Large-bodied piscivore removal project from a warm water riverine system

Authors: Clayton D. Crowder, Anthony T. Robinson

Year: 2014 (xlvi)

Abstract

Fulfilling objectives identified in the multi-agency Blue River Native Fish Restoration Project to protect and restore the native fish assemblage within the Blue River drainage in eastern Arizona, personnel from Arizona Game and Fish Department completed four efforts to remove nonnative piscivorous fishes from an 18.6 km portion of the lower Blue River. Removal efforts occurred in June of 2009, 2012, 2013, and 2014. Snorkeling equipment, including spear fishing poles and guns, was used to target and remove large-bodied nonnative piscivorous fish (i.e., flathead Pylodictis olivaris and channel catfish Ictalurus punctatus) and common carp Cyprinus carpio. In 2009, surveyors removed 70 channel catfish, 4 flathead catfish, and 1 common carp, and 3 rainbow trout, Onchorhyncus mykiss. Removal efforts resumed in June 2012, after a fish exclusion barrier was completed at the downstream end of the removal reach, and large-scale fish kills associated with the Wallow Fire of 2011 had occurred. Seven channel catfish were removed in 2012, three channel catfish in 2013, and surveyors did not detect any large-bodied piscivorous fish in 2014, indicating that this large-bodied piscivore removal project may have succeeded.