Final Report: Influences of Changes in Discharge and Stream Temperature on the Persistence Across a sub-set of Rio Grande Cutthroat Trout Populations
Dates
Publication Date
2023-01-31
Citation
Colleen A Caldwell, Brock M Huntsman, Abigail J Lynch, Lauren M Flynn, and Fitsum Abadi, 2023-01-31, Final Report: Influences of Changes in Discharge and Stream Temperature on the Persistence Across a sub-set of Rio Grande Cutthroat Trout Populations.
Summary
We studied the impacts of drought and invasive trout on survival and productivity on Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis, RGCT) populations. Rio Grande cutthroat trout is the southernmost subspecies of cutthroat trout and endemic to the Rio Grande, Canadian, and Pecos River basins of Colorado and New Mexico. The subspecies is reduced to less than 11% of its historic range with most populations occupying isolated high elevation headwater streams. One of the greatest threats to its survival is the effect that low stream flow due to drought will have on this coldwater trout living at the edge of its range. Our work will provide insight into the current and future threats of RGCT populations under environmental [...]
Summary
We studied the impacts of drought and invasive trout on survival and productivity on Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis, RGCT) populations. Rio Grande cutthroat trout is the southernmost subspecies of cutthroat trout and endemic to the Rio Grande, Canadian, and Pecos River basins of Colorado and New Mexico. The subspecies is reduced to less than 11% of its historic range with most populations occupying isolated high elevation headwater streams. One of the greatest threats to its survival is the effect that low stream flow due to drought will have on this coldwater trout living at the edge of its range. Our work will provide insight into the current and future threats of RGCT populations under environmental and biological pressures (e.g., drought and temperature). We investigated the effects of stream temperature, stream flow, and food resources has on time to reproduction, survival, population growth, recruitment of young into the population. We developed population models using these effects to better understand the risks to RGCT persistence under current and projected climate scenarios. Lastly, we explored the consequences of climate on RGCT population productivity through the characterization of the prey base.
