Sterile Grass Carp

Certified Sterile Triploid Grass Carp 

  • Native to East Asia
  • Unable to Reproduce
  • 15 Year Life Expectancy
  • Prefer a Hydrilla Diet
  • Will Not Muddy the Water

Timeline of Expectations

Late June – October 2026

Phase One: Acclimation and Initial Grazing 

Released in late June, the 200 young carp are currently acclimating to their new environment and beginning to feed. However, because Hydrilla grows at its fastest rate during the hot peak-summer months, the carp cannot immediately out-eat the active growth. Visible progress will be minimal during this initial summer.

July – September 2026

Phase Two: Volunteer Monitoring

While the carp steadily feed through the warmest months, Aquatic Vegetation Monitoring (AVM) volunteers submit critical monthly reports (July, August, and September). This continuous citizen-science data tracks active growth areas and helps TLAC map exactly where the carp are making an impact. A summary of the AVM reports will be shared with the Smith Mountain Lake Association (SMLA) and Appalachian Power Company (APCO) as reference for their fall surveys.

Fall 2026

Phase Three: Survey Reviews 

The TLAC Environmental Committee reviews the compiled community data alongside professional lake surveys conducted by the SMLA and APCO. This provides a complete picture of the 2026 vegetative canopy.

Spring 2027

Phase Four: Determine Next Steps

Data compiled from the SMLA and APCO surveys, combined with the reports from AVM, will be evaluated to determine the effectiveness of the current population of Sterile Grass Carp and whether a secondary maintenance restocking or other remediative action is necessary. 

Year 2 & Beyond

Looking Ahead

Because biological control is a gradual, cumulative process, an additional stocking may be considered to maintain control of the Hydrilla canopy.

Aquatic Vegetation Monitoring Program (AVM)

The Aquatic Vegetation Monitoring Program (AVM) is a volunteer-supported initiative designed to monitor and document the presence and changes in Hydrilla beds as well as other non-native and/or invasive vegetation in Smith Mountain Lake. The primary objective for the 2026-2027 season is to evaluate the effectiveness of Sterile Grass Carp (SGC) in reducing invasive aquatic vegetation and to track changes in Hydrilla over time. Data collected will be shared in collaboration with APCO, SMLA, and other organizations to support aquatic vegetation surveys.

Monitor Reported Images

Get Involved

If you have invasive aquatic vegetation around your cove or impacting your recreation, consider becoming an Aquatic Vegetation Monitor. The success of AVM relies on a network of volunteers to help us track the changes in vegetation beds over time to support data-driven aquatic management decisions.

It is unlawful to harvest Sterile Grass Carp.

To give these carp the best chance to do their job, please remember that sterile grass carp is not a game fish, and it is unlawful to harvest them from Smith Mountain Lake.

  • Catch and Release Only: If you accidentally hook a grass carp while fishing for other species, please gently release it back into the water immediately.