A Comparison of Fish Populations before and after Extensive Grass Carp Stocking

Abstract

Abstract The grass carp, Ctenopharyngodon idella, has been introduced into more than 100 lakes, totaling over 20,000 hectares of water, in Arkansas as a biological weed control agent. The introduction was effective for controlling or eliminating submersed aquatic weeds. There were some significant fluctuations in some aspects of the fish populations in some of these lakes, but the lack of general trends suggests that the introduction of grass carp alone did not produce these fluctuations. An examination of total standing crop, shad biomass, numbers of catchable largemouth bass, sunfish, crappie, and young-of-the-year sunfish and largemouth bass reveals both increases and decreases with no trend in either direction. Plant removal by grass carp did appear to improve the condition factor of largemouth bass, bluegill, and redear sunfish. Other variables such as weather, water level fluctuation, fertilization, or fishing pressure may have a more profound influence upon fish populations. Variation in these para...