Seasonal Abundance, Movement and Diversity of Fishes in an Ozark Stream

Abstract

Seasonal fluctuations in fish abundance in Mud Creek occurred throughout the year at all sampling stations. At the two upper stations abundance was high and unstable during winter and early spring and decreased after heavy rainfall in mid-April. Abundance was low throughout the summer months, increasing in the fall due to large numbers of young-of-the-year. However, a different seasonal cycle occurred at the lower station which included deeper pools. Numbers were low and stable throughout the winter and early spring but high and unstable during the summer. Bigeye shiners (Notropis boops) and bluntnose minnows (Pimephales notatus) were the most mobile species marked. Populations of brook silversides (Labidesthes sicculus) remained fairly isolated, stable, and showed little mobility. Mean species diversity fluctuated during the winter, spring, and fall; diversity values were highest and most stable during summer months when high and relatively stable numbers were collected. The main difference in mean species diversity between stations was the greater stability throughout the year at the upper station