Cooperative Fish and Wildlife Research Units Program: Oklahoma
Education, Research and Technical Assistance for Managing Our Natural Resources

Oklahoma has several self-sustaining populations of paddlefish (Polyodon spathula) andthose at Grand Lake and Keystone Lake are some of the best studied and both provide valuable fisheries for the state. Both reservoirs are eutrophic, but portions of Keystone Lake are classified as hyper-eutrophic. We worked with the Oklahoma Department of Wildlife Conservation (ODWC) to investigate differences in paddlefish ecology in these two systems. Paddlefish diets in both reservoirs contained much more calanoid copepods and the invasive zooplankter Daphnia lumholtzi than what was available in the environment, suggesting selection for these two prey items. While relative abundance of paddlefish was similar between lakes, those at Keystone Lake were heavier for their size with more fat. These results are useful for ODWC biologists to manage paddlefish throughout the state, while also providing information on how lake-specific variations may be manifested in local population dynamics.