Estimations of Fish Population Size and Sampling Efficiency of Electrofishing and Rotenone in Two Kentucky Tailwaters

Abstract

Two mark-and-recapture techniques were used to estimate the size of fish populations in tailwaters below two flood-control reservoirs. The use of electrofishing for both mark and recapture was generally unsuccessful. Capture of fish by electroshocker for marking and rotenone for recapture was more successful but was influenced by handling mortality and site selection. Capture efficiency of electrofishing ranged from 5 to 54% for eight species while capture efficiency for rotenone ranged from 36 to 100%. This study illustrates the difficulty of obtaining valid population estimates for multi-species, riverine fish communities.