Date of Award


Document Type


Degree Name

Master of Science



First Advisor

William S. Woolcott

Second Advisor

Eugene G. Maurakis


The goal of this study was to demonstrate the feasibility of using triploid ·Ctenopharvngodon idella (grass carp) to control Hydrilla verticillata in the Waste Heat Treatment Facility (WHTF) in Lake Anna, Virginia. The four objectives were to determine: the frequency of occurrences of grass carp over hydrilla; the proportions of hydrilla to other aquatic macrophytes in the guts of grass carp; effects of physical and chemical factors on movement of grass carp; and a theoretical stocking rate of grass carp for the WHTF. Frequency of occurrence of grass carp over hydrilla was calculated to be 84% and correlated with impoundment size. The proportion of hydrilla in the guts of two adult triploid grass carp captured from Lake Anna averaged 88%. Physical and chemical factors had no significant effects on movements of triploid grass carp. There were no statistical correlations between fish movement and final location to water chemistry and presence/absence of hydrilla and other macrophytes. A theoretical stocking rate of grass carp to control the approximate biomass of hydrilla in the WHTF was calculated to be 6, 134 fish. This theoretical stocking rate is consistent with the stocking rate employed by the Department of Game and Inland Fisheries of seven fish per acre of infestation or approximately 6,800 grass carp to control hydrilla in the WHTF in Lake Anna, Virginia.

Included in

Biology Commons