Declines in native trout populations Salmonid populations in general have been declining due to numerous factors, including invasive species, hybridization, wildfires, and climate change. Native salmonid fish in the western and southwestern United States are threatened by non-native species that were introduced decades ago. Non-native salmonids were introduced to enrich recreational fishing; however, they quickly started outcompeting and displacing native salmonids upon their arrival. Non-native, invasive species are quick to adapt to their new environment and learn to outcompete any native species, making them a force the native salmon and trout have to reckon with. Not only do the non-native fish drive the native fish to occupy new niches, but they also try to hybridize with them, contaminating the native gene construction. As more hybrids between native and non-native fish are formed, the lineage of the pure fish is continuously being contaminated by other species and soon may no longer represent the sole native species. The Rio Grande cutthroat trout (Oncorhynchus clarki virginalis) are susceptible to hybridization with other salmonids such as rainbow trout (Oncorhynchus mykiss) and yield a new "cutbow" trout, which is a contamination of both lineages’ genes. One solution to this issue is implemented by New Mexico Department of Game and Fish hatcheries: stock only sterile fish in river streams. Hatcheries serve as a reservoir of fish for recreational activities but growing and stocking non-sterile fish would worsen the hybridization issue on a quicker, more magnified time scale. By stocking sterile fish, the native salmonids can't share genes with the non-native hatchery fish, thus, preventing further gene contamination of the native trout in New Mexico. Fire is also a factor in deteriorating Gila trout (Oncorhynchus gilae) populations because of the ash and soot that can enter streams following fires. The ash lowers water quality, making it more difficult for the Gila trout to survive. In some New Mexico streams, the native Gila trout will be evacuated from streams that are threatened by nearby fires and be reintroduced after the threat is resolved.
Declines in native trout populations Salmonid populations in general have been declining due to numerous factors including invasive species hybridization wildfires and climate change Native salmonid fish in the western and southwestern United States are threatened by non-native species that were introduced decades ago Non-native salmonids were introduced to enrich recreational fishing; however they quickly started outcompeting and displacing native salmonids upon their arrival Non-native invasive species are quick to adapt to their new environment and learn to outcompete any native species making them a force the native salmon and trout have to reckon with Not only do the non-native fish drive the native fish to occupy new niches but they also try to hybridize with them contaminating the native gene construction As more hybrids between native and non-native fish are formed the lineage of the pure fish is continuously being contaminated by other species and soon may no longer represent the sole native species The Rio Grande cutthroat trout (Oncorhynchus clarki virginalis) are susceptible to hybridization with other salmonids such as rainbow trout (Oncorhynchus mykiss) and yield a new "cutbow" trout which is a contamination of both lineages’ genes One solution to this issue is implemented by New Mexico Department of Game and Fish hatcheries stock only sterile fish in river streams Hatcheries serve as a reservoir of fish for recreational activities but growing and stocking non-sterile fish would worsen the hybridization issue on a quicker more magnified time scale By stocking sterile fish the native salmonids can't share genes with the non-native hatchery fish thus preventing further gene contamination of the native trout in New Mexico Fire is also a factor in deteriorating Gila trout (Oncorhynchus gilae) populations because of the ash and soot that can enter streams following fires The ash lowers water quality making it more difficult for the Gila trout to survive In some New Mexico streams the native Gila trout will be evacuated from streams that are threatened by nearby fires and be reintroduced after the threat is resolved