Red Tank Draw drainage nonnative fish mechanical removal

Authors: Elizabeth Grube, Brian Hickerson, Anthony Robinson

Year: 2019

Abstract

Restoration efforts to benefit the conservation of native fish through securing native fish from nonnatives and increasing distribution of native fish in the desert southwest has had limited success due to the establishment of nonnative and piscivorous species. During 2016, the Arizona Game and Fish Department began a project in the Red Tank Draw Drainage to remove nonnative piscivorous fish and to expand the range of native species within the drainage. Red Tank Draw is a tributary to Wet Beaver Creek on the Coconino National Forest that supports an assemblage of native fish species including Roundtail Chub, Gila robusta, Longfin Dace, Agosia chrysogaster, Desert Sucker, Catostomus clarki, and Sonora Sucker, Catostomus insignis. Red Tank Draw also supports a compliment of nonnative fishes including Green Sunfish, Lepomis cyanellus, Black Bullhead, Ameiurus melas, and Fathead Minnow, Pimephales promelas. In 2016 the Department began mechanical removal efforts of nonnative fish in Red Tank Draw. After limited initial success a comprehensive survey of the drainage (including two tributaries, Rarick Canyon and Mullican Canyon) and several stock tanks within the drainage was completed in 2017. Green Sunfish and Black Bullhead were detected in Mullican Place Tank and in downstream tinajas in the Mullican Canyon drainage. Fathead Minnow were detected in two tanks and downstream tinajas in the Rarick Canyon drainage in 2017 and Black Bullhead were detected in downstream tinajas in 2018. Mechanical removal of Black Bullhead in Rarick Canyon began in April, 2019 with eradication achieved by August, 2019 after the removal of 14 Bullhead. Removal efforts in Red Tank Draw have been ongoing since the project began in 2016. The size class structure of Green Sunfish has shifted to mostly smaller fish, and fewer Black Bullhead have been detected. A comprehensive approach to the Red Tank Draw drainage allowed for the suppression or eradication of nonnative fishes and will hopefully allow for an increase in distribution of native species. Considering the importance of upstream sources of nonnative fishes and opportunities for creating refugia for native species resulted in a successful approach for native fish conservation and will help inform future efforts.