The impact of introduced grass carp on the aquatic and wetland plant communities of a western Washington lake

The state of Washington allowed grass carp to be stocked at Silver Lake in southwestern Washington to monitor the impact of this species on the lake ecosystem. Three years after introduction of grass carp, the biomass and cover of aquatic plants remarkably decreased and boat navigation was no longer hindered. This led to increased sports fishing pressure and a potential for the decline in native bass. Colder winter temperatures and greater age of the carp led to a decline in feeding rate. The grass carp also showed a preference for submersed plants over emergent plants.