Influence of Stream Temperature on Eight Populations of Rio Grande Cutthroat Trout in Northern New Mexico
Dates
Start Date
2016-01-15
End Date
2019-12-30
Citation
Caldwell, C.A., B. Huntsman, and A.J. Lynch. 2020. Influence of Stream Temperature on Eight Populations of Rio Grande Cutthroat Trout in Northern New Mexico. https://doi.org/10.21429/kbmw-6z60
Summary
The impacts of climate change on cold water species will likely manifest in populations at the trailing edge of their distribution. Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis, RGCT) occupy arid southwestern U.S.A. streams at the southern-most edge of all cutthroat trout distributions; thus making RGCT particularly vulnerable to the anticipated warming and drying in this region. We collected stream temperature and stream drying to determine how these environmental constraints influence life-history trait expression (length- and age-at-maturity), demography, and extirpation risk in RGCT populations from northern New Mexico, U.S.A. We found the rate at which RGCT reached maturity was highest at warm to intermediate stream [...]
Summary
The impacts of climate change on cold water species will likely manifest in populations at the trailing edge of their distribution. Rio Grande cutthroat trout (Oncorhynchus clarkii virginalis, RGCT) occupy arid southwestern U.S.A. streams at the southern-most edge of all cutthroat trout distributions; thus making RGCT particularly vulnerable to the anticipated warming and drying in this region. We collected stream temperature and stream drying to determine how these environmental constraints influence life-history trait expression (length- and age-at-maturity), demography, and extirpation risk in RGCT populations from northern New Mexico, U.S.A. We found the rate at which RGCT reached maturity was highest at warm to intermediate stream temperatures, which was the demographic trait most strongly linked to RGCT persistence. Interestingly, older life-stages contributed more to population growth as temperatures decreased, providing further evidence of strong temperature effects controlling life-history trait expression in RGCT.
The purpose of the data collected was to assess the impacts of stream temperature on the life-history traits, persistence, and productivity of Rio Grande Cutthroat Trout (Oncorhynchus clarkii virginalis, RGCT) populations. The stream temperature provided insight into the current and future threats of RGCT populations under environmental and biological pressures (e.g., drought, temperature). We empirically assessed the effects of stream temperature and intermittency on life-history traits (i.e., age- and length-at-maturity) and vital rates (i.e., apparent survival, population growth, recruitment); and developed population models from these vital rate relationships with respect to environmental temperature and flow to better understand the risks to RGCT persistence.
