Hermosa Creek Special Management Area: Colorado River Cutthroat Trout Management Colorado Parks and Wildlife Colorado River cutthroat trout captured in Clear Creek, June 2014. The Colorado River cutthroat trout is the only native trout to the Hermosa Creek drainage and the Colorado River Basin. Colorado River cutthroat trout (CRCT) currently occupy about 11% of the estimated historic range (Hirsch et al. 2010; Figure 1). Habitat alterations and the introduction of non- native trout have isolated many of these populations to headwater streams and lakes. Many of the cutthroat trout populations occupy very small “first order” steep gradient streams with marginal habitats. Other threats to CRCT include competition with non-native salmonids, predation of smaller life stages, and, most importantly, hybridization with close relatives such as rainbow trout and other non- native cutthroat trout (i.e., Yellowstone cutthroats). Colorado, Utah, and Wyoming natural resource agencies all had programs aimed at countering the threats against CRCT with the goal of stabilizing and expanding existing populations. In 1994, all three states recognized that a coordinated conservation effort would be much more effective at preventing a listing under the federal Endangered Species Act (ESA) than individual programs. In 2001 a Conservation Strategy and Agreement among the States was crafted and agreed upon. Since then many federal agencies, tribes, and non-governmental organizations have signed the Conservation Agreement to conserve CRCT across its historic range. The CRCT Strategy guides how cutthroat trout are managed in Colorado and, more locally, in Hermosa Creek. The three most important cutthroat trout Figure 1. Historic distribution of CRCT. management strategies that apply to the Hermosa Creek Special Management Area (SMA) are: 1. Secure and enhance conservation populations 2. Restore populations 3. Secure and enhance watershed conditions All of the potential streams that might contain CRCT in the Hermosa Creek Basin have been identified and genetically characterized. Pure “core” conservation populations of CRCT are found in the headwaters of Hermosa Creek (plus tributaries downstream to Hotel Draw confluence), E.F. Hermosa Creek (downstream to Sig Creek Falls), Big Bend, and Clear Creek (population founded from fish transplanted out of Big Bend Creek in 1989). These core populations are protected by either natural or artificial barriers to non-native trout migration. Streams with hybridized or non-native cutthroat trout include the mainstem of Hermosa Creek to the Animas River, Cross, Big Lick, Deer, North Hope, Elk, S.F. Hermosa, and Dutch creeks (CRCT Database). Colorado Parks and Wildlife’s (CPW) first priority in the SMA is to secure the Hermosa Creek headwaters area, Big Bend and Clear creeks. “Secure” means keeping non-native trout out of the current populations, restricting the spread of disease, removing any non-natives that might persist in these waters, and regulating angling by artificial fly and lure only and catch and release along with enforcement of these regulations. The next objective is to restore CRCT populations in the Hermosa Creek drainage. “Restore” means to remove non-native trout from currently occupied habitat and replace them with a genetically pure CRCT. Removal efforts take place above a fish migration barrier and are done by electrofishing (non- lethal) and chemical (lethal - using rotenone, an EPA registered and approved fish pesticide) means. Electrofishing is used only to salvage trout for recreational purposes prior to a chemical treatment. The use of rotenone is a temporary modification of the water quality and allowed in waters designated as “Outstanding” by the Colorado Water Quality Commission. Rotenone is an organically derived pesticide that affects gill breathing organisms only. Rotenone degrades naturally from sunlight and binding with organic matter in the stream but residual amounts are also de-activated with potassium permanganate, a strong oxidizing agent used in may water treatment plants, at the end of the treatment site. Restoration of CRCT in the Hermosa Creek headwaters is a critically important management activity for the conservation of the species. Less than 8% of the 249 core cutthroat trout populations across the Colorado River Basin occupy habitats longer than 20 cumulative miles in length (Hirsch et al. 2010). These large “metapopulations” are the key to long term resilience of the species because they are less susceptible to removal by post fire debris flows, disease, long-term genetic introgression, and other anthropologic disturbances over time. The goal of the Hermosa Creek CRCT restoration project is to link the headwaters and the E.F. of Hermosa Creek together to form a single metapopulation that would be about 20 miles in total stream length. Increasing the number of metapopulations across the CRCT historic range is a good “hedge” against a federal ESA listing which could impact land use activities in the Hermosa Creek drainage. What makes Hermosa Creek so attractive for CRCT restoration efforts is its outstanding water quality and habitat characteristics coupled with easy access and one primary landowner, the U.S. Forest Service. There are other streams in the San Juan River Basin that would support large CRCT populations but the logistics of removing non-native trout and securing the population with a barrier are often not feasible. Because Hermosa Creek is so accessible by the public, it is also a wonderful location for anglers to pursue a native trout and reach out to non-anglers regarding the importance of ecological restoration efforts and recreation. Colorado Parks and Wildlife has identified other waters in the Hermosa Creek Basin where CRCT restoration efforts would be an appropriate management activity. Top on that list is Big Bend Creek. Colorado River cutthroat trout occupy only the upper most mile or two of the creek in relatively marginal habitat. Downstream of the natural barrier rainbow trout and cutthroat hybrids are abundant and in good condition suggesting the habitat conditions are excellent. Extending this Big Bend population of cutthroat trout to the confluence with Hermosa Creek would be a valuable conservation activity in the future. Other potential waters include extending Clear Creek and reclaiming the S.F. of Hermosa Creek drainage. The logistics of removing fish in these drainages are significant but warrant future study. Other restorative measures applicable to Hermosa Creek include broodstock development. Currently, CPW maintains two broodstocks of genetically pure CRCT. Genetic technology and testing continues to evolve and improve. Recent advances now make it possible to analyze the genetic characteristics of fish specimens collected over 150 years ago, before widespread fish stocking occurred. A 2012 analyses of these old collections reveal that there were possibly three unique genotypes of CRCT occupying the western slope of Colorado instead of just one genotype. The genotype unique to the San Juan River Basin to date does not appear to exist on the landscape. The broodstock fish CPW is using for restoration efforts are pure CRCT but they share a “family” relationship with CRCT found in the NW part of their historic range. From a range-wide conservation strategy standpoint, it is unlikely the NW Colorado origins of the headwater Hermosa Creek fish are an issue but devising ways to hold and replicate the tiny population of Big Bend Creek fish would be a desirable future management action CPW is interested in pursuing. The last objective deals with securing and enhancing watershed conditions for CRCT populations. The Hermosa Creek Watershed Protection Act “conserves and protects” habitat values along with wildlife, geologic, and cultural resources in the Hermosa Creek drainage. The Colorado Water Quality Control Commission designated Hermosa Creek as one of Colorado’s “Outstanding Waters” which provides protective measures for existing water quality. Several fish habitat improvement projects are completed and/or planned along with the improvement of undesignated campsite areas along the stream. The Hermosa Creek drainage is well positioned for holistic watershed management that may perpetuate CRCT populations for generations to come. Approximately 75% of the upper Hermosa Creek headwaters have been restored with CRCT. A 2009 fish survey in the E.F. of Hermosa Creek suggests the population of cutthroat trout range from 300 to almost 700 fish per mile of stream. A good cutthroat trout stream averages about 400 fish per mile. The E.F. population of CRCT was established after a 1991 and 1992 chemical treatment using rotenone to remove non-native trout. Brook, rainbow and cutthroat hybrid trout were removed from the upper Hermosa Creek watershed in 2011 and 2012 with rotenone. The affected stream was restocked with larger cutthroat trout about a month after the last treatment and stocked with fingerling trout in 2012- 2014. An electrofishing survey in the fall of 2014 revealed multiple age classes of trout (including naturally reproduced fish) and a fish density of 696 fish per mile. The majority of these fish were too small to catch on hook and line but should grow into a size range in 2015 and 2016 that will provide ample fishing opportunities for anglers. Hermosa Creek, and its associated populations of Colorado River cutthroat trout, are a very important part of the CRCT Range-Wide Conservation plan. The restoration actions taken by the San Juan National Forest, Colorado Parks and Wildlife, Trout Unlimited and other important stakeholders not only assists Colorado with its Wildlife Management mission and Statewide goals but also contributes to the same responsibilities Utah and Wyoming shoulder as well. Hirsch, C.L., M.R. Dare, and S.E. Albeke. 2013. Range-wide status of Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus): 2010. Colorado River Cutthroat Trout Conservations Team Report. Colorado Parks and Wildlife, Fort Collins. .