Greenback Cutthroat Trout

Greenback Cutthroat Trout
Name	Greenback Cutthroat Trout
Status	Threatened
Status system	ESA
Genus	Oncorhynchus
Species	clarkii
Subspecies	stomias
Authority	(Cope, 1874)

Greenback Cutthroat Trout The greenback cutthroat trout is a native North American freshwater fish historically associated with high-elevation streams and lakes in the Rocky Mountains. First described during 19th-century explorations, the taxon has been central to conservation actions involving federal agencies, state wildlife agencies, and non-governmental organizations after declines from introduced species, habitat alteration, and overharvest.

Taxonomy and Description

The taxon is classified within the genus Oncorhynchus and recognized as the subspecies stomias of Oncorhynchus clarkii following 19th-century descriptions by Edward Drinker Cope and later revisions by ichthyologists linked to institutions such as the Smithsonian Institution and the American Fisheries Society. Diagnostic characters historically used by taxonomists at the Museum of Comparative Zoology and the Natural History Museum, London include body coloration, scale counts, and gill raker counts, with early specimens compared during surveys by the United States Geological Survey and expeditions organized by the Hayden Geological Survey of 1871. Modern genetic analyses published by researchers affiliated with the University of Colorado Boulder, Colorado State University, and the National Park Service used mitochondrial DNA and nuclear markers to reassess relationships among cutthroat trout subspecies, prompting taxonomic debate involving curators at the Field Museum and laboratories funded by the National Science Foundation.

Distribution and Habitat

Historically the subspecies inhabited tributaries of the Arkansas River and headwaters in the South Platte River basin across the Front Range and Rocky Mountains, with early range maps produced by surveyors working with the U.S. Fish and Wildlife Service and state agencies like the Colorado Division of Wildlife. Reintroductions and translocations have used alpine lakes and montane streams within Rocky Mountain National Park, Pike National Forest, and Arapaho National Forest to reestablish populations, while introductions outside the historic range involved hatcheries operated by entities such as the Boise Hatchery and the Fort Collins Fish Culture Station. Habitat descriptions by hydrologists tied to the Bureau of Reclamation and ecologists from the Colorado River Water Conservation District emphasize cold, well-oxygenated water, substrate complexity influenced by beaver activity documented by researchers at the University of Wyoming, and riparian zones dominated historically by willows studied by botanists at the Denver Botanic Gardens.

Life History and Ecology

Life history studies by biologists associated with the Rocky Mountain Biological Laboratory and the Colorado Parks and Wildlife describe spawning in spring at shallow gravel beds, with larval development paralleling patterns reported for other cutthroat taxa in publications from the Ecological Society of America and the American Institute of Fishery Research Biologists. Diet analyses conducted by researchers at the University of Montana and the Montana Fish, Wildlife & Parks show reliance on aquatic insects such as mayflies studied by entomologists at the Smithsonian Institution and terrestrial invertebrates associated with riparian corridors inventoried by the Natural Resources Conservation Service. Predator–prey interactions documented by field teams collaborating with the National Park Service include predation by birds monitored by ornithologists from the Cornell Lab of Ornithology and competition with introduced species examined by ecologists at the Johns Hopkins University and the University of California, Davis.

Conservation Status and Recovery Efforts

The subspecies was listed under the Endangered Species Act and subsequently managed under recovery plans developed by the U.S. Fish and Wildlife Service in coordination with the Colorado Department of Natural Resources, Trout Unlimited, and the Nature Conservancy. Recovery efforts have included captive propagation at federal and state hatcheries, reintroduction projects overseen by teams from the National Fish Hatchery System and monitoring programs funded by the National Fish and Wildlife Foundation and the Gates Foundation for allied projects. Litigation and policy actions related to listing decisions involved environmental law firms and conservation groups such as the Sierra Club and the Wilderness Society, while scientific oversight for reestablishment used protocols developed by panels convened by the American Fisheries Society and peer review from researchers at the University of Washington.

Management and Threats

Management strategies implemented by state agencies including Colorado Parks and Wildlife and federal land managers at the United States Forest Service address threats such as hybridization with nonnative rainbow trout introduced via anglers associated with organizations like the Trout Unlimited and unauthorized stocking incidents investigated by the U.S. Fish and Wildlife Service. Other threats evaluated in impact assessments by the Environmental Protection Agency and the Bureau of Land Management include stream dewatering linked to policies debated in the Colorado Water Congress and wildfire effects studied by scientists at the U.S. Forest Service Rocky Mountain Research Station. Disease outbreaks monitored by veterinary teams at the National Veterinary Services Laboratories and invasive species incursions assessed by researchers at the U.S. Geological Survey further inform adaptive management plans produced in coordination with the National Park Service.

Cultural and Economic Significance

The subspecies figures in recreational angling economies supported by outfitters regulated by the Colorado Department of Natural Resources and regional tourism bureaus for communities in counties such as Park County, Colorado and Lake County, Colorado, with economic analyses conducted by researchers at the University of Denver and the Colorado Mesa University. Cultural connections include mentions in interpretive exhibits at Rocky Mountain National Park visitor centers and outreach materials produced by the Trout Unlimited educational programs and the Nature Conservancy, while historical accounts appear in 19th-century expedition journals archived at the Library of Congress and the Newberry Library.

Category:Oncorhynchus Category:Fish of the Rocky Mountains