Habitat Restoration as a Means of Controlling Non‐Native Fish in a Mojave Desert Oasis

Abstract

Non-native fish generally cause native fish decline, and once non-natives are established, control or elimination is usually problematic. Because non-native fish colonization has been greatest in anthropogenically altered habitats, restoring habitat similar to predisturbance conditions may offer a viable means of non-native fish control. In this investigation we identified habitats favoring native over non-native fish in a Mojave Desert oasis (Ash Meadows) and used this information to restore one of its major warm water spring systems (Kings Pool Spring). Prior to restoration, native fishes predominated in warm water (25-32°C) stream and spring-pool habitat, whereas non-natives predominated in cool water (•23°C) spring-pool and marsh/ slack water habitat. Native Amargosa pupfish (Cyprinodon nevadensis) and Ash Meadows speckled dace (Rhinichthys osculus nevadensis) inhabited significantly faster mean water column velocities (MWCV) and greater total depth (TD) than non-native Sailfin molly (Poecilia latipinna) and Mosquitofish (Gambusia affinis) in warm water stream habitat, and Ash Meadows speckled dace inhabited significantly faster water than non-natives in cool water stream habitat. Modification of the outflow of Kings Pool Spring from marsh to warm water stream, with MWCV, TD, and temperature favoring native fish, changed the fish composition from predominantly nonnative Sailfin molly and Mosquitofish to predominantly Ash Meadows pupfish. This result supports the hypothesis that restoring spring systems to a semblance of predisturbance conditions would promote recolonization of native fishes and deter non-native fish invasion and proliferation.

Is Mass Removal an Efficient Measure to Regulate the North American CatfishAmeiurus melasOutside of Its Native Range?

“…In the Grande Briere Mottibre, the invasion of natural habitats (grasslands) by reed beds during the last century has substantially altered ecosystem function (Eybert et al 1998). This habitat modification is Scoppettone et al (2005) demonstrated that habitat restoration could be valuable to control non-native fish species. Consequently, we propose that managers continue the systematic mass removal but in conjunction with natural habitat restoration to more efficiently regulate the black bullhead population in the Grande Britre Mottiere marsh.…”

Advancing Environmental Flow Science: Developing Frameworks for Altered Landscapes and Integrating Efforts Across Disciplines

“…Therefore, feedbacks between individual threats may result in potential unintended Environmental Management consequences from restoration, such as restored flow conditions benefiting non-native species (Marks et al 2010). Although examples of flow regime restoration leading to the reestablishment of native species are apparent in the literature (e.g., Scoppettone et al 2005;Kiernan et al 2012), both positive and negative ecological feedbacks have been observed and predicted (Reich et al 2010). The restoration of a more natural flow regime in New Zealand streams is predicted to allow non-native brown trout Salmo trutta to colonize areas that provide refuges for the native roundhead galaxias Galaxias anomalus potentially leading to the species' extirpation (Leprieur et al 2006).…”

Assessing the Effects of Climate Change on Aquatic Invasive Species

“…Restoring natural flow regimes, including periods of high and low flows, may help reduce populations of invasive aquatic species. In the western United States, the success of non-native fish species can be reversed, in part, by restoration of natural flow regimes (Marchetti & Moyle 2001;Scoppettone et al 2005). …”