CRAIG PAUKERT AND WILLIAM FISHER, Oklahoma Cooperative Fish and Wildlife Research Unit, Oklahoma State University, 404 Life Sciences West, Stillwater, Oklahoma 74078, USA

Paddlefish Polyodon spathula are native to the Arkansas River, including Keystone Reservoir in northcentral Oklahoma. Since creation of the reservoir in 1964, there have been anecdotal reports that paddlefish are increasing in abundance; however, to date there has been no surveys to verify this. Our objective was to determine the abundance and distribution of the paddlefish in the Arkansas River below Kaw Dam, the lower Cimarron River, and Keystone Reservoir. In winter 1996, paddlefish were captured in large-mesh gill nets at 19 randomly selected sections of the reservoir. Captured fish were measured, weighed, and jaw tagged with a monel tag. Eighty-four percent of the 443 fish collected were in the Cimarron River arm, 12% in the Arkansas River arm, and 4% in the main pool. Catch rates were significantly higher in the Cimarron River arm than the Arkansas River arm and main pool, but the mean size of fish in the Cimarron Arm was smaller. Using a modified Schnabel procedure, we estimated a population of 7,779 paddlefish (95% C.I. of 5,734 - 26,044) for 1996. Limited spawning occurred in 1996 because of low water flow in the Arkansas and Cimarron rivers. We will compare these findings with those from winter 1997 collections to identify potential trends.