The Carp are Jumping!

Asian silver carp — known for jumping in large schools when stimulated by watercraft vibrations — can multiply quickly and disrupt river ecosystems. The invasive species is already established in Kentucky and Pickwick reservoirs.

TVA and the U.S. Fish & Wildlife Service (FWS), Tennessee Wildlife Resources Agency, U.S Geological Survey, and several other State and Federal agencies are partnering to prevent the spread of invasive fish in the Tennessee River.

Asian silver carp — known for jumping in large schools when stimulated by watercraft vibrations — can multiply quickly and disrupt river ecosystems. The invasive species is already established in Kentucky and Pickwick reservoirs.

Photo courtesy of U.S. Fish and Wildlife.
Silver carp jumping from the water at Barkley Dam. Photo courtesy of U.S. Fish and Wildlife.

Extensive aquatic surveys by TVA, TWRA and others have shown that silver carp are scarce elsewhere in the Tennessee River system. However, the potential ecological, economic and recreational threat they pose could be devastating if unchecked.

To address the issue, TVA is part of a multiagency carp-deterrent effort led by FWS. While TVA is not the lead agency on the invasive-fish effort, the joint collaboration is generating an effective plan and testing experimental methods that have shown promise for controlling the spread.

“The issue with silver carp is that that they reproduce in large quantity, causing adverse impacts to native fish because they are capable of outcompeting them for food and space,” said Dennis Baxter, TVA’s manager of River & Reservoir Compliance. “They can also be a safety risk to boaters and fisherman. When startled, these fish jump out of the water in droves and can injure boaters.”

TVA helped host a recent virtual-media event designed to facilitate the coordination and conversation to stop the migration of silver carp within the Tennessee River system. You can view a recording of the webinar here. Event partners included the Tennessee Aquarium, Tennessee Wildlife Resources Agency, U.S. Army Corps of Engineers, U.S. Geological Survey, Mississippi, Alabama and Kentucky state fisheries, Tennessee Wildlife Federation and the Mississippi Interstate Cooperative Association (MICRA).  

“Our goal was to provide a forum for sharing information with outdoor media and professional fishermen,” Baxter said. “The briefing included educational reports from participating agencies, including TVA, and an explanation of supporting actions and work that has been done to date. At the heart of this approach is our multiagency alliance that has formed to actively address the silver carp issue.”

TVA’s role includes conducting a Programmatic Environmental Assessment (PEA) to evaluate potential fish-barrier options at 10 lock and dam sites and to consider potential environmental and economic impacts from the installation of Asian carp deterrent systems across the Valley. The PEA is underway and should be final by June 2021.

What is a Silver Carp?

Of the four invasive Asian carp species (bighead, black, grass, and silver) that can be found in the Tennessee River, the most problematic is the silver carp.

Imported to the United States in the 1970s for aquaculture and other purposes, silver carp spread via flooding first into the Mississippi and Ohio rivers, then to the Tennessee and Cumberland rivers. In the Tennessee River, silver carp have been officially documented in Wheeler Reservoir with a reported sighting by an angler as far as upstream as Chickamauga Reservoir.

“Recent efforts from alliance members have shown good potential. This includes commercial fishing at Kentucky Lake, which led to the harvest of nearly 6 million pounds of Asian carp in 2019 and testing of bio-acoustic barriers at Barkley Lake,” Baxter said.

A bio-acoustic fish fence sends a wall of bubbles, sound and light from the riverbed to the water’s surface, which prevents the noise-sensitive fish from entering the lock chamber.