Effects of Water Level Manipulation on Abundance, Mortality, and Growth of Young-of-Year Largemouth Bass in West Point Reservoir, Alabama-Georgia

Abstract

Water level manipulation was examined as a potential management technique for increasing recruitment of largemouth bass (Micropterus salmoides) in a reservoir where prey availability and utilization were major factors influencing the largemouth bass population. Raising the water level above normal summer pool inundated terrestrial vegetation and provided cover for young-of-year (YOY) largemouth bass. A positive relationship was observed between early survival of YOY largemouth bass and water level during the spawning period. In the post-spawning period, survival rate and abundance of YOY were related directly to water level, but growth was inversely affected. Average standing stock of YOY largemouth bass in August was similar during the 5 years of study, indicating the system supports a particular biomass, and growth decreased when greater number of young were added through enhanced survival. Results of this study suggest that, unless carrying capacity and food availability for YOY largemouth bass are increased concurrently with water level, use of this technique may not result in a strong year class.