Characteristics of Two Self-sustaining Populations of Paddlefish in Northeast Oklahoma

Abstract

Oklahoma has several self–sustaining populations of paddlefish (Polyodon spathula) that support sport fisheries, including Grand Lake O’ The Cherokees (Grand Lake) and Keystone Lake. The Oklahoma Department of Wildlife Conservation (ODWC) has operated a Paddlefish Research Center (PRC) on Grand Lake since 2008, which has increased communication with paddlefish anglers and provided information about fishery–dependent population trends, suggesting declines in overall fish size. Whether these declines were unique to Grand Lake or indicative of a broader pattern were unknown. Comparing angler harvest and paddlefish population characteristics between these two self–sustaining populations would aid managers in conserving this species in Oklahoma. Thus, I sought to: 1) determine differences in fishing pressure between reservoirs and, 2) estimate and compare characteristics of these two paddlefish populations. Post–season paddlefish angler surveys indicated no significant difference in per–angler effort (days fishing per angler) between the two reservoirs in both 2010 and 2011. However, Grand Lake had significantly higher per–angler harvest. Paddlefish gillnetting data from winter 2010 and 2011 showed no significant difference in relative abundance between the populations although, differences in length frequencies, relative weights, growth and reproductive condition were documented. Mean lengths, relative weights and gonadal fat indices for both male and female paddlefish from Keystone Lake were significantly greater than those from Grand Lake, while gonadosomatic index values were significantly greater for females from Grand Lake.