Triploid Grass Carp Stocking for Aquatic Vegetation Management in Parksville Reservoir/ Ocoee #1

Polk County, Tennessee

The Tennessee Valley Authority (TVA) has issued a final environmental assessment (EA) and finding of no significant impact for its proposal to introduce certified sterile (triploid) grass carp into TVA’s Ocoee Project #1 Reservoir, locally referred to as Parksville Reservoir, to control the spread of the invasive aquatic plant, hydrilla. Grass carp eat aquatic vegetation, including hydrilla, and therefore are an effective measure to address infestations of hydrilla that would otherwise continue to spread.  Triploid carp are sterile and cannot naturally reproduce, which enables the fish populations to be easily monitored and controlled without chance of long term establishment. Stocking grass carp is cost effective, provides long term aquatic vegetation management, and reduces the need for large scale herbicide and mechanical management techniques.

In recent years, invasive aquatic plants have continued to spread within the TVA reservoir system, causing environmental and economic impacts.  Currently, hydrilla occurs in roughly 182 acres (10 percent) of Parksville Reservoir.  Unabated, hydrilla has the potential to spread into the rest of Parksville Reservoir, and potentially to other reservoirs in the TVA system. Hydrilla is capable of rapid growth and reproduction given ideal growing conditions. Hydrilla plant fragments can also be easily transported from one water body to another via recreational and commercial boating. The control of hydrilla increases the overall health and function of newly affected reservoirs, which is an important environmental stewardship objective of TVA’s Natural Resources program.

TVA released the draft EA for a 30-day public review period.  TVA received one letter during the comment period and it was incorporated into the final EA.