Skip to main content
U.S. flag

An official website of the United States government

National and South Central CASC-supported researchers assessed the impacts of climate change and the expansion of non-native fish on native Rio Grande cutthroat trout in Colorado and New Mexico. 

Like many fish species across the western U.S, Rio Grande cutthroat trout (RGCT) in southern Colorado and central New Mexico are increasingly threatened by climate change impacts (drought, changes in water temperatures and streamflow patterns) and the encroachment of non-native fish species (increased competition for resources). These two factors are the leading cause of habitat loss and population decline for RGCT which makes addressing them a top priority for local resource managers.  

With support from the National and South Central CASCs, USGS scientists Abigail LynchColleen Caldwell, and their collaborators are working with managers and researchers from local universities and state agencies to address the current lack of data on RGCT’s ability to adapt to increasing stream temperatures and drought conditions, and to explore strategies for possibly limiting the invasion of non-native fish species.

Thus far, researchers have found that RGCT have a lower-than-expected tolerance of warmer water temperatures than their non-native counterparts. This disadvantage may mean that RGCT won’t be able to persist in a changing climate. However, the team’s projections of future RGCT populations indicate that non-native fish pose the greatest threat to RGCT if no intervention is taken. By implementing ‘fish barriers’ to aid in the separation of native and non-native fish, they estimate the probability of RGCT survival could increase eight-fold.  

The research team created a new geonarrative summarizing this research and the impacts of climate change and non-native species to inform management strategies for RGCT in New Mexico and Colorado.  

Get Our News

These items are in the RSS feed format (Really Simple Syndication) based on categories such as topics, locations, and more. You can install and RSS reader browser extension, software, or use a third-party service to receive immediate news updates depending on the feed that you have added. If you click the feed links below, they may look strange because they are simply XML code. An RSS reader can easily read this code and push out a notification to you when something new is posted to our site.