The hybridization between native species and invasive trout could be affected by climate change.
Research suggests warming stream temperatures contributed to the hybridization of native westslope cutthroat trout and introduced rainbow trout in Montana and British Columbia, a U.S.Geological Society news release reported.
Hybridization can lead to the extinction of existing species.
"Climatic changes are threatening highly prized native trout as introduced rainbow trout continue to expand their range and hybridize with native populations through climate-induced 'windows of opportunity,' putting many populations and species at greater risk than previously thought," project leader and USGS scientist Clint Muhlfeld, said in the news release. "The study illustrates that protecting genetic integrity and diversity of native species will be incredibly challenging when species are threatened with climate-induced invasive hybridization."
Westslope cutthroat trout and rainbow trout can produce fertile offspring when they interbreed. If the mating continues only hybrid species will be left.
Over the past 30 years hybridization has spread upstream; genetically pure cutthroat trout now inhabit only occupy about 10 percent of their original habitat.
The spread of hybridization is believed to be linked to dramatic climate changes that took place in the region between 1978 and 2008. River locations that saw the highest rates of warming and changes in stream flow also showed the most hybridization.
The changes could have increased the spawning of rainbow trout, leading to higher rates of hybridization.
"The evolutionary consequences of climate change are one of our greatest areas of uncertainty because empirical data addressing this issue are extraordinarily rare; this study is a tremendous step forward in our understanding of how climate change can influence evolutionary process and ultimately species biodiversity," said Ryan Kovach, a University of Montana study co-author.
These aquatic ecosystems have been experiencing earlier snow melt in the spring as well as hotter and drier summers.
