Evaluation of Paddlefish Harvest at Osawatomie Dam, Marais Des Cygnes River, Kansas, From 1992 to 2006

Abstract

Paddlefish (Polyodon spathula) are an ancient fish species native to large rivers in eastern Kansas. They were first managed in the state in the 1970s and several snag fisheries have since developed. Osawatomie Dam on the Marais des Cygnes River supports the second most popular Paddlefish fishery in Kansas behind Chetopa Dam on the Neosho River. Mandatory check of harvested fish occurred in the Marais des Cygnes River beneath Osawatomie Dam from 1992 to 2006. These data were recently summarized to quantify harvest during the study period, determine the influence of discharge on harvest, and evaluate effects of a minimum length limit. Mean annual harvest during the study period was 50 fish and annual harvest ranged from 0 fish in four years to 454 fish in 1999. Annual harvest was largely dependent on magnitude and duration of high flows near Osawatomie Dam as measured by the 75th percentile of mean daily discharge (m3sec-1) during annual snagging seasons but was not affected by regulation period. Mean eye-fork length (EFL) of harvested fish was 82 cm across the entire study period, but fish were larger after 2001 (mean = 98 cm) when an 86.4 cm EFL minimum length limit was implemented. These results provide insight into fishery characteristics at Osawatomie Dam and can be referenced for evaluations of this and other Paddlefish fisheries throughout the state.