Evaluation of Paddlefish Length Distributions and Catch Rates in Three Mesh Sizes of Gill Nets

Abstract

–We evaluated the length distribution and catch rates of paddlefish Polyodon spathula collected in three mesh sizes of gill nets in Keystone Reservoir, Oklahoma, during the winters of 1996–1998. In all, 1,454 paddlefish were collected in monofilament gill nets with bar measures of 127, 152, and 203 mm. Mean lengths of paddlefish increased with increasing mesh size. The smallest and the largest mesh sizes caught age-0 paddlefish in 1996, a year when 152-mm mesh was not used and the only year we collected age-0 paddlefish. Median catch rates for all sizes of paddlefish were highest in 152-mm-mesh net and lowest in 127-mm-mesh nets. For population size and age structure sampling, we recommend a range of mesh sizes (e.g., 127–203 mm) to collect the broadest size range of paddlefish. To collect sexually mature fish for broodstock, we recommend using large mesh sizes (e.g., 152 and 203 mm) to increase catch rates of adult paddlefish and reduce bycatch of other species. Net height (4.6–9.1 m) and duration of net set (16–22 h) did not significantly influence catch rates. Other gill-net variables (e.g., net length) need to be evaluated to determine their potential influence on catch rates of paddlefish.