Triploid grass carp are sterile, weed eating fish that often provide effective control of unwanted aquatic vegetation in ponds and lakes.
NC Administrative Code (15A NCAC 10C .0211 POSSESSION OF CERTAIN FISHES) allows triploid grass carp certified to be sterile to be bought, possessed and stocked locally for control of aquatic vegetation under a permit issued by the NC Wildlife Resources Commission.
Grass carp is an exotic species that can have unintended impacts on desirable aquatic vegetation within the waters stocked as well as adjacent waters if the grass carp escape. Aquatic vegetation provides valuable habitat to game and nongame fishes.
Inland, public fishing waters – Anyone stocking public waters must apply for a permit from the NC Wildlife Resources Commission.
Private ponds – The North Carolina Wildlife Resources Commission authorizes the private pond owner to use the receipt from a licensed triploid grass carp distributor as their stocking permit if all the following conditions apply:
Anyone wanting to purchase more than 150 triploid grass carp or stock a pond greater than 10 acres must apply for a permit.
Upon receiving the application, the fisheries biologist in your district, along with regional and state fisheries personnel, will review the proposed request and its potential impacts to the existing fish community, other aquatic organisms, and aquatic habitat in the water body to be stocked as well as downstream. Once a thorough review of the proposed stocking has been completed, the chief of the Division of Inland Fisheries will send you a written response.
A source list of licensed triploid grass carp distributors is available from the NC Department of Agriculture.
The price of grass carp varies with the current supply and demand. Contact a licensed triploid grass carp distributor for a quote.
In most waters, a stocking rate of 10-15 fish per surface acre of water will result in control of unwanted vegetation. The ultimate level of control will depend on the type and amount of vegetation present.
Vegetation identification information is available through N.C. State University and the N.C. Division of Water Resources – Aquatic Weed Control Program.
Private pond owners can also contact the Agricultural Extension Service in their county for additional assistance.
Triploid grass carp are not effective in controlling the following plants: eelgrass, Eurasian watermilfoil, smartweed, stonewort, water hyacinth, American lotus, yellow waterlily, fragrant waterlily, maidencane, dollarweed, alligatorweed, torpedograss, and cattails. These plants are generally characterized as emergent or floating aquatics with sturdy, vascular stems. Grass carp are not recommended for control of these species.
The total elimination of all rooted aquatic vegetation from a pond or lake is not desirable. Vegetation provides valuable habitat that serves as nursery areas, refuges for small fish, and foraging areas. Eliminating this habitat can alter the ecological balance of a water body.
If all rooted vegetation is removed, it is probable that nutrients may express themselves in undesirable vegetation forms, such as dense blue-green or filamentous algal blooms. A body having algal blooms and no rooted aquatic vegetation is more likely to develop summer oxygen depletions that result in fish dieoffs.
Additional information is available through N.C. State University and the N.C. Division of Water Resources – Aquatic Weed Control Program.
Grass Carp Stocking Permit Application
(PDF- opens new window. If possible, complete application online before printing.)
Need to contact your district biologist? Click on the map below.