Good news for Rio Grande
Cutthroat conservation effort shows success, is testament to hard work
A multi-pronged effort to save remaining populations of Rio Grande cutthroat trout has paid dividends.
The U.S. Fish and Wildlife Service announced earlier this month that the Rio Grande cutthroat trout, one of three remaining native trout species in Colorado, has recovered to the point the fish no longer needs the protection of the Endangered Species List.
The news doesn’t mean the fish completely is out of danger but it illustrates the success of a multi-pronged conservation effort.
“The conservation of the Rio Grande cutthroat has been a high priority for more than 20 years,” said John Alves, Southwest Senior Aquatic Biologist for Colorado Parks and Wildlife. Alves has been working on Rio Grande cutthroat restoration since 1991 and has been a member of the Conservation Team since 2003, when the initial range-wide species protection plans were designed.
“This news is a marker of success on many levels and a testament to the years of hard work by the conservation team,” Alves said
The conservation plan included wildlife agencies from Colorado and New Mexico along with three American Indian tribes and several federal agencies as well as private landowners and Colorado Trout Unlimited and the New Mexico Council of Trout Unlimited.
The other native trout species in Colorado include the Colorado River cutthroat and the Greenback cutthroat. The fourth — the Yellowfin cutthroat in the Arkansas River drainage — is extinct.
A continuation of the original Rio Grande cutthroat conservation agreement was signed just last March as the members waited for the Fish and Wildlife Service’s listing decision.
Alves emphasized the fish, first described in 1541 by gold-seeking Spanish explorers, never was entirely threatened by extinction thanks to pro-active conservation efforts dating from the 1970s by Colorado Parks and Wildlife.
The efforts included restoring Rio Grande cutts to historic habitats from which non-native fish were removed, creating conservation populations, monitoring populations, and genetic testing.
Several factors led to the demise of Rio Grande cutthroat, historically confined to streams in southern Colorado, northern New Mexico and possibly Texas.
Competition and genetic dilution by non-native trout species, particularly brown trout but also brook and rainbow trout, is considered the biggest threat to the survival of Rio Grande cutthroat populations.
Habitat loss, over-grazing and potential drought also contribute to the decline in Rio Grande cutt populations.
Today, Rio Grande cutthroat trout are found in only 12 percent of the historic habitat in approximately 800 miles of stream, mostly on private land, in headwaters of the Rio Grande in southern Colorado and north-central New Mexico.
Biologists estimate that 127 conservation populations now exist in the two states, and 57 of those populations are considered to be secure.
Colorado Parks and Wildlife recently produced a population modeling sample that predicts Rio Grande cutthroat will persist at least through 2040.