Department of Agriculture Genetic Grant

Razorback sucker (Xyrauchen texanus, hereafter RASU) and bonytail chub (Gila elegans, hereafter BONY) are two of the four species of large, long-lived, endemic fishes that were once abundant and broadly distributed throughout the Colorado River basin (Minckley et al. 2003). Water development and introduction and establishment of non-native species resulted in widespread extirpation and declines in distribution and abundance of these and other native species beginning early in the 20th century.

This effort supports Work Task 40: Genetic and Demographic Studies to Guide Conservation Management of RASU and BONY in Off-Channel Habitats of the Lower Colorado River Multi-Species Conservation Program (MSCP). The project funds efforts to implement one aspect of a multifaceted research and monitoring effort that focuses on endangered RASU and BONY. Despite significant efforts over many years by many groups, these two critically imperiled species continue to decline. This project will evaluate genetic and demographic factors affecting the use of off-channel habitats as management tools for big-river fishes, using RASU as a model system. This will be achieved by genotyping and tracking all adults and samples of their progeny from at least two replicate groups of RASU established in backwater ponds on Lake Mohave, Arizona and Nevada. Characterization of microsatellite variation will allow researchers to assign the parentage of individual progeny to specific adults. Remote sensing information generated from the same locations will allow for the tracking PIT tagged adults, allowing for the determination of their presence in spawning areas at specific times, and to estimate population abundance.

Information generated from this research will provide assessment and direction for the MSCP repatriation program, and provides important information also identified in other MSCP Work Tasks (e.g., Work Tasks B1-B7 related to larval collection, rearing, and stocking of the two endangered fishes [especially Work Task B7: Lake-side Rearing Ponds], Work Task C12: Demographics and Post-Stocking Survival of Repatriated Razorback Suckers in Lake Mohave, Work Task C25: Imperial Ponds Native Fish Research, Work Task G1: Data Management, and other related tasks.

This combination of demographic and genetic information will identify the presence of specific individuals in spawning aggregations and their reproductive success, to contrast effective and census population sizes, and to quantify patterns of survivorship. This basic information is a necessary precursor to full development of off-channel habitats as locations for long-term conservation and management of endangered big river fishes, directly addressing a fundamental goal of the MSCP by enhancing the conservation of the BONY and RASU.

RECIPIENT RESPONSIBILITES

The Recipient shall carry out the Scope of Work in accordance with the terms and conditions stated herein. The Recipient shall adhere to Federal, state, and local laws, regulations, and codes, as applicable, and shall coordinate with Reclamation on all required approvals and permits. The Recipient will be responsible for managing and coordinating all components of the proposed study, including development of experimental design, laboratory testing and statistical analysis, management of collected data, as well as the presentation and reporting of findings.

RECLAMATION RESPONSIBILITES

Reclamation will monitor and provide federal oversight of activities performed under this Agreement. Monitoring and oversight includes review and approval of financial status and performance reports, payment requests, and any other deliverables identified as part of the Scope of Work. Additional monitoring activities may include site visits, conference calls, and other on-site and off-site monitoring activities. At the Recipient’s request, Reclamation may also provide technical assistance to the Recipient in support of the Scope of Work and objectives of this Agreement.

Substantial involvement by Reclamation is anticipated during the performance of activities funded under this cooperative agreement. In support of this Agreement, Reclamation will be responsible for the following:

1. Reclamation will provide technical assistance to the Recipient, as requested, in support of the scope of work and objectives of this agreement.

2. Reclamation will collect and provide the Recipient with adult and larval RASU tissue samples required for genetic analysis.

3. Reclamation will provide PIT tagged live adult RASU for introduction into backwater habitats.

4. Reclamation will provide the Recipient with monthly RASU population data reports for use during the study.