Optimizing sampling protocol for largemouth bass and bluegill in small impoundments

摘要

Fisheries managers need to minimize sampling effort required to provide statistically reliable data for cost effective monitoring and assessment. Shoreline electrofishing methods used to estimate abundance and size structure of largemouth bass (Micropterus salmoides) and bluegill (Lepomis macrochirus) may be affected by seasonal variability of littoral habitat use by these species. A fixed standard of 3 15-minute electrofishing samples did not provide CPUE estimates that we considered precise enoughto consistently use for management decisions on 4 50- to 119-ha Kentucky impoundments. Due to intra-reservoir variability that resulted in occasional over-sampling and, more commonly, under-sampling, we proposed dynamic sample-size protocols that arc unique to each system and derived from reservoir-specific variability. This approach is the equivalent of highly specific stratification by reservoir type and is more consistent with current reservoir-specific management and regulation trends.