Asian Carp in Tennessee
*Red indicates known distribution of Asian Carp in Tennessee
Asian Carp in Tennessee and Management Efforts
There are four species of Asian carp in the United States and in Tennessee. All are from the Yangtze and Amur River systems in China. They were imported into the United States for various aquaculture purposes back as early as 1970. They were unintentionally introduced into the waters of our country in the late 1980’s and early 1990’s when they escaped from aquaculture ponds in the delta areas of the Mississippi River during extreme floods.
All four Asian carp species were first found in the Mississippi River, where they are still abundant, and they migrated into Tennessee waters via locks at Kentucky and Barkley dams. Carp are also known to have entered Reelfoot Lake during high flows through its spillway. All four Asian carp species can affect the fish and aquatic life in numerous ways.
This species of Asian carp consume microscopic zooplankton. Zooplankton is an important part of the diet for many native fish such as shad, buffalo, and paddlefish. Larval sport fish such as crappie, bass, and bluegill also depend upon zooplankton in their early life stage. Bighead carp are problematic because they compete with our native species of fish for food and space. Bighead carp can grow as large as 100 pounds. This species is thought to be most abundant in the lower reservoirs of the Tennessee and Cumberland rivers, but a few individuals have been observed as far upstream as Nickajack Reservoir.
This species of Asian carp eats microscopic algae and zooplankton. They are problematic for the same reasons as mentioned for the bighead carp. They compete for food and space with our native species. In addition, when silver carp are startled they have a tendency to leap out of the water and can jump as high as eight feet. Therefore they are even more problematic because of the potential to injure boaters, jet skiers, and water skiers. Silver carp can grow as large as 60 pounds. In the Tennessee River Silver carp are most abundant in Kentucky Reservior, with an emerging population in Pickwick Reservoir as well. The most upstream report of Silver Carp on the Tennessee River was Wheeler Reservoir in Decatur, Alabama. On the Cumberland River they have been observed as far upstream as Cordell Hull Dam.
This species of Asian carp eats snails and mussels. It was brought into the U.S. to control snails in commercial catfish ponds. Snails serve as a host for parasitic worms that get into fish flesh thus making catfish meat unappealing. Eliminating the snails eliminates the parasitic worms. Black carp are problematic because they could eat the many species of snails and mussels that are native to Tennessee. A 70 pound black carp was caught by a commercial fisherman in the mouth of the Obion River on the Mississippi River in 2012. Until recently black carp had only been reported in the Mississippi River. Since 2017 there have been a few documented catches of black carp in Barkley and Kentucky reservoirs .
Grass carp, also known as White Amur, eat aquatic vegetation. This species was introduced into the U.S. to control excess aquatic vegetation (weeds) in commercial catfish ponds. Grass carp are a concern because they eat many types of aquatic vegetation and much of this vegetation provides excellent cover for a variety of sport fish such as largemouth bass, crappie, and bluegill. Many species of aquatic vegetation also provide food for waterfowl. Reproductively sterile grass carp are commonly used to manage aquatic vegetation in small lakes and are legal to stock in private lakes and ponds as long as they are sterile (triploid). Grass carp can reach sizes in excess of 80 pounds. Grass carp are increasingly a cause of concern because recent testing of grass carp in wild populations has revealed that many of these fish are not the sterile variety, and so they can and likely have been reproducing when they get the right conditions.
Why is the Tennessee Wildlife Resources Agency Concerned About Carp?
The most immediate concern is for the safety of boaters. Silver carp are known to jump when disturbed by boats. A jumping carp that collides with a passenger in a moving boat can cause serious injury. This scenario is most common in shallower waters and boaters should slowly retreat from areas with jumping carp to avoid impact.
Asian carp have the capacity to deplete and alter the current food web of the reservoirs that support natural resources, including highly-valued recreational and commercial fisheries. As mentioned above silver and bighead carp are both filter feeders that feed on microscopic plankton. This plankton is vital food for some species of fish, and young fish of all species. By outcompeting native fish for a limited resource, the silver and bighead carp have the ability to reduce growth rates of native fish or displace them almost completely. The black carp pose a risk to Tennessee’s diverse and already threatened mussel fauna.
While there is still much concern about large schools of carp in Kentucky and Barkley reservoirs, TWRA biologists report that the abundance of native fish (crappie, shad, bass, etc) are still within the normal range of natural fluctuations. In addition, when a large school of Asian carp move into an area, they will displace many of the native species in that area. Although the native fish will return when the Asian carp move from the area, fishing patterns will be disrupted while the Asian carp are present.
Asian Carp Management is a National Effort
Asian carp are a national problem and control of carp is a national effort. Tennessee representatives actively serve on the Ohio River Asian Carp Task Force where they work collaboratively with other state representatives, the U.S. Fish and Wildlife Service, Tennessee Valley Authority, and U.S. Army Corps of Engineers in the Ohio Basin to make the best use of the limited federal dollars that are available for carp control in our basin. Tennessee is also an active participant in the Mississippi River Interstate Cooperative Resource Association, an organization of 28 states and federal agencies that are working together to lobby for additional carp management funds. Find out more... http://www.asiancarp.us
Controlling the Spread of Asian Carp in Tennessee
It is illegal to move live carp in Tennessee. TWRA continues to spread the message about carp to reduce the likelihood that someone will accidently move them as bait. TWRA annually cautions against bait bucket introductions in the annual fishing regulations, “The Angler’s Guide to Tennessee Fish” publication, through lake-side signs, fishing shows, and other presentations annually. One of TWRA earliest outreach efforts was a video filmed with Bill Dance, shown on this website.
Unchecked, Asian carp will eventually use the navigation locks on Tennessee and Cumberland rivers to spread their range upstream. Each time a lock opens and closes fish have an opportunity to move up and down the river. TWRA and other participants in the Ohio River Asian Carp Task Force identified a need to conduct research on carp movement, especially as it related to lock passage. As a result TWRA received funding to evaluate the movement of carp in the Tennessee River, including Mississippi and Alabama sections. This research effort lead by Tennessee Tech University started in late 2016 and is expected to continue through 2020. Over one hundred carp are tagged with sonic transmitters, and they are being tracked throughout the river system by passive receivers. This research will tell us how and when the carp are using areas of the reservoirs, and it will also be used to evaluate newly-developed technology that could create barriers at locks.
Silver Carp Educational Video with Bill Dance - Produced in 2005
Sound Barriers for Carp at Locks
Asian carp are extremely sensitive to sound. Researchers at the U.S. Geological Survey and U.S. Fish and Wildlife Service have developed techniques to use underwater sound to “scare” fish in controlled settings. In concept, these sounds would be able to prevent carp from using the locks, while native fish that are less sensitive to sound would continue to use the locks. The next step is to test this theory and that test has been tentatively scheduled to begin in the spring of 2019 at Barkley Dam in Kentucky. Multiple state agencies including TWRA support this effort. This location was chosen because carp are abundant immediately below the dam, so the barrier would be tested repeatedly by the abundant carp. The sonic tagging and tracking work that TWRA is funding will allow this technology to be deployed and evaluated at strategic locations throughout the Tennessee River.
Removal of Asian Carp
In areas where Asian carp are already established, there is still a need to reduce their numbers. This will reduce their threat to boaters and aquatic resources. Carp removal is also strategic to controlling the spread of carp because upstream movement is thought to be less likely if the population in the current reservoir is not too high. These mechanisms are not fully understood but to be on the safe side TWRA is encouraging carp harvest .
While more high-tech solutions may eventually be developed, commercial fishing is presently the most practical method to reduce the abundance of Asian carp in Tennessee waters. The industry was slow to respond to the market possibilities, but the abundance of Asian carp has now attracted private industry into purchasing and processing Asian carp for consumer use. Commercial fishing has the ability to remove millions of pounds of carp annually. At the recommendation of the Tennessee General Assembly’s Asian Carp Task Force, TWRA funded a $75,000 grant in 2017 to the Paris Henry County Industrial Committee to develop local commercial fishing businesses for carp. As a result recipient businesses have increased their interest in harvest of Asian carp. TWRA is currently drafting another plan to provide even more incentives to commercial fishers and wholesale fish dealers (buyers). On May 18, 2018 the Tennessee Fish and Wildlife Commission approved a $500,000 budget request to provide incentives for the commercial harvest of Asian carp in Kentucky, Barkley, Cheatham, and Old Hickory lakes.
Many potential consumers of Asian carp are wary of eating a fish named “carp” that they know little about. To promote carp as food, TWRA serves Asian carp at a few events each year. If more people appreciated carp for its great taste and texture, the agency believes demand should increase along with the price of harvested carp. This increased value would generate additional commercial harvest of carp. TWRA has also been working with product labeling consultants to develop carp label standards that would let the buyer know that purchasing that product will help natural resources.
TWRA encourages bowfishers and bowfishing tournaments to consider a carp-only format.
For example, on June 23, 2018, TWRA partnered with the KY Department of Fish and Wildlife Resources to host a carp-only bowfishing tournament.
During the 12-hour events 81 boats harvested 17,000 lbs of Asian carp, predominantly silver carp.
TWRA has been intensively monitoring carp for several years and in the early days of their invasion TWRA first collected Asian carp in the Mississippi River. Later, fisheries staff were responding to sporadic calls about carp in Kentucky Reservoir and Reelfoot Lakes, but in past five years TWRA Region 1 Fisheries staff have incorporated carp monitoring in their routine samples multiple times each year.
Monitoring carp abundance is also an important component of TWRA supported research at TTU. It is critical that we have repeatable methods to monitor the carp abundance so that we can evaluate the success of control and removal strategies. The harvest of Asian carp by commercial fishers is also reported monthly.
In 2015 Asian carp had a successful spawn somewhere in the Ohio/Tenn/Cumberland system. These fish represent nearly all of the silver carp that are collected on the reservoirs today. Details about the production of this cohort are not known. Since 2015 TWRA has been intensively monitoring Kentucky and Barkley reservoirs to determine when and where they are spawning. Such information could prove useful in carp removal efforts. Monitoring efforts include light-trap surveys and special traps for juvenile carp.
TWRA investigated multiple fish kills that appeared to be carp specific in the spring and fall of 2017. Thousands of carp were observed dying in shallow water and samples of dying fish were sent to diagnostic labs for testing Results suggested that a bacteria commonly found in Tennessee waters, Aeromonas hydrophila contributed to the fish dying .
TWRA annually monitors the status of gamefish species such as bass and crappie. They also monitor the abundance of their prey species - gizzard and threadfin shad. In addition to these ongoing efforts, they are also monitoring the condition of gizzard shad to see if they are being impacted by carp. Gizzard shad are thought to be a good indicator species because their diet most directly overlaps with silver and bighead carp. This data will allow biologists to determine impacts of Asian carp on population densities and condition of both important prey and game species.
The agency will continue to post information about Asian carp and efforts to combat the growth and expansion of these fish into our waters. Please keep informed and help spread the word to help stop the spread of Asian carp in Tennessee’s lakes and rivers.