Sunfish and Bullhead Removal for Native Fish

Introduction

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Red Tank Draw is located primarily in the Coconino National Forest in north-central Arizona. It flows into Wet Beaver Creek downstream, and its drainage also includes upstream Rarick and Mullican Canyons. Each of these canyon reaches contain stretches of perennial pools that enable several distinct native fish species to survive. Red Tank Draw contains a perennial range of approximately 2.4 km, isolating non-native fish movement upstream from Wet Beaver Creek. This isolation may be due to a 7.7 km stretch of intermittent to ephemeral stream conditions further downstream that block fish movement seasonally, with the potential for fish passage fish passage
Fish passage is the ability of fish or other aquatic species to move freely throughout their life to find food, reproduce, and complete their natural migration cycles. Millions of barriers to fish passage across the country are fragmenting habitat and leading to species declines. The U.S. Fish and Wildlife Service's National Fish Passage Program is working to reconnect watersheds to benefit both wildlife and people.

Learn more about fish passage only during high flows. Native species in Red Tank Draw drainage include Roundtail Chub (Gila robusta), Longfin Dace (Agosia chrysogaster), Desert Sucker (Catostomus clarkii), and Sonora Sucker (Catostomus insignis). As such, Arizona Game and Fish Department deems Red Tank Draw a “high priority” to manage and conserve native aquatic species (AZGFD 2014). 

Roundtail Chub, a species of cyprinid, in Red Tank Draw are of particular concern for conservation and management. The Red Tank Draw population was formerly classified as “Gila Chub (Gila intermedia)” before a 2014 reclassification as “Roundtail Chub (Gila robusta)”. Although the American Fisheries Society does not recognize them, Gila Chub are still federally recognized as endangered, recognized in New Mexico as endangered, and remain a species of concern in Arizona. Roundtail Chub populations that were formally recognized as Gila Chub face several conservation challenges, including habitat degradation and the introduction of non-native species, and Arizona Game and Fish Department therefore manages them in accordance with the 2014 Gila Chub recovery plan. This includes reducing the negative impacts from established populations of non-native Green Sunfish (Lepomis cyanellus), Black Bullhead (Ameiurus melas), Fathead Minnow (Pimephales promelas), and Northern Crayfish (Faxonius virilis) in Red Tank Draw, since they are predators of native species like Roundtail Chub and outcompete them for limited water resources. 

Key Issues Addressed

Green Sunfish, native to eastern North America, and Black Bullhead, native to central North America, have established populations in perennial waters in Red Tank Draw. Once established, complete eradication is difficult to achieve as suppressed populations are quick to recover and can recolonize new areas rapidly. Typical control methods for non-native fish include biocides (difficult to approve and implement) and mechanical removal (time intensive). Both methods are most effective in closed and isolated systems, and mechanical removal is often effort intensive to ensure that suppression or eradication has been achieved. To better protect native species, biologists from Arizona Game and Fish Department are working to mechanically remove non-native Sunfish and Bullhead, while expanding local populations of Roundtail Chub, through the Red Tank Draw Native Fish Restoration Project. Red Tank Draw was selected by project biologists because it contains complex habitat with side channels and deep pools; it is also relatively isolated from non-native fish invasions downstream from Wet Beaver Creek.

Project Goals

• Conduct baseline surveys to determine feasible locations for native fish restoration in Rarick and Mullican Canyons
• Suppress or eradicate Green Sunfish and Black Bullhead based on survey results
• Recover native fish such as Roundtail Chub by expanding populations 

Project Highlights

Restoring Native Fishes: Effective Sunfish and Bullhead removal efforts have led to increasing numbers of native Roundtail Chub in Red Tank Draw. 

• Widespread Stream Surveys to Inform Conservation: Biologists surveyed all of Red Tank Draw to prioritize areas best suited for native fish conservation. Extensive surveys that included three to five person field crews quantified the number and location of perennial pools and stock tanks throughout each basin. Visual surveys were used to detect non-native fish presence in deeper waters. A combination of angling, dipnets, and seines were used to detect native and non-native species in stock tanks. In addition, the team identified two waterfalls that served as a natural barrier to upstream fish movement in Rarick Canyon.
• Working with Site Access: A point source for non-native Sunfish (a stock tank) was identified on private land that limited sampling access in Mullican Canyon. Project biologists therefore adapted and re-focused efforts on Rarick Canyon, located on National Forest lands, expanding the scope of this project from Red Tank Draw to a broader drainage-level effort that included the upper canyons.
• Increasing Numbers of Native Fishes in Red Tank Draw: While Sunfish eradication has not been achieved, biologists have found decreased size structure structure
  Something temporarily or permanently constructed, built, or placed; and constructed of natural or manufactured parts including, but not limited to, a building, shed, cabin, porch, bridge, walkway, stair steps, sign, landing, platform, dock, rack, fence, telecommunication device, antennae, fish cleaning table, satellite dish/mount, or well head.
  
  Learn more about structure , e.g. mostly small juveniles with few large adults within the Green Sunfish population since they started mechanical removal efforts. This trend, coupled with Bullhead eradication, has led to a 10-fold increase in catch per unit effort of Roundtail Chub from 2018 to 2019.
• Roundtail Chub Translocations: With non-native fish eradicated, suitable habitat identified, and natural barriers from waterfalls that prevent re-colonization, 319 juvenile Roundtail Chub (<100mm Total Length) were collected and translocated from Red Tank Draw into three canyon pools in Rarick Canyon.
• Non-Native Aquatics Treatment Techniques: Project members sampled each year from April through August and used a combination of methods for non-native fish removal. Backpack electrofishing was primarily used in the perennial stretches of Red Tank Draw, while passive fishing gear such as mini-hoop nets was used in deeper pools. Overall, Green Sunfish populations were suppressed and Bullhead were eradicated in Red Tank Draw, and it is now two years since the last bullhead detection. Mini hoop nets, Swedish gill nets, and snorkeling with spears were used for mechanical removal in the isolated pools and tanks in Rarick Canyon. Here, Bullhead were successfully removed.

Lessons Learned

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Extensive baseline surveys were critical for implementing non-native Sunfish and Bullhead removal. By taking the time to survey the entire drainage, project members determined feasible and practical locations for non-native fish removal. Initial assessments included visual surveys within-stream locations and were also scaled to above Red Tank Draw drainage to include stock tanks, another source of non-native fish. Baseline surveys and monitoring also prioritized pools in Rarick Canyon for Chub translocations. Favorable pool conditions included pools that were usually >2m deep and between 10-15m wide, already supported fish (in this case, non-native Bullhead or Minnows), and provided complexity through large rock, tree rootwads, submerged organic debris, or undercut cliff walls for cover as well as and shade from direct sunlight. 

Baseline surveys also indicated why the project team was not successful in eradicating green sunfish from Red Tank Draw. From these surveys, they were able to identify a point source for green sunfish contribution located on private land in Mullican Canyon. Project biologists were unable to obtain access to remove sunfish from two stock tanks on this land. Accordingly, project members remained flexible to achieve project goals, and subsequently adapted to focus their efforts on Rarick Canyon. 

The success of native species recovery documented here stemmed from concentrated removal efforts and initiatives to seek new opportunities when facing setbacks, such as blocked land access to the point source in Mullican Canyon. This has been time and effort intensive, but necessary to ensure favorable conditions for native species. Bullhead were effectively eradicated while Green Sunfish were suppressed within Red Tank Draw. Sunfish were not present in Rarick Canyon, while the team re-focused efforts to remove Bullhead and Fathead Minnow from isolated pools and stock tanks. Having a viable Chub population in Rarick Canyon will be critical if nonnatives outcompete other populations elsewhere in Red Draw Tank basin.

Eradication is also challenging without isolating native populations or having a fish barrier. Success in Rarick Canyon in part stems from natural dry barriers during intermittent stream flows. Utilizing natural barriers, such as the two natural waterfalls in Rarick Canyon, was essential to prevent future upstream movement and recolonization of both non-native species. This also supported Roundtail Chub translocations upstream of these barriers to ensure that translocations would not be a waste of time and effort. Native species recovery and conservation therefore results from a combination of habitat surveys, intensive non-native removal, and long-term monitoring to prevent future invasions. 

Next Steps

• Sites will continue to be monitored for recolonization and additional sites will be included to remove non-native species throughout the Red Tank Draw drainage.
• Project members will continue to actively work with local landowners to make progress with native fish conservation in Mullican Canyon.
• Continued monitoring of translocated Roundtail Chub in Rarick Canyon is necessary to assess population viability.
• In fall 2019, project members deployed temperature loggers in pools in Rarick Canyon to better understand annual temperature variation.
• In 2020, temperature loggers will be retrieved and data will be analyzed to determine temperature suitability for future native Roundtail Chub translocations to Rarick Canyon. Native Gila Topminnow, which are at the edge of their native habitat range in Red Tank Draw, will also be considered for translocations to Rarick Canyon depending on the results from the temperature loggers. 

Funding Partner

• Bureau of Reclamation: Central Arizona Project (CAP) Funds Transfer Program

Resources

• CCAST Webinar July 2020
• Arizona Game and Fish Department. 2014. Verde River Watershed Management Plan. Phoenix, AZ.
• AZGFD species page: Green Sunfish
• AZGFD species page: Black Bullhead

Contacts

• Betsy Grube, Gila River Basin Native Aquatic Wildlife Specialist I, Arizona Game and Fish Department: egrube@azgfd.gov
• Tony Robinson, Gila River Basin Native Fishes Lead, Arizona Game and Fish Department: trobinson@azgfd.gov
• Brian Hickerson, Gila River Basin Native Aquatic Wildlife Specialist III, Arizona Game and Fish Department: bhickerson@azgfd.gov

Case Study Lead Author

• Alex Koeberle, CART Research Specialist, University of Arizona, akoeberle@email.arizona.edu

Suggested Citation

Koeberle, A.L. (2020) “Sunfish and Bullhead Removal for Native Fish Recovery in Red Tank Draw.” CART. Retrieved from https://www.fws.gov/project/sunfish-and-bullhead-removal-native-fish.