Influence of Reservoir Characteristics on Collection of Representative and Precise Fish Samples: Implications for Determining Minimum Sampling Effort

Effective reservoir fisheries management requires representative and precise samples of fish populations. These samples are typically obtained with fish sampling gears using standardized protocols. Some standardized protocols for sampling reservoir fishes promote objective-based sampling, and many include a minimum number of gear deployments. This minimum number is often a function of reservoir surface area. However, reservoir size may not adequately predict number of gear deployments needed to obtain particular measures of catch and sample precision. We used multiple linear regression to determine relationships between physical, chemical, and biological characteristics of reservoirs and the number of gear deployments needed to sample 100 stock-length fish (N100) and to obtain relative standard error of stock-length catch-per-effort (CPE) ≤ 25% (RSE25). These analyses were conducted using data from 34 Kansas reservoirs and six fish species. The variable explaining historic CPE was identified in N100 models for six target species and RSE25 models for five. Conversely, reservoir surface area was identified in only one model for N100 and two for RSE25. These results suggest that reservoir characteristics other than surface area, particularly historic CPE, should be considered when developing minimum sample sizes for objective-based fish sampling protocols.