Relations of Crappie (Pomoxis spp.) Abundance and Size Structure to Hydrologic Connectivity of Oxbows in the Dale Bumpers White River National Wildlife Refuge, Arkansas

The Dale Bumpers White River National Wildlife Refuge is located between Clarendon, Arkansas and the confluence of the White and Mississippi Rivers, a distance of about 91 river miles. This 160,000 acre refuge contains approximately 350 oxbow lakes of various sizes and hydrologic connectivity to the lower White River.  Crappie (Pomoxis spp.) are the most sought after sport fish, and a better understanding of the factors that influence crappie is needed. Oxbow lakes are hydrologically open systems but during periods of hydrologic isolation, crappie are often exposed to variable water quality; high rates of predation by fish, avian, and mammalian predators; and high rates of angling harvest. However, it is possible that recruitment from adjacent rivers during times of hydrologic connectivity may compensate for or exceed the amount of exploitation and mortality from angling pressure, predation, and water-quality stressors.  Our three agencies have initiated what we hope to be a long-term study to improve understanding of how crappie abundance and age or size class characteristics fluctuate in relation to hydrologic connectivity for selected oxbows. This study will compare hydrologic metrics related to flood duration, extent, and timing to crappie metrics related to abundance, age, and size.