AbstractWe evaluated the precision of samples and the number of stock‐length fish collected by means of standard methods used for sampling North American freshwater fishes from 2010 to 2013 in Kansas. Additionally, we used resampling procedures to determine the number of gear deployments needed to achieve a relative standard error (RSE) of 25% for the CPUE and collect 100 stock‐length individuals. Median RSE of electrofishing samples was generally less than 25% for Largemouth Bass Micropterus salmoides in all sizes of reservoirs and for Channel Catfish Ictalurus punctatus in medium (251–1,000 acres) and large reservoirs (greater than 1,000 acres). The RSE estimates were generally >25% for Bluegill Lepomis macrochirus and crappies Pomoxis spp. collected in trap nets and palmetto bass (female Striped Bass Morone saxatilis × male White Bass M. chrysops) and Walleye Sander vitreus sampled in gill nets. With few exceptions, 100 stock‐length individuals of all target species (e.g., Largemouth Bass, Bluegill, crappies, palmetto bass, Channel Catfish, Walleye) were not sampled at current levels of effort. Resampling procedures indicated that fewer than 20 deployments were usually needed to obtain an RSE ≤ 25% and 100 stock‐length fish for Largemouth Bass in smaller impoundments (i.e., <250 acres); however, more than 20 deployments were needed in larger impoundments. The median effort needed to achieve an RSE ≤ 25% for Bluegills and crappies in trap nets varied and may exceed what some biologists find practical. Fewer gill‐net deployments were needed to reach an RSE ≤ 25% for palmetto bass and Walleyes than to collect 100 stock‐length fish. Our results indicate that more samples than are currently prescribed are generally needed to precisely sample sport fishes by means of standardized protocols in Kansas reservoirs. In some instances, obtaining precise samples may not be logistically feasible. In these situations, biologists should be aware of the potential shortcomings of sampling protocols and set objectives accordingly.Received May 12, 2014; accepted August 23, 2014
Read full abstract