extirpated through the activities 

or presence of Asian carps, then the affected species might be cultured and released in 

affected areas to enhance these populations. In fishes, this would be most effective if 

the affected life stage was a larval or juvenile form, in which fish larger than the affected 

life stage could be stocked. If black carp populations increase and are found to prey on 

native mussels, it may be necessary to expand on-going efforts to propagate such 

mussels to a size above which most predation occurs and to stock cultured mussels into 

the wild to maintain stocks of native species. If adult life stages are adversely affected 

through competition (e.g., native filter feeders, such as paddlefish), then such efforts 

would not likely be effective because the stocked fish would suffer the same effects as 
 94

naturally recruited fish. Stocking fish, mussels, or other organisms is expensive, does 

not solve the problem, and potentially may create other problems. Complex questions 

involving such issues as genetic concerns and funding must be addressed before 

stocking plans are developed for fish or other aquatic organisms. Stocking programs 

should be developed as part of a comprehensive program designed to address the 

specific problems that are causing reduced populations of desired species. 

Recommendation 3.4.1.3. Protect or restore native species through methods 

other than stocking. 

Where possible, federal, state, and university researchers should accurately determine 

effects of Asian carps on the environment and undertake mitigation efforts where 

appropriate and feasible. Ongoing studies of the life history and effects of Asian carps 

may provide new methods to minimize the effects of Asian carps on native species. 

Actions may include: translocating mussels to uninfested watersheds or upstream of 

natural barriers, collection of wild individuals to serve as captive broodstock for perilously 

endangered animals, or using physical barriers to protect mussel beds from black carp. 

Another example might be to implant vegetation substitutes or construct grass carp 

exclusions in areas denuded by grass carp. 

Strategy 3.4.2. Minimize damage to waterway users that results from silver carp. 

Silver carp leap from the water when startled. 

Because watercrafts elicit this behavioral response in 

silver carp, these fish often jump into boats and 

cause damage to boaters and equipment (Figure 

3.4.1). Although the speed and weight of the fish is 

sufficient to cause injury, fish that jump into rapidly 

moving boats have the additive effect of boat speed. 

These effects can be devastating and create a new 

source of danger for boaters in the United States 

where these fish are introduced. Informing boaters is 

necessary to acquaint them to this threat and to 

provide recommendations on how to protect 

themselves. 

Boaters can lower the possibility of being hurt or 

having their equipment damaged by jumping silver 

carp by understanding where these fish are most 

likely to be found (primarily low-velocity waters), by 

not following other boats because silver carp tend to 

jump behind boats, and by not waterskiing in silver carp habitat. Other things that can be done 

to minimize problems with jumping silver carp are the construction of guards that deflect silver 

carp from the boaters, or, very importantly, from the boat throttle. The throttle mechanism on 

small boats is often located on the gunwale where it is easily struck by jumping silver carp. 

When silver carp strike the throttle of a boat, the boat can respond violently and dangerously. 

Recommendation 3.4.2.1. Inform and train boaters to avoid damage from jumping 

silver carp. 

Figure 3.4.1. Boater reacting to silver 

carp jumping into boat. Picture courtesy 

of Brian Johnson, U.S. Army Corps of 

Engineers.
 95

Informing boaters on the danger of jumping silver carp and how to avoid injuries and 

equipment damage should be a high priority. Education and information programs 

should be undertaken by both state and federal agencies, including state water patrols, 

Coast Guard Auxiliary, conservation agencies, USACE, USFWS, the National Park 

Service, and others. The boating industry should be directly involved in the development 

and dissemination of materials and programs to inform and train boaters. Information on 

this new hazard to boaters should be included in boating safety publications of states 

with silver carp, and included in other types of public outreach. 

The Missouri Department of Conservation has released a press bulletin with information 

on how to avoid silver carp strikes, and included similar information on the television 

show “Missouri Outdoors”. Also, several media outlets (Doyle 2005; Cleveland 2005) 

have provided information to boaters on how to avoid silver carp strikes. 
 96

Goal 3.5. Provide information to the public, commercial 

entities, and government agencies to improve 

effective management and control of bighead, 

black, grass, and silver carps in the United States. 

There is a need to develop accurate science-based information concerning Asian carps and to 

develop an effective, nationally coordinated educational initiative that provides this information 

to diverse audiences. An effective education and outreach initiative will provide specific 

audiences with the information necessary to take actions and adopt practices that prevent 

accidental and deliberate unauthorized releases of Asian carps; and contain, reduce, and 

minimize adverse effects of feral Asian carp populations. A long-term education and outreach 

program is warranted to accomplish these objectives. This initiative must be dynamic to reach 

and effect desired results on the diverse audiences associated with Asian carps. The 

identification of needs and the development of information and education materials and 

programs should be a stakeholder participatory process that is led by the ANS Task Force or an 

implementation committee (Recommendation 3.7.1.1). The Working Group suggested that the 

ANS Task Force would be an appropriate organization to lead the coordination and 

implementation of this comprehensive national education and outreach initiative. 

For greatest effectiveness, each component of the education and outreach program should be 

monitored, evaluated, and managed adaptively to ensure that objectives are being met. 

Strategy 3.5.1. Understand the specific information needs and the most effective 

approaches to reach and affect desired results with each key audience. 

The Working Group identified potential key audiences that should be engaged in a 

comprehensive education and outreach initiative (Table 3.5.1). Although the Working Group’s 

knowledge regarding the education and outreach needs of some key target audiences is 

considered adequate, others are only poorly to partially understood (Table 3.5.2). Some 

information that is likely relevant to each audience can be developed immediately and with 

comparatively minimal effort. However, considerable work is needed to fully understand the 

education and outreach needs of many key audiences. 

Recommendation 3.5.1.1. Engage potential key audiences in the development of a 

comprehensive education and outreach program. 

The key audiences must be engaged and an understanding developed of how each 

audience can help to accomplish the goals of this plan. This understanding of each key 

audience is necessary to fully develop a comprehensive and effective education and 

outreach program. In addressing the education and outreach needs of each key 

audience it is essential to address the following: identify specific needs for information 

and education; identify the most effective approaches to reach and affect desired 

changes in each audience; gather and validate the credibility of materials; become both 

partners and leaders in planning, implementing, and evaluating; and identify gaps in 

knowledge or needs that can be addressed by applied or adaptive research. 
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Table 3.5.1. List of potential key target groups for which education and outreach needs are 

identified within this plan or need further assessment. 

Academia and Research Community 

Local extension offices 

Schools / Students 

Universities 

Commercial and Recreational Baitfish Harvesters 

Commercial Fishers 

Community Groups 

Angler groups 

Community organizations 

Divers 

Lake associations 

Local extension offices 

Consumers 

Food consumers 

Recreational and farm pond owners 

Marketers 

Fish farms 

Live haulers 

Retail sales (grocers and pond stockings) 

Wholesalers 

Natural Resources Management Agencies/Organizations 

Great Lakes Fishery Commission 

International Joint Commission 

Land Grant institutions 

Local municipalities 

Mississippi Interstate Cooperative Resource Association 

National Park Service 

Regional Aquatic Nuisance Species Panels 

Sea Grant institutions 

State Commerce agencies 

State DNR/DEC/DEP/AGR agencies 

State/County DOT agencies 

Tribal Natural Resources Management agencies 

U.S. Army Corps of Engineers 

U.S. Department of Agriculture 

U.S. Environmental Protection Agency 

U.S. Fish and Wildlife Service 

U.S. Geological Survey 

U.S. Department of Transportation 

U.S. Forest Service 
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Table 3.5.1. Continued. 

Pet Trade Industry 

Aquarium and water garden owners and hobbyists 

 Internet trade 

 Retail store owners 

Wholesalers 

Producers and Growers 

Grow-Out facilities 

Hatcheries 

Recreational Anglers and Boaters 

Boating and sailing clubs 

Large- and small-scale bait/tackle shops 

Marinas 

Transporters 

 Consumers 

Fish farms 

Live haulers 

Retail sales

Wholesalers 
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Table 3.5.2. The Asian Carp Working Group’s understanding of the education and outreach 

needs for potential key target groups.

Target Groups Understanding of Needs 

Academia and Research Communities Adequately Understood 

Commercial Fishers Adequately Understood 

Commercial and Recreational Baitfish Harvesters Adequately Understood 

Natural Resources Management Agencies/Organizations Adequately Understood 

Recreational Anglers and Boaters Adequately Understood 

Community Groups Partially Understood 

Pet Trade Industry Partially Understood 

Producers and Growers Partially Understood 

Transporters Partially Understood 

Consumers Poorly Understood 

Marketers Poorly Understood 
 100

Strategy 3.5.2. Prepare science-based materials based on key audience needs that can 

be used to develop curricula for effective education and outreach programs. 

A series of “informational modules” are recommended for the specific issues that are identified 

as critical to an educational and outreach effort. Specific education and outreach needs 

identified within other sections of the plan are listed in Appendix 6.15. 

Recommendation 3.5.2.1. Develop an information module that defines and 

describes Asian carps, efforts to contain and reduce feral populations, and 

sources from which to learn more about these fishes. 

Articles on Asian carps are presented frequently in the popular media, thereby 

introducing the issue of Asian carps to the general public. An information module is 

needed that provides accurate information on general issues relevant to Asian carps. 

These materials should include answers to some of the most general questions such as 

what are Asian carps, how did they get here, what is being done to contain and reduce 

feral populations, and how additional, accurate information about Asian carps can be 

obtained. 

Many fact sheets have been developed already. Stakeholders representing a cross 

section of interests should work together to identify and evaluate existing materials, and 

to develop new materials for use in this information module. New materials need to be 

developed to provide a complete source of accurate information on these and other 

topics identified for a general information module. This module should serve as an 

introduction to anyone looking for accurate information on Asian carps and connect 

users to additional modules for more detailed information on the management and 

control of these fishes. The module could also be used for environmental education 

programs. 

Once developed national media outlets such as news programs, media journalists, and 

educational television to provide nation-wide attention and accurate information 

regarding Asian carps. The support of well known celebrities associated with natural 

resources and angling (e.g., Bill Dance) to cooperate in these efforts. 

Recommendation 3.5.2.2. Develop an information module on the United States’ 

Asian carp industry, size, scope, economics, and current farming practices. 

Accurate information on the history, size, scope, economics, and current farming 

practices with Asian carps in the United States is needed to develop credible education 

and outreach materials. Stakeholders representing a cross section of interests should 

work together to identify and evaluate existing materials, and to develop new materials 

for use in this information module. New materials need to be developed to provide a 

complete source of accurate information on these topics. These materials may be 

PowerPoint presentations, videos, fact sheets, and postings on web sites. 

In many instances, an unproductive atmosphere between fish farmers and natural 

resources managers has developed because of mistrust and a lack of accurate 

information concerning farm practices. Accurate information and understanding by all 

parties are needed to forge productive partnerships. Accurate information on farming 

practices and site selection for fish farms is needed. There is a need for information on 
 101

management of static ponds, their location with respect to natural waterways, levee 

elevations with respect to potential flooding levels, and water management on fish farms. 

Currently, much information is available on proper siting, management, and construction 

of fish farms. Much of this information is available from land-grant university 

Cooperative Extension programs and from state permitting authorities. The recent 

USEPA final rule for aquaculture effluents addresses new federal requirements for 

discharge permits (USEPA 2004). This rulemaking process also included survey 

information from regulated fish farms that may be relevant to this activity (USEPA rule 

web site: www.epa.gov/fedrgstr/EPA-WATER/2004/August/Day-23/w15530.htm). This 

information should be reviewed and summaries included in the information module for 

those unfamiliar with aquaculture practices. 

The following educational materials are already available on current farming practices of 

carp in the United States: 

• Fact sheets on the economics of raising bighead carp in mono and co-culture with 

channel catfish (Arkansas) 

• Fact sheets on bighead carp production 

• Fact sheets on the use of grass carp 

• Fact sheets on the trematode infestations in catfish ponds 

• Information on aquatic vegetation control 

• Educational information on transporting warmwater fish 

Recommendation 3.5.2.3. Develop an information module on potential effects of 

Asian carps and reasons to contain and reduce their feral populations. 

Concern over the potential effects of increasing numbers of Asian carps has grown. 

Much of this concern stems from media materials highlighting the jumping abilities of 

silver carp, which can literally impact anglers and boaters. In addition to the potential 

harm to boaters, the public may not be familiar with the potential environmental effects of 

Asian carp. Species and habitat interactions make it very difficult to predict ecological 

effects when a new species is introduced into a new water body. Scientifically valid 

information on the effects of Asian carps in natural aquatic ecosystems is needed. 

Much information exists and can be disseminated to a greater extent. Sources such as 

the Foreign Nonindigenous Carps and Minnows in the United States - a guide to their 

identification, distribution, and biology (Schofield et al. 2005); Black Carp: Biological 

Synopsis and Risk Assessment of an Introduced Fish (Nico et al. 2005); Managing 

Aquatic Vegetation with Grass Carp (Cassani 1996); the USGS Non-Indigenous Aquatic 

Species website (http://nas.er.usgs.gov/taxgroup/fish/default.asp); and various other 

publications are available. It is important that this information reaches the general 

public, governmental natural resources management programs, and aquaculture-related 

groups, such as, producers, sellers, and transporters so that an understanding of effects 

is realized. 

It is also crucial to inform the public of the potential adverse consequences associated 

with the release of unwanted fish. Aquarium and water gardens, sport or commercially 

captured fish, stocked fish (e.g., farm ponds), and fish purchased live in food markets 

are some of the potential sources of unwanted releases. Materials such as instructions 

on the proper disposal of unused bait fish, environmentally safe procedures for draining 
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farm ponds, and guidance on how to dispose of unwanted live fish need to be made 

broadly available to the public. 

Recommendation 3.5.2.4. Develop an information module on the identification of 

all life stages of Asian carps. 

The need for a module on the identification of all life stages for each of the four species 

of Asian carps has been identified for several target audiences including live haulers 

(wholesale and distributors), retail markets, food fish consumers, pond owners, natural 

resources managers, commercial fishers, recreational anglers, live baitfish dealers and 

wholesalers, aquarium owners, and the general public. The ability of these stakeholders 

to correctly identify Asian carps is important in the prevention of accidental and 

deliberate unauthorized releases, as well as a critical component for early detection and 

rapid response efforts. 

Currently, several educational materials are available for the identification of bighead 

and silver carps. Bighead and silver carp WATCH cards and posters are being 

distributed by the Illinois-Indiana Sea Grant, the USFWS, and several states. The cards 

identify adult fishes only, while the larger 11” x 17” posters have pictures of adult 

bighead and silver carps and compare juvenile bighead and silver carps with native 

gizzard shad. The Mississippi River Basin Regional Panel of the ANS Task Force has 

posted a key to the identification of adult Asian carps on the Internet 

(http://www.asiancarp.org/Key/asiancarp%20key.pdf) and the USGS has recently 

published Foreign Nonindigenous Carps and Minnows (Cyprinidae) in the United States 

– A Guide to their Identification, Distribution, and Biology. 

Several obstacles exist for this recommendation. Reaching individuals within identified 

target audiences may be difficult due to the diversity of these groups. Second, there is a 

lack of information for identifying juvenile stages of bighead and silver carps. Many 

target groups handle small bighead and silver carps, which are difficult to identify and 

distinguish from other species. Despite these obstacles, this is a high priority so that 

field personnel, the general public, and others included in this group can effectively 

begin and/or improve the accuracy of the early detection process. There should also be 

a long-term process of updating the module and materials.

Recommendation 3.5.2.5. Develop an information module on why and how to 

report sightings of Asian carps. 

Agency field personnel cannot monitor all waters for the presence of Asian carps. This 

task can be more efficiently achieved by recruiting the interested public to help monitor 

and aid in the early detection of high priority aquatic nuisance species. Materials and 

training are needed to inform the public about the importance of reporting sightings, 

species identification, appropriate contact information, and their role as volunteer 

monitors. 

Timely reporting by the public can assist natural resources managers in tracking the 

introduction and spread of Asian carps. Early detection and tracking of Asian carp 

migration and the monitoring of established populations will improve opportunities for 

rapid responders to successfully plan and implement control interventions or eradication 

measures. This may be especially beneficial near dispersal barriers and other waters of 
 103

particular concern. Public assistance with the monitoring of Asian carps is critical for 

successful management. 

There are several resources currently available for use in identification and reporting of 

sightings or catches. Bighead and silver carp WATCH cards and posters that contain 

Asian carp identification and contact information are being distributed by the Illinois – 

Indiana Sea Grant, the USFWS, and several states. Fishing guide booklets from the 

State of Illinois and the Fishing Chicago Program contain information on how to identify 

bighead and silver carps, why they could be harmful to our natural resources, and how 

to report a sighting. Agency websites such as Alabama Department of Conservation 

and Natural Resources, Illinois Department of Natural Resources, Iowa Department of 

Natural Resources, USGS, and USFWS have information on why and how to report 

Asian carp sightings. Some of these websites contain information on all four species. 

There are several obstacles to fulfill this recommendation. These include securing funds 

for materials and distribution, coordinating the contact information to report sightings, 

and determining whether materials will be issued by states, federal entities, or a regional 

association, such as one of the Regional Panels of the ANS Task Force. 

Recommendation 3.5.2.6. Develop an information module on Hazard Analysis and 

Critical Control Point planning procedures. 

There is a need to distribute broadly a general description of the Hazard Analysis and 

Critical Control Point (HACCP) planning process and to provide guidance for more 

detailed information and points of contact for receiving training from the Sea Grant 

network or the USFWS. Knowledge of HACCP principles can help prevent accidental 

introductions. 

An information module on HACCP principles has been identified for several target 

audiences including producers, growers, livehaulers (wholesale and distributors), retail 

markets, food fish consumers, natural resources managers, wild baitfish collectors, 

commercial anglers, recreational anglers, aquarium owners, and the general public. The 

ability of these stakeholders to correctly identify Asian carps is important in the 

prevention of unauthorized releases, and a critical component for early detection and 

rapid response efforts. 

 

Sea Grant network conducts numerous Aquatic Nuisance Species- HACCP trainings 

throughout the country and has a recently updated manual, CD-ROM, and video that 

already incorporates Asian carps. USFWS conducts HACCP trainings in each of its 

seven regions. The USFWS Region 2 maintains the HACCP website (www.HACCPNRM.org) which provides sample plans, the updated USFWS HACCP manual, a 

downloadable HACCP planning wizard, educational materials, and training 

announcements. The “Stop Aquatic Hitchhikers!” campaign describes general steps to 

remove nuisance plants and animals from recreational equipment. Although this is not a 

HACCP process, it may be more applicable for certain audiences within this group 

including recreational anglers and the general public who are less likely to employ an 

actual “HACCP“ plan. 

Because HACCP implementation is not the only means to affect management controls 

at critical points to prevent spread of nuisance species, alternative management 

activities should also be recognized. This general information is not to be construed as 
 104

mandatory for implementation of HACCP plans, especially among those industries which 

already address these pathways by other means. Rather, this should be used as an 

opportunity to distribute additional information as needed, or to assist in modifications to 

existing facility plans. Some industry segments may wish to pursue pathway 

management approaches such as following management practices recommended by 

the Extension Service or develop Best Management Practices with input from industry 

groups. Regardless of the method employed, documentation of management actions, 

and the process followed to evaluate and develop those actions should be maintained 

and periodically reviewed. It will be necessary to promote the importance and value of 

HACCP planning, especially for audiences that are not familiar with the program and 

who may be less than enthusiastic to adopt these principles. 

Recommendation 3.5.2.7. Develop an information module on the construction and 

maintenance of effective spillway barriers to reduce the risk of escape of Asian 

carps from private impoundments. 

Develop an information module and appropriate outreach products for recreational pond 

owners and commercial aquaculture producers to encourage the construction and 

maintenance of spillway barriers where Asian carps are being held. During heavy rain 

events, spillways may allow fish to move out of a pond. Appropriate measures must be 

taken to assure fish remain contained within designated target areas. However, 

recreational pond owners and commercial aquaculture producers have differing uses for 

these fish and therefore the educational programs designed will need to be specific to 

each group. 

Recommendation 3.5.2.8. Develop an information module to provide general 

information about regulations related to Asian carps. 

Stakeholders representing a cross section of interests should work with audiences 

identified in this recommendation to identify obstacles to communicating regulatory 

information that will result in a reduced risk of accidental and deliberate unauthorized 

Asian carp handling, possession, sale or release. Asian carp regulations vary from 

state-to-state, or city-to-city, as well as between and within states. There is widespread 

confusion and lack of up-to-date information. States advertise rule changes through 

administrative publications and/or news releases that are of limited distribution. A small 

number of outdoor writers publish articles sporadically in regional or local newspapers. 

These announcements are not always noticed by the general public or may blend in with 

other news items. Effective communication will be challenging because of competing 

stories in the media and a sense of information overload by the public in the United 

States media. 
 105

Goal 3.6. Conduct research to provide accurate and 

scientifically valid information necessary for the 

effective management and control of bighead, 

black, grass, and silver carps in the United States.

Natural resources managers need scientifically valid information to effectively manage and 

control Asian carps. Some Asian carps currently have valued applications in aquaculture, lake 

and recreational pond management, and are in demand as a food source (human and animal); 

therefore, research efforts need to develop improved methods for the safe use of these species, 

or derive ecologically and economically safe alternatives. The Working Group agreed that 

identifying viable alternatives to black carp for snail control in aquaculture ponds is the highest 

research priority. 

Research is needed to determine the distribution and abundance of populations; develop 

methods to contain Asian carps with minimal effects on native fishes; develop an effective 

control program that does not adversely affect native species and their habitats; and to develop 

ecological models that predict accurately where Asian carps will become established, and the 

nature of their ecological interactions within aquatic food webs. Additional research is needed 

to quantify ecological and economic effects of Asian carps and to develop methods that 

minimize the adverse effects of populations, or individuals in the case of black carp. To answer 

these questions with scientifically sound information, targeted research is needed in six broad 

areas: 1) fundamental biology and life history, 2) development of effective sampling gears and 

monitoring methods, 3) development of effective containment methods, 4) development of an 

integrated management strategy to extirpate or reduce abundance of feral Asian carps, 5) 

assessment of ecological and economic effects of current and potential Asian carp populations, 

and 6) development of economically viable and environmentally safe alternatives to use of 

Asian carps. 

A fundamental understanding of Asian carp biology and life history requirements in waters of the 

United States underpins nearly all other areas of potential research in the development of 

management options to control these species. Concurrent development of effective sampling 

gears and physical, chemical, or biological controls is required to estimate reliably the 

abundance of Asian carp species and the potential for reducing or preferably eliminating feral 

populations. The ecological and economic effects of introductions of Asian carps need to be 

quantified and accurate, predictive models developed to provide managers, stakeholders, and 

the general public with accurate information concerning the effects of introductions. 

Many research recommendations have been identified in previous sections of this plan and are 

listed in Appendix 6.16. Where appropriate, recommendations listed here only summarize the 

detailed narratives and justifications in these earlier sections. 

Strategy 3.6.1. Develop effective sampling gears and monitoring methods for all life 

stages of Asian carps in both standing and flowing water environments. 

Development of scientifically sound and cost-effective sampling methods is essential to all 

aspects of management, control, and research of Asian carps. Sampling techniques are 

needed that provide natural resources managers with a high level of confidence (i.e., statistically 

meaningful) in the information collected about feral populations of Asian carps. Methodologies 

need to be evaluated to understand how well samples represent the entire population (i.e., 
 106

accuracy), how repeatable the sampling results are (i.e., precision), and to understand biases 

associated with the collected data. 

Recommendation 3.6.1.1. Develop and evaluate effective methods for sampling 

feral populations of Asian carps. 

Conventional sampling methods have not been effective for determining the distribution 

and abundance of Asian carps (Stancill 2003). Sampling methods and protocols 

effective for detecting new introductions or range expansions of Asian carps are critically 

needed (see Recommendation 3.2.4.3). Effective management requires reliable 

estimates of Asian carp abundance to track populations over time, and to target and 

evaluate control efforts. Gear evaluation studies must be conducted under a variety of 

habitats, seasons, and environmental conditions to ensure gear accurately reflect the 

actual abundance and size distributions of these populations (Hayes et al. 1996). 

Strategy 3.6.2. Assemble information about the distribution, biology, life history, and 

population dynamics of bighead, black, grass, and silver carps. 

Fundamental biological and life history information provides the foundation to manage fish 

populations and is essential to several goals of this management plan. General information of 

the life history and distribution of all four species were described by Fuller et al. (1999). 

Comprehensive biological synopses have been completed for each of these species (Shireman 

and Smith 1983; Cassani 1996; Kolar et al. 2007; Nico et al. 2005), however, relatively little 

research has been completed on the biology and life history of feral Asian carps in river systems 

of the United States. Management-oriented strategies and procedures based on research are 

needed to effectively prevent accidental and deliberate unauthorized introductions, contain and 

control populations, reduce population abundances, and minimize potential adverse effects. 

Michael Hoff, Andy Starostka (USFWS); Duane Chapman, Cindy Kolar, Diana Papoulias 

(USGS); John Dettmers (Great Lakes Fishery Commission); John Chick (Illinois Natural History 

Survey); Mark Pegg (University of Nebraska); and Valerie Barko (Missouri Department of 

Conservation) are some of the scientists currently involved in investigating life history and 

population dynamics of Asian carps in the Mississippi River Basin. 

Recommendation 3.6.2.1. Describe current and temporal changes in distribution 

to better understand the invasion and colonization process. 

Understanding the distribution and spread of bighead, black, grass, and silver carps in 

the United States is essential to developing targeted control strategies for these species. 

Watersheds currently uninhabited by each Asian carp species need to be identified so 

efforts to prevent expansions into these areas can be prioritized. Although some field 

studies on distribution are underway, generally they are of limited scope and will not 

provide all information needed. Assessments of the biotic and abiotic factors that 

contribute to the distribution and abundance of feral Asian carps in different watersheds 

are needed. Unpublished results in agency and university reports are often difficult to 

locate or obtain and conclusions based on them should be considered as tentative until 

supported by peer-reviewed materials. Mapping the current distributions of each Asian 

carp species requires focused effort to collate previously reported sightings and to 

initiate specific research studies in vulnerable watersheds. Accomplishing this task will 

require coordinated efforts by federal, state, tribal, and provincial agencies; universities; 

and commercial fishers to compile recent maps that will provide the requisite data to 
 107

analyze and understand the invasion and colonization processes. Knowledge of past 

routes of invasion and rates of colonization by each species can provide insights to 

prevent further spread. This task is also dependant upon the development of effective 

sampling methods (Recommendation 3.6.2.1). 

Recommendation 3.6.2.2. Describe movements and distribution of Asian carps in 

waters of the United States (e.g., habitat preference, habitat selection, and 

habitats used). 

Understanding habitat use and preferences for these species is essential to developing 

targeted control strategies. Information about distribution, probable natural limits to 

range expansion (e.g., temperature, latitude, etc.), and the effects of nuisance 

populations (e.g., trophic interactions and competition) are required to refine predictions 

about potential interactions of Asian carps with native aquatic species. Delineation of 

habitat use for all life stages of Asian carps may identify vulnerable points in each 

species life cycle where population control or eradication is feasible. 

Recommendation 3.6.2.3. Describe diets, evaluate food selection and availability, 

estimate food consumption, and assess feeding interactions (i.e., predation and 

competition) with native biota (trophic ecology). 

Understanding food webs, especially at lower trophic levels is necessary to evaluate 

competition and to predict effects on aquatic biota and ecosystems. Food consumption 

patterns are well documented for grass carp (Cassani 1996) and food consumption 

research is ongoing for black carp. When combined with information about diet, food 

selection and availability, habitat selection, food consumption estimates based on 

bioenergetics models should allow reliable predictions of dietary and other ecological 

interactions between Asian carps and native fishes. Development of bioenergetics 

models requires fundamental research on consumption rates, thermal tolerances, and 

metabolism of Asian carps (Recommendation 3.6.1.4). Once developed, bioenergetics 

models provide managers and researchers with a powerful tool to study energy flow in 

ecosystems, predator-prey interactions, habitat quality, and the bioaccumulation of toxic 

chemicals (Hansen et al. 1993). 

Recommendation 3.6.2.4. Assess ecologically important aspects of physiology 

and behavior such as environmental tolerances, endocrine functions, and sensory 

capabilities. 

This recommendation provides a foundation to predict abundance, distribution, and 

routes of dispersion. Physiological and behavioral information will provide the basis for 

other important research topics, such as developing attractants, repellants, and barriers 

or predicting interactions with other species through predation or competition.

Recommendation 3.6.2.5. Estimate key population variables such as mortality, 

emigration and immigration, growth rates, fecundity, and stock-recruitment 

relations for population modeling. 

Effects of Asian carps and the degree to which the effects are negative will depend upon 

their population sizes (i.e., number of individuals or biomass). Population growth and 

size can be predicted with models (Quinn and Deriso 1999) that require accurate input 

about vital population rates (mortality, emigration and immigration, growth, and 
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reproduction) and stock-recruitment relationships. Estimating growth rates will first 

require developing age assessment procedures (DeVries and Frie 1996) that are valid 

for long-lived fishes throughout broad climatic ranges.

Strategy 3.6.3. Develop effective methods to contain feral Asian carp populations and 

prevent their further spread.

The need for effective barriers to prevent the continued spread of Asian carps into uninhabited 

waters is a high priority and requires more complete biological and physiological information 

about these fishes (Recommendation 3.6.1.4). 

Recommendation 3.6.3.1. Develop effective physical and behavioral barriers for 

controlling the movement of Asian carps. 

In addition to evaluating existing technologies (Recommendation 3.2.1.2), research is 

needed to explore innovative methods to contain feral Asian carp populations and 

prevent their further spread. 

Strategy 3.6.4. Develop an integrated management strategy to extirpate or reduce 

abundances of feral Asian carps.

To control distribution and, where possible, reduce abundances or eliminate unwanted 

populations, techniques to eradicate or reduce abundances of all life stages of Asian carps are 

needed. Population control methods (physical, chemical, biological, and molecular) need to be 

developed to reduce the abundance of Asian carps, without unintended effects on native 

species and their habitats. Field assessments and predictive models that estimate effects of 

various control measures are needed. As developed, population control strategies should be 

integrated into a single management strategy to maximize effectiveness of available 

technologies. 

Recommendation 3.6.4.1. Develop and evaluate effective attractants and 

repellents. 

Attractants (chemical, physical, or biological) can be used to concentrate fish for 

sampling or population control. Species-specific attractants (baits, pheromones, or other 

unknown chemicals) may be used, for example, to concentrate grass carp in areas 

targeted for aquatic vegetation reduction, thereby increasing the effectiveness of 

biological control and reducing the numbers of grass carp that need to be stocked. 

Repellants (chemical, physical, or biological) may be useful in reducing the spread of 

Asian carps by increasing the effectiveness of barriers in large river systems. 

Recommendation 3.6.4.2. Evaluate existing piscicides and, if necessary, develop 

new piscicides that are selective for Asian carps. 

Sea lamprey in the Great Lakes have been controlled for decades using chemicals that 

target and kill larval sea lamprey (www.glfc.org/seaslamp/how.php). The feasibility of 

targeting Asian carps with toxicants should be investigated. The effectiveness and 

selectivity of piscicides currently registered for use in the United States for bighead, 

black, and silver carps have not been evaluated sufficiently and new piscicide 

development efforts are not underway at this time. Development of new piscicides is 
 109

expensive after a chemical is identified; costs of research to support registration can 

exceed $5 million dollars for each chemical (Dawson and Kolar 2003). If effective 

chemicals are identified, formulations and application methods will need to be developed 

and environmental and human safety concerns will need to be investigated thoroughly.

Recommendation 3.6.4.3. Evaluate the potential for physical removal of feral 

Asian carps to control their abundance in public waters. 

Commercial and recreational fishers, and natural resources managers and researchers 

make targeted and untargeted collections of Asian carps. Managers have experimented 

with several methods (e.g., herding, angling, attracting, lift nets, and toxic fish baits) for 

removing grass carp from lake systems, however all techniques failed to remove a major 

portion of the carp population (Hoyer et al. 2005). Preliminary modeling of the bighead 

carp population in portions of the Illinois (LaGrange Pool) and Mississippi (Pool 26) 

rivers indicates that controlling adult stock size (not to exceed 0.05 adults/unit of fishing 

effort) will reduce recruitment and adult abundance over the long term (Hoff et al. In 

press). More research in this vein is needed. 

Development of commercial uses of Asian carp biomass potentially could reduce 

abundance in the wild and concurrently provide useful products. A limited market 

currently exists for bighead carp as human food, but this specialized, ethnic market 

prefers purchase of live fish. Proposals have been made to commercially harvest Asian 

carps for pet foods, fish meal, surimi, and bio-fuel. Additional research will be needed to 

evaluate market acceptance of wild-caught, processed (e.g., dressed whole, fillets, 

smoked) Asian carps (Recommendation 3.6.4.2). If attractants can be developed, 

catches would increase, thereby benefiting commercial fishers while further reducing 

Asian carp populations. Additional research is needed to confirm the potential 

bioaccumulation of persistent toxins in these fishes and their suitability for human 

consumption, use as fish meal in aquaculture, and use as feedstuffs and fertilizers in 

agriculture (Recommendation 3.3.2.6).

Strategy 3.6.5. Determine the demonstrated and probable ecological and economic 

effects of Asian carps in the United States and determine the degree to which these 

effects are negative. 

The adverse ecological and economic effects of certain nuisance species in North America have 

been estimated in several scientific papers (e.g., Mills et al. 1994 for Great Lakes). Food habit 

information alone indicates that Asian carps will likely affect native biota through competition, 

which may affect valuable sport fisheries. However, the extent to which native species and 

ecosystems may be affected by Asian carps has not been quantified. Scientifically valid 

assessments of ecological effects are imperative to effective management and resource 

allocation decisions. Addressing this strategy will require much research specified above 

(Strategies 3.6.1 and 3.6.2), as well as, analyses and modeling of population dynamics, 

dispersal, and bioenergetics. 

Decisions regarding the management and control of Asian carps can have an economic effect 

on facilities producing farm-raised carp species and associated businesses. Asian carps 

contribute to the supply of human food, the control of economically important parasites of farmraised fishes, and to control nuisance aquatic vegetation. Policy makers need accurate and 

comprehensive information on all facets of conflicts and issues. Consideration of the economic 

effects on the aquaculture industry is also required for assessments to be comprehensive. 
 110

Economic effects to the United States farm-raised Asian carp industry that have not been 

thoroughly studied include: 1) economic trade-offs of aquatic vegetation control with grass carp 

versus alternative control methods; 2) economic losses mitigated by snail control using black 

carp in the catfish, minnow, and bass industries; 3) economic effects of banning live sale of 

bighead and grass carps for ethnic food markets; and 4) mandatory use of triploids only. 

Recommendation 3.6.5.1. Assess the ecological effects of bighead, black, and 

silver carps on individual aquatic species and aquatic ecosystems. 

In North American watersheds where Asian carps have become established, field 

inventories and research should commence immediately to document any changes in 

the distribution, abundance, and growth of native aquatic fauna. Black carp are thought 

to have high potential to reduce populations of native mussels, including numerous 

imperiled species, through direct consumption (Nico et al. 2005). Bighead and silver 

carps are primarily planktivores. If plankton availability is or becomes limiting, food 

consumption rates and abundances of Asian carp populations could disrupt food webs, 

thereby altering aquatic ecosystems. Limited studies to date indicate competition for 

food resources might be possible among bighead and silver carps, gizzard shad, and 

bigmouth buffalo (Sampson 2005) and age-0 bighead carp and age-0 paddlefish 

(Schrank et al. 2003). Further study of dietary overlap of Asian carps and native fish 

species, particularly juvenile fishes is needed. Alternatively, bighead and silver carp fry 

and small juveniles may serve as additional prey for native species; however, these 

fishes grow rapidly and outgrow the feeding abilities of native piscivorous fishes in a 

short time (Kolar et al. 2007). Modeling the interactions of Asian carps with native fishes 

and other aquatic species based on laboratory and field studies will help to predict their 

potential ecological effects and will help decision makers to target funds for control 

strategies.

Recommendation 3.6.5.2. Document the actual ecological effects of bighead, 

black, grass, and silver carps. 

Comparing conditions before and after ecological disruption, such as colonization by a 

nonnative species, is an accepted method to assess effects of disruptions (Bernstein 

and Zalinski 1983; Stewart-Oaten et al. 1986), but validated information to make these 

comparisons is often lacking (Meroneck et al. 1996). Establishment and maintenance of 

long-term ecological monitoring programs are invaluable to detect ecological change 

(e.g., Oneida Lake, New York United States; Mayer et al. 2001). Comprehensive 

assessments should be encouraged immediately in areas where Asian carps are likely 

to expand to provide baseline data before these potential invasions. Although, this 

research objective seems to entail a “wait and see” approach to an inevitable invasion of 

some watersheds by Asian carps, documentation of ecological changes will improve 

predictive ability for risk assessments of uninfested waters. Thus, information about 

distribution and paths of invasions are needed to select ecosystems for assessment. 

Recommendation 3.6.5.3. Conduct analyses of economic effects of feral bighead, 

black, and silver carps. 

Economic analysis is defined as “the study of how best to use limited means to pursue 

unlimited ends” (Baumol and Blinder 2005). Given the reality that “virtually all resources 

are scarce, choices must be made among a limited set of possibilities.” Economics is 

the discipline that provides the framework for quantifying the possible outcomes of 

various decisions that affect the allocation of resources. 
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In the context of economic analyses related to the issue of Asian carps, there are three 

basic questions that were discussed within the Working Group. These are: 

1. What are the economic value and effect of feral Asian carp populations? 

 

2. What are the economic value and effect of the commercial production and trade in 

Asian carps? 

3. What are the economic trade-offs associated with alternative policy options proposed 

for management and control of Asian carps? 

Research to quantify the economic value and effect of feral Asian carp populations will 

require a comprehensive effort that addresses the topic on a variety of levels. Economic 

value is estimated by quantifying both benefits and costs from perspectives of both the 

current situation and likely future scenarios. Economic costs to be estimated would 

include efforts to prevent unintentional distribution and spread; construction, operation, 

and maintenance of barriers to prevent dispersal; management efforts to reduce 

population abundances; any negative changes in landings of commercial harvests of 

other species; declines in recreational use of waters with jumping silver carp (e.g., 

declines in sport fishing and boating activities); personal injury; damage to watercraft; 

and breakage or loss of equipment. Economic benefits to be estimated would include 

the value of aquatic vegetation control by grass carp, sales of bighead and silver carp 

harvested, any positive changes in landings of other species (if such were the case) and 

recreational value of new Asian carp related activities (e.g., bowfishing and tours to view 

jumping silver carp). A comprehensive economic analysis would also include 

environmental benefits and costs. Environmental costs would occur if negative effects 

were to occur on imperiled species, native fishes, and water quality; environmental 

benefits would occur if positive effects occurred to those resources. A careful economic 

analysis would select the most appropriate valuation method for each variable and would 

likely include both market and non-market valuation techniques. Economic effects would 

be measured through impact analyses. There are two broad categories of analytical 

techniques to measure economic impacts: input-output analysis and social welfare 

analysis. Greater detail on these two categories and on specific analytical models, data 

requirements, and estimation procedures can be found from the Minnesota IMPLAN 

Group Inc. (2005) for input-output analysis and in Green (2000) for social welfare 

analysis. Comprehensive impact studies measure direct and indirect effects to various 

economic sectors, in other words, which sectors benefit and which sectors bear the 

greater cost burdens. 

Research to quantify the economic value and effect of the commercial production and 

trade in Asian carps similarly would quantify the benefits and costs associated with 

production, transport, and sale of Asian carps. Economic benefits would include the 

revenue received at each stage in the supply chain and costs would include production 

inputs, labor, and management. Additional costs to other sectors to prevent and 

address unintentional introductions should also be considered. Economic effects would 

be measured through impact analyses as described above. 

Research to quantify the economic trade-offs associated with alternative policy options 

proposed for management and control of Asian carps would draw upon the impact 

analyses described above. Various policy options proposed for the management and 
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control of Asian carps would be modeled. These models would then be used to estimate 

the overall economic effect as well as differential economic effects to various geographic 

sectors, industry sectors, and user group sectors. Policy options to be analyzed would 

include those described in this plan, including analysis of various monitoring options and 

eradication alternatives as well as proposals to prohibit the sale of live fish, mandatory 

use of triploid bighead and grass carps, and prohibit the use of black carp. 

Strategy 3.6.6. Develop ecologically safe and economically viable alternatives to the 

uses of farm-raised Asian carps. 

Research is needed to develop environmentally safe and economically viable alternatives for 

the use of farm-raised bighead, black, and grass carps (Strategy 3.1.13). Black carp are used 

to control snails and prevent infestations of digenetic trematodes that adversely affect 

aquaculture production of several economically valuable food and bait fishes. Grass carp have 

proven to be an effective and economical solution to aquatic vegetation management in public 

and private waters (Cassani 1996). Bighead and silver carps are thought by some to be 

effective at reducing nuisance phytoplankton blooms in polyculture with channel catfish 

(Henderson 1980); however, this perceived benefit is equivocal (Stone et al. 2000). Bighead 

and grass carps are also shipped live to retail seafood markets in some major United States and 

Canadian cities, but these markets are poorly understood; thus it is difficult to hypothesize 

feasible substitutes at the present time. 

Research is needed to develop environmentally safe alternatives to the use of bighead, black, 

and grass carps as biological controls. Research to identify feasible alternatives to the use of 

black carp for biological control of snails is the highest priority. Alternatives to grass carps for 

biological control of nuisance aquatic vegetation, especially triploid grass carp, is a lower priority 

than finding alternatives to the uses of other Asian carps for biological control. 

Research is also needed to develop environmentally safe alternatives for the live seafood 

markets. Characterization of current ethnic markets for live fish and fresh fish on ice is needed. 

Consumer preferences for product attributes such as species, size, product forms and 

associated prices need to be determined to assess potential substitutes for the current live sale 

of bighead and grass carps in ethic food fish markets. The market potential and economic 

feasibility of growing and selling triploid fish for food are unknown. Additional useful research 

may include measures to improve the safety of hauling trucks and tanks such as improved latch 

systems and trigger systems to release rotenone in the event of a truck overturn to further 

reduce risks related to unintentional escapes. 

Recommendation 3.6.6.1. Evaluate ecologically safe and economically viable 

alternatives to black carp for snail control. 

Additional research is needed to seek alternative technologies using native species for 

biological control and/or chemical treatment of snails. Fundamental biological and 

physiological research of Bolbophorus spp. (trematodes) should be assessed to 

elucidate potential vulnerabilities in the parasite’s life cycle where effective controls are 

feasible. Combinations of native fishes (species, sizes, densities) to effectively control 

the intermediate snail host should be tested. Potential chemical controls to disrupt any 

or all stages of the life cycle of parasitic trematodes including eradication of the primary 

intermediate snail host, prevention of snail immigration into aquaculture ponds, and the 

direct treatment of infected fish must be evaluated. Use of targeted chemical treatments 

for snail control based on season, temperature, and water chemistry of ponds, as well 
 113

as, the size (life stage) of the production fishes should also be investigated. 

Combinations of biological control with native species and limited chemical treatments 

should also be assessed. Based on economic effect analyses the potential to combine 

various biological and chemical control alternatives should be evaluated. All 

management alternatives, biological control, chemical treatment, or some combination 

thereof need to be tested on a commercial scale. 

Recommendation 3.6.6.2. Characterize ethnic markets for live fish and for fresh 

fish on ice. Determine consumer preferences for various attributes including size, 

product form, and price. 

Additional levels of environmental safety can be achieved by killing bighead and grass 

carps at the point of sale or by hauling the fish fresh on ice. Understanding the current 

market for live fish, for fresh fish on ice, and the preferences of consumers in these 

markets, is paramount for development of feasible alternative products. Descriptive 

information on sales volumes and pricing of the various sizes, species, and product 

forms is required to develop hypotheses related to potential substitutes for Asian carps. 

Quantitative consumer preference analysis (Green 2000) is necessary to identify those 

specific product attributes (i.e., live or fresh on ice, whole, whole-dressed, filleted, 

canned, size, and species) that are most important in consumer choices of fish products. 

When combined with the information about sales patterns, consumer preference 

analysis should allow reasonable predictions of the types of species and product forms 

that can be substituted for Asian carps or to what extent fresh fish on ice can be 

substituted for live fish. 

Recommendation 3.6.6.3. Evaluate the economic feasibility of growing and selling 

triploid bighead and grass carps for the live and fresh-on-ice markets. 

Use of triploid bighead and grass carps for the food fish markets would lessen the 

environmental risk of spreading these species to the wild during rearing, transport or 

after the sale. Determining economic feasibility requires both market analysis and 

analysis of production costs. Price and quantity information for both bighead and grass 

carps for each product form will provide the basis for assessing the market and, 

ultimately, the economic feasibility of these products. The costs of producing triploid 

bighead and grass carps need to be estimated to compare with projected market prices 

to determine if their production and sale will be feasible. Increased costs resulting from 

lowered yields due to slow fish growth have been well documented in the aquaculture 

economics literature (Engle and Hanson 2004; Jolly and Clonts 1993; Shang 1990). 

Tave (1993) reported that triploid bighead carp grew more slowly than diploids and there 

have been anecdotal reports of slower growth of triploid grass carp when compared to 

diploids. Additional pond trials are needed to quantify differences between triploid and 

diploid growth rates using various diets, stocking densities and sizes. According 

economic costs from lowered triploid growth rates along with comparisons of production 

costs and market prices will provide the basis to determine the economic feasibility of 

replacing diploid bighead and grass carps in the food fish markets with triploids. If it is 

determined to be economically feasible, educational efforts and regulations should be 

directed towards working to substitute triploid bighead and grass carps for the diploid 

forms currently sold in some markets. 
 114

Goal 3.7. Effectively plan, implement, and evaluate 

management and control efforts for bighead, black, grass, 

and silver carps in the United States. 

Bighead, grass, and silver carps, have become established as reproducing populations over a 

large geographic range in the central United States and probably will continue to expand unless 

a concerted, proactive effort is made to restrict their spread. A nationally coordinated approach 

is required to successfully implement this plan by employing effective management and control 

interventions. Numerous strategies and plans to control and manage Asian carp species are 

actively being developed by federal, state, and tribal agencies; non-governmental organizations 

(NGOs); private commercial interests; and the public. Each of these groups has a vested 

interest in preventing the dispersal and colonization by Asian carps in additional aquatic 

ecosystems of the United States. Implementation of this plan will be most effective when the 

efforts of these diverse groups are integrated within nationally or regionally coordinated 

strategies. 

Management and control of Asian carps are especially challenging because of different 

perspectives and interests among the various consumer groups for commercial and recreational 

uses, and the natural resources management agencies charged with the responsibility to 

manage, conserve, and preserve aquatic ecosystems. These contrasting perspectives and 

interests result in different priorities and approaches for managing, controlling, or eliminating 

Asian carps. Some segments of the aquaculture industry are engaged in producing and 

marketing bighead, black, and grass carps for a wide range of uses by consumers, while natural 

resources management agencies are developing plans to minimize or eliminate potential 

adverse effects of feral populations on native species. The involvement of diverse stakeholders 

and the potential for conflicting interests warrants the development of a defined process for 

conflict resolution. 

One approach to address these challenges is to establish formal institutional agreements and 

arrangements that facilitate the implementation of this plan. For example, numerous federal 

departments and agencies collaborate on issues of national scope and importance through the 

Joint Subcommittee on Aquaculture to effectively address issues related to aquaculture. The 

Department of the Interior and the Department of Commerce are the lead federal agencies 

responsible for coordination of aquatic nuisance species in the United States in collaboration 

with USDA and other agencies under the auspices of the ANS Task Force. 

With any plan it is necessary to identify how it will be put into action. Strategies and 

recommendations can be developed, but to successfully and efficiently manage and control 

Asian carps, these plans must be funded adequately, put into action, and effectively sequenced 

and coordinated. Estimated costs for implementation of all Recommendations contained in this 

plan (years 1-20) are approximately $286 million (see Table 4.1, page 120). Limited funding will 

require that recommendations be prioritized and implemented in accordance with their strategic 

importance. Advance planning and coordination are essential to determine the availability of 

resources (e.g., staff, equipment, expertise, and funds), to effectively integrate and mobilize 

these resources, and to determine methods for evaluating success. There is much to learn 

regarding management and control of Asian carps, and it is essential that new information be 

readily assimilated into the management framework, and that strategies and recommendations 

are refined accordingly. 
 115

For implementation of this plan to successfully prevent further introduction and spread, and to 

reduce or eradicate feral populations, coordination of management and control actions is 

paramount. A coordination structure and consortium for Asian carp management must be 

organized early in the process of implementing this plan. It is imperative that the dialogue 

among stakeholders initiated through the Working Group be continued. That dialogue will 

require that stakeholders, including the aquaculture industry, are members of the 

implementation team and coordinating structure for this plan. Action to establish this 

implementation program should begin at once. 

Strategy 3.7.1. Develop an implementation program that effectively coordinates, 

oversees, and drives implementation efforts. 

 

Implementation of this plan will require the sustained and dedicated efforts of numerous 

individuals to adequately coordinate and implement recommendations, seek funding, evaluate 

program success, and to modify strategies and recommendations based on lessons learned. 

This team should be comprised of a wide variety of individuals, representing agencies, 

organized interest groups, and individuals with appropriate expertise, to bring their collective 

experience and capabilities to bear on the issues. Agencies must allocate adequate staff 

support to this effort. The committee should be formalized to the degree necessary to clarify 

roles and responsibilities and to insure support of the agencies or partners involved. An 

effective implementation committee will turn recommendations into actions and will serve as a 

communication and coordination center for management and control of Asian carps. 

Recommendation 3.7.1.1. The Aquatic Nuisance Species Task Force should 

create a committee composed of key partners and stakeholders with needed 

expertise to oversee the implementation of this plan. 

This recommendation is a critical first step to develop an effective implementation team 

and is best conducted under the oversight of the ANS Task Force. This task should be 

accomplished quickly so that relevant programs and needed resources can contribute to 

implementation of this plan. The Working Group recommends the ANS Task Force take 

immediate action to form this team upon approval of the plan and for the team to 

convene within 3 to 6 months. Implementation will be a national effort and will require 

flexibility by the team and by the individual agencies and stakeholders so that the needs 

of the team and the individuals are recognized and supported in a way that leads to 

coordinated and effective management and control of Asian carps. 

Recommendation 3.7.1.2. Develop institutional arrangements that formalize the 

roles and responsibilities of partner agencies and organizations in plan 

implementation. 

The purpose of an institutional arrangement is to formalize a process for government 

agencies and private stakeholders to work together. In this case, the common interest is 

the management and control of Asian carps. Formal institutional arrangements are 

essential for effectively coordinated and collaborative efforts, and for establishing 

decision-making processes among multiple entities and programs. Implementing an 

institutional arrangement framework can be challenging because it is often a change 

from the usual decision-making process. However, if this obstacle can be overcome, 

management decisions become integrated, science-driven, inclusive, efficient and costeffective. A process for conflict resolution should be defined and agreed to during the 

development of institutional arrangements. 
 116

These institutional arrangements may be formalized through interagency agreements 

(e.g., Memoranda of Understanding or Agreement) among key governmental agencies 

as needed to foster communication, consultative processes, resource sharing, and 

information exchanges. While Memoranda of Understanding or Agreement are not 

always necessary for agencies and institutions to work together, they can help define 

and articulate responsibilities and expectations for all groups involved. These 

Memoranda are also an effective method to share resources and to exchange 

information. 

Implementation of the Management and Control Plan requires a long-term commitment 

to the allocation of substantial human and financial resources. Institutional 

arrangements could require full-time employees to perform assigned tasks effectively. 

Regardless, management and control of four species of Asian carps in large river 

ecosystems, and at least three species with private commercial interest, will be very 

complex and will require substantial investment. 

Establishing and agreeing on the details of institutional arrangements will be needed 

almost immediately after acceptance of this plan. Specifically, the agreement to 

establish the institutional arrangements will need to address: 1) what functions and thus 

what groups are needed, 2) who will comprise the groups, 3) who will chair the groups 

and for how long, 4) how the chairs will rotate, 5) how the groups will operate 

(consensus vs. majority), 6) to whom will the groups be accountable (e.g., ANS Task 

Force, USFWS, USDA), and 7) the decision-making process and leadership hierarchy (if 

needed) for the groups constituting any institutional arrangements must be specifically 

outlined. 

Recommendation 3.7.1.3. Integrate, sequence, and prioritize recommendations 

from among all sections of this plan. 

This plan is organized into specific sections that address the primary issues of Asian 

carp control and management: 1) preventing accidental or deliberate unauthorized 

introductions, 2) containment, 3) population control, 4) minimize potential adverse 

effects, 5) education and outreach, 6) research, and 7) implementation. Additional 

efforts are needed to integrate, prioritize, and sequence projects across all sections of 

this plan and should be one of the earliest tasks undertaken by the newly formed 

Implementation Committee (3.7.1.1). 

This plan contains a comprehensive list of recommendations, but not all 

recommendations can or should begin immediately. Many are building blocks that must 

be completed in the appropriate sequence. Also, the recommendations presented are 

very much interdependent. Management and control of Asian carps are not practical by 

just implementing selected recommendations. It is the combination of a suite of actions 

across the various sections of the program that will result in the desired effect. 

Projects should be sorted relative to available funding. Lower priority projects that have 

funding should proceed, even if higher priority projects that lack funding must wait. 

Some recommendations may be put into action immediately given existing agency 

staff/funding or some redistribution of agency funds. Other recommendations will 

require “new” money that can be sought over the short-term but that may take some time 

for approval through agency budgeting processes. Actions that are high priority, 
 117

properly sequenced, and can be completed with existing funds should be implemented 

immediately. 

Recommendation 3.7.1.4. Seek “new” funds from various sources to implement 

this plan. 

Funding is a critical component to fully address all components of this plan. The 

Working Group estimates the costs for implementation of all Recommendations (years 

1-20) are approximately $286 million (see Table 4.1, page 120). Due to the large scope 

of projects to be undertaken in this plan, no single agency or institution will be able to 

provide the amount of funding needed to implement all elements of this plan. Even if 

agency budgeting processes are aligned with implementation of this plan, securing the 

needed funds will require special initiatives and efforts in new and different areas. This 

will be challenging with many competing interests for new funds. However, clear, 

accurate, and effective communication on the need to manage and control Asian carps, 

the potential threats that they pose, the array of recommendations identified, and the 

need for substantial and immediate funding will help to improve the probabilities for 

obtaining these funds. 

Funding initiatives and support of budgetary planning for management and control of 

Asian carps are essential. However, without new and bold funding initiatives, 

implementation of recommendations will be too slow and too limited to be effective. 

Also, it will take time for federal and state agencies to incorporate new funding initiatives 

within their respective funding processes. Alternative sources may need to be 

investigated until the formal budgeting processes respond. 

Given the many challenges, collaborative funding strategies will be needed. 

Development of cooperative funding agreements to optimize resources and secure 

funds for implementation should be considered. Cooperative Agreements are normally 

the preferred method to transfer funds, to share resources, and to exchange information. 

These are normally done on a case-by-case basis. However, a standard cooperative 

agreement could be developed to speed the process. The initial efforts to develop 

cooperative agreements will be the most challenging, but should become easier after 

initial efforts. 

Recommendation 3.7.1.5. Develop criteria and/or performance measures to 

evaluate the effectiveness of management and control efforts. 

For appropriate accountability of expenditures and to evaluate the effectiveness of 

management and control efforts, tools for assessing progress are needed. The first step 

will be to develop appropriate performance measures that can be tracked over time to 

monitor progress. Development of these performance measures should occur jointly 

with development of standardized sampling methodologies and a monitoring program so 

that methods used will provide the data needed for performance measures and so that 

performance measures developed are realistic given sampling/data limitations. Once 

developed, a program must be set in place to collect the appropriate data and to 

regularly develop progress reports. 

Recommendation 3.7.1.6. Develop an adaptive management framework that 

allows the flexibility to readily change and adapt management strategies as 

knowledge is gained and techniques are refined or developed. 
 118

Our level of knowledge and experience in the management and control of Asian carps is 

somewhat limited. Ongoing and future research will answer many questions as will 

initial attempts at management and control. A strong adaptive management framework 

is needed to apply what we currently know, identify what else must be learned, and to 

adapt management strategies based on what is learned both through research and 

actions in the field. The framework must be designed for rapid incorporation of new 

information, particularly in the early stages of management and control so that managers 

can effectively prevent new introductions, stop the spread, and reduce or eradicate 

existing populations of Asian carps. 

Recommendation 3.7.1.7. Develop an effective strategy for communication and 

coordination among those implementing recommendations for management and 

control of Asian carps. 

An effective communication/coordination strategy and action plan is needed to enhance 

communications among stakeholders leading to timely exchanges of accurate 

information that is required to facilitate implementation of this plan. Without effective 

communication and coordination, the full potential of this plan cannot be achieved. The 

strategy should be inclusive and must outline efforts to communicate with the myriad 

audiences who are important for the success to this effort. Some stakeholders may not 

have access to a computer or the internet, therefore traditional media and methods of 

communication must be included in a comprehensive communication and coordination 

strategy. 

One tool to facilitate communication is a database of key institutional contacts that could 

be posted on the Internet. Agencies and institutions should identify their main points of 

contact for issues related to Asian carps and this plan. Identifying key agency and 

institutional contacts is a logical step to facilitate communications with the public and 

among agencies and institutions involved. 

Another tool is the creation and maintenance of a web site (.gov) with pertinent 

information to facilitate the timely access and exchange of accurate information relative 

to the Working Group and implementation of this plan. The Internet has quickly become 

one of the most effective tools to communicate large amounts of information in a timely 

manner to large audiences. The need for centralized information collections and 

dissemination, communication tools, or web sites reoccurs throughout this plan. 

Creating and maintaining a single Internet web site to consolidate communication and 

coordination needs are crucial for implementation of this plan. 

Development of peer-review procedures to ensure the scientific integrity and accurate 

reporting of information before broad circulation to the public is also needed. To help 

improve the quality of communication, a multidisciplinary ‘expert’ and communication’s 

team should be formed to evaluate the content of information, develop effective 

educational messages, and facilitate the sharing of information. The integrity and 

accuracy of information are very important. A peer-review process should be developed 

to achieve a highly respected scientific standard for information released. 

While formal communications are important, we must also recognize the continued need 

for regular communications with partners and stakeholders, including face-to-face 

meetings, telephone, and electronic communications. These personal interactions 

cannot be replaced by more formal channels and procedures for communication.
 119

CHAPTER 4. TABLE OF RECOMMENDATIONS 

Chapter 3 of the Management and Control Plan for Asian Carps in the United States is divided 

into 7 sections based on goals necessary to successfully address Asian carp issues: 1) prevent 

accidental and deliberate unauthorized introductions, 2) contain and control, 3) reduce 

abundance of feral populations, 4) minimize potential adverse effects, 5) education and 

outreach, 6) research, and 7) implementation. Strategies were developed to address each goal 

and numerous recommendations were developed to address each strategy. Table 4.1 is a 

compilation of the recommendations developed and a subjective estimate of the cost to 

independently implement each action. 

This plan contains a comprehensive list of recommendations, but not all recommendations can 

or should begin immediately. Many are building blocks that must be completed in the 

appropriate sequence. The recommendations presented are very much interdependent. 

Management and control of Asian carps are neither practical nor effective by just implementing 

selected recommendations. It is the combination of the entire suite of actions across the 

various sections of the program that will result in the desired effect. Current priorities should be 

reassessed once integration and sequencing have been completed. 

A coordination structure and consortium for Asian carp management must be organized early in 

the process of implementing this plan. Goal 3.7 (page 114) identifies several recommendations 

to develop a coordination structure to effectively coordinate, oversee, and drive implementation 

efforts. Action to establish this implementation program should begin immediately. The 

coordination structure should include stakeholders, including the aquaculture industry, who will 

be partners in the implementation of this plan. Once this coordination structure is established, 

the initial actions of the implementation program will be to integrate, prioritize, and sequence 

recommendations across all sections of this plan. 

 

Funds to implement each recommendation were subjectively estimated by the drafting team 

leaders as a starting point for further discussion and development. Costs for each 

recommendation were estimated independent of other recommendations; shared costs of some 

actions may reduce the total estimated costs for all recommendations. Full development of 

costs associated with each recommendation will not be possible without further exploration of 

recommendations; however, preliminary cost estimates were developed to begin to understand 

the scope of the management and control needs for Asian carps and to begin discussion of 

funding needs. 
Table 4.1. Recommendations and estimated costs for management and control of Asian carps in the United Stgoal. Prioritization of recommendations across all goals is needed and should occur early in the implementation (Recommendation 3.7.1.3). 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.1.1. Assist states to develop, promulgate, and enforce regulations that manage the harvest, transport, import, trade, and release of live wild-harvested aquatic bait. 

B,BL,G,S 100 100 1

3.1.1.2. Explore the use of baitfish grown in monoculture, and certified to be disease-free and uncontaminated by other aquatic species. 

B,BL,G,S 20 20 

3.1.1.3. Develop and provide information to commercial and recreational baitfish harvesters that will help prevent accidental and deliberate unauthorized introductions of Asian carps. 

B,BL,G,S 50 50 

3.1.2.1. Encourage states to develop regulations that prohibit the stocking of any diploid Asian carps into non-aquaculture waters for biological control. 

B,BL,G,S 20 20 

3.1.2.2. Remove or contain diploid Asian carps that have been previously stocked into non-aquaculture waters for biological control. 

B,BL,G,S 2000 2000 2

Goal 3.1 

Prevention 

3.1.3.1. Encourage states that allow the legal importation of grass carp to adopt consistent, uniform regulations that allow only certified triploid grass carp to be shipped or stocked. 

G 20 20 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.3.2. Encourage states to conduct routine and random inspections of all live grass carp shipments within the state. 

G 1000 1000 1

3.1.3.3. Encourage the USFWS to provide ploidy determination for states conducting inspections of grass carp shipments. 

G 300 100 1

3.1.5.1. Encourage states to prohibit stocking triploid bighead, black, and silver carps for biological control in non-aquaculture waters. 

B,BL,S 20 20 

3.1.5.2. Encourage states to allow stocking triploid grass carp for biological control in non-aquaculture waters only within watersheds where grass carp are already present in the wild.

G 100 0 

3.1.5.3. Remove or contain triploid Asian carps that have been previously stocked in non-aquaculture waters within watersheds where the fish are not currently self-sustaining in the wild. 

B,G,S 20 20 

3.1.6.1. The USFWS should seek an independent scientific review and evaluation of the Triploid Grass Carp Inspection and Certification Program. 

G 100 0 

3.1.6.2. Develop and provide information on the USFWS Triploid Grass Carp Inspection and Certification Program. 

G 15 10 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.7.1. Investigate fully the risks associated with ballast water transfers or other means of water transfer by commercial vessels and recreational watercraft. 

B,BL,G,S 100 100 

3.1.7.2. Inform boaters, barge operators, and others of the risks 

of moving infested water and encourage voluntary actions to reduce this risk. 

B,BL,G,S 50 50 

3.1.8.1. Natural resources managers should employ pathway management tools, such as Hazard Analysis and Critical Control Point planning in the review of Standard Operating Procedures, to prevent introductions of Asian carps through natural resources management related pathways. 

B,BL,G,S 50 50 

3.1.8.2. Develop and provide information to natural resources managers and field staff that will help prevent unintentional introductions and spread of feral Asian carps.

B,BL,G,S 50 50 

3.1.9.1. Prohibit international importation of Asian carps under federal and state regulations, except for research purposes under a controlled permit. 

B,BL,G,S 20 20 

3.1.9.2. Inform USFWS Law Enforcement Officers, other federal inspectors, and state conservation law enforcement officers about laws that apply to the import of live Asian carps, the importance of preventing the illegal import of Asian carps, and Asian carp identification. 

B,BL,G,S 50 50 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 3 

3.1.9.3. Inform potential importers of applicable state and federal laws and associated risks with international shipments of live Asian carps. 

B,BL,G,S 50 50 5

3.1.9.4. Increase the numbers of trained USFWS Law Enforcement Officers and increase physical inspections of international shipments of live fish and eggs at designated or non-designated ports of entry. 

B,BL,G,S 200 200 2

3.1.11.1. Urge the development and enforcement of state regulations that prohibit the production and use of Asian carps at poorly sited facilities. 

B,BL,G,S 20 20 2

3.1.11.2. Develop and provide information to Asian carp producers and growers that will help upgrade poorly sited facilities such that they are no longer high-risk to contain farmraised Asian carps and prevent accidental introductions. 

B,BL,G,S 100 100 5

3.1.12.1. Form a coordinating research group that includes representatives from the aquaculture industry, the ethnic retail grocer industry, marketing scientists and developers, aquaculture scientists, and natural resources managers to focus research efforts on the highest priority alternatives to the use of Asian carps. 

B,BL,G,S 100 100 5

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 3 

3.1.12.2. Develop an information module on economic and effective alternatives to replace the use of bighead and black carps on aquaculture facilities. 

B,BL 20 10 5 

3.1.13.1. Review Standard Operating Procedures and recommend Best Management Practices that include requirements for suppliers and purchasers to conduct inspections of fish prior to shipment and release. 

B,BL,G 50 0 

3.1.13.2. Encourage states to develop regulations that allow for random inspections of live fish shipments into and within the state. 

B,BL,G 20 20 2

3.1.13.3. Prohibit the use of surface waters containing Asian carps from being used in aquaculture facilities unless effective treatment is in place with a monitoring program. 

B,BL,G,S 20 20 2

3.1.14.1. Review Standard Operating Procedures and develop Best Management Practices for properly sited aquaculture facilities. 

B,BL,G 50 0 

3.1.14.2. Encourage states to prohibit the use of grass carp on aquaculture facilities within watersheds where grass carp are not present in the wild. 

G 20 20 2

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 3 

3.1.14.3. Encourage states to restrict the use of grass carp to certified triploids only on aquaculture facilities within watersheds where grass carp are present but not reproducing. 

G 20 20 2

3.1.14.4. Verify functional sterility of triploid bighead carp and develop a triploid certification program for bighead carp. 

B 100 50 5

3.1.14.5. Encourage states to prohibit the use of bighead carp on aquaculture facilities within watersheds where bighead carp are not self-sustaining in the wild. 

B 20 20 2

3.1.14.6. Encourage states to restrict the use of bighead carp on aquaculture facilities within watersheds with self-sustaining populations to certified triploids only. 

B 20 20 2

3.1.14.7. Encourage states to prohibit the use and production of silver carp on aquaculture facilities. 

S 20 20 2

3.1.14.8. Encourage states to prohibit the use and production of diploid black carp on aquaculture facilities. 

BL 20 20 2

3.1.15.1. Where legal for commercial or recreational fishers to possess Asian carps, encourage states to prohibit the possession of live wild-caught Asian carps. 

B,BL,G,S 20 20 2

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.15.2. Review Standard Operating Procedures and actions of commercial fishers to identify Best Management Practices that reduce risks of live transport and introduction. 

B,BL,G,S 100 50 

3.1.15.3. Develop an information module and provide materials to commercial and recreational fishers and commercial live haulers that will help prevent accidental and deliberate unauthorized introductions of Asian carps. 

B,BL,G,S 50 50 

3.1.16.1. Require informational labeling of truck and invoice for shipments of Asian carps to avoid improper handling and potential introduction of fish that may be involved in an accident (e.g., “Nonnative fish: Unauthorized release prohibited”). 

B,G 20 20 

3.1.16.2. Review Standard Operating Procedures and develop Best Management Practices for fish haulers regarding containment and water transfer. 

B,G 50 0 

3.1.16.3. Prohibit the use of water from natural water bodies for water exchange during transport. 

B,BL, G 20 20 

3.1.16.4. Investigate improvements for containment methods on trucks carrying Asian carps. 

B,BL,G 75 75 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.16.5. Develop an information module and provide materials to commercial transporters of live farm-raised Asian carps that will help prevent accidental and deliberate unauthorized introductions. 

B,BL,G,S 75 75 

3.1.18.1. Encourage states to prohibit the sale, live transport, and unauthorized release of live Asian carps for non-commercial uses. 

B,BL,G,S 20 20 

3.1.18.2. Encourage states that allow sales of live Asian carps for human consumption to require retail grocers to kill the fish using prescribed humane methods, immediately upon sale. 

B,G 20 20 

3.1.18.3. Use educational campaigns such as HabitattitudeTM to 

convey messages to the public that they should not release live Asian carps. 

B,BL,G,S 20 20 

3.1.18.4. Develop an information module and provide materials to producers, growers, marketers, and foodfish consumers of live Asian carps that will help prevent accidental and deliberate unauthorized introductions. 

B,G 75 75 

3.1.18.5. Promote the national Aquatic Nuisance Species Hotline and encourage the general public to report illegal possession or stocking of Asian carps and other activity that could effect an introduction or rapid response. 

B,BL,G,S 10 10 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.1.19.1. Encourage states to prohibit the trade of Asian carps for aquaria and hobby purposes. 

B,BL,G,S 20 20 

3.1.20.1. Urge states to develop and enforce regulations to reduce risks associated with the possession and disposal of Asian carps for research and exhibition purposes.

B,G 20 20 

3.1.20.2. Develop an information module and provide materials to the academic and research communities that will help prevent accidental and deliberate unauthorized introductions of Asian carps. 

B,BL,G,S 75 75 

3.1.20.3. Encourage states to prohibit the trade of live Asian carps by commercial biological supply companies. 

B,BL,G,S 20 10 

3.1.21.1. Develop an information module and provide materials to recreational fishers and boaters that will help prevent accidental and deliberate unauthorized introductions of Asian carps. 

B,BL,G,S 20 20 

Goal 3.2 

Containment 

3.2.1.1. Develop a Decision Support System to assist natural 

resources managers in prioritizing specific locations for the construction, maintenance, monitoring, or removal of barriers to carp dispersal. 

B,BL,G,S 100 100 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.2.1.2. Evaluate the effectiveness afforded by alternative technical containment measures (i.e., physical and behavioral barriers). 

B,BL,G,S 500 500 5

3.2.1.3. Promote, support, and provide technical analysis and comment for the field testing of novel containment methods. 

B,BL,G,S 100 100 1

3.2.1.4. Anticipate and address consequences of specific containment actions on native biological communities. 

B,BL,G,S 250 250 2

3.2.2.1. Develop and implement redundant barrier systems within the Chicago Sanitary and Ship Canal to limit the unrestricted access of Asian carps to Lake Michigan. 

B,S 3000 3000 3

3.2.2.2. Develop and implement reasonable and effective measures that prevent the spread of Asian carps via canals, water ways, or other water diversions between basins. 

B,BL,G,S 2000 2000 1

3.2.2.3. Construct and operate a Sound Projector Array-based acoustic bubble curtain fish deterrent at two locks and dams on the Upper Mississippi River to prevent the spread of Asian carps throughout the basin. 

B,S 12000 12000 2

3.2.2.4. Identify additional containment measures needed to limit intrabasin movements of feral populations of Asian carps within the Mississippi River and other basins where established. 

B,BL,G,S 0 100 1

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.2.3.1. The USFWS and other natural resources management agencies should provide technical assistance and biological information to the USACE and participate in collaborative planning of fish passage and habitat restoration projects. 

B,BL,G,S 100 100 1

3.2.3.2. Require federal and state agencies to consider the potential range expansion and ecological effects of Asian carps when designing or reviewing water control structure projects and permits. 

B,BL,G,S 25 25 

3.2.4.1. Develop an early detection Decision Support System to: 1) identify high risk locations susceptible to introductions or range expansions of Asian carps, 2) identify watersheds of special concern, 3) prioritize specific locations for implementing comprehensive early detection monitoring programs. 

B,BL,G,S 150 150 1

3.2.4.2. Adopt and/or adapt an Incident Command System to provide for national coordination and management of early detection and rapid response programs. 

B,BL,G,S 250 250 2

3.2.4.3. Develop and conduct routine early detection monitoring programs in locations where risk of introductions or range expansions of Asian carps exists. 

B,BL,G,S 150 150 1

3.2.4.4. Develop Rapid Response Plans that identify where rapid response actions can effectively eradicate Asian carps and how those actions will be carried out. 

B,BL,G,S 150 150 1

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.2.5.1. Encourage states to identify the location of captive stocks of Asian carps and to develop a communication network for the reporting of escapees. 

B,BL,G,S 75 0 

3.2.5.2. Create an information sharing system with early detection monitoring and rapid response project managers. 

B,BL,G,S 75 0 

3.2.6.1. Develop a website and centralized databases to provide information on early detection and rapid response programs. 

B,BL,G,S 75 5 

3.2.6.2. Develop a list-server to provide a forum for information exchange. 

B,BL,G,S 5 5 

3.2.6.3. Utilize and support the Nonindigenous Aquatic Species Information Center for accurate and spatially referenced biogeographic information and the Nonindigenous Aquatic Species Alert System to track expansion. 

B,BL,G,S 100 100 1

3.3.1.1. Determine life history parameters of Asian carps in the Mississippi River Basin. 

B,BL,G,S 1000 1000 1

3.3.1.2. Create population, biomass, and recruitment models for Asian carps. 

B,G,S 120 120 1

Goal 3.3 

Extirpate or 

Reduce Feral 

Populations 

3.3.2.1. Evaluate gear and harvest method effectiveness, develop new gears if necessary, and provide information to commercial fishers. 

B,S 200 200 1

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.3.2.2. Increase the number of commercial fishers. B,S 100 100 13.3.2.3. Examine commercial fishing regulations and consider changes to increase harvest. 

B,S 30 30 

3.3.2.4. Provide financial incentives to commercial fishers to increase harvest of Asian carps. 

B,S 100 100 1

3.3.2.5. Develop new markets for Asian carps. B,G,S 100 100 13.3.2.6. Determine contaminant concentrations in edible portions of feral Asian carps. 

B,G,S 15 5 

3.3.3.1. Examine recreational harvest regulations to eliminate barriers to recreational harvest of Asian carps. 

B,G,S 20 20 

3.3.3.2. Inform recreational fishers about Asian carp harvest and preparation methods. 

B,G,S 25 25 

3.3.4.1. Biologists should physically remove Asian carps collected as a result of management actions or research. 

B,BL,G,S 10 10 

3.3.5.1. Examine the potential efficacy of introduction of monosex tetraploid fish as a control method. 

B,S 400 400 4

3.3.6.1. Adapt “daughterless carp” genetic technology to Asian carps. 

B,S 0 0 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.3.7.1. Sex pheromone research should continue with the goal of production and application of field-applicable technologies. 

B,S 300 300 3

3.3.7.2. Investigate aggregation pheromones for juvenile Asian carps. 

B,S 300 300 3

3.3.8.1. Provide technical assistance and biological information to the USACE and participate in collaborative planning of habitat improvement projects (e.g., Navigation and Ecosystem Sustainability Program, Missouri River Mitigation Project, and other authorities). 

B,S 50 50 

3.3.9.1. Determine effectiveness of registered piscicides to control Asian carps. 

B,BL,G,S 180 180 1

3.3.9.2. Identify conditions where rotenone or antimycin could be used to control populations of Asian carps. 

B,BL,G,S 180 180 1

3.3.9.3. Determine potential of other chemicals to control Asian carps. 

B,BL,G,S 800 800 8

3.3.9.4. Determine feasibility and applicability of piscicide bait deployment to control black and grass carps. 

BL,G 120 120 1

3.3.9.5. Determine registration needs, if any, for the use of piscicides to control Asian carps, and ensure that piscicides are available for appropriate uses. 

B,BL,G,S 300 300 3

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

 3.3.10.1. Develop information on the factors that determine the 

efficacy of native predator enhancement to control Asian carps. 

B,S 200 200 1

3.4.1.1. Monitor populations of species most likely to be affected by Asian carps. 

B,BL,G,S 500 500 5

3.4.1.2. Restore or supplement numbers of native species through direct release (i.e., stocking). 

B,BL,G,S 50 50 

3.4.1.3. Protect or restore native species through methods other than stocking. 

B,BL,G,S 35 35 

Goal 3.4 

Minimize 

Adverse Effects 

3.4.2.1. Inform and train boaters to avoid damage from jumping silver carp. 

S 25 15 

3.5.1.1. Engage potential key audiences in the development of a comprehensive education and outreach program. 

B,BL,G,S 60 15 

3.5.2.1. Develop an information module that defines and describes Asian carps, efforts to contain and reduce feral populations, and sources from which to learn more about these fishes. 

B,BL,G,S 60 5 

Goal 3.5 

Education and 

Outreach 

3.5.2.2. Develop an information module on the United States’ Asian carp industry, size, scope, economics, and current farming practices. 

B,BL,G,S 60 5 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.5.2.3. Develop an information module on potential effects of Asian carps and reasons to contain and reduce their feral populations. 

B,BL,G,S 60 0 

3.5.2.4. Develop an information module on the identification of all life stages of Asian carps.

B,BL,G,S 60 5 

3.5.2.5. Develop an information module on why and how to report sightings of Asian carps. 

B,BL,G,S 60 5 

3.5.2.6. Develop an information module on Hazard Analysis and Critical Control Point planning procedures. 

B,BL,G,S 60 5 

3.5.2.7. Develop an information module on the construction and maintenance of effective spillway barriers to reduce the risk of escape of Asian carps from private impoundments. 

B,BL,G 60 5 

3.5.2.8. Develop an information module to provide general information about regulations related to Asian carps. 

B,BL,G,S 60 5 

3.6.1.1. Develop and evaluate effective methods for sampling feral populations of Asian carps. 

Goal 3.6 B,BL,G,S 600 600 6

Research 

3.6.2.1. Describe current and temporal changes in distribution to better understand the invasion and colonization process. 

B, BL, S 5000 5000 1

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.6.2.2. Describe movements and distribution of Asian carps in waters of the United States (e.g., habitat preference, habitat selection, and habitats used).

B,BL,G,S 5000 5000 1

3.6.2.3. Describe diets, evaluate food selection and availability, estimate food consumption, and assess feeding interactions (i.e., predation and competition) with native biota (trophic ecology). 

B,BL,G,S 100 100 1

3.6.2.4. Assess ecologically important aspects of physiology and behavior such as environmental tolerances, endocrine functions, and sensory capabilities. 

B,BL,G,S 500 100 1

3.6.2.5. Estimate key population variables such as mortality, emigration and immigration, growth rates, fecundity, and stockrecruitment relations for population modeling. 

B,BL,G,S 500 500 1

3.6.3.1. Develop effective physical and behavioral barriers for controlling the movement of Asian carps. 

B,BL,G,S 5000 5000 5

3.6.4.1. Develop and evaluate effective attractants and repellents. 

B,S 250 250 2

3.6.4.2. Evaluate existing piscicides and, if necessary, develop new piscicides that are selective for Asian carps. 

B, BL, S 100 100 1

3.6.4.3. Evaluate the potential for physical removal of feral Asian carps to control their abundance in public waters. 

B,BL,G,S 100 100 1

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.6.5.1. Assess the ecological effects of bighead, black, and silver carps on individual aquatic species and aquatic ecosystems. 

B,BL, S 500 500 5

3.6.5.2. Document the actual ecological effects of bighead, black, grass, and silver carps. 

B,BL, S 500 500 5

3.6.5.3. Conduct analyses of economic effects of feral bighead, black, and silver carps. 

B,BL,G,S 500 500 1

3.6.6.1. Evaluate ecologically safe and economically viable alternatives to black carp for snail control. 

BL 500 500 5

3.6.6.2. Characterize ethnic markets for live fish and for fresh fish on ice. Determine consumer preferences for various attributes including size, product form, and price. 

B,BL,G,S 250 250 1

3.6.6.3. Evaluate the economic feasibility of growing and selling triploid bighead and grass carps for the live and fresh-on-ice markets. 

B,G 75 75 

Goal 3.7 

Implementation 

3.7.1.1. The Aquatic Nuisance Species Task Force should create a committee composed of key partners and stakeholders with needed expertise to oversee the implementation of this plan. 

B,BL,G,S 50 0 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
Table 4.1. Continued. 

Recommendations 

Goal Recommendation Species1 Estimated Fundi

 1 2 

3.7.1.2. Develop institutional arrangements that formalize the roles and responsibilities of partner agencies and organizations in plan implementation. 

B,BL,G,S 50 0 

3.7.1.3. Integrate, sequence, and prioritize recommendations from among all sections of this plan. 

B,BL,G,S 50 50 

3.7.1.4. Seek “new” funds from various sources to implement this plan. 

B,BL,G,S 50 0 

3.7.1.5. Develop criteria and/or performance measures to evaluate the effectiveness of management and control efforts. 

B,BL,G,S 100 100 

3.7.1.6. Develop an adaptive management framework that allows the flexibility to readily change and adapt management strategies as knowledge is gained and techniques are refined or developed. 

B,BL,G,S 25 50 

3.7.1.7. Develop an effective strategy for communication and coordination among those implementing recommendations for management and control of Asian carps. 

B,BL,G,S 25 100 

1 B = bighead carp, BL = black carp, G = grass carp, S = silver carp 
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male grass carp (Ctenopharyngodon idella). Aquaculture 86: 111-125. 

Venable, D.L., A.P. Gaude, III, and P.L. Klerks. 2000. Control of the trematode Bolbophorus 

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carp (Hypophthalmichthys molitrix), the bighead carp (Aristichthys nobilis), and the grass 

carp (Ctenopharyngodon idella) in the Syr-Darya River. Journal of Ichthyology 18(1):80-

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160

CHAPTER 6. APPENDICES

Appendix 6.1. Summary of State Regulations Pertaining to 

Asian Carps. 

Some states prohibit or restrict the possession of certain species of Asian carps. State 

regulations pertaining to bighead, black, grass, and silver carps were obtained by contacting 

state natural resources management agencies and/or reviewing regulations posted on agency 

websites. Many states prohibit or restrict all stockings of any fish species into public waters. 

State regulations pertaining to the import, possession, or stocking of Asian carps in private 

waters were categorized as either prohibited, restricted (i.e., permit required), or not restricted 

(i.e., permit not required) and summarized in Table 6.1.1. State regulations for each species 

vary from prohibited to not restricted (Figures 6.1.1, 6.1.2, 6.1.3, and 6.1.4). Some states that 

restrict possession of Asian carps by approved permits effectively prohibit possession by only 

issuing permits under very limited circumstance (e.g., approved scientific research). 

Information included in this appendix was current as of August 2007. The information included 

in this appendix summarizes state regulations, however many states have very specific 

requirements. States should be contacted for full regulations prior to purchasing, shipping, or 

stocking Asian carps (or any aquatic organism).
Table 6.1.1. Summary of state regulations pertaining to import, possession, or stocking of bighead, black, graswaters (as of 8/2007). Regulations are categorized as either prohibited, restricted (i.e., permit required), or not required). 

State Summary of State Regulations by Species Alabama Bighead, silver, and grass carp are not restricted (i.e., No regulations or restrictions for these spec

Black carp are restricted (i.e., Possession and import are restricted to accredited educational facilitie

permitted rehabilitation facilities by permit.) 

Alaska Bighead, black, and grass carp are restricted (i.e., A permit is required to transport, possess, expor

Silver carp are prohibited (i.e., A person may not import, own, possess, breed, transport, distribute, rspecimens.) 

Arizona Bighead, silver, black, and diploid grass carp are restricted (i.e., A permit is required to import, po

specimens.) Triploid grass carp are restricted (i.e., Only triploid grass carp can be stocked.) 

Arkansas Bighead and silver carp are restricted (i.e., A permit is required to possess live specimens.) 

Diploid black carp are restricted (i.e., A permit is required to possess live diploid specimens.) Triploid black carp are not restricted (i.e., A permit is not required to import or trade live triploid spec

purposes.) Grass carp are not restricted (i.e., A permit is not required to possess, import, or trade live specimen

California Bighead and silver carp are restricted (i.e., A permit is required for importation, transportation, or po

Black carp are not restricted (i.e., A permit is not required for importation, transportation, or possess

Triploid grass carp are restricted (i.e., A permit is required for importation, transportation, or posses

grass carp are prohibited.) 

Colorado Bighead, silver, and black carp are restricted (i.e., A permit is required to import, transport, possess

Grass carp are restricted (i.e., A permit is required to import, transport, possess, or release grass ca

carp may be stocked West of the continental divide and in the headwaters of the Colorado and Rio Gra

Connecticut Bighead, silver, and black carp are restricted (i.e., A permit is required to posses or import live spec

Triploid grass carp are restricted (A permit is required to possess, import, or liberate live specimensprohibited.) 

Delaware Bighead, silver, and black carp are not restricted (i.e., A permit is not required for any live specime

Triploid grass carp are restricted (i.e., A permit is required to import, possess, or liberate triploid gra
Table 6.1.1. Continued. 

State Summary of State Regulations by Species Florida Bighead, silver, black carp, and their hybrids are conditionally restricted (i.e., A permit is required 

and specific production system conditions are imposed that regulate culture to prevent escape or unauGrass carp are conditionally restricted (i.e., An assessment is made by state or local governments grass carp may be stocked and a specific stocking rate is determined prior to the issuance of a permit 

otherwise transfer, buy or otherwise receive, transport, or stock grass carp.) 

Georgia Bighead and silver carp are restricted (i.e., A permit is required to possess live specimens.) 

Black carp are not restricted (i.e., A permit is not required to possess live specimens.) Grass carp are restricted (i.e., A permit is required to possess grass carp. Only triploid grass carp m

Hawaii Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to import or possess Idaho Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to import, propagate, Illinois Black carp, bighead carp, silver carp are restricted species (i.e., A permit is required to “transport, 

specimens.) Diploid and triploid grass carp are restricted (i.e., A permit is required to possess live diploids in aqproduction of triploids]. A permit is required to either ship or stock live triploids. 

Indiana Black carp, bighead carp, and silver carp are restricted species (i.e., A permit is required to “transp

live specimens.) Grass carp is a restricted species (i.e., Triploids may be stocked in lakes and ponds. A permit is req

Iowa Black, bighead, and silver carp are restricted species (i.e., A permit is required to “possess, introdu

barter, propagate, or transport” specimens “in any form” (i.e., live or dead). Grass carp are not restricted (i.e., diploid and triploid grass carp may be possessed or stocked witho

Kansas Bighead, silver, and black carp are restricted (i.e., A permit is required to import or possess live spe

Grass carp are not restricted (i.e., A permit is not required to import or possess live specimens.) 

Kentucky Bighead, silver, and black carp are restricted (i.e., A permit is required to sell, possess, import, use

Grass carp are restricted (i.e., A permit is required to possess, import, sell, or propagate diploid gras

can be stocked.) 

Louisiana Bighead, silver, and black carp are restricted (i.e., A permit is required to import or possess live spe

Grass carp are restricted (i.e., A permit is required to possess or sell grass carp. Only triploid grass 
Table 6.1.1. Continued. 

State Summary of State Regulations by Species Maine Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to introduce, import, Maryland Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to import, transport, p

or sell live specimens. A permit is not required for dead specimens.) 

Massachusetts Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to import, transport, p

liberate, or sell live or dead specimens.) 

Michigan Black, bighead, grass, and silver carp (and hybrids) are restricted species (i.e., Possession of liv

is prohibited with the exception of permits issued by the Department of Natural Resources for educatio

Minnesota Bighead, black, grass, and silver carp are restricted (i.e., A permit is required to “possess, sell, imp

introduce” live and dead specimens.) 

Mississippi Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to stock, place, relea

specimens.) 

Missouri Black and silver carp are restricted species (i.e., A permit is required to culture diploids of these spe

carp can be cultured without a permit. A permit is not required to buy, sell, transport, take, or possess 

Bighead and grass carp not restricted species (i.e., A permit is not required to buy, sell, transport, peither live or dead specimens). 

Montana Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to possess live speciNebraska Bighead, silver, and grass carp are restricted (i.e., A permit is required to possess, sell, export, or t

specimens.) Black carp are not restricted (i.e., A permit is not required to possess, sell, export, or transport live o

Nevada Bighead, silver, and black carp are restricted (i.e., A permit is required to import, transport, or posse

Grass carp are restricted (i.e., A permit is required to import, transport, or possess diploid grass carp

be stocked.) 

New Hampshire Bighead, silver, and black carp are restricted (i.e., A permit is required to import, display, propagate

specimens. The release of these species is prohibited.) 

New Jersey Bighead, silver, black, and grass carp are prohibited (i.e., The release or stocking of any live speci
Table 6.1.1. Continued. 

State Summary of State Regulations by Species New Mexico Bighead, silver, and black carp are restricted (i.e., A permit is required to import, transport, or posse

Grass carp are restricted (i.e., A permit is required to import, transport, or possess live specimens.)

New York Bighead, silver, and black carp are restricted (i.e., A permit is required to sell, possess, transport, im

specimens.) Grass carp are restricted (i.e., A permit is required to import, export, own, possess, acquire, or dispo

Only triploid grass carp can be stocked.) 

North Carolina Bighead and silver carp are not restricted (i.e., A permit is not required to transport, purchase, poss

Black carp are restricted (i.e., A permit is required to transport, purchase, or possess triploid black ca

Grass carp are restricted (i.e., A permit is required for triploid grass carp to be bought, possessed, angrass carp are prohibited.) 

North Dakota Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to possess, transportOhio Black, bighead, silver, and diploid grass carp and their hybrids are restricted (i.e., A permit is req

or stock live specimens). Triploid grass carp are restricted (i.e., A permit is required to import or sell "certified" triploid grass c

Oklahoma Bighead, silver, and black carp are restricted (i.e., A permit is required to possess live specimens fo

Grass carp are restricted (i.e., A permit is required to possess, import, or stock grass carp into privat

Oregon Bighead, silver, and black carp are restricted (i.e., A permit is required to possess, import, sell, purc

specimens.) Triploid grass carp are restricted (i.e., A permit is required to possess, stock, or import only triploid g

Pennsylvania Bighead, silver, and black carp are prohibited (i.e., It is illegal to import, stock, or possess live spec

Grass carp are restricted (i.e., Diploid grass carp are prohibited. A permit is required to import, stock

carp.) 

Rhode Island Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to stock live specimeSouth Carolina Bighead, silver, and black carp are restricted (i.e., A permit is required to import, possess, transpor

Grass carp are restricted (i.e., A permit is required to possess reproducing grass carp for display or s

required for stocking non reproducing grass carp.) 
Table 6.1.1. Continued. 

State Summary of State Regulations by Species South Dakota Bighead, silver, and black carp are restricted (i.e., A permit is required to possess, propagate, or st

Triploid grass carp are restricted (i.e., A permit is required to possess triploid grass carp. Diploids a

Tennessee Bighead, silver, and black carp are restricted (i.e., A permit is required to import or possess live spe

Grass carp are restricted (i.e., A permit is required to import and possess diploid grass carp. A permpossess triploid grass carp.) 

Texas Bighead, silver, and black carp are restricted (i.e., A permit is required to possess, propagate, trans

Triploid grass carp are restricted (i.e., A permit is required to possess, propagate, stock, transport, o

Diploid grass carp are prohibited.) 

Utah Bighead, silver, and black carp are restricted (i.e., A permit is required to produce, propagate, rear, 

transport, or possess live specimens.) Triploid grass carp are restricted (i.e., A permit is required to import, possess, or stock triploid grass prohibited.) 

Vermont Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to import or possess 

stock into public waters or chances of entering public waters. Permit not needed if for personal use lik

Virginia Bighead, silver, and black carp are restricted (i.e., A permit is required to import, possess, liberate, 

Grass carp are restricted (i.e., A permit is required to import, possess, liberate, or sell grass carp. O

stocked in private waters.) 

Washington Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to possess, sell, tran

specimens.) 

West Virginia Bighead, silver, black, and grass carp are restricted (i.e., A permit is required to possess or transpoWisconsin Black, bighead, grass, and silver carp are restricted species (i.e., A permit is required to import, sto

dead specimens. DNR policy limits permits to a short list of species, and Asian carp are not being per

Wyoming Bighead, silver, and black carp are restricted (i.e., A permit is required to import, possess, stock, or 

Grass carp are restricted (i.e., A permit is required to import, possess, or transport grass carp. Only 

stocked.) 
166

Figure 6.1.1. State regulations pertaining to import and possession of bighead carp (as of 8/2007). 

Regulations are categorized as either prohibited, restricted (i.e., permit required), or not restricted 

(i.e., permit not required). 
167

Figure 6.1.2. State regulations pertaining to import and possession of black carp (as of 8/2007). 

Regulations are categorized as either prohibited, restricted (i.e., permit required), or not restricted 

(i.e., permit not required).
168

Figure 6.1.3. State regulations pertaining to import and possession of grass carp (as of 8/2007). 

Regulations are categorized as either prohibited, restricted (i.e., permit required), or not restricted 

(i.e., permit not required). 
169

Figure 6.1.4. State regulations pertaining to import and possession of silver carp (as of 8/2007). 

Regulations are categorized as either prohibited, restricted (i.e., permit required), or not restricted 

(i.e., permit not required).
170

Appendix 6.2. Asian Carp Working Group Drafting Team 

Members 

Prevention Drafting Team

Mike Conlin Illinois Department of Natural Resources 

Greg Conover1 U.S. Fish and Wildlife Service 

Carole Engle2 University of Arkansas at Pine Bluff 

Thad Finley Farm Cat Livehaulers 

Tom Flatt Indiana Department of Natural Resources 

Mike Freeze Keo Fish Farm 

Gary Jensen U.S. Department of Agriculture - Cooperative State Research, Education and 

Extension Service 

Paula Moore Jones and Eaker Farms 

Marshal Myers Pet Industry Joint Advisory Council 

John Nickum Private Consultant, Aquatic Policy and Information Center - 

International 

Bob Pitman U.S. Fish and Wildlife Service 

Jay Rendall1

 Minnesota Department of Natural Resources 

Steve Shults2 Illinois Department of Natural Resources 

Containment Drafting Team

Joel Brammeier Lake Michigan Federation 

Matt Cochran FishPro 

Greg Conover U.S. Fish and Wildlife Service 

John Dettmers Illinois Natural History Survey 

Bill Mattes1

 Great Lakes Indian Fish and Wildlife Commission 

Phil Moy University of Wisconsin - Sea Grant 

John Nickum Private Consultant, Aquatic Policy and Information Center – 

International 

Jay Troxel2

 U.S. Fish and Wildlife Service 

Paul Zajicek2 National Association of State Aquaculture Coordinators 

Population Control and Minimization of Impacts Drafting Team

Joel Brammeier Lake Michigan Federation 

Duane Chapman1,2 U.S. Geological Survey 

Mike Freeze Keo Fish Farm 

Joanne Grady2

 U.S. Fish and Wildlife Service 

Cindy Kolar U.S. Geological Survey 

John Nickum Private Consultant, Aquatic Policy and Information Center – 

International 

Laura Sanders U.S. Geological Survey 

Steve Shults2 Illinois Department of Natural Resources 

Rob Simmonds U.S. Fish and Wildlife Service 

Andy Starostka U.S. Fish and Wildlife Service 

 

1 Team lead for first draft

2 Team lead for revisions to first draft
171

Education and Outreach Drafting Team

Jimmy Avery2 Mississippi State University 

Greg Conover U.S. Fish and Wildlife Service 

Carole Engle University of Arkansas at Pine Bluff 

Jeff Finley U.S. Fish and Wildlife Service 

Mike Goehle1,2 U.S. Fish and Wildlife Service 

Chris Horton B.A.S.S. 

Gary Jensen U.S. Department of Agriculture - Cooperative State Research, Education and 

Extension Service 

Ron Kinnunen Michigan State University - Sea Grant 

Phil Moy University of Wisconsin - Sea Grant 

John Nickum Private Consultant, Aquatic Policy and Information Center – 

 International 

Nathan Stone University of Arkansas at Pine Bluff 

Kristin TePas Illinois Natural History Survey / Illinois - Indiana Sea Grant 

Paul Zajicek National Association of State Aquaculture Coordinators 

Research Drafting Team

Greg Conover U.S. Fish and Wildlife Service 

Carole Engle2

 University of Arkansas at Pine Bluff 

Jim Garvey Southern Illinois University 

Mike Hoff U.S. Fish and Wildlife Service 

Gary Jensen U.S. Department of Agriculture - Cooperative State Research, Education and 

Extension Service 

Anita Kelly Southern Illinois University 

Jack Kilgore U.S. Army Corps of Engineers 

Rob Klumb2

 U.S. Fish and Wildlife Service 

Cindy Kolar U.S. Geological Survey 

John Nickum Private Consultant, Aquatic Policy and Information Center - International 

Leo Nico U.S. Geological Survey 

Mark Pegg University of Nebraska 

Hal Schramm1

 U.S. Geological Survey 

Implementation Drafting Team

Mike Armstrong2 Arkansas Game and Fish Commission 

Greg Conover1 U.S. Fish and Wildlife Service 

Gary Jensen U.S. Department of Agriculture - Cooperative State Research, Education and 

Extension Service 

John Nickum Private Consultant, Aquatic Policy and Information Center – International 

Mike Oetker U.S. Fish and Wildlife Service 

Rob Simmonds U.S. Fish and Wildlife Service 

 

1 Team lead for first draft

2 Team lead for revisions to first draft
172

Appendix 6.3. Unresolved Issue: Use of Triploid Black Carp 

on Aquaculture Facilities. 

Background

Aquaculture facilities have a critical need for effective control of snail-borne parasites (i.e., 

trematodes). The United States aquaculture industry is most concerned with several 

trematodes, particularly yellow grub, white grub, eye fluke, and one or more species of the 

genus Bolbophorous, that can adversely affect aquaculture production of several economically 

valuable food and bait fishes (Collins 1996; Venable et al. 2000; Terhune et al. 2002, 2003; Nico 

et al. 2005). In addition, a nonnative gill trematode that affects the health of both cultured and 

wild fish species, including endangered species, and its nonnative first intermediate host, the 

red-rim melania snail (Melanoides tuberculatus), is spreading in southern and western states 

(Mitchell et al. 2005). Since the mid-1990s, Bolbophorous trematode infestations have been of 

great concern to United State’s channel catfish producers (Terhune et al. 2002). 

The Bolbophorous trematodes have a complex life cycle involving one final host, the American 

white pelican (Pelecanus erythrorhyncos), and two intermediate hosts: ram’s horn snails 

(Planorbdella trivolvis) and fish (Terhune et al. 2003). Evidence suggests that infection with this 

trematode is becoming widespread, with the more severely affected farms being in close 

proximity to pelican roosting or resting sites (Terhune et al. 2002; personal communication, 

David Wise, Thad Cochran National Warmwater Aquaculture Center). Channel catfish fry and 

fingerlings suffer high mortality rates and production of larger fish is reduced in severely affected 

production ponds (Terhune et al. 2002). Hanson and Wise (2005) estimated the net returns for 

channel catfish production ponds with relatively light infection of Bolbophorous trematodes were 

reduced by 80.8%, and production from ponds with more severe infection rates experienced net 

losses ranging on average from $1,251 to $1,560 per hectare. They further estimated the loss 

from Bolbophorous trematodes to producers in the main United States catfish-producing region 

as $45.4 million annually, more than 10% of the $450 million in catfish farm sales during 2004. 

Snail control is also a critical issue to commercial aquaculturists producing hybrid striped bass 

(Wui and Engle 2007). 

No U.S. Food and Drug Administration approved therapeutic treatment for fish infected with 

trematodes currently exists (Terhune et al. 2002, 2003; Ledford 2003). In the absence of 

therapeutic drugs, control of Bolbophorous trematodes is limited to preventing infestations by 

breaking the life cycle of the trematode. Breaking the life cycle requires controlling or 

eliminating the introduction of trematode eggs by pelicans, the trematode’s free swimming life 

stages within production ponds, or ram’s horn snails, the only known intermediate host for 

Bolbophorous trematodes (Kelly 2000; Ledford 2003; Terhune et al. 2003; Avery et al. 2004). 

Control of snail populations is the most practical option for breaking the parasite’s life cycle 

(Ledford 2003; Terhune et al. 2003). Optimal control of snail populations requires a 

combination of biological, chemical, and mechanical controls (Ledford 2003; Avery et al. 2004). 

Removing vegetative growth in ponds and limiting the presence of pelicans near ponds are 

additional prophylactic measures for lessening infestations (Terhune et al. 2002). 

Several chemical treatments provide some control of snails in production ponds with limited 

effects on fish (Terhune et al. 2002). Hydrated lime, copper sulfate, and copper sulfate with 

citric acid can be effective in eliminating snails that live along pond margins, where most ram’s 

horn snails are found (Venable et al. 2000). Bayluscide®, rock salt (NaCl), and copper sulfate 

can be effective options for treating some whole ponds (Kelly 2000; Mitchell 2002; Ledford 
173

2003; Mitchell and Hobbs 2003; Terhune et al. 2003; Avery et al. 2004; personal 

communication, David Wise, Thad Cochran National Warmwater Aquaculture Center). 

Available chemical treatments each offer unique benefits and limitations (Ledford 2003; Mitchell 

and Hobbs 2003; Terhune et al. 2003). Preliminary evidence suggests that an integrated plan 

to control snails may have potential on some facilities (i.e., farms not located near pelican 

roosting areas) (personal communication, David Wise, Thad Cochran National Warmwater 

Aquaculture Center). However, statewide surveys of channel catfish ponds in Arkansas during 

2006 and 2007 indicate that only triploid black carp had provided effective trematode control 

(unpublished data, Larry Dorman and Andrew Goodman, University of Arkansas at Pine Bluff). 

Chemical treatments must be repeated for long-term snail control (Terhune et al. 2003) which 

increases costs to producers and are not effective in all situations. For example, hydrated lime 

and copper sulfate can not be used in ponds with low alkalinity and Bayluscide can only be used 

to control snails in ponds with no fish (Terhune et al. 2003). Moreover, these compounds are 

not approved for use as a molluscicide. Therefore, it is not legal to use these for snail control. 

Biological control for the intermediate hosts of Bolbophorus trematodes offers a practical 

approach and may provide the best long-term control (Ledford 2003; Avery et al. 2004). Black 

carp, which feeds on snails, are an economical and effective tool for long-term biological control 

of snails (Slootweg et al. 1994; Shelton et al. 1995; Huckins 1997; Ledford 2003), especially in 

high risk areas where other means of snail control have been unsuccessful. In aquarium 

studies by Ledford (2003), black carp were the most effective consumers of ram’s horn snails 

(mean=98%), irrespective of size of snail or water temperature. Collins (1996) reported that it is 

difficult for black carp to control snails that burrow into the pond bottom and that snail control is 

greatly reduced by the amount of vegetation in the pond. Black carp have additional limitations 

such as eating channel catfish fry, reduced snail consumption when catfish feed is available, 

and potential environmental consequences due to the escape of a nonnative molluskivore 

(Ledford 2003). 

There have been limited studies to date to evaluate the effectiveness of native molluskivores for 

the control of ram’s horn snail in production ponds (Ledford and Kelly 2006). In aquarium 

studies by Ledford (2003), redear sunfish consumed significantly less snails (mean = 38%) than 

black carp but were the most effective native species evaluated in the study. Ledford (2003) 

recommended redear sunfish for the biological control of ram’s horn snail based on 

comparisons with other native species and the possible prohibition of black carp. However, 

when redear sunfish were presented with a range of snail sizes, the largest snails were uneaten 

or consumed in relatively small quantities (Ledford 2003); only fish >32 cm (12.5”) total length 

were capable of consuming all sizes of snails offered (Wang et al. 2003). Preliminary 

evaluations of additional native species have shown the potential to provide some control of 

ram’s horn snails, especially in combination with other control techniques, and warrant 

evaluation (Kelly 2000; Ledford 2003; Nico et al. 2005). 

It is likely that no single method is the solution for snail control; rather different methods should 

be evaluated for use in conjunction with one another (Venable et al. 2000; Ledford 2003; 

Terhune et al. 2003; Avery et al. 2004). Several chemical and biological alternatives to the use 

of black carp for snail control in ponds have been studied (e.g., Venable et al. 2000; Mitchell 

2002; Ledford 2003; Mitchell and Hobbs 2003; Terhune et al. 2003), but are less effective or 

present other limitations to their effective use. The escape of black carp due to a natural 

disaster is possible (e.g., flood, tornado, or hurricane). The Southern Regional Aquaculture 

Center had an on-going, multi-state project related to Bolbophorus trematodes that included 

work on native species and chemical alternatives to snail control. This $598,947 project of 20 

scientists at 9 different institutions was not able to develop an economically viable alternative to 
174

the use of black carp (www.msstate.edu/dept/srac/). It is evident that additional research is 

needed to further evaluate alternative techniques for snail control. Consequently, the North 

Central Regional Aquaculture Center has issued a request for proposals to address possible 

methods of snail control using native fish species or a combination of native fish species and 

approved chemical controls for elimination of snail populations from commercial aquaculture 

ponds. 

Beginning in the 1980’s, private production facilities attempted to market black carp, primarily as 

a biological control agent for snails (Nico et al. 2005). Currently, triploid black carp are the only 

form of black carp sold. They are used primarily in Arkansas, Missouri, Mississippi, and North 

Carolina as a biological control agent for nuisance snails (personal communication, Mike 

Freeze, Keo Fish Farm). However, the functional sterility of triploid black carp has not been 

evaluated, nor is there an established inspection and certification program for black carp. 

If functionally sterile, the inability of triploid black carp to reproduce in the wild would greatly 

reduce the long-term effects of escaped black carp, but would not eliminate the potential effects 

of non-reproducing fish on critically imperiled mussel fauna. Freshwater mussels are more 

diverse in eastern North America than any other continent in the world, yet more than half of the 

mussel species of the Midwest are threatened or endangered (Cummings and Mayer 1992). 

Nico et al. (2005) examined mouth gape of black carp and concluded that all size-classes of 12 

(85%) of the 14 federally endangered unionid species in the Midwestern United States are 

within the gape limits of a 2-meter long black carp. Based on the results of their work, Nico et 

al. (2005) believe that black carp, whether introduced individuals or a reproducing population, 

could pose a serious threat to many of the remaining populations of endangered and threatened 

mollusks. However, other scientists question the extent of potential damage if only a limited 

number of non-reproducing individuals escape to the wild. 

Some commercial fishers operating in the Mississippi River and its tributaries have been 

capturing black carp in the wild since the early 1990s and black carp captures have reportedly 

been an annual event in portions of the lower Mississippi Basin for more than a decade (Nico et 

al. 2005; personal communication, Leo Nico, USGS). Most of the fish captured were not 

retained, however at least 14 of the wild-caught black carp specimens were examined by 

experts and their identifications verified (Nico et al. 2005; Nico 2007; personal communication, 

Mark McElroy, Louisiana Department of Wildlife and Fisheries). The reported and verified 

collections, including one fish that blood tests indicated was triploid (Nico et al. 2005), confirms 

the difficulty of containing black carp on aquaculture facilities. However, triploid black carp are 

used on hybrid striped bass (Morone saxatilis x M. chrysops) farms in North Carolina, but no 

black carp have been reported in the wild in North Carolina (personal communication, Jeff 

Hinshaw, North Carolina Cooperative Extension Service). 

A synopsis of the following potential alternatives regarding the use of triploid black carp on 

aquaculture facilities is presented below for consideration by natural resources management 

policy and decision makers: 

a. Permit the use of certified triploid black carp (100% inspected/retested), with appropriate 

controls for containment, until feasible alternatives are proven and available for snail 

control; 

b. Permit the use of certified triploid black carp (100% inspected/retested), with appropriate 

controls for containment, until December 31, 2008; 

c. Immediately prohibit the use of all black carp.
175

This list of potential alternatives is not intended to be exhaustive, but highlights the principle 

ideas that have been discussed during the development of this plan. Working Group members 

agreed that the desired endpoint is to have no black carp in use on aquaculture facilities (or 

present in the wild), but did not agree on the manner or how long it should take to reach this 

endpoint. Each alternative includes a discussion divided into ‘pro’ and ‘con’ positions. These 

different positions represent the differing views and opinions of Working Group members. 

The order in which the alternatives are presented does not reflect any preference among the 

alternatives. 

Potential Alternatives

a. Permit the use of certified triploid black carp (100% inspected/retested), with 

appropriate controls for containment, until feasible alternatives are proven and 

available for snail control. 

Triploid black carp would be permitted until such time that alternatives for snail control are 

proven and available. This alternative would require that 100% of black carp be screened 

for ploidy prior to being inspected and then each fish would be retested during an inspection. 

All black carp would be used with appropriate controls for containment (e.g., 

Recommendation 3.1.14.1). This approach was supported by both aquaculture and a 

number of natural resources management representatives on the Working Group. 

Pro. Allowing the use of certified triploid black carp until feasible alternatives for snail 

control are proven and available assures fish farmers of a long-term, effective approach to 

minimize production losses as a result of trematode infestations. This approach also 

assures fish farmers of adequate time to develop alternatives, prove that these are effective 

and economically viable, and make them available on a commercial scale. Aquaculturists 

have developed the procedures to produce triploid black carp. Triploid black carp are 

thought to be effectively sterile and if so, should not establish a reproducing population if 

any should escape and survive in the wild. 

Con. The effective sterility of triploid black carp has not been established through peer 

reviewed research. Regardless, allowing the use of certified triploid black carp until feasible 

alternatives for snail control are proven and available may lead to the indefinite use of 

triploid black carp and may not adequately protect the nation’s natural resources. The 

USFWS and some states agencies are concerned that the use of triploid black carp for any 

period of time presents an unacceptable level of risk to the nation’s natural resources. To 

produce triploid black carp, fish farmers must maintain stocks of diploid black carp that are 

also a continued risk for escape. Black carp have been captured in the wild for more than a 

decade (Nico et al. 2005; Nico 2007). The continued use of triploid black carp may result in 

the continued introduction of black carp to the wild. 

b. Permit the use of certified triploid black carp (100% inspected/retested), with 

appropriate controls for containment, only until a predetermined date (e.g., December 

31, 2008) after which all use of black carp would be prohibited. 

This alternative would allow the use of certified triploid black carp only until a predetermined 

date (e.g., December 31, 2008) specified by state management agencies that currently 

permit their use. Use of all black carp would be prohibited after this date. This alternative 

would require that 100% of black carp be inspected and retested during an inspection. All 

black carp would be used with appropriate controls for containment. 
176

Pro. The continued use of triploid black carp violates the charge to the Working Group of 

developing a management plan that first and foremost is protective of the Nation’s natural 

resources. Black carp are capable of consuming all size-classes of 85% of federally 

endangered unionid species in the Midwestern United States (Nico et al. 2005). The use of 

black carp has already resulted in the annual collection of black carp from the wild for more 

than a decade. The continued use of triploid black carp for any duration of time may result 

in the continued introduction of black carp to the wild and risks ecologic and economic 

consequences. Some proposed chemical and biological alternatives have shown the 

potential to provide some control of ram’s horn snails (Kelly 2000; Venable et al. 2000; 

Mitchell 2002; Terhune et al. 2002, 2003; Ledford 2003; Mitchell and Hobbs 2003; Avery et 

al. 2004; Nico et al. 2005), although not enough to prevent serious economic losses on 

infested catfish farms. 

Con. This alternative violates the charge made to the Working Group of leaving a viable 

aquaculture industry standing. Research to date on alternatives has shown the difficulty of 

developing a viable alternative to the use of black carp. It is highly unlikely that a viable 

alternative can be developed in less than 18 months (the time remaining before the 

deadline). Thus, this alternative condemns fish farmers to severe economic losses. 

Compensation programs to cover the losses to farmers must accompany this alternative so 

that fish farmers can remain competitive and stay in business. These losses have been 

estimated at $45 million/year to the catfish industry alone, based on the current distribution 

of the trematode (Hanson and Wise 2005). 

c. Immediately prohibit the use of all black carp. 

This alternative would immediately prohibit the use of all black carp. 

Pro. This alternative provides the greatest level of resource protection by immediately 

eliminating all captive stocks of black carp and preventing continued unintentional 

introductions and consequences to imperiled mussels and aquatic ecosystems. Available 

resources would be directed at developing alternative long-term strategies to the problem of 

snail control, rather than using limited resources to validate a tool (i.e., triploid black carp) 

and establish a program that presents a continued risk to imperiled mussels. 

Con. This alternative violates the charge made to the Working Group of leaving a viable 

aquaculture industry standing and condemns fish farmers to severe economic losses. 

Compensation programs to cover the losses to farmers must accompany this alternative so 

that fish farmers can remain competitive and stay in business. These losses have been 

estimated at $45 million/year to the catfish industry alone, based on the current distribution 

of the trematode (Hanson and Wise 2005). The states that will be highly affected by 

restrictions on the use of black carp are highly rural and among the most impoverished 

states. 
177

Appendix 6.4. Unresolved Issue: Use of Grass Carp on 

Aquaculture Facilities and Farm Ponds in Watersheds with 

Self-Sustaining Populations of Grass Carp.

Background

Millions of dollars are spent on aquatic vegetation management in the United States annually 

(Greenfield et al. 2004). While many control measures exist, the use of grass carp is the least 

expensive, costing $45 to $125 per acre (Greenfield et al. 2004). A substantial trade in the 

species exists for use in commercial aquaculture facilities, private ponds and lakes, public 

ponds and lakes, and municipal irrigation projects. Grass carp are used widely for vegetation 

control by private aquaculture facilities; approximately 42% of catfish production facilities use 

grass carp for vegetation control (APHIS 2003). 

Both diploid and triploid grass carp have been widely stocked in the United States to control 

nuisance aquatic vegetation for more than 35 years. The vast majority of the grass carp 

populations in the wild have resulted directly from stocking programs by state and federal 

natural resource programs, although stocking grass carp in some private waters may contribute 

to feral populations. Reproducing grass carp populations in the wild have continued at relatively 

constant levels (LTRMP 2007) and environmental effects of feral populations generally have not 

been studied or well documented. Ten states (nine within the Mississippi River Basin and 

Hawaii) continue to authorize the stocking of diploid grass carp for aquatic vegetation control 

(see Table 2.3.1). Self-sustaining populations of grass carp are established within or along the 

borders of at least nine states, reproducing in rivers such as the Mississippi, Missouri, Ohio, and 

Trinity (Elder and Murphy 1997; Schofield et al. 2005; Nico et al. 2006). Twelve states (and the 

District of Columbia) prohibit the use of any grass carp in their waters, and 29 states restrict the 

stocking of grass carp to triploids only. 

Triploid grass carp are functionally sterile and can be considered sterile for management 

purposes (Allen et al. 1986; Allen and Wattendorf 1987; Thorgaard and Allen 1987; Van 

Eenennaam et al. 1990; Benfey 1999; Devlin and Nagahama 2002; Nico et al. 2005). However, 

triploid grass carp are more expensive to produce and are sold at approximately 2-3 times the 

price of diploid fish (personal communication, Mike Freeze, Keo Fish Farm). Stocking triploid 

grass carp will create a higher cost for consumers, including state natural resources 

management agencies, private pond owners, and aquaculture facilities. Typical stocking rates 

in commercial catfish ponds, for example, are about 10 fish/acre, which can quickly make the 

additional cost to stock triploids instead of diploids substantial. 

A synopsis of the following potential alternatives regarding the use of grass carp on aquaculture 

facilities in watersheds with self-sustaining populations of grass carp is presented below for 

consideration by natural resources management policy and decision makers: 

a. Allow the continued use of diploid grass carp on aquaculture facilities in watersheds with 

self-sustaining populations of grass carp. 

b. Restrict the use of grass carp to certified triploids only for aquatic vegetation control on 

aquaculture facilities in watersheds with self-sustaining populations of grass carp.

This list of potential alternatives is not intended to be exhaustive, but highlights the principle 

ideas that have been discussed during the development of this plan. Each alternative includes 

a discussion divided into ‘pro’ and ‘con’ positions. These different positions represent the 
178

differing views and opinions of Working Group members. The order in which the alternatives 

are presented does not reflect any preference among the alternatives. 

Potential Alternatives

a. Allow the continued use of diploid grass carp on aquaculture facilities in watersheds 

with self-sustaining populations of grass carp. 

States that currently allow diploid grass carp to be stocked on aquaculture facilities for 

aquatic vegetation control within watersheds with self-sustaining populations of grass carp 

could continue to do so. 

Pro. This alternative would not impose additional cost on the private or public sectors that 

depend on grass carp for aquatic vegetation control. The cost of requiring private 

individuals to stock only certified grass carp would be substantial. The Catfish 2003 survey 

of the major catfish producing states showed that 42% of foodsized catfish surface acres 

stock grass carp (APHIS 2003). Thus, of the 170,000 acres in catfish production in the U.S. 

in 2006, 71,400 acres would be stocked with grass carp. Typical stocking rates in 

commercial catfish ponds are about 10/acre. Thus, 714,000 grass carp would be present at 

any point in time in commercial catfish ponds. If these are replaced at the rate of every 4 

years, 178,500 fish would be replaced each year. At an additional cost of $2 per fish, the 

increased cost would be $357,000 per year for the catfish industry alone. This estimate 

does not include grass carp stocked in commercial ponds dedicated to production of other 

species. It also does not include acreage in fish production by state and federal agencies. 

Many states refer to having more than 100,000 farm ponds in each state. If half of these 

farm ponds are stocked with grass carp, and if each averages only 1 acre, then each state 

would have about 50,000 acres of farm ponds stocked with grass carp. Stocking at the rate 

of 4 grass carp per acre would mean 200,000 grass carp stocked in farm ponds in each 

state. If these are replaced at the rate of every 4 years, and triploid grass carp cost $2 more 

each than certified grass carp, then an additional $100,000 would be spent each year in 

each state to stock certified triploid grass carp instead of diploid grass carp. If only 10 states 

opt for this, the annual cost of this recommendation is $1 million. 

It is clear that the additional cost of using certified triploid grass carp only could be in the 

millions of dollars each year. The above estimates of costs are conservative because, if 

diploids were no longer available, the demand for triploid grass carp would increase and, as 

with any other product, the increased demand would be expected to, at least initially, push 

the price of grass carp higher. This, combined with the other conservative assumptions 

used above, makes these estimates of costs conservative. However, increased demand 

could also foster more growers, increasing supply and competition, and could potentially 

lower costs for triploid grass carp. 

The majority of commercial aquaculture facilities are not connected directly to open 

waterways. The escape of diploid grass carp from those that are will only add a few more 

fish with reproductive potential to an already established population. Since grass carp are 

already established in these watersheds, the likelihood of benefit to the environment from 

encouraging use of triploid grass carp only is very low, however the additional costs to 

private aquaculturists would be substantial. This cost will be born entirely by private 

individuals who were not responsible for the stocking programs of state and federal 

agencies. 
179

The call for additional regulations are based either on studies in which grass carp were 

intentionally overstocked in closed systems with the purpose of defining optimal stocking 

rates or largely anecdotal observations. The environmental effects of feral populations 

generally have not been studied or well documented. The existence of reproducing grass 

carp populations in the wild resulted in large part from deliberate stockings allowed by 

natural resource agencies, and therefore the costs should not be imposed strictly on private 

individuals. 

Con. The Working Group agreed that the desired endpoint for this management plan is the 

extirpation of Asian carps in the wild, except for non-reproducing (i.e., sterile triploid) grass 

carp contained within planned locations. This management plan recommends spending 

millions of dollars for management related to feral populations of grass carp. Grass carp 

can escape from both aquaculture and non-aquaculture waters and enter natural systems. 

Measures such as the use of only sterile, triploid grass carp are warranted to prevent the 

introduction of additional fertile, diploids into any watershed, including those with selfsustaining populations. The continued stocking of diploid grass carp contradicts efforts to 

reach the desired end-point agreed to for this plan. 

Although diploid grass carp are more cost-effective than triploid grass carp, triploids remain 

a more cost effective approach to aquatic vegetation control than other available options 

(e.g., chemical or mechanical removal) and have less risk of prolonged unintended 

consequences to the environment than fertile, diploid grass carp. In fact, based on the 

estimated additional cost of using triploid grass carp in a 1-acre farm pond as presented 

above, the additional annual cost to farm pond owners using triploid grass carp would only 

be approximately $2.00/acre/year more than diploid grass carp. Thus, the cost burden 

ranges from $2 for a 1-acre pond to $200/year for a 100-acre pond. The additional annual 

cost would be greater for fish farmers and could range from $500/year to $10,000 a year 

depending upon the size and acreage of ponds owned. Shireman and Smith (1983) 

concluded that grass carp stockings should proceed with caution because of potential 

unintended environmental effects and that stocking sterile (triploid) grass carp offers a 

desirable margin of safety. Wattendorf and Phillippy (1996) concluded that “a sound permit 

system for triploid grass carp, with occasional checks and legal action, is the best approach 

for those states authorizing the use of herbivorous fish for plant control.” 

Grass carp are stocked for the purpose of altering “undesirable” habitats. Effects of grass 

carp introductions have been most extensively evaluated in closed systems where it is well 

documented that grass carp are an extremely powerful management tool capable of 

manipulating and rapidly changing whole lake ecosystems (Cassani 1996). There has been 

little research completed to document the abundance or environmental effects of feral grass 

carp populations in open systems; consequently, the effects of self-sustaining populations to 

native ecosystems is poorly understood (Cassani 1996). Grass carp have the potential for 

being a nuisance in open aquatic systems because of their ability to consume large volumes 

of aquatic vegetation, tolerate a wide range of environmental conditions, and disperse 

widely from target waters (Bain 1996). 

This ability of grass carp to disperse widely from target waters once they enter an open 

system creates a regional management issue. The majority of states, several with selfsustaining feral grass carp populations, prohibit the use of diploid grass carp. Diploid grass 

carp can escape, disperse beyond the state where it was stocked, and adversely affect the 

management efforts of a neighboring or distant state. Dispersal and distant congregations 
180

can be significant through time and difficult to manage (Bain 1996). Rules and regulations 

for the use of grass carp vary from state to state and create a mosaic of jurisdictions and 

associated regulations that has been ineffective in preventing grass carp from occurring in 

areas where they were unwanted (Cassani 1996) and enforcement of regulations arduous. 

The additional costs of using triploid grass carp, by all grass carp users, are reasonable and 

warranted. 

b. Restrict the use of grass carp to certified triploids only for aquatic vegetation control 

on aquaculture facilities in watersheds with self-sustaining populations of grass carp.

States that currently allow diploid grass carp to be stocked on aquaculture facilities for 

aquatic vegetation control in watersheds with self-sustaining populations of grass carp 

would restrict the future use of grass carp to certified triploids only, with adequate and 

redundant controls to prevent escape. 

Pro. This alternative provides a redundant measure that minimizes risks associated with the 

escape of fish from farm ponds and properly sited aquaculture facilities. This alternative and 

Strategy 3.1.2 would bring the use of grass carp in non-aquaculture and aquaculture waters 

into agreement and compliments recommendations within this management plan to control 

and eradicate feral populations of fertile, diploid grass carp. Although diploid grass carp are 

more cost-effective than triploid grass carp, triploids remain a more cost effective approach 

to aquatic vegetation control than other available options (e.g., chemical or mechanical 

removal) and have less risk of prolonged unintended consequences to the environment than 

fertile, diploid grass carp. Although the increased costs appear substantial when considered 

on a national or regional scale, the additional annual cost of triploid grass carp to individual 

farm pond owners would only be approximately $2.00/year more than diploid grass carp, 

based on the estimates provided above for a 1-acre farm pond. Thus, the cost burden 

ranges from $2 for a 1-acre pond to $200/year for a 100-acre pond. The additional annual 

cost would be greater for fish farmers and could range from $500/year to $10,000 a year 

depending upon the size and acreage of ponds owned. The additional costs of using triploid 

grass carp are reasonable and warranted for both small farm ponds and larger aquaculture 

facilities. 

Con. Opponents of this alternative point to the substantial costs associated with 

encouraging states to restrict use of grass carp to only triploid. This unresolved issue is 

related to watersheds with self-sustaining populations of grass carp. Since grass carp are 

already established in these watersheds, the likelihood of benefit to the environment from 

encouraging use of triploid grass carp only is very low. Regulations that impose costs to 

members of society with little or no benefit to the environment would do not constitute good 

policy. The risk to the environment is low because grass carp are already established in 

these watersheds and environmental effects of feral populations generally have not been 

studied or well documented. The use of diploid grass carp is also good policy because it 

does not impose additional costs to society with little or no benefit to the environment. 
181

Appendix 6.5. Unresolved issue: Commercial, domestic 

transport of live farm-raised bighead and grass carps.

Background

Farm-raised bighead and grass carps are sold live to specialty food markets as a live product. 

Grass carp are also sold live and stocked for aquatic vegetation control. The major markets for 

live bighead and grass carps are in states other than those where they are raised. This requires 

transport of live fish to market. Live fertile, diploid bighead and grass carps are transported and 

sold, however only triploid grass carp are transported to states that do not allow the import or 

stocking of diploid grass carp. 

Most live foodfish markets for bighead and grass carp are located outside the range of selfsustaining populations of these species in the wild (e.g., Canada represents over 50% of the 

market for bighead and grass carps cultured in the U.S.; Mandrak and Cudmore 2004). 

Bighead and grass carps generally are transported by commercial live haulers. Some working 

group members believe that even a single accident could potentially introduce large numbers of 

these fish into new waters. Additional or improved containment measures to prevent escape 

during commercial transport may further reduce the probability of escapes (Recommendation 

3.1.16.4). Studies of live transport have been suggested to provide an understanding of the 

frequency that accidents and potential introductions might be expected to occur. However, it is 

generally accepted that the probability of an accident occurring is low. What is not generally 

accepted is whether the low probability of an accident occurring and the potential introduction of 

bighead or grass carp into a new watershed is a substantial enough risk to the environment to 

warrant management actions that would likely have an economic impact on the farmed carp 

industry. 

A synopsis of the following potential alternatives regarding the commercial transport of live 

bighead and grass carps is presented below for consideration by natural resources 

management policy and decision makers: 

Bighead carp

a. Allow the unrestricted transport of live diploid bighead carp; 

b. Allow the live transport of only triploid bighead carp; 

c. Allow only intra-state transport of live bighead carp within portions of the United States 

where feral bighead carp are determined to be self-sustaining as of a pre-established 

date (e.g., December 31, 2007); 

d. Prohibit all transport of live bighead carp; 

Grass carp

e. Allow the unrestricted transport of live diploid grass carp; 

f. Allow the live transport of triploid grass carp only; 

g. Prohibit all transport of live grass carp. 

This list of alternatives is not intended to be exhaustive, but highlights the principle ideas that 

have been discussed during the development of this plan. Each alternative includes a 

discussion divided into ‘pro’ and ‘con’ positions. These different positions represent the differing 

views and opinions of Working Group members. The order in which the potential alternatives 

are presented does not reflect any preference among the alternatives. 
182

Potential Alternatives

Bighead carp 

a. Allow the unrestricted transport of live diploid bighead carp. 

This alternative would allow the unrestricted transport of live diploid bighead carp. 

Pro. Diploid bighead carp could be shipped across all watersheds regardless of whether or 

not bighead carp are absent, present without evidence of natural reproduction, or are selfsustaining within a given watershed. The unrestricted transport of live diploid bighead carp 

provides the greatest flexibility, lowest production costs, and highest gross returns to fish 

farmers. High volumes of live bighead carp have been transported throughout North 

America for more than two decades with few reports of unintentional releases or escaped 

fish. Additional actions are recommended in this plan to reduce the risk of an unintentional 

introduction as the result of live commercial transport (Strategy 3.1.16). 

Con. This alternative does not adequately protect the Nation’s natural resources and is 

counter productive to efforts to manage and control feral populations. Although the 

likelihood of an introduction via this pathway is small, the risks of ecologic and economic 

consequences due to unintentional introductions are high in watersheds without established 

populations of these species. Self-sustaining populations of feral bighead carp are currently 

confined within the Mississippi River Basin; however, each shipment of live diploid bighead 

carp outside the current distribution of feral populations of this fish creates the opportunity 

for a new introduction and establishment. 

b. Allow the live transport of only triploid bighead carp. 

This alternative would continue to allow transport of live bighead carp, but it requires that all 

bighead carp be sterile, triploids. 

Pro. Aquaculturists have developed processes to produce triploid bighead carp on a 

commercial scale. Allowing the live transport of triploid bighead carp could provide fish 

farmers with the continued opportunity to grow, transport, and sell live bighead carp in food 

fish markets. This alternative provides greater natural resource protection than allowing the 

unrestricted transport of diploid bighead carp. Triploid bighead carp, though not confirmed 

through peer-reviewed research, are thought to be effectively sterile and if so, should not 

establish a reproducing population if any should escape and survive in the wild. 

Con. The economic feasibility of raising only triploid bighead carp for the food fish market is 

unknown. Research would be needed prior to implementation of this alternative to develop 

viable recommendations for triploid bighead carp production. The effective sterility of triploid 

bighead carp has not been established through peer reviewed research and should be 

confirmed prior to adopting this alternative. Moreover, a triploid bighead carp inspection and 

certification program would need to be developed and operated. 

c. Allow only intra-state transport of live bighead carp within portions of the United 

States where feral bighead carp are determined to be self-sustaining as of a preestablished date (e.g., December 31, 2007). 
183

This alternative would not allow interstate transport of live bighead carp. Live bighead carp 

could be transported within portions of the U.S. where feral bighead carp are known to be 

self-sustaining as of a pre-established date (e.g., December 31, 2007), but only dead 

bighead carp could be transported across state lines. 

Pro. This alternative is highly protective of the nation’s natural resources by minimizing the 

potential for a transport related accident near a waterway to result in an unintentional 

introduction of bighead carp into new waters as a result of live commercial transport. Many 

state (Appendix 6.4) and local governments have already adopted regulations that restrict or 

prohibit the possession and/or sales of live Asian carps. In the absence of live bighead 

carp, some consumers in California have purchased “freshly dead” bighead carp, but at a 

much lower price. 

Con. This alternative violates the charge made to the Working Group of leaving a viable 

aquaculture industry standing. Disallowing interstate transport of live bighead carp would 

abolish the live bighead carp industry in the U.S. by eliminating access to the markets for 

this product. It is not known to what extent an equivalent or viable market could be 

developed for dead bighead carp. 

d. Prohibit all transport of live bighead carp. 

This alternative would not allow the transport of any live bighead carp, regardless of whether 

diploid or triploid. 

Pro. This alternative provides the highest level of resource protection by eliminating the risk 

of unintentional introductions of bighead carp into any waters as a result of live commercial 

transport. The risks of introducing live bighead carp into waters with existing self-sustaining 

populations are counter-productive to efforts to eradicate the species from the wild. Freshly 

dead bighead carp products are currently marketed in a few locations within the U.S., but at 

a much lower price. Additionally, grass carp are more in demand and sell for a higher price 

than bighead carp in ethnic live fish markets (Stone et al. 2000) and are already widely 

distributed in the wild (Fuller et al. 1999). Therefore live triploid grass carp may provide a 

viable alternative to the live bighead carp food fish industry. 

Con. This alternative violates the charge made to the Working Group of leaving a viable 

aquaculture industry standing. Disallowing interstate transport of live bighead carp would 

abolish the live bighead carp industry in the U.S. by eliminating access to the markets for 

this product. It is not known to what extent an equivalent or viable market could be 

developed for dead bighead carp. The states that will be highly affected by a prohibition on 

all transport of live bighead carp are highly rural and among the most impoverished states. 

Grass carp 

e. Allow the unrestricted transport of live diploid grass carp. 

This alternative would allow the unrestricted transport of live diploid grass carp. Diploid 

grass carp may be shipped across all watersheds regardless of whether or not grass carp 

are absent, present without evidence of natural reproduction, or are self-sustaining within a 

given watershed. 
184

Pro. The unrestricted transport of live diploid grass carp provides the greatest flexibility, 

lowest production costs, and highest gross returns to fish farmers. High volumes of live 

grass carp have been transported throughout North America for more than two decades with 

few reports of unintentional release or escaped fish. The likelihood of an introduction via 

this pathway is small and additional actions are recommended in this plan to reduce the risk 

of an unintentional introduction as the result of live commercial transport (Strategy 3.1.16). 

Con. This alternative does not adequately protect the nation’s natural resources and is 

counter productive to efforts to manage and control feral populations. A single accident 

could potentially introduce large numbers of these fish into new waters. The risks of 

ecologic and economic consequences from an unintentional introduction of grass carp in a 

watershed without established populations of these species is likely high (Mandrak and 

Cudmore 2004). Most states have watersheds without self-sustaining populations of grass 

carp. Each shipment of live diploid grass carp outside the current distribution of feral 

populations of grass carp is an opportunity for a new introduction and establishment. 

f. Permit the live transport of triploid grass carp only. 

This alternative would allow the live transport of triploid grass carp only. 

Pro. This alternative provides fish farmers with the continued opportunity to grow, transport, 

and sell live grass carp for both nuisance aquatic vegetation control and food fish markets. 

Thirty-eight states authorize triploid grass carp stocking for aquatic vegetation control, 

twenty-nine of which permit triploid fish only. Restricting all live transport to triploid grass 

carp only provides greater natural resource protection than allowing the transport of diploid 

grass carp. Triploid grass carp have been rigorously evaluated and are considered 

effectively sterile. An unintentional introduction of sterile triploid grass carp would not result 

in a newly established population and the potential consequences of an introduction are 

therefore greatly reduced. Commercial transport of live triploid grass carp places fewer 

watersheds at risk of a transport related accident that results in an unintentional introduction 

than does the transport of live diploid bighead or grass carp. 

Con. Some state natural resource management agencies, primarily within the Mississippi 

River Basin, have stocked, or authorized stocking, diploid grass carp in open waters for 

more than 30 years. Disallowing the transport of live diploid grass carp would abolish the 

current market for diploid grass carp in the U.S. The economic effect of such an action on 

federal and state agencies that rely on diploid grass carp for aquatic vegetation control is not 

known. The economic feasibility of producing and selling certified triploid grass carp is not 

known for the live food fish market. The majority of the grass carp populations in the wild 

have resulted directly from stocking programs conducted or authorized by state and federal 

natural resources management agencies. Some members of the Working Group do not 

believe that it is reasonable to impose costs on farm pond owners and fish farmers by 

preventing them from continued access to diploid grass carp. Escape of some additional 

diploid grass carp will only add a relatively few more fish with reproductive potential to an 

already-established population that in many places had been stocked intentionally. 

g. Prohibit all transport of live grass carp. 

This alternative would not allow the transport of any live grass carp, regardless of whether 

diploid or triploid. 
185

Pro. This alternative provides the highest level of resource protection by eliminating the risk 

of a transport related accident that results in an unintentional introduction of grass carp into 

new waters. Currently, 12 states either prohibit possession or do not issue permits to 

authorize stocking grass carp (Appendix 6.4). 

Con. This alternative violates the charge made to the Working Group of leaving a viable 

aquaculture industry standing. Grass carp are in wide demand for nuisance vegetation 

control and this market is dependent upon the transport and stocking of live fish. 

Disallowing interstate transport of live grass carp would abolish the live grass carp industry 

in the U.S. by eliminating access to the markets for this product. It is not known to what 

extent an equivalent or viable food fish market could be developed for dead grass carp. 
186

Appendix 6.6. Summary of Asian Carp Working Group 

Decisions for Developing Recommendations to Prevent 

Unauthorized Introductions of Asian Carps (Nashville, 

Tennessee, August 22-25, 2005). 

• Need to develop and share a common big picture perspective 

“Goal:” no AC in the wild, with exception of sterile grass carp within planned locations only 

o non-reproducing grass carp may be used in targeted, controlled locations, as part of an 

aquatic vegetation management plan. (Managed use includes appropriate risk analysis 

and/or planning.) 

o nobody wants to see unintentional introductions into the wild 

o need to deal with ramifications of “no” in the statement...does it lead to 100% prevention 

or allow some room for risk 

o feral (fish in non-target, unplanned areas) populations (reproducing or otherwise) of all 

AC are a continued risk for spread; active controls are needed in “high risk” situations 

(not warranted in all situations due to low risk and/or high costs) and must be balanced 

with effects of control efforts on natives. 

o domestic stocks of AC (which species?) warrant a framework under which these species 

can be used responsibly (managed risk?) as this is one of many potential pathways 

o prevention efforts must be prioritized using a variety of factors (matrix), such as relative 

risk (chance of occurring and effect if it occurs) and resource affected – for example: 

1) uninvaded waters – new basins (Great Lakes, East Coast, etc.) 

2) uninvaded waters of high resource value within an invaded basin (need to know rate 

of invasion and what is an “uninvaded” water) 

3) additional introductions into existing range 

o Need to address issues such as ploidy, live transport, and live sales for each species 

individually 
187

Grass carp 

- Literature supports that triploidy produces functionally sterile grass carp 

- Effectiveness of triploidy for protecting natural resources is dependent upon 

effectiveness of inspection and certification programs 

- Must use other control measures for redundancy when opting to use triploidy, e.g. 

locking lids, improved latches, hazard labeling, rotenone on rollover, etc. 

Location Grass Carp – Natural Resources – Biocontrol 

(farm ponds, lakes, etc.) 

Recommendation 

Grass carp completely absent 

(e.g. Alaska) 

No grass carp. 

States must carefully consider using grass carp. If 

decide to use grass carp, then should only use certified 

triploids with appropriate controls for containment. 

Grass carp present, but no 

evidence of reproducing 

population. 

Certified triploid only 

Self-sustaining grass carp 

population 

Certified triploid only 

Note: There needs to be acknowledgment about the 

potential impact to small farm pond owners. There may 

be a financial impact by switching to triploids. Estimate of 

$2/fish or $20/acre. 
188

Location Grass Carp – Aquaculture – Biocontrol and food 

fish production 

Recommendation 

Grass carp completely absent 

(e.g. Alaska) 

No grass carp. 

States must carefully consider using grass carp. If 

decide to use grass carp, then should only use certified 

triploids with appropriate controls for containment. 

Grass carp present, but no 

evidence of reproducing 

population. 

Certified triploid only 

Self-sustaining grass carp 

population 

Certified triploid only 

Allow diploids if adequate and redundant containment 

controls in place. 

Location of Live Transport Grass Carp – Live transport and sales as food fish 

Recommendation 

Grass carp completely absent 

(e.g. Alaska) 

No live transport or live fish sales. 

States must carefully consider allowing live grass carp. 

If decide to allow live grass carp, then should only allow 

certified triploids and require killing fish at point of sale. 

Dissenting opinion: Should allow diploids if they are 

transported with adequate controls and killed at point of 

sale. Need to understand the economic effect to 

industry by switching to triploid production for food fish 

sales. Industry needs 4 years to phase out diploids. 

Grass carp present, but no 

evidence of reproducing 

population. 

Certified triploid only; kill fish at point of sale? 

Same dissenting opinion. 

Self-sustaining grass carp 

population 

Certified triploid only; kill fish at point of sale? 

Same dissenting opinion. 
189

Bighead carp 

- Raising triploids will cost producers more money, not certain if economically feasible. 

- Research needed to verify the sterility of triploid bighead carp; not certain if 100% sterile 

- If functionally sterile, a triploid bighead carp inspection and certification program would 

be needed. There was some discussion that the FWS should expand its triploid grass 

carp certification program to include bighead carp. 

- Recommendation for triploids dependent upon research to determine if triploid bighead 

carp are functionally sterile and the establishment of an effective triploid inspection and 

certification program in place. 

- Effectiveness of triploidy is dependent upon effectiveness of inspection and certification 

programs 

- Must use other control measures for redundancy when opting to use triploidy, e.g. 

locking lids, improved latches, hazard labeling, rotenone on rollover, etc. 

Location Bighead Carp – Bio-control for aquaculture 

Recommendation 

Bighead carp completely absent No bighead carp. 

Triploid, if state allows, but state must manage risk 

through adequate and redundant controls. 

Bighead carp present, but no 

evidence of reproducing 

population. 

No bighead carp. 

Triploid, if state allows, but state must manage risk 

through adequate and redundant controls. 

Self-sustaining bighead carp 

population 

Triploid 

Diploid, only if farm has adequate and redundant 

controls. 
190

Location of Live Transport Bighead Carp – Live transport and sales as food 

fish 

Recommendation 

Bighead carp completely absent No live transport or live fish sales. 

States must carefully consider allowing live grass carp. 

If decide to allow live grass carp, then should only allow 

certified triploids and requiring killing fish at point of 

sale. 

Dissenting opinion: Should allow diploids if they are 

transported with adequate controls and killed at point of 

sale. Need to understand the economic effect to 

industry by switching to triploid production for food fish 

sales. Industry needs 4 years to phase out diploids. 

Bighead carp present, but no 

evidence of reproducing 

population. 

Certified triploids only and require killing of fish at point 

of sale. 

Same dissenting opinion. 

Self-sustaining bighead carp 

population 

Certified triploids only and require killing of fish at point 

of sale. 

Same dissenting opinion. 
191

Black carp 

- Common goal is no black carp but different views on how long to reach that goal 

- Research needed to verify the functional sterility of triploid black carp 

- If functionally sterile, a triploid black carp inspection and certification program would be 

needed. There was some discussion that the FWS should expand its triploid grass carp 

certification program to include black carp with 100% of fish inspected (retested). 

- Recommendation for triploids is dependent upon research to determine if triploid black 

carp are functionally sterile, the establishment of an effective triploid inspection and 

certification program, and redundant containment measures. 

- Effectiveness of triploidy for protecting natural resources is dependent upon 

effectiveness of inspection and certification programs and effectiveness of containment 

measures 

- Must use redundant control measures when opting to use triploid black carp 

- Consider individual/batch tagging for purpose of identifying and correcting escapes 

- Research needed to find alternatives to black carp for snail control 

Location Black Carp – Aquaculture Bio-control 

Recommendation 

AC completely absent (all 

states except for AR, MS, MO) 

No black carp 

Dissenting opinion: Black carp will continue to be 

needed as there is no alternative; some states (Florida, 

Alabama) may still want black carp in their tool kit 

AC introduced, but no evidence 

of reproducing population. (AR, 

MS, MO) 

Common desired endpoint – no black carp, but given 

lack of alternatives recommend limited use of certified 

triploids with redundant controls for containment 

Note – concurrent research for alternatives paramount 

Dissenting opinion: Triploid black carp are too high risk 

to imperiled mollusks and are not an acceptable 

alternative; individual black carp can negatively effect 

imperiled mollusks; black carp should be immediately 

phased out and all stakeholders should work together 

to seek alternatives (including short-term subsidies if 

necessary). 

Silver carp 

- Currently no commercial interest 

- Recommend no production, no live haul, no live sales 

- Recommend possession of live silver carp be prohibited 
192

Appendix 6.7. Overview of Physical and Behavioral Barriers

Behavioral Technologies

Acoustic Barriers or Deterrents: Fish vary in their sensitivity to underwater sound, which will 

clearly influence the potential efficacy of an acoustic barrier. Asian carp species are known to 

be sensitive to sound. Fish size is also an important factor in relation to acoustic deterrence 

efficiency. Observations have confirmed that smaller sized fish may be more tolerant and could 

require stronger, higher frequency sound in order to be effective. 

Acoustic barriers have shown promise in research trials. Bighead and silver carps have acute 

hearing and are sensitive to frequencies outside the range of many native species. Thus, an 

acoustic array could be designed such that it primarily affects bighead and silver carps and has 

less effect on non-target species. 

Bubble Curtain: The bubble curtain is the most elementary form of behavioral fish barrier, 

which in its simplest form consists of a perforated tube laid across a river bed through which 

compressed air is forced. The rising curtain forms a wall of bubbles that can deflect fish. 

Efficacy of the bubble curtain may be enhanced when combined with light or sound. 

Electrical Barriers or Deterrents: The electrical fish barrier or deterrent can function either as 

an impassable barricade or as a fish guidance system. In either case, the system consists of a 

series of metal electrodes submersed in water to create an electrical field capable of repelling 

fish. 

Electrical barriers have been evaluated for preventing the expansion of feral Asian carp 

populations in both the Chicago Sanitary and Ship Canal and the Upper Mississippi River 

System. While considered feasible for the Chicago Sanitary and Ship Canal, it was determined 

that electrical barriers would be less effective and less feasible on the Upper Mississippi River 

System (FishPro 2004). Although currently in use, electric barriers are not the end-all solution 

to the range expansion of feral Asian carps in the United States. Electric barriers are not 

selective as to species affected. The electric field affects all species and sizes of fish to varying 

degrees. Large fish are more susceptible to the electric field than small fish and some species 

of fish are more sensitive to the presence of the field. Since the barrier relies on the ability of 

organisms to respond and move away form the discomfort caused by the electrical current, 

organisms unable to swim against the water flow will be carried through the electrical field. 

Asian carp are approaching the barrier from downstream, therefore the eggs and larvae of these 

species would be flushed away from the barrier (personal communication, Phil Moy, University 

of Wisconsin – Sea Grant). Corrosion of the electrodes reduces their effectiveness over time, 

so these components will require replacement. As such, electric barriers should be viewed as 

one component of a near-term approach for Asian carp containment. 

High Pressure Sodium and Mercury Lights: High pressure sodium lights (1,000 watts) have 

been used to attract and hold fish to slow water areas located near a powerhouse spillway. 

Mercury lights have also been used as attractants for species-specific applications. Attractants 

may be used in combination to congregate fish that are avoiding other behavioral barriers or 

deterrents. 

Hydrodynamic Louver Screens: Hydrodynamic louver screens are basically fins angled to the 

flow direction that are structurally supported in panels across the channel. Although a structure, 
193

the louvers cause a velocity increase that would repel some fish. They would generate a head 

to produce the increased velocity, would require a uniform channel, and are species and size 

specific for a given flow. 

Pheromones: Research on pheromones, either alarm substances or attractants for spawning 

aggregation, is underway but is in the early stages of development for Asian carps. These 

species-specific substances hold promise as a powerful tool in preventing Asian carp expansion 

and in Asian carp population management. 

 

Strobe light: The strobe light has been extensively evaluated as a fish deterrent in both 

laboratory and field situations and has been used in conjunction with other behavioral devices to 

increase the level of fish diversion. Combinations with bubble curtains may enhance the 

effectiveness of both, as the light can be projected onto the bubble sheet. Strobe lights can 

repel fish by producing an avoidance response. 

Physical Technologies

Vertical drop: The vertical drop barrier is basically an overflow weir as a component of a dam, 

which would provide a hydraulic drop over the structure higher than the leaping ability of the 

target species. Spatial geometry of the downstream pool would incorporate the consideration of 

creating hydraulic conditions that would prevent good staging behavior of the fish, prior to the 

jump, from occurring. 

Rotating drum screens: Rotating drum screens continuously rotate to pass debris over the top 

of the drum to the downstream side, where flow through the screen can carry it away. A set of 

drum screens could be oriented perpendicular to or at a slight angle to the flow, depending on 

the site configuration. Provisions are typically made for lifting individual drums out for 

maintenance. Rotating drum screens are well-proven systems for smaller applications under 

the proper conditions. Because wetted screen elements are constantly exposed to air, drum 

screens will not function in severely cold weather with a completely enclosed structure above 

the water surface. Sizing screens to accommodate downstream passage is not practical. 

Traveling screens: Traveling screens have been most commonly used in the past for smaller 

river diversion barriers. The unit would rotate continuously, lifting debris over the top and 

depositing it on the downstream side, similar to the rotating drum concept. As with the rotating 

drum, continuous exposure to wetted elements would make cold weather operation difficult or 

impossible without a completely enclosed structure above the water surface. Traveling screens 

would be subject to the same approach velocity and surface area requirements as for a 

stationary, or rotating self-cleaning screen, and would also appear impractical for use on Upper 

Mississippi River locks and dams. 

Floating curtains: Floating curtain systems generally consist of a piling or float supported cable 

with nylon nets or hanging chains attached. Using nets or hanging chains as a barrier for major 

structures on the Upper Mississippi River with the high water velocities, substantial depths and 

debris loading would not be practical. There may, however, be a possibility to use smaller 

floating barriers to guide fish to a control area. 
194

High velocity barriers: High velocity barriers are commonly configured as a flat apron below or 

part of a dam spillway, which generally has a high water velocity at variable flows. The velocity 

of the water must exceed the burst, or by distance, the sustained swimming speed of the target 

species. While these high velocity barriers may not be feasible or practical for the Upper 

Mississippi River, there may be potential for consideration on smaller tributary scale 

applications. 
Table 6.7.1. Summary of potential alternatives to limit the invasion of Asian carps. Table courtesy of FishPro 2004. 

Control Method 

Type of 

Alternative 

Optimum Diversion Efficiency1 

Probable Risk 

of Failure 

Navigational

Effect 

Construction 

and/or 

Implementation 

Complexity 

Operational 

and/or 

 Maintenance 

Issues 

P

S

Co

Strobe Lights 

~50 - 95% Moderate to High: Species 

and size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.) 

None to minimal 

Moderate: Packaged unit 

Low: Lamp and power delivery system maintenance 

Air Bubble Curtain 

~50 - 95% High: Does not work in 

high water velocity and turbulence 

None to minimal 

Moderate: Air piping in varying depths 

Moderate : Compressor and air line maintenance 

Acoustic Deterrent: Sound Projector Array (SPA) at Lock Entrance 

~60 - 90% Moderate to High : Species 

and size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.) 

None to minimal 

Moderate: Packaged unit 

Low : Transducer and power delivery system maintenance 

Behavioral 

Barriers 

and 

Deterrents 

Acoustic Deterrent: Sound Projector Array (SPA) at Spillway gates 

~60 - 90% Moderate to High: Species 

and size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.) 

None to minimal 

Moderate: Packaged unit 

Low: Transducer and power delivery system maintenance 

1 Optimum efficiency ranges obtained from existing references in literature for species specific case studies, site specific installation

results. Actual diversion efficiencies may vary according to site conditions and species targeted for deterrence.
Table 6.7.1. Continued. 

Control Method 

Type of 

Alternative 

Optimum Diversion Efficiency1 

Probable Risk 

of Failure 

Navigational

Effect 

Construction 

and/or 

Implementation 

Complexity 

Operational 

and/or 

 Maintenance 

Issues 

P

S

Co

Acoustic Deterrent: Pneumatic Acoustic Bubble Curtain (BAFF) at Lock Entrance 

~60 - 90% Moderate to High: Species and 

size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.); does not work in high water velocity 

None to minimal 

Moderate: Packaged unit; air piping in varying depths 

Low: Transducer and power delivery system maintenance; compressor and air line maintenance 

N

Acoustic Deterrent: SPA Based Acoustic Bubble Curtain (SPA/BAFF) at Lock Entrance 

~90%+ Moderate to High: Species and 

size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.); does not work in high water velocity; enhances the overall effectiveness of a standard BAFF in areas with intermittent turbulence and barge traffic. 

None to minimal 

Moderate: Packaged unit; air piping in varying depths 

Low: Transducer and power delivery system maintenance 

N

Hybrid Comb. System (Strobe light/acoustic) 

~60 - 95% Moderate to High: Species and 

size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.) 

None to minimal 

Moderate: Packaged unit 

Low: Transducer and power delivery system maintenance 

N

Hybrid Comb. System (Str. light/bubble curt.) 

~60 - 95% Moderate to High: Species and 

size specific; location & day/night specific; effectiveness varies with time of year (water temperature, flow, etc.); does not work in high water velocity 

None to minimal 

Moderate: Packaged unit; air piping in varying depths 

Moderate: Compressor, air line and power delivery system maintenance 

N

1 Optimum efficiency ranges obtained from existing references in literature for species specific case studies, site specific installation

results. Actual diversion efficiencies may vary according to site conditions and species targeted for deterrence. 
Table 6.7.1. Continued. 

Control Method 

Type of 

Alternative 

Optimum Diversion Efficiency1 

Probable Risk 

of Failure 

Navigational

Effect 

Construction 

and/or 

Implementation 

Complexity 

Operational 

and/or 

 Maintenance 

Issues 

PS

Co

Electrical Barrier (Main stem or at spillway gates/culverts) 

~90 - 99% Moderate: Variable depth for 

electrical field, silt, maintenance, size dependent 

None to minimal 

High: Electrode installation in water 

High Power 

outages, 

maintenance, 

debris, etc. 

H

S

is

ne

Per

Electrical Barrier (Inside Lock) 

~90 - 99% Moderate: Variable depth for 

electrical field, silt, maintenance, size dependent 

None to minimal 

High: Electrode installation in water 

High: Safety 

S

is

ne

Pe

Electrical Deterrent (Lock Channel Entr.) 

~90 - 99% Moderate: Variable depth for 

electrical field, silt, maintenance, size dependent 

None to minimal 

High: Electrode installation in water 

High: Safety H

S

is

ne

Per

Hyb.Comb. System (Electric Barrier & SPA/BAFF) at Lock 

~90 - 99% Moderate: Variable depth for 

electrical field, silt, maintenance, size dependent 

None to minimal 

High: Electrode installation in water 

High: Safety H

S

is

ne

Per

Hydrodynamic Louver Screens 

~86 - 97% High: Fouling problems; 

species and size specific 

Significant Moderate : 

Anchor system in water 

High: Icing and fouling by debris 

S

Mo

1 Optimum efficiency ranges obtained from existing references in literature for species specific case studies, site specific installation

results. Actual diversion efficiencies may vary according to site conditions and species targeted for deterrence.
Table 6.7.1. Continued. 

Control Method 

Type of 

Alternative 

Optimum Diversion Efficiency1 

Probable Risk 

of Failure 

Navigational

Effect 

Construction 

and/or 

Implementation 

Complexity 

Operational 

and/or 

 Maintenance 

Issues 

PS

Co

Vertical Drop (Existing Overflow Spillways) 

~95 - 100% Low: Site dependent Significant at 

spillway; Access through locks 

Site dependent Low Ex

Sp

Rotating Drum &/or Traveling Screens, Floating Curtains 

~95 - 100% Low to Medium Significant 

Effect at locks 

Extreme: Extensive civil works; Cofferdams 

High: Icing; Fouling 

Va

app

Physical 

Barriers 

High Velocity (Point Release) 

Unknown; 

species 

specific 

Low: Site dependent None if 

installed at spillway gates 

Site and species dependent 

Moderate; debris may clog or damage 

Un

dep

1 Optimum efficiency ranges obtained from existing references in literature for species specific case studies, site specific installation

results. Actual diversion efficiencies may vary according to site conditions and species targeted for deterrence.
199

Appendix 6.8. Additional Information on the Chicago 

Sanitary and Ship Canal

The City of Chicago was established in its present location because of the site’s advantages in 

gaining navigational access between the Great Lakes and the Mississippi River. The 28 mile 

long Chicago Sanitary and Ship Canal reversed the flow of the Chicago River in 1900 by linking 

the South Branch of the Chicago River with the Des Plaines River (Chicago Historical Society 

2005). The canal, which was designed both as a transportation route and a means to improve 

water quality by sending Chicago's sewage south into the Illinois River instead of into Lake 

Michigan, connected the two ecosystems with a continuous flow of water. To accommodate 

developing navigation demands, the Calumet River was joined to the Chicago Sanitary and Ship 

Canal via the Cal-Sag Channel and the Chicago River Locks and Controlling Works, the T.J. 

O’Brien Lock and Dam, and the Indiana Harbor Canal were constructed (Figure 6.8.1). 

Figure 6.8.1. Map of the Cal-Sag and Chicago Sanitary and Ship Canal and its connections to Lake 

Michigan and the Illinois River. Figure courtesy of Jerry Rasmussen, USFWS. 

Prior to enactment and implementation of the Clean Water Act, the canal was severely polluted 

with both domestic and industrial wastes (Rasmussen 2001). As a result dissolved oxygen 

levels in canal waters were depleted and aerobic organisms could not survive, thus creating a 

chemical barrier to movement of freshwater organisms between the two ecosystems. However, 

as technology developed and waste treatment methods improved, the Metropolitan Reclamation 

District of Greater Chicago did a marvelous job cleaning up the city's wastes and increasing 

dissolved oxygen levels in canal waters to the point that freshwater organisms now thrive in the 

canal (Rasmussen 2001). 

Unfortunately, a byproduct of this success is the fact that the canal now provides an artificial 

gateway between these two ecosystems and serves as a viable pathway for nuisance species 
200

infestations (Rasmussen 2001). The biological results can be seen in the growing exchange of 

organisms between the two ecosystems [e.g., zebra mussels, white perch (Morone americana), 

round goby (Neogobius melanostomus)]. Zebra mussels, which have spread throughout the 

Great Lakes and the Mississippi and Hudson River basins, have had a number of negative 

ecological and economic effects (MIT Sea Grant 2002). Zebra mussels are expected to cost the 

United States $5 billion in control efforts and reparation (MIT Sea Grant 2002). They have 

displaced native freshwater mussels of the area and drastically altered the food web (MIT Sea 

Grant 2002). Asian carps threaten to invade the Great Lakes via the same pathway, with 

potentially similar results. Recently, bighead carp have been collected within 50 miles of Lake 

Michigan, and the Chicago Sanitary and Ship Canal is the primary key to stopping large 

numbers of these nuisance fishes from reaching Lake Michigan and the other Great Lakes. 

The National Invasive Species Act of 1996 authorized the USACE to investigate the potential for 

implementing a dispersal barrier to prevent the spread of aquatic nuisance species via the 

Chicago Sanitary and Ship Canal. After considering the range of options available, the multiagency Dispersal Barrier Advisory Panel recommended using an electrical barrier as the first 

step in the development of the project. An electrical barrier was perceived to have the fewest 

permitting and safety issues. The technology was commercially available and the members 

agreed that the approach had a high likelihood of being effective on fish. Though the original 

target organism was Eurasian ruffe (Gymnocephalus cernuus), focus soon turned to the round 

goby which appeared in Calumet Harbor in the mid 1990’s. Unfortunately, due to funding and 

construction delays the round goby expanded its range beyond the barrier site before 

construction could begin. Today, the focus of barrier development is on stopping the spread of 

Asian carps into the Great Lakes. 

Kolar and Lodge (2002) developed predictive models to assess the risk to the Great Lakes from 

introduced fishes. The models predict that black carp would not become established in the 

Great Lakes if introduced and that silver carp could become established, but would neither 

spread quickly nor be perceived as a nuisance in the Great Lakes. The authors caution that 

model predictions about these two fishes “should be interpreted with caution [because] these 

species exhibit characteristics that differ substantially from those of species on which the 

models were developed, and our models may not be robust to such deviations.” In addition, the 

model “predictions are applicable to the Great Lakes proper, not to tributaries and large river 

systems in which these carp species ... are already established [outside the Great Lakes] and 

causing strongly negative consequences.” Access to rivers with 100km or more of undammed 

flowing water are required for successful reproduction and will play a large role in determining 

the potential range of bighead, black, and silver carps (Kolar et al. 2007; Nico et al. 2005). 

Kolar et al. (2007) identified 22 tributary rivers to Lakes Erie, Huron, Michigan, and Superior that 

could potentially serve as spawning sites for bighead and silver carps. These same rivers could 

potentially serve as spawning sites for black and grass carps, which have similar spawning 

requirements to bighead and silver carps (Nico et al. 2005). 
201

Appendix 6.9. Additional Information on Acoustic Dispersal 

Barriers 

Asian carps have been documented as sound sensitive (Nedwell 2005) and reactive to 

disturbances (Skelton 1993; Pflieger 1997). By exploiting the audio sensitivity of Asian carps, it 

may be possible to use acoustic technologies to direct or alter the behavior of these fishes. 

When considering audible range frequencies, hearing sensitivity is determined by the presence 

or absence of a swim bladder and by any anatomical specializations that improve the 

conduction of sound from the swim bladder to the inner ear (Hawkins 1981). Fish size is also 

an important factor in relation to acoustic deterrence efficiency. 

Deflection is the most effective action for an acoustic deterrent system, where the fish are 

diverted away from a structure and into a targeted area. Blocking such as a barrier 

perpendicular to river flow can be more difficult if the fish are not diverted away from the 

protected area because the risk of habituation to the sound signal increases. The ideal sound 

field should form a steep acoustic gradient approaching the entrance, free from acoustic nulls 

(voids) caused by destructive interference within the sound field. The presence of such nulls 

could cause fish to be guided into instead of away from the river structure. 

A Sound Projector Array (SPA) low frequency acoustic deflection system consists of an 

electronic signal generator, one or more power amplifiers and an array of underwater sound 

projectors. The Sound Projector Array system uses underwater sound projectors powered by 

audio amplifiers and electronic signal generators to create a repellant field ahead of a structure. 

Annual maintenance requirement involves removing the underwater units to check moving 

components and repair if necessary. 

 

The disadvantage of a Sound Projector Array is that the sound is not concentrated as with a 

Bio-Acoustic Fish Fence (BAFF, introduced below). A Sound Projector Array is more suited to 

covering an opening or intake where there is a flow past the opening and the Sound Projector 

Array system pushes the fish away from the opening and into the main flow of the river, as an 

example. In applications, where it is necessary to deflect fish swimming 'head long' into the 

barrier, a higher and more concentrated sound field (as in a Bio-Acoustic Fish Fence) is 

required to deflect the fish. 

The Bio-Acoustic Fish Fence is a proprietary product that uses a combination of a sound source 

and a bubble curtain to create a field that is largely contained within the bubble sheet. 

Physically, the system consists of an electromagnetic or pneumatic sound transducer coupled to 

a bubble-sheet generator, causing sound waves to propagate within the rising curtain of 

bubbles. 

Operating costs for a Bio-Acoustic Fish Fence generally are higher than for an equivalent Sound 

Projector Array system, because it requires an air blower or compressor. However, the 

compressed air demand is less than an equivalent stand-alone bubble curtain system because 

a smaller volume of air is typically required. The Bio-Acoustic Fish Fence is typically used to 

divert fish from a particular flow area and may be regarded as analogous to a conventional 

angled fish screen. It utilizes an air bubble curtain to contain a sound signal through refraction 

that essentially becomes a “wall of sound” (an evanescent sound field) that can guide fish 

around and /or away from river structures. The sound level inside the bubble curtain may be as 

high as 170 dB and decaying to as much as 5% of this value within 0.5 to 1.0 meters away from 
202

the bubble curtain. The disadvantage of the conventional Bio-Acoustic Fish Fence is that it is 

less capable of being tailored directly to the audiogram of the carp (depending on the audiogram 

frequencies) than the Sound Projector Array system. 

A hybrid system has been developed recently by Fish Guidance Systems (FGS) that utilizes the 

Sound Projector Array-based sound projection system coupled with an air driven bubble curtain. 

This system differs from the conventional Bio-Acoustic Fish Fence system in that the Sound 

Projector Array projectors can be calibrated to produce a sound signal that matches a particular 

fish deterrent audiogram, whereas the pneumatically driven sound source of the conventional 

Bio-Acoustic Fish Fence system cannot. In addition to the enhanced sound calibration 

capability, the omni-directional sound projectors would couple with the bubble curtain as a focus 

medium for the sound projection. 

A conventional Bio-Acoustic Fish Fence has an audio driver unit that produces the sound 

pneumatically, directly into the air supply for the bubble curtain, so in a conventional “pneumatic 

Bio-Acoustic Fish Fence” the sound is contained within the bubbles at very high sound levels. 

The sound drops off very quickly from the bubble curtain, which makes it ideal for guiding fish. 

With a Sound Projector Array, the sound field is more widespread, but acoustic modeling would 

ensure that a smooth even sound field is produced from a Sound Projector Array-based system. 

The hybrid Sound Projector Array driven Bio-Acoustic Fish Fence has an advantage over either 

conventional system since it combines both the ease of signal selection of an Sound Projector 

Array, and the concentrated sound field of a Bio-Acoustic Fish Fence. It will be important to 

insure that the sound from the sound projector array 'couples' with the bubble curtain, which 

could be incorporated in the design of the deployment system, and could be field-tested before 

the system went into functional operation. 

Implementation and Operational Issues

As outlined in the Feasibility Study to Limit the Invasion of Asian Carp in the Upper Mississippi 

River Basin (FishPro 2004), evolution of the bio-engineering approach has resulted in several 

valuable lessons that can benefit future efforts to achieve maximum efficiency in acoustical 

barriers and deterrents. The first lesson is that there are no overnight successes. A second 

lesson is that fish response to sound varies among species, and environmental conditions, 

including factors such as morphology of the site, water current patterns, seasonal stratification 

and turbidity, among others, can influence performance of a system both from the standpoint of 

the physics of sound in water and the physiological response of fish to sound. The third lesson 

is that field scale testing and monitoring is absolutely necessary throughout all phases of 

development, such as acquisition of baseline information, typical behavior of the target species, 

and installation and testing of the full scale system. It has been observed that smaller, less 

mature fish generally appear to have lower sensitivity to sound than larger, more mature fish. 

Differences in basic sensory capability such as this could be very important in determining the 

specifications of sound behavior modification and/or deterrent systems. 

Some of the common causes of acoustic deterrent system failure include: 1) emission of sounds 

at frequencies outside the main hearing band of fish (0 to 600 kHz); 2) ineffective signal types; 

3) inadequate sound levels; 4) failure to compensate for background noise; 5) unsuitable or 

inadequate sound generation equipment; 6) unusual sound propagation patterns caused by 

interference; 7) excessive water velocities; 8) failure to provide a clear escape route or diversion 

area; or 9) poor design. 
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The Illinois Natural History Survey has conducted Sound Projector Array driven Bio-Acoustic 

Fish Fence barrier experiments within concrete raceways at the Jake Wolf Memorial Fish 

Hatchery near Manito, Illinois. It was determined that the system was 57% effective in repelling 

3,219 attempts of adult bighead carp under raceway-scale conditions (Taylor et al. 2003). 

However, it should also be noted that the number of attempts decreased consistently on the 2nd

and 3rd day of the experiment and the percentage of repels versus attempts increased 

significantly, possibly as a result of a learned response. Although the test barrier was 

somewhat effective in restricting the movement of the captured bighead carp, it was observed 

that the fish were capable of crossing the barrier when frightened and that further testing and 

sound calibration will be required. It is important to note that the design of the experiment did 

not allow for fish to disperse to another area. Follow-up testing utilizing audiograms developed 

specifically for Asian carps have increased the estimated efficiency of this type of system to 

97+% (Nedwell 2005), therefore, these are not considered a complete barrier. 
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Appendix 6.10. Additional Considerations for the 

Enhancement of Commercial Harvest of Asian Carps 

The extent of commercial harvest of Asian carps is controlled by commercial fishers and the 

market for the fish. To enhance the harvest of Asian carps, it may be necessary to work with 

harvesters, fishery product developers and testers, processors, 

marketers, and consumers. Other than the inherent risk involved in 

beginning new industries, the primary impediments to enhancement of 

commercial markets for Asian carps for human consumption include a 

perception that “carp” flesh is low quality and the presence of 

intramuscular bones (Perea 2002). However, research has been 

conducted on the marketability of fresh Asian carps (Crawford et al. 

1978, Engle 1978) and in a side-by-side taste test, bighead carp was 

preferred over catfish (Shelton and Smitherman 1984). Chapman 

(2004) described methods to de-bone the filets and to prepare the 

bone-in filets in ways that render the bones less offensive. While 

intramuscular bones are an issue with the fresh product, canning offers 

a viable alternative. The marketability of canned silver carp was tested 

by Woodruff (1978) and several studies have examined consumer 

acceptance of canned bighead carp (Figure 6.10.1; Engle and Kouka 

1995; Thomas and Engle 1995; Freeman 1999). Additional research 

on development and testing of products for human consumption, as 

well as and additional products not for human consumption is needed to 

create a demand for the large number of fishes that can be harvested 

from the Mississippi River Basin. 

It is clear that with a high degree of fishing effort Asian carps can be harvested to reduce their 

populations. In their native China, wild populations of Asian carps are often considered overharvested (Yi et al. 1988). Although it is highly unlikely that Asian carps could be extirpated 

from the United States by fishing alone, and the amount of fishing pressure required to 

substantially reduce the population of Asian carps is unknown, decreasing the population of 

Asian carps to a substantial degree through harvest enhancement has a reasonable probability 

of success. Enhanced commercial harvest is also an approach that can be initiated 

immediately. 

Enhancement of Asian carp harvest and markets would create jobs for commercial fishers and 

processors. Potentially, it would generate new support for ecosystem improvement from 

previously untapped constituencies. Market creation for a broadly distributed product could 

create substantial localized economic benefits. Product development that is under exploration 

in Illinois could lead to over 350 jobs, with potential expansion to other states if desirable 

(personal communication, Steve Shults, Illinois Department of Natural Resources). Product 

development should include food products for humans and animals. Product development 

initiatives should re-examine material published by the National Sea Grant College Program in 

the 1970s and 1980s that dealt with products and market development for under-utilized 

species and the by-catch from targeted capture fisheries. 

Another barrier is the inconsistent supply of fish (personal communication, Duane Chapman, 

USGS). While Asian carps are abundant in the Mississippi River Basin, seasonal fluctuations in 

catch and weather conditions could cause an irregular supply. If Asian carp populations are 

Figure 6.10.1. Canned 

bighead carp. Photo 

courtesy of Carole 

Engle, University of 

Arkansas at Pine Bluff. 
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successfully depleted through harvest, this will create a problem with fish for the processing 

facilities. It is possible that commercial harvest of alternate species, such as common carp, or 

Asian carps from aquaculture may supplement fish to facilitate a consistent supply for 

processors during times of short supply of feral Asian carps. If efforts to reduce, or eliminate, 

populations of Asian carps are successful, and ecosystems are restored to previous biological 

communities, the potential for supplying processors with native species should be explored. 

Harvest enhancement has potential negative, as well as, positive effects. By-catch of nontarget species can be problematic. A sustainable market for Asian carps demands that prices 

rise so a commercial fishing operation can make a reasonable profit. If a reliable, profitable 

market exists, intentional stocking of Asian carps into additional waters to increase sources of 

these fishes could result. Asian carps are known to live and grow well in a variety of lacustrine 

habitats (Li and Senlin 1995, Xie 2003) and can recruit successfully in reservoirs that have 

tributaries with sufficient length to support spawning (Nikolsky 1963, Tripathi 1989). The degree 

to which such illegal stocking is a threat to lakes and reservoirs in the United States is unknown, 

but must be considered. Intentional unauthorized stocking of fish has occurred elsewhere in the 

country. Yellowstone National Park where lake trout (Salvelinus namaycush) were illegally 

stocked is a notable example (National Parks Conservation Association 2004). Possession or 

transportation of live Asian carps by commercial or recreational anglers should be made illegal, 

but this will not completely eliminate the risk. 

Commercial markets based on the sustained presence of nuisance species may conflict with an 

accepted ecological restoration paradigm for natural resources managers. It is generally 

acknowledged that “habitat restoration”, or even “species restoration” does not require a 

complete return of an ecosystem to a pre-European settlement character to be considered 

beneficial or successful. Restoration can seek to achieve meaningful targets for ecosystem 

structure and function based on analysis of reference habitats and historic conditions (Restore 

America’s Estuaries 2002). Management efforts that provide for improved sustainability and 

health of native aquatic communities and habitats will be an important component of an 

integrated management program to reduce adverse effects of Asian carps. 

Population reduction through harvest enhancement is likely to be an important component of an 

integrated management program; however, harvest enhancement alone is not expected to 

eradicate feral populations. The abundance of feral populations may continue to increase if 

harvest is not sustained, and markets and commercial enterprises do not persist. Therefore, 

feral populations may need to be sustained to allow commercial harvest and marketing 

operations to persist until research is completed and additional components of an integrated 

management program can be developed and implemented. 

 

A successful, large-scale market for Asian carps will create a constituency that depends on 

maintenance of feral populations. The capital required for development (e.g., surimi or other 

highly processed foods) and the generation of a moderate-sized labor force may result in a 

desire and political pressure for the continued availability of an abundant supply of Asian carps. 

If sustainable populations of Asian carps are required to support these businesses, this may 

present an obstacle to achieving meaningful restoration goals for the Mississippi ecosystem. 

Despite these concerns, harvest enhancement is the only method likely to result in substantial 

lowering of Asian carp populations over the near term, and it is the opinion of this Working 

Group that harvest enhancement should be a primary goal in the control of Asian carps. These 

stated concerns may be ameliorated if 1) Mississippi Basin natural resources managers agree 

that restoration targets can be met in the presence of controlled (rather than eliminated) 
206

populations of Asian carps; 2) markets are developed with Asian carp eradication as a goal; or 

3) financial protections or exit strategies for investors are established prior to any market 

development. 

Bighead and silver carps are more net shy than most native fishes and are not susceptible to 

standardized research methods for sampling fish (Stancill 2003, Ickes et al. 2005). However, 

directed fishing within certain habitat types can be successful at trapping large numbers of adult 

bighead and silver carps. Bighead and silver carps are susceptible to being driven by boats into 

entanglement gear if they can be trapped in areas with limited egress (Li and Senlin 1995). 

Likewise, Asian carps are sometimes susceptible to hoop netting (Figure 6.10.2). Most of the 

commercially harvested black carp reported in the United States have been collected as nontarget catch in hoop nets (Nico et al. 2005). However, capture of Asian carps may require that 

fishers develop, learn, and apply new techniques. Techniques to capture Asian carps might not 

be available in all environments occupied by the fish. In this case, development and evaluation 

of entirely new methods and gears should be completed. Commercial fishers are likely to be the 

most innovative fishers, but transfer of information from one to another is generally very low. 

There appear to be economic incentives for successful fishers to avoid such information 

transfer. Nevertheless, to maximize harvest, technology transfer should move both ways 

between private and government entities. Government agencies should ensure that harvest 

technology is transferred between sub-basins. 

Figure 6.10.2. Commercial fishers harvesting bighead carp with a hoopnet in 

Louisiana. Photo courtesy of Jody David, Louisiana Department of Wildlife 

and Fisheries. 

A bounty system could increase the harvest of Asian carps, but would require a very high 

degree of oversight and funding. Under a federally funded bounty system, such as that 

implemented for nutria (Myocastor coypus) control in Louisiana (Louisiana Department of 

Wildlife and Fisheries 2003), federal money would pay for harvested Asian carps. The 

carcasses could be channeled into commercial markets if they existed, or be provided to 

commercial industries free of charge or at a reduced rate as a subsidy to assist in the 

development of those markets. To be effective, bounties might have to be directed at fish from 

relevant “hotspots”. Otherwise, fishes could be taken from aquaculture ponds or river sections 

that were less meaningful for control purposes and submitted for bounty payments. There could 

be enforcement difficulties in the implementation of bounties that restrict the capture locations of 

the fish because it will be impossible, without excessive expense, to determine the location of 
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capture. Despite the potential benefits of a bounty system, the high cost and difficulties inherent 

in managing a bounty system seem prohibitive. We do not recommend instituting bounties or a 

study of the effectiveness of a bounty system. 

A subsidy that may have promise is provision of transportation from the fisher to markets and 

processors. Refrigerated trucks or portable processing units could be provided at the boat 

ramp. These vehicles could be located in areas where managers wish to direct harvest. This 

form of subsidy has several positive aspects. Markets for Asian carps exist, but the costs of 

transportation can be prohibitive for small commercial fishers. The quality of fish delivered to 

market would be improved, due to better transportation and handling once the fish are landed. 

Providing transportation would mean that experienced fishers spend more time fishing and less 

time transporting, storing, or processing fish. The expense of such subsidy would be known 

before implementation, unlike a bounty that would depend on the numbers of fish harvested. 

Lastly, this form of subsidy would be simple to phase out, should it no longer be required to 

sustain a high rate of commercial fishing. Whether this form of subsidy would be economically 

feasible, accepted by fishers, practical to implement, or would provide sufficient economic 

incentive to substantially increase harvest is unknown. However the potential benefits of this 

harvest support system should be investigated. The administration and costs of fish 

transportation might be born by federal (perhaps Department of Interior or Small Business 

Administration) or state entities (perhaps State Departments of Commerce) or by the fish 

processors. 

Another incentive could be contract fisheries. In this case, commercial fishers would be paid a 

fee for fishing within designated high-priority areas. Payment could be based on the removal of 

a certain biomass or in selected situations to stimulate interest in fishing areas with low 

population densities. Another example is opening a contract fishery specifically for Asian carps 

in areas that are closed to other commercial fishing. This strategy has the advantage that 

populations of Asian carps could be reduced in areas where they do the most damage or where 

there is high potential that they will spread to new areas. While the fishers are free to sell their 

catch, the fishing pressure can remain high even when the price of the fish would not provide 

sufficient economic return. This may be important if populations of Asian carps are reduced 

greatly within an area of high importance for resource management. As with other types of 

harvest enhancement, administering and enforcing the program must be weighed against the 

value of fish removal in the specific area. 

Development of Asian carp products for human consumption and investigation of market 

acceptability of those products should be encouraged. Some methods of processing Asian 

carps (e.g., canning or de-boning) eliminate the issue of boniness (Stone et al. 2000). Canned 

bighead carp compared favorably to tuna in taste tests (Stone et al. 2000). Minced bighead 

carp may be used in fish sticks or patties, fish cakes, fish paste, fish soups, fish surimi (crab 

substitute), fish jelly (kamaboko), or dehydrated fish powder (Stoller Fisheries 2005). The 

minced product resulting from de-boning fish can even be used as a highly nutritious substitute 

for ground meat products, especially in dishes with flavored seasonings or sauces. Other Asian 

carp species could possibly be processed in a similar fashion. Minced Asian carps could 

compete with low-cost fish derived from ocean fisheries, and would be made primarily from the 

white meat portion of the fish. 

Development of products and markets for whole fish, and portions of fish that are not acceptable 

for human consumption, should be encouraged. One problem that must be overcome when 

marketing for human consumption is that bighead carp have a relatively low dressout weight, 

especially when only the white meat portions are used (Engle and Brown 1998). Bighead carp 
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have large heads and, for white meat products, the strip of red meat along the lateral line must 

be removed (Stone et al. 2000), which increases the expense of processing and decreases 

dress-out weight. Even less information on dress-out weight is available for other Asian carps, 

but silver carp have very similar morphology to bighead carp and are likely to have similar 

dress-out weights. Thus, while products made from the white meat may be marketable and 

have a relatively high-value, it would also be beneficial to develop uses, such as pet foods, for 

the remainder of the fish, if such products will be economically feasible. In addition to the 

market for human consumption, there are many other outlets for fish flesh that could potentially 

create demand for large amounts of Asian carps. These include a protein source for livestock 

rations (Maddox et al. 1978), pet food, fish oils for the health food industry, fertilizer, and use as 

bait for crabs, crawfish, or other commercial fisheries. 

Funding and low interest loans to provide the above encouragements should most likely come 

from sources like the Small Business Administration, and/or state commerce departments. 

While use of a wild product would be somewhat outside their normal area of operation, federal 

and state agricultural agencies have experience in encouraging the development of new 

products for agricultural commodities and these agencies should assist in these endeavors. 

Requests for proposals should be requested from private, university, and government entities. 
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Appendix 6.11. Additional Information on “Daughterless 

Carp” Technology 

The concept of “daughterless carp” will provide an elegant and practical solution to reproduction 

of feral Asian carps, if it works. Daughterless carp technology is being developed in Australia 

for controlling the common carp, which is a severe pest there (Department of Conservation 

2003). The Australian Federal Government and the Provincial Governments of New South 

Wales Queensland, Victoria, and South Australia are promoting this concept strongly, with 

substantial funding to conduct research and develop management strategies and techniques. 

The target of Australian efforts is the common carp; however, the basic concept should work on 

other species of fish, including Asian carps. It must be emphasized, however, that the 

Australian program, which began in 2002, is still in the development stage and has not even 

been tested under controlled field simulation conditions to determine the safety and 

effectiveness of the concept. For maximum efficiency, it seems wise to allow the work with 

common carp to progress and to work the “bugs” out of this technology before proceeding with 

another species. Research of daughterless carp technology to control Asian carps should begin 

only after the technology has been applied to common carp in the wild and has shown evidence 

of success. 

Daughterless carp are produced by manipulating common carp genes so that all offspring 

produced by the experimental animals are phenotypically males. When these males mate with 

“normal” females, once again, all offspring are phenotypic males. In theory, as the numbers of 

males carrying the daughterless genes builds to a larger and larger proportion of the population, 

the number of normal females continues to fall. Fewer and fewer females are produced each 

generation until the common carp population is mostly males. The total reproductive potential of 

the population is reduced drastically and the number of common carp in the fish community falls 

to very low levels. The length of time needed to accomplish the desired reduction in common 

carp numbers will be determined by the size of the initial population, the number of daughterless 

males that can be introduced into it, and the capability of the daughterless males to survive and 

function normally within the breeding population. A period of 20 – 30 years has been estimated 

as necessary to reduce common carp populations in Australia to the desired levels (CISRO 

2002), with large-scale production and stocking of daughterless common carp over most of 

those years. In theory, common carp populations can be forced into extinction, but it is not 

known whether or not this can be accomplished in practice. 

The genetic basis of this technology is as follows: Every embryo has the potential to be a 

phenotypic male or a phenotypic female. The actions of specific promoters during embryonic 

development determine the gender that results. Aromatase is the key enzyme responsible for 

stimulating female development at the embryo stage in common carp and other species of fish. 

When this key enzyme is not activated, the embryo becomes a phenotypic male, regardless of 

its genotype. The “daughterless” gene inhibits production of this enzyme. The gene is 

heritable; when these males mature they will produce sperm carrying the “daughterless” gene, 

even if they are genetically female. 

The daughterless genetic sequence is the sequence of genes that inhibits the activation of the 

aromatase enzyme, and is found naturally in all genotypically male common carp (and in many 

other fishes as well). To make a daughterless male common carp, this gene is replicated and 

inserted into multiple other gene locations, so that the offspring of the daughterless carp are 

phenotypically male regardless of whether they are genotypically male or female. Thus, 
210

although the techniques involved in the processes of inserting the daughterless gene into 

common carp chromosomes are considered to be genetic engineering, no interspecies 

transgenic manipulations are required. The daughterless genetic sequence is found naturally in 

the common carp, is species-specific, and, therefore, is expressed only in fish of the species 

from which the material was derived. Risk assessment research would be needed to determine 

if the transgene could be spread to closely related species and what the potential impacts of this 

might be. 

The release of genetically modified daughterless common carp into feral populations is 

predicted to lead eventually to all male populations and, as a result, extirpation of that 

population. This result is, however, dependent upon the daughterless common carp having 

equivalent mating success, survival through early life stages, and survival to maturity in 

comparison to their normal counterparts in the feral population. If the daughterless gene does 

not result in negative natural selection initially or in subsequent generations, the gene should 

spread rapidly through the feral population. Models of these dynamics predict extirpation of the 

target population if sufficient stocking of daughterless common carp is continued over enough 

years. Such models include a series of assumptions that are yet to be verified. Even if a 

slightly lower degree of fitness for the daughterless common carp is assumed, sex ratios 

skewed toward males should result and common carp numbers would be expected to be 

reduced. This technology has potential application not only with Asian carps, but with a variety 

of other nonnative fishes. 

One disadvantage of this technique is that it requires, at its onset, release of additional 

individuals of the species targeted for eradication into the environment. The numbers of 

individuals added would be relatively small in comparison to the size of the total target 

population and the numbers of young fish would start to decline as soon as the fish carrying the 

daughterless gene attempted to spawn. The ecosystem impacts of stocking daughterless fish 

could be minimal in comparison to the long range benefits for bighead, grass, and silver carps; 

however this would need to be further researched. This technique is likely not applicable to 

black carp because, due to their food preferences, introduced individuals could pose a serious 

threat to many of the remaining populations of threatened and endangered mollusks (Nico et al. 

2005). 

The development of daughterless common carp technology should be monitored and if 

successful in common carp control, this technology should be expanded to Asian carps. 

Research to develop daughterless common carp has been under way since 2002. Common 

carp achieve reproductive status at an earlier age than Asian carps and thus are a better and 

faster test of the technology than Asian carps. At this stage of development, expanding the 

technology to Asian carps would constitute duplication of effort. It would be imprudent to invest 

in the production of daughterless Asian carps until successes with daughterless common carp 

are seen. 

Adequately addressing policy, regulatory, and legal considerations related to developing a 

transgenic Asian carp could take many years. Kapuscinski and Patronski (2005) reviewed the 

relevant policy and regulatory considerations related to development and release of a 

transgenic animal for biological control in the United States. It should also be noted that this 

technology is patented by the Australian government, and research in this area should progress 

only with a full understanding of the legal implications, and may require working with the 

Commonwealth Scientific and Industrial Research Organization. 

For additional information on this topic see CISRO (2002) and Thresher et al. (2002). 
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Appendix 6.12. Additional Considerations Regarding the 

Development and Application of Habitat and Hydrological 

Manipulations to Control Feral Asian Carps 

The recommended alternative in the USACE (2004) Final Feasibility Report for the Upper 

Mississippi River-Illinois Waterway (UMR-IWW) System Navigation Feasibility Study includes 12 

categories of restoration measures potentially benefiting 388,281 acres of aquatic and terrestrial 

habitat. Identified restoration measures include: island building, fish passage, floodplain 

restoration, water level management of navigation pools, backwater restoration and water 

management, side channel restoration, wing dike alteration, island protection, increasing 

topographic diversity, and implementing dam-point control. In addition, the USACE’s Report 

includes $205 million in mitigation measures to offset the adverse effects of the proposed 

navigation improvements on the Upper Mississippi River Basin system. Approximately $60 

million of this mitigation cost is targeted to fishery effects. 

It is well within the scope of these restoration and mitigation projects to consider actions to 

prevent the spread, limit the abundance, and minimize the effects of Asian carps on aquatic 

habitats and native fish communities. Restoration planning should occur systemically and 

attempt to identify a mosaic of projects that provide the least possible benefit to Asian carps yet 

achieves pre-determined goals for habitat improvements and native aquatic community 

sustainability. For example, Nico et al. (2005) discussed a number of environmental and habitat 

requirements that are necessary to stimulate black carp to spawn, as well as for the survival of 

eggs and larvae following a spawning event. Habitat restoration planners must understand the 

biological needs of both native and nonnative species and develop plans that will provide the 

greatest benefits possible to native species. 

Habitat manipulations that might be useful in controlling Asian carps include changes in 

floodplain connectivity or the timing of that connectivity, barriers to upstream spawning 

migrations, changes in the timing of releases from reservoirs, or changes in wing dike 

morphology. Asian carps that have been introduced to the United States are rheophilic 

spawners with semi-buoyant eggs that are thought to require a long stretch of flowing water for 

development and recruitment (Soin and Sukhanova 1972; Yi et al. 1988). Juveniles of these 

fish seek out slow moving off-channel habitats (Kolar et al. 2007). Habitat manipulations that 

shortcut these life-cycle characteristics have great potential to control Asian carp populations. 

Blocking upstream migration through the use of low-head dams or other structures would be an 

example of this strategy. Blocking of upstream migration would be especially useful if Asian 

carps are established within a reservoir, because the only available spawning habitat would be 

inaccessible. Similarly, barriers and low head dams could be used to create low-velocity 

sections of river that would allow the eggs to settle to the bottom and die. However, such 

barriers may also prevent upstream spawning migrations or recruitment of native species and 

must be considered cautiously and with a holistic view of the entire biological community. 

It may be possible to design habitats that are very attractive to Asian carps and that 

simultaneously allow their easy removal or to alter habitats that are currently very attractive to 

Asian carps to enhance the ability to remove the fish. For example, habitats attractive to 

juvenile Asian carps might be modified so that they can be fished or drained. The spawning 

habits of Asian carps in the United States are not understood fully, but in China large numbers 

of these fishes spawn in relatively few locations (Yi et al. 1988). It may be possible to identify 

locations where large numbers of carp spawn in the United States and focus fishing in these 
212

areas. It may also be possible to create habitats that encourage spawning in areas where the 

fish may be caught easily, or in which the eggs and larvae are not likely to survive. Adult 

bighead and silver carps are known to congregate in the low water velocity habitats behind 

certain types of wing dikes (unpublished data, Duane Chapman, USGS). Some of these wing 

dikes are easily fishable using standard gears and others are not. Minor modifications to wing 

dike structure might make fishing much more effective, by minimizing escape routes. 

Habitat manipulations may be made that simply benefit native fishes over Asian carps. For 

example, the notching of wing dikes that has been done by the USACE for fish habitat 

improvement may affect Asian carps adversely. Although flow through notches carves scours 

that provide deeper water preferred by adult bighead and silver carps in the Missouri River, 

notching also allows exchange of river water into wing dike pools and increases water velocity 

within the wing dike pool, changes that may not be beneficial to Asian carps (unpublished data, 

Duane Chapman and Robb Jacobson, USGS). Data on wing dike usage by bighead and silver 

carps is being analyzed currently, and may shed light on this issue. The USACE’s recent effort 

to create large amounts of shallow water habitat on the Missouri River should also be evaluated 

in terms of its effect on Asian carps. This effort may inadvertently create hundreds or thousands 

of acres of Asian carp nursery habitat. It is critical that habitat usage of Asian carps be 

understood and that habitat manipulations intended to benefit native fish be considered 

alongside their effects on Asian carps. 

The timing of water releases through dams might be used in Asian carp control. Water rises are 

thought to initiate spawning of Asian carps (Yi et al. 1988). There may be ways to use timing of 

the release of water from dams to interfere with Asian carp spawning or increase their 

catchability. One simple way in which this might be achieved involves the propensity of Asian 

carps to congregate below dams, apparently for spawning or feeding (MICRA 1999; personal 

communication, Duane Chapman, USGS). A short-term slowing of the flow may allow the 

setting of nets and the removal of large numbers of fish. Other methods to control Asian carps 

using flow manipulations might involve floodplain connectivity or timing of spawning. Such 

methods would require further research before they are usable.
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Appendix 6.13. Additional Considerations Regarding the Use 

of Piscicides to Control Feral Asian Carps 

Only two general piscicides and two selective piscicides [3-trifluoromethyl-4-nitrophenol (TFM) 

and Bayluscide®] are currently registered for use in the United States by the USEPA. Both 

selective piscicides are registered only for use to control sea lamprey in the Great Lakes and 

Lake Champlain. 

Selective control of fishes requires that the target fish be more sensitive to the piscicides than 

non-target fishes. Rotenone and antimycin are general piscicides and are primarily used to kill 

all fish in the area of application. There have been rare instances in which these chemicals 

have been used selectively. Willis and Ling (2000), describe a technique for using rotenone to 

control nonnative mosquitofish (Gambusia affinis) in wetlands containing native black mudfish 

(Neochanna diversus), a species twice as resistant to rotenone as mosquitofish. Burress and 

Luhning (1969) and Cumming (1975) used antimycin to remove scaled fish from production 

ponds without affecting channel catfish. Radonski (1967) used antimycin to eliminate yellow 

perch (Perca flavescens) from a Wisconsin lake while leaving the remaining fish unharmed. 

Because bighead, grass, and silver carps are more sensitive to rotenone and antimycin than 

channel catfish in production ponds, these chemicals are potentially useful in aquaculture. 

However, a limited number of studies (Henderson 1976, Marking and Bills 1981, Chapman et al. 

2003) have shown that bighead, grass, and silver carps are not especially susceptible to 

rotenone compared with published toxicity values of most other fish (Marking and Bills 1976, 

Berger et al. 1969). The contact time required to kill bighead, grass, and silver carps using 

rotenone and antimycin requires further investigation. Because treating waters with these 

chemicals to control wild Asian carps would require using concentrations that would also kill 

many native species, rotenone and antimycin should be considered for removing Asian carps 

only when sensitive native species are not present or are of insignificant concern. Other 

obstacles to implementing chemical control of Asian carps in the wild is that no field testing in 

open waters has been conducted to specifically target bighead, grass, or silver carps; the 

sensitivity of black carp to antimycin and rotenone is unknown; chemical treatments are 

expensive and treatment of the Mississippi River and other large rivers in the United States is 

not logistically or economically feasible; chemical treatments would need to be conducted 

regularly; treatments may adversely effect imperiled native species such as the federally 

endangered pallid sturgeon (Scaphirhyncus albus); and treatments would require public and 

regulatory agency support. 

However, there are situations in which using rotenone or antimycin to control Asian carp 

populations may be warranted, especially when Asian carps are congregated in areas from 

which escape is impossible or unlikely such as isolated backwater areas. Larval and early 

juvenile Asian carps are sometimes present in large numbers in intermittently connected 

backwaters after flood waters recede (unpublished data, Nate Caswell, USFWS; personal 

communication, Duane Chapman, USGS). Fish in these waters must remain there until flooding 

reconnects the backwater with the river. While the relative importance of these habitats to 

Asian carps is not understood and other habitats are also used by juvenile Asian carps (Kolar et 

al. 2007; unpublished data, Louise Mauldin, USFWS), their presence in these isolated habitats 

may provide an opportunity to destroy large numbers of juvenile Asian carps before they can 

return to the river. Before treatment, backwaters would need to be assessed for the presence of 

imperiled fishes and the relative abundance of Asian carps. Criteria would need to be 
214

developed to decide which backwaters are suitable for treatment. Economic feasibility and the 

overall efficacy of such treatments in reducing Asian carp populations would also need to be 

evaluated. Other situations in which targeted chemical treatments could be used to control 

populations of Asian carps may occur when the fishes are congregated for spawning or overwintering. Strategic piscicide use could also be useful in reducing the spread of Asian carps by 

increasing the effectiveness of barriers in large river systems. 

Piscicide-laced baits represent a special application of piscicides. Poisoned baits have been 

used to control grass carp (Rowe 1999; Thomas 2004) and common carp (Rach et al. 1994). 

Such applications require training the target fish on unpoisoned bait followed by application of 

the poisoned bait. Although complete removal of grass carp with poisoned bait has not always 

been possible, and mortality of non-target fishes sometimes occurs (Gehrke 2003, Rowe 2003), 

use of rotenone-laced bait such as Prentox® for grass carp may be useful if specific areas 

where grass carp are problematic can be identified. The extremely strong crushing teeth of 

black carp allow them to crush food items that cannot be crushed by any native North American 

fish of similar size. It seems possible that baits for black carp could be devised that would be 

little consumed by native fishes. Ideally, such bait should be of a size and character that would 

not easily break down to smaller pieces which then could be consumed by non-target 

organisms. Development of baits at this time may be premature because the density of black 

carp in the wild is low and the locations to be baited are not understood. Baits should be 

developed if densities of feral black carp increase. Baits could be targeted in areas where black 

carp could potentially feed on threatened and endangered mollusks.
215

Appendix 6.14. Additional Considerations Regarding the Use 

of Biological Controls to Reduce the Abundance of Feral 

Asian Carps 

The introduction of disease agents, parasites, or predators that attack a target species may 

provide methods for biological control of some organisms. For nuisance species, the control 

agent typically is imported from the native range of the target species (i.e., a “natural enemy”). 

It is critical that a biological control agent prey specifically on the target species and not on 

native non-target species. Substantial research, planning, and care are needed to avoid 

introducing additional pest species (Cox 2004). 

Spring viremia of carp virus (SVCV) has been proposed in Australia for common carp control 

(Crane and Eaton 1997), however the use of a disease agent as a biological control is not 

recommended in this plan. SVCV is caused by the virus Rhabdovirus carpio and can 

sometimes cause epizootics and mass mortality of several species of carps, especially common 

carp (Crane and Eaton 1997). However, SVCV is a highly dangerous fish disease, reportable to 

the Office International des Epizootics (Office International des Epizootics 2003). When a case 

of SVCV has been confirmed in the United States by a USDA approved laboratory, the state 

veterinarian and appropriate USDA, Animal and Plant Health Inspection Service, Veterinary 

Services officials must be notified (Hartmann et al. 2004). SVCV has also been isolated from 

several non-carp and even non-cyprinid species. SVCV is not known to have caused the 

eradication of common carp in any place where epizootics have occurred, and populations 

eventually develop some resistance to the virus (Crane and Eaton 1997). SVCV is not likely to 

result in long term control of Asian carps and may be pathogenic in native fishes, especially 

cyprinids, one of the most diverse groups of fishes in North America. Therefore, use of SVCV 

as a biological control agent is not recommended. However, it should be noted that SVCV is 

likely to spread within the Mississippi River Basin without intentional human intervention, and 

may cause localized mass mortalities of carps. 

Predators have been reported to lead to the decline of some Asian carp populations (Kolar et al. 

2007). Stocking predator fishes (e.g., northern pike, walleyes, and largemouth bass) has been 

used commonly by fisheries managers in the past to control early life stages of common carp. 

However, these fish control projects have highly variable effectiveness and rarely have included 

adequate monitoring to truly assess success (Meronek et al. 1996). Programs to stock 

predators as a means of reducing prey populations must consider the size and abundance of 

the predator, the size and abundance of the target prey, the size and abundance of alternative 

prey, and the physical-chemical characteristics of the habitat. Unfortunately, little is known 

about the susceptibility of Asian carps to native piscivores. Experience in aquaculture indicates 

that bighead and grass carps are highly susceptible to predacious fishes (personal 

communication, Mike Freeze, Keo Fish Farm), but little is known about which native predators 

will prey effectively on Asian carps, at what sizes, and the effects of environmental factors or 

habitat types on this relationship. Research is needed to determine which native predator fish 

can effectively prey on Asian carps, the vulnerability (sizes and life stages) of Asian carps to 

predation, and the stocking size and density of predators required for effective population 

control. Most rivers in the United States where Asian carps are abundant are highly turbid 

which may limit effectiveness of sight-feeding predators. It is not known if native predators will 

preferentially consume Asian carps or native prey fish. Stocking of native predators can have 

negative as well as positive effects, and should not be done indiscriminately. Adequate 

evaluation of the effects on both Asian carps and native fish populations should accompany 
216

efforts to control Asian carps through predator enhancement.
217

Appendix 6.15. Additional Education and Outreach 

Recommendations 

Table 6.15. Education and outreach recommendations identified in sections other than Goal 

3.5 are referenced by Goal, Recommendation, and Page number. 

Goal Recommendation Page

3.1 3.1.1.1 Assist states to develop, promulgate, and enforce regulations 36 

 that manage the harvest, transport, import, trade, and release 

 of live wild-harvested aquatic bait. 

 3.1.1.3 Develop and provide information to commercial and recreational 37 

baitfish harvesters that will help prevent accidental and deliberate 

 unauthorized introductions of Asian carps. 

3.1.2.1 Encourage states to develop regulations that prohibit the stocking 39 

of any diploid Asian carps into non-aquaculture waters for 

biological control. 

 3.1.3.1 Encourage states that allow the legal importation of grass carp to 40 

 adopt consistent, uniform regulations that allow only certified 

 triploid grass carp to be shipped or stocked. 

 3.1.3.2 Encourage states to conduct routine and random inspections of 40 

 all live grass carp shipments within the state. 

 3.1.5.2 Encourage states to allow stocking triploid grass carp for 42 

 biological control in non-aquaculture waters only within 

 watersheds where grass carp are already present in the wild. 

 3.1.6.2 Develop and provide information on the USFWS Triploid Grass 43 

 Carp Inspection and Certification Program. 

 3.1.7.2 Inform boaters, barge operators, and others of the risks of 44 

moving infested water and encourage voluntary actions to reduce 

 this risk. 

 3.1.8.1 Natural resources managers should employ pathway management 45 

 tools, such as Hazard Analysis and Critical Control Point planning 

 in the review of Standard Operating Procedures, to prevent 

 introductions of Asian carps through natural resources management 

 related pathways. 

 3.1.8.2 Develop and provide information to natural resources managers 45 

 and field staff that will help prevent unintentional introductions and 

 spread of feral Asian carps. 

 3.1.9.2 Inform USFWS Law Enforcement Officers, other federal 47 

 inspectors, and state conservation law enforcement officers about 

 laws that apply to the import of live Asian carps, the importance of 

 preventing the illegal import of Asian carps, and Asian carp 

 identification. 
218

Table 6.15. Continued. 

Goal Recommendation Page

 3.1.9.3 Inform potential importers of applicable state and federal laws and 47 

 associated risks with international shipments of live Asian carps. 

 3.1.11.1 Urge the development and enforcement of state regulations that 49 

 prohibit the production and use of Asian carps at poorly sited 

facilities. 

 3.1.11.2 Develop and provide information to Asian carp producers and 49 

 growers that will help upgrade poorly sited facilities such that they 

 are no longer high-risk to contain farm-raised Asian carps and 

 prevent accidental introductions. 

 3.1.12.2 Develop an information module on economic and effective 50 

alternatives to replace the use of bighead and black carps on 

aquaculture facilities. 

3.1.13.1 Review Standard Operating Procedures and recommend Best 51 

 Management Practices that include requirements for suppliers and 

 purchasers to conduct inspections of fish prior to shipment and 

 release. 

3.1.13.2 Encourage states to develop regulations that allow for random 51 

 inspections of live fish shipments into and within the state. 

 3.1.13.3 Prohibit the use of surface waters containing Asian carps from 51 

 being used in aquaculture facilities unless effective treatment is 

 in place with a monitoring program. 

 3.1.14.1 Review Standard Operating Procedures and develop Best 54 

 Management Practices for properly sited aquaculture facilities. 

 3.1.14.6 Encourage states to restrict the use of bighead carp on 55 

 aquaculture facilities within watersheds with self-sustaining 

 populations to certified triploids only. 

 3.1.15.1 Where legal for commercial or recreational fishers to possess 58 

 Asian carps, encourage states to prohibit the possession of live 

 wild-caught Asian carps. 

 3.1.15.2 Review Standard Operating Procedures and actions of commercial 58 

 Fishers to identify Best Management Practices that reduce risks of 

 live transport and introduction. 

 3.1.15.3 Develop an information module and provide materials to 59 

 commercial and recreational fishers and commercial live haulers 

 that will help prevent accidental and deliberate unauthorized 

 introductions of Asian carps. 

 3.1.16.5 Develop an information module and provide materials to 61 

 commercial transporters of live farm-raised Asian carps that will 

 help prevent accidental and deliberate unauthorized introductions. 

 
219

Table 6.15. Continued. 

Goal Recommendation Page

 3.1.18.1 Encourage states to prohibit the sale, live transport, and 63 

 unauthorized release of live Asian carps for non-commercial uses. 

 3.1.18.2 Encourage states that allow sales of live Asian carps for human 63 

 consumption to require retail grocers to kill the fish using 

 prescribed humane methods, immediately upon sale. 

 3.1.18.3 Use educational campaigns such as HabitattitudeTM to convey 63 

messages to the public that they should not release live Asian 

 carps. 

 3.1.18.4 Develop an information module and provide materials to 64 

 producers, growers, marketers, and foodfish consumers of live 

 Asian carps that will help prevent accidental and deliberate 

 unauthorized introductions. 

 3.1.18.5 Promote the national Aquatic Nuisance Species Hotline and 64 

 and encourage the general public to report illegal possession or 

 stocking of Asian carps and other activity that could affect an 

 introduction or rapid response. 

 3.1.19.1 Encourage states to prohibit the trade of Asian carps for aquaria 65 

 and hobby purposes. 

 3.1.20.1 Urge states to develop and enforce regulations to reduce risks 66 

 associated with the possession and disposal of Asian carps for 

 research and exhibition purposes. 

 3.1.20.2 Develop an information module and provide materials to the 66 

 academic and research communities that will help prevent 

 accidental and deliberate unauthorized introductions of Asian 

 carps. 

 3.1.20.3 Encourage states to prohibit the trade of live Asian carps by 66 

 commercial biological supply companies. 

 3.1.21.1 Develop an information module and provide materials to 67 

 recreational fishers and boaters that will help prevent accidental 

 and deliberate unauthorized introductions of Asian carps.

3.2 3.2.2.1 Develop and implement redundant barrier systems within 70 

 the Chicago Sanitary and Ship Canal to limit the unrestricted 

 access of Asian carps to Lake Michigan. 

 3.2.2.4 Identify additional containment measures needed to limit 73 

 intrabasin movements of feral populations of Asian carps within 

 the Mississippi River and other basins where established. 

3.2.5.1 Encourage states to identify the location of captive stocks of 78 

Asian carps and to develop a communication network for the 

reporting of escapees. 
220

Table 6.15. Continued. 

Goal Recommendation Page

 3.2.5.2 Create an information sharing system with early detection 78 

 monitoring and rapid response project managers. 

 3.2.6.1 Develop a website and centralized databases to provide 78 

 information on early detection and rapid response programs. 

 3.2.6.2 Develop a list-server to provide a forum for information exchange. 79 

 3.2.6.3 Utilize and support the Nonindigenous Aquatic Species 79 

 Information Center for accurate and spatially referenced 

 biogeographic information and the Nonindigenous Aquatic 

 Species Alert System to track expansion. 

3.3 3.3.3.2 Inform recreational fishers about Asian carp harvest and 85 

 preparation methods. 

3.4 3.4.2.1 Inform and train boaters to avoid damage from jumping silver carp. 94 

3.7 3.7.1.4 Seek “new” funds from various sources to implement this plan. 117 

 3.7.1.7 Develop an effective strategy for communication and coordination 118 

 among those implementing recommendations for management 

 and control of Asian carps.

 
221

Appendix 6.16. Additional Research Recommendations 

Table 6.16. Research recommendations identified in sections other than Goal 3.6 are 

referenced by Goal, Recommendation, and Page number. 

Goal Recommendation Page

3.1 3.1.1.2 Explore the use of baitfish grown in monoculture, and certified to 37 

 be disease-free and uncontaminated by other aquatic species.

3.1.7.1 Investigate fully the risks associated with ballast water transfers 44 

 or other means of water transfer by commercial vessels and 

 recreational watercraft. 

 3.1.12.1 Form a coordinating research group that includes representatives 50 

 from the aquaculture industry, the ethnic retail grocer industry, 

 marketing scientists and developers, aquaculture scientists, and 

 natural resources managers to focus research efforts on the 

 highest priority alternatives to the use of Asian carps. 

 3.1.14.4 Verify functional sterility of triploid bighead carp and develop 54 

 a triploid certification program for bighead carp. 

3.2 3.2.1.1 Develop a Decision Support System to assist natural 68 

 resources managers in prioritizing specific locations for the 

 construction, maintenance, monitoring, or removal 

 of barriers to carp dispersal. 

 3.2.1.2 Evaluate the effectiveness afforded by alternative technical 69 

 containment measures (i.e., physical and behavioral barriers). 

 3.2.1.3 Promote, support, and provide technical analysis and 70 

 comment for the field testing of novel containment methods. 

 3.2.1.4 Anticipate and address consequences of specific containment 70 

 actions on native biological communities. 

 3.2.2.1 Develop and implement redundant barrier systems within the 70 

 Chicago Sanitary and Ship Canal to limit the unrestricted 

 access of Asian carps to Lake Michigan. 

 3.2.2.3 Construct and operate a Sound Projector Array-based 72 

 acoustic bubble curtain fish deterrent at two locks and dams 

 on the Upper Mississippi River to prevent the spread of Asian 

 carps throughout the basin. 

 3.2.2.4 Identify additional containment measures needed to limit 73 

 intrabasin movements of feral populations of Asian carps within 

 the Mississippi River and other basins where established. 

 3.2.3.1 The USFWS and other natural resources management 74 

 agencies should provide technical assistance and biological 

 information to the USACE and participate in collaborative 

 planning of fish passage and habitat restoration 

projects. 
222

Table 6.16. Continued. 

Goal Recommendation Page

 3.2.4.1 Develop an early detection Decision Support System to: 1) 75 

 identify high risk locations susceptible to introductions or range 

 expansions of Asian carps, 2) identify watersheds of special 

 concern, 3) prioritize specific locations for implementing 

 comprehensive early detection monitoring programs. 

 3.2.4.3 Develop and conduct routine early detection monitoring 76 

 programs in locations where risk of introductions or range 

 expansions of Asian carps exists. 

 3.2.4.4 Develop Rapid Response Plans that identify where rapid 76 

 response actions can effectively eradicate Asian carps and 

 how those actions will be carried out. 

3.3 3.3.1.1 Determine life history parameters of Asian carps in the 81 

 Mississippi River Basin. 

 3.3.1.2 Create population, biomass, and recruitment models for 81 

 Asian carps. 

 3.3.2.1 Evaluate gear and harvest method effectiveness, develop 82 

 new gears if necessary, and provide information to 

 commercial fishers. 

 3.3.2.5 Develop new markets for Asian carps. 83 

 3.3.2.6 Determine contaminant concentrations in edible portions of 84 

 feral Asian carps. 

 3.3.5.1 Examine the potential efficacy of introduction of monosex 87 

 tetraploid fish as a control method. 

 3.3.6.1 Adapt “daughterless carp” genetic technology to Asian carps. 88 

 3.3.7.1 Sex pheromone research should continue with the goal of 89 

 production and application of field-applicable technologies.

 3.3.7.2 Investigate aggregation pheromones for juvenile Asian carps. 89 

 3.3.8.1 Provide technical assistance and biological information to the 90 

 USACE and participate in collaborative planning of habitat 

 improvement projects (e.g., Navigation and Ecosystem 

 Sustainability Program, Missouri River Mitigation Project, and 

 other authorities). 

 3.3.9.1 Determine effectiveness of registered piscicides to control 90 

 Asian carps. 

 3.3.9.2 Identify conditions where rotenone or antimycin could be used 90 

 to control populations of Asian carps. 

 3.3.9.3 Determine potential of other chemicals to control Asian carps. 91 

 
223

Table 6.16. Continued. 

Goal Recommendation Page

3.3.9.4 Determine feasibility and applicability of piscicide bait 91 

 deployment to control black and grass carps. 

 3.3.10.1 Develop information on the factors that determine the efficacy 92 

 of native predator enhancement to control Asian carps.

3.4 3.4.1.3 Protect or restore native species through methods other than 94 

 stocking.

3.7 3.7.1.5 Develop criteria and/or performance measures to evaluate 117 

 the effectiveness of management and control efforts.