Comparison of Single-cod and Dual-cod Trap Nets for Sampling Crappie in Texas Reservoirs

Fisheries Outstanding Technical Paper

Shoreline-set single-cod trap nets are the standard gear used by Texas Parks and Wildlife to assess crappie (Pomoxis spp) populations. In some reservoirs, standardized trap net catch is too low to provide the desired information. In 2006, we compared offshore-set dual-cod trap nets to shoreline-set single-cod and offshore-set single-cod trap nets in ten Texas reservoirs. Catch rates of shoreline-set single-cod trap nets (13.4 fish per net night; F/NN) were similar to each end of the offshore-set dual-cod trap nets (27.1 F/NN when both cod-ends were summed) and all were statistically greater than offshore-set single-cod trap nets (8.0 F/NN). In 2007, we compared shoreline-set single-cod trap nets to offshore-set dual-cod trap nets for one and three night soak times in eight reservoirs and offshore-set dual-cod trap nets only for one and three night soak times in five reservoirs. Like 2006 results, catch rate per cod-end in 2007 was similar in shoreline-set single-cod trap nets (7.8 F/NN) and offshore-set dual-cod trap nets (25.9 F/NN when both cod-ends were summed). Multiple-night sets did increase overall catch, but did not increase catch rate proportional to soak time. In general, offshore-set dual-cod trap nets tripled the overall catch compared to shoreline-set single-cod trap nets, but catch per cod-end was similar. Personnel time required for multiple-night sets was similar to single night sets, therefore catch can be increased without additional labor cost. Offshore-set dual-cod trap nets and/or multiple-night sets may be effective alternatives for fisheries managers desiring to increase overall catch of crappie.

Starting page
125
Ending page
130
ID
61146