Populations of Colorado River cutthroat trout (CRCT) have experienced dramatic declines throughout their historic range. Current distributions of CRCT are typically limited to isolated headwater streams and lakes. Primary threat to the CRCT is the introduction of non-native salmonids and loss of habitat. A fish barrier on Dirtyman Creek was placed on BLM administered lands to prevent invasion of non-native salmonids and maintain a genetically pure population of Colorado River cutthroat trout. However, the existing structure has degraded over time and needs to be replaced before the integrity of the barrier is lost. The goal of this project is to prevent non-native fish from invading upstream of the existing barrier thus maintaining a genetically pure population of CRCT. Funding for this project would cover hiring a contractor to remove and replace the degrading fish barrier on Dirtyman Creek.
Declines in populations of CRCT have limited current population distributions to isolated headwater streams and lakes. Dirtyman Creek is one example of an isolated headwater streams in the Colorado River basin. Previous conservation efforts in Dirtyman Creek included the removal of non-native fish species, construction of a fish barrier, and re-introduction of genetically pure CRCT. However, the construction of the barrier occurred over 20 years ago and is degrading and needs to be replaced. The BLM actively participates in the Conservation Agreement for Colorado River Cutthroat trout in the states of Colorado, Utah, and Wyoming. Implementation of this project coincides with Objective 2 “secure and enhance conservation populations” of the Conservation Agreement by restricting the introduction of non-native fish species by constructing (maintaining) in channel barriers to maintain sources of genetically pure CRCT. Recently, the CRCT was petitioned for listing under the Endangered Species Act (ESA). Protection of headwater populations is one of the first steps in restoring populations of CRCT to other streams within their native range. Replacing this fish barrier in cooperation with the Wyoming Game and Fish Department and private landowners would protect this important headwater population of CRCT. Ultimately, implementation of projects like replacing the fish barrier on Dirtyman Creek will help prevent CRCT from listing under the ESA.
The fish barrier is located on BLM administered lands near private land. The current landowner is in support of the project and would allow access through private land. This would reduce the overall time needed for travel and reduce the cost and time needed to complete the project. Recent sampling in Dirtyman Creek by the BLM, WGFD, and USFS has indicated a healthy population of CRCT. Replacement of the barrier was recommended and encouraged by the WGFD. Due to recent ESA petitioning of the CRCT and conservation agreement for the species, many biologists engaged in native fish conservation within the Colorado River Basin are interested in the project. Implementation of this project would ensure a healthy population of of CRCT in Dirtyman Creek.
2010 Update: There was no fisheries biologist for several months consequently work was not done this field season. This project is planned for fall of 2011 after high flow is over.
2011 Update: Due to the high water year and complications with finalizing land owner access and maintenance agreements the barrier will not be installed until 2012. The WGFD is completing land owner access agreements with two private landowners and completion of this is anticipated during the winter of 2012. These documents are currently under legal review by both parties. In addition changes to the final design required additional funding. The additional funding for this project was secured during this Fiscal year. Changes to the final design also required new interdisciplinary clearances (e.g., cultural and wildlife) and these were completed this year Dirtyman (1120) 1 JF, 2 JG, 1 JH, 1 JI.