Study recommends nasty bubble curtains to fence Asian carp in Tennessee waters


Seven dams on the Tennessee River are expected to have barriers installed to mitigate invasive Asian carps that pose problems for native fish and can even injure boaters, according to a final environmental assessment by the Tennessee Valley Authority last week.

“Fish barriers in the Kentucky, Wilson and Pickwick locks should be immediately installed, followed by installation in the Guntersville, Nickajack, Chickamauga and Watts Bar locks,” a press release on the assessment read.


Asian Carp Mitigation Final Programmatic Environmental Assessment, November 2021


Although TVA is not the agency responsible for controlling the spread of Asian carp in the Tennessee River, the Federal Public Service conducted the assessment to support a national multi-agency effort including the Tennessee Wildlife Resources Agency, the US Fish and Wildlife Service and 28 other agencies. with the fisheries management competence to control Asian carp in the river system, TVA officials said in the statement.

(READ MORE: Tennessee officials optimistic about progress in Asian carp control but worried about the future)

Currently, the Kentucky and Wilson Dams are expected to have the first barriers installed once funding is secured, and the remaining installation schedule will be determined as funding is received, according to TVA. Congressional funding is needed to install the barriers because the effort involves multiple states.

Photo gallery

Study recommends nasty bubble curtains to fence Asian carp in Tennessee waters

The barriers will be a combination of bio-acoustic fish fences and carbon dioxide emitters designed to prevent Asian carp from entering a dam’s airlock with a curtain of nasty bubbles. When the lock opens, the barrier emits sound, light and bubbles to keep Asian carp away from the lock. Tests conducted by the US Fish and Wildlife Service and other agencies at the Barkley Dam in Kentucky indicate that barriers prevent the movement of fish upstream when boats stop through the dam.

Construction of the fence at Barkley Lake began in July 2019 and preliminary field test data “showed the fence to be approximately 98% effective in preventing all sizes of Asian carp from entering the lock. “, indicates the evaluation. An image of a silver carp was reportedly taken in Chickamauga Lake in 2019, but state officials said the fish are not yet spawning.

The barrier plan has an opponent in Watts Bar Ecology and Fisheries Council chairman Tim Joseph, an expert in fisheries biology who says the state plan is backward and speculative. The first barrier should be installed at Watts Bar Lock to protect the still uncontaminated upstream waters of the Tennessee River above the dam between Meigs and Rhea counties, he argues.

Joseph, who has been critical throughout the planning of the barriers so far downstream, said in a November 8 letter to TVA that the presence of silver carp at Chickamauga means that the fish are already appearing upstream and that now is the time to stop their movement before it is too late.

State and federal planners “never considered the impacts of fish exceeding the upper four lakes and never calculated the economic decline or devastation of the ecosystem. They only speculated on the best way. to slow them down, ”Joseph said in the letter. The current plan “would allow an invasive species to gain access to the upper basin, which would have disastrous consequences for thousands of landowners, boaters, fishermen, businesses and nine local county governments, while destroying the ecological health of the only four remaining carp. free lakes. “

Joseph said in an email Tuesday that he plans to bring the issue to Governor Bill Lee.

TVA spokesperson Scott Fiedler said the utility recognizes the potential threat posed by carp to the river system.

“We are partners in the process and will continue to be involved in a partnership to support efforts to mitigate their spread,” he said in an email Tuesday.

National Wildlife Agency Fisheries Chief Frank Fiss spoke about the ideas of the Watt’s Bar group in February, saying the state has a broader view of the regional problem and is seeking an interstate solution by teaming up with d ‘other agencies.

“These are the groups that we do our planning and research with, and that is the group that we base our decisions on,” Fiss said at the time.

The wildlife agency’s Harmful Aquatic Species Coordinator Cole Harty said on Tuesday that actions taken in the lower Tennessee River would benefit all of its reservoirs, including Watts Bar and reservoirs upstream from there.

“Our problem is migration. We have been monitoring breeding in the Tennessee and Cumberland rivers since 2016 and have not seen successful breeding,” Harty said.

(READ MORE: Asian carp gathering in Kentucky opens new front in battle)

Congressional funding was not allocated to the project, Harty said. He noted that the assessment can still be changed as new information on carp develops.

Asian carp were first imported in the 1960s and 1970s as a potential food fish and to improve water quality on fish farms, according to the assessment. Intentional stocking, accidental releases and escapes allowed Asian carp to establish themselves in the Mississippi River watershed in the 1980s, and since then have dramatically expanded their range throughout the watershed. of the Mississippi, including the Tennessee River.

Asian carps are generally large fish that prefer large, warm, turbid, slow-flowing rivers, but also inhabit reservoirs, lakes and ponds. Adult Asian carp can reach over 80 pounds and live for over a decade. A large female Asian carp can produce up to a million eggs per year.

Contact Ben Benton at or 423-757-6569. Follow him on Twitter @BenBenton.


Comments are closed.