Bear Lake Sculpin

The Bear Lake Sculpin (Cottus extensus) is the only cottid species found in Bear Lake and is an important prey source for the sport fish community (Dalton et al. 1965; Ruzycki 1995; Ruzycki et al. 1998). The fish is endemic to Bear Lake and is a species of concern within the state of Utah. Bear Lake Sculpin (hereafter referred to as sculpin), mature at age 2 and spawn in cavities of large cobble and small boulders in the littoral zone (Ruzycki et al. 1998). The upper length for sculpin observed in Bear Lake is about 137 mm for females and 173 mm for males with a maximum age of 4 years old (Ruzycki et al. 1998).

The projected increase in frequency and duration of drought conditions under future climate (Seager and Vecchi 2010, Cook et al. 2014, Seager et al. 2007) may reduce the area of submerged littoral zone cobble in Bear Lake due to drought-driven lake level declines. Habitat reductions resulting from increased periods of drought and human water usage could influence fish ecology or biology. We want to test whether (i) a relationship exists between lake level and submerged littoral habitat, specifically cobble, available to fishes and (ii) the response of fishes to persistent declines in available littoral habitat. We hypothesized that drought-driven lake level reductions would decrease the amount of littoral cobble available to fishes and have a negative effect on fish density and year class strength.

Admiring the trawling success: Bear Lake sculpin.