The Effects of Water Development on the Population Connectivity of Burbot in the Upper Wind River Basin, Wyoming

Burbot (Lota lota) are a unique freshwater fish species of ecological, recreational, and cultural importance throughout their Holarctic distribution. In the state of Wyoming, USA, burbot are native to the Wind/Bighorn River drainage where they are a popular sport fish and an apex native predator. Regional declines in abundance and demographic shifts have been observed, spurring increased conservation efforts. One main factor attributed to these declines is water development for agricultural purposes. We used otolith strontium isotope ratios, genotyping by sequencing, and entrainment monitoring to identify the effects of dams and irrigation structures on the source-sink dynamics of the region’s burbot populations at different temporal scales. Otolith strontium ratios indicated little movement between populations, and that fish from irrigation waters were spawned with-in irrigation waters. Genetically divergent groups were observed within both the natural and human-made waters, but little mixing of genetically distinct groups within certain human-made waters suggest regional source-sink interactions are limited. Likewise, low abundances of burbot leaving potential source populations were low. Our findings suggest limited population connectivity currently and predating the implementation of irrigation structures, and will aid fisheries managers in the conservation of burbot within this region, and within other regions affected by water development.