The Development of a Bonytail Fish Population in Lake Mead or Lake Powell

Project ID: 2372
Principal Investigator: Mark McKinstry
Research Topic: Ecosystem Needs
Funded Fiscal Years: 2015
Keywords: bonytail, recovery, conservation, propagation

Research Question

Bonytail (Gila elegans) are an endangered species in the Colorado River Basin. Bonytail are likely the most imperiled fish species in the Basin with no known spawning or recruiting populations. Bonytail are maintained in the river strictly through hatchery and stocking operations, but recaptures of stocked fish is extremely rare. In natural situations recruitment apparently fails due to predation on larvae by a host of introduced fish species (Minckley et al. 1991).

While spawning and wild bonytail are not detected anywhere in the Colorado River Basin, captive bonytail have readily spawned in ponds at various hatcheries (M. Ulibarri, USFWS, Southwest Native Aquatics Research and Recovery Center). We propose to develop a scoping proposal to develop a full proposal to construct and build a natural rearing area for bonytail at a river inflow area on either Lake Mead or Lake Powell. This facility would allow adult bonytail to spawn in relatively protected areas (netted) and allow the larvae and young to leave the areas to recruit nearby.

Need and Benefit

The Bureau of Reclamation funds and assists in the management of two Programs responsible for recovering or conserving bonytail--the UCRIP and LCR-MSCP. To date there has been no success in recovering, or even developing stable populations of this fish species anywhere in the Basin. The operation of many facilities and projects requires compliance with ESA and making sufficient progress towards recovery and conservation activities. This proposal is an attempt to explore a different approach for conserving and recovering bonytail.

Contributing Partners

Contact the Principal Investigator for information about partners.

Research Products

Bureau of Reclamation Review

The following documents were reviewed by experts in fields relating to this project's study and findings. The results were determined to be achieved using valid means.

The Development of a Bonytail Fish Population in Lake Mead or Lake Powell (final, PDF, 584KB)
By Mark McKinstry
Publication completed on September 30, 2015

Bonytail Gila elegans is one of four endangered fish species in the Colorado River basin. To date, there has been no measurable success in recovering, or developing stable populations of this fish species outside of a hatchery or controlled pond-type settings. Since 1996, nearly 250,000 Bonytail have been stocked into the upper Colorado River basin. Despite these stocking efforts less than 10,000 (<4%) individuals have been captured or detected via various sampling methods. The longest period between captures was 7 years with most others being at-large less than one year. Due to the poor survival and recruitment biologists from the upper and lower Colorado River basins discussed research-based approaches that may be beneficial to increase survival and recruitment of the species. One supported approach was to release Bonytail into coves within Lake Powell that provide turbidity and cover near the Colorado inflow. The goal would be to establish a population that reproduces in areas that contain habitat necessary for rearing, growth, and potentially recruitment. Under this approach stocked fish would be tracked, reproduction assessed, and recruitment measured through continued monitoring. These approaches are aimed at improving recovery potential.

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Last Updated: 6/22/20