Virgin River Chub

Authors: Kody Callister, Rick Fridell, Martin Schijf, Melinda Bennion

Year: 2022

Abstract

The Virgin River Chub, Gila seminuda, is an endangered fish species currently inhabiting about 16 miles of the Virgin River in Utah, USA. Factors threatening Virgin River Chub include competition with non-native species – specifically Red Shiner, Cyprinella lutrensis, drought, elevated water temperature, decreased turbidity, alteration of natural flow regimes, and fluctuations in spawning and rearing habitat. Capture rates of Virgin River Chub age classes vary with sampling methodology; therefore, the Utah Division of Wildlife Resources (UDWR) has developed a monitoring program for adult Virgin River Chub to supplement previously established fish monitoring programs that effectively sample young chub. Since 2006, UDWR has conducted population monitoring for adult Virgin River Chub using hoop nets set overnight at five sampling stations between Pah Tempe Hot Springs and the Washington Fields Diversion on the Virgin River, with the addition of a station above Webb Hill barrier in 2014. After a steep decline between 2006 and 2007, the number of Virgin River Chub captured during monitoring has varied, but the population appears to be stable. Years with high spring run-off tend to produce a lot of young chub and those young chub persist to maintain a stable population. Since 2016, chub monitoring results have increased to the highest ever catch in 2020, and then fell in 2021, but still represented the 4th highest catch since Virgin River Chub monitoring began.