Assessing the potential for rainbow trout reproduction in tributaries of the Mountain Fork River below Broken Bow Dam, southeastern Oklahoma
Stocked trout (Salmonidae) in reservoir tailwater systems in the Southern United States have been shown to use tributary streams for spawning and rearing. The lower Mountain Fork of the Little River below Broken Bow Dam is one of two year-round tailwater trout fisheries in Oklahoma, and the only one with evidence of reproduction by stocked rainbow trout (Oncorhynchus mykiss). Whether stocked trout use tributaries in this system for spawning is unknown. Furthermore, an inventory of the resident fish communities in these tributaries is lacking. To address these gaps, we surveyed 10 tributaries, from intermittent through third order, for fishes during presumed spawning periods of rainbow trout; we used backpack electrofishing in February and April 2015 and 2016 to determine the composition of the fish assemblages and whether trout were present. Stocked adult trout were found in three tributaries in 2015; wild juvenile rainbow trout were found in Bee Branch in 2015 and in an intermittent tributary of Spillway Creek, just above the “Cold Hole,” in 2016. Fish assemblages were dominated by highland stonerollers (Campostoma spadiceum) in larger, wider systems and by orangebelly darters (Etheostoma radiosum) in smaller, narrower streams. These data fill an information gap in our understanding of small streams in the Ouachita Mountains, and they demonstrate that some streams are suitable for rainbow trout reproduction.