Is there an alternative to using the western mosquitofish, Gambusia affinis? Meet the Arroyo chub, Gila orcutti, a California native

Arroyo chub, Gila orcutti, a fish endemic to Southern California watersheds, has been proposed as a replacement biological control agent for the invasive Western mosquitofish, Gambusia affinis, in sensitive watersheds throughout southern California. Survival and efficacy of the chub at controlling larval mosquitoes, specifically Culex tarsalis, the Western encephalitis mosquito, will be evaluated at the Prado Wetlands in Orange County, California. Mosquito-eating fish are not strictly larvivorous in their diets and have the potential to impact non-target organisms, leading to trophic shifts in systems where they are introduced. We will study the impact of predation by the chub on the aquatic community that co-occurs with larval mosquito populations, specifically the macroinvertebrate and planktonic communities. The chub has been designated as a “Species of Special Concern” by Cal. Dept. of Fish and Game and the long-term goal is to provide Vector Control Districts with a native alternative to Gambusia, while helping to enhance the chub population and return the fish to its native range.