BLM and partners remove invasive fish from Aravaipa Creek

Considered one of the premier native fish assemblages in the state, Aravaipa Creek supports seven native fish species: roundtail chub, speckled dace, longfin dace, Sonora sucker, desert sucker, and federally endangered loach minnow and spikedace. Additionally, nonnative predatory and competitive fishes, including yellow bullhead and red shiner inhabit the mainstem of Aravaipa Creek and threaten the native fishes. A third nonnative fish species, green sunfish, was successfully removed from Horse Camp Canyon, a tributary to Aravaipa Creek, by the BLM's Safford Field Office and partners in 2015.

Yellow bullhead were first documented in Aravaipa Creek in 1963. Although Aravaipa Creek is monitored bi-annually, the distribution and abundance of yellow bullhead was poorly understood since they are primarily nocturnal and are not easily captured during monitoring. In 2017, fisheries biologist Heidi Blasius and partners started sampling specifically for them to determine their range and abundance throughout the creek. The data gathered in 2017 coupled with dietary data from 2005-2006 elucidated the threat from Yellow Bullhead to the Aravaipa Creek native fishery. To address the threat, the BLM and partners began mechanical removal in 2018.

To expedite the removal of yellow bullhead and to cover the entire creek at one time, biologists with expertise and experience in nonnative fish removal were recruited to participate in a large-scale mechanical removal effort. A total of 51 biologists from three states, Arizona, New Mexico, and Texas united at Aravaipa Creek in late March and early April 2021 to remove nonnative Yellow Bullhead that threaten the survival of the native fish community. Participants represented:

• the BLM's Safford and Lake Havasu field offices and Arizona State Office;
• the U.S. Fish and Wildlife Service’s Pinetop, Parker, and Tucson offices; 
• the Bureau of Reclamation’s Glendale office; 
• the Arizona Game and Fish Department’s Phoenix and Tucson offices;
• the U.S. Forest Service’s Albuquerque and Alpine offices;
• the U.S. Geological Survey’s Flagstaff office;
• the Nature Conservancy’s Aravaipa Canyon Preserve;
• the University of Arizona;
• Gila Watershed Partnership;
• Arizona-Sonora Desert Museum;
• Marsh and Associates; and
• private citizens 

To make the removal more manageable, Aravaipa Creek was divided into three reaches, west, canyon, and east. Crews were comprised of anywhere from five to seven biologists and sampled all likely yellow bullhead habitat encountered, including slow-moving pools, woody debris, vegetation, and undercut banks. 

During the first week, one crew, comprised of seven biologists, worked the west-end, and removed 243 yellow bullhead. For the second week, six crews were evenly split amongst the three reaches (two crews on the west end, two crews in the canyon, and two crews on the east-end) and collectively removed a total of 1,920 yellow bullhead. 

Protecting and recovering native desert fishes and their habitats across the southwest will require partners working cooperatively across geographic and jurisdictional boundaries as funding limitations, lack of personnel, and limited coordination within agencies will make it impossible for any agency or any individual to do it alone.