Rio Grande Cutthroat Trout (Oncorhynchus clarkii virginalis)

Data: Cutthroat Trout Status Assessment - 2008 Conservation Agreement for Rio Grande Cutthroat Trout - 2013 Partners: Parks and Wildlife, Dept. of Game and Fish, U.S. Forest Service, U.S. Fish and Wildlife Service, National Park Service, U.S. Bureau of Land Management, Jicarilla Apache Nation, Mescalero Apache Nation, Taos Pueblo, 15 CO County Coalition, Trout Unlimited

Photo credit: Colorado Trout Unlimited. ii | Western Native Trout Status Report - Updated May 2016

Species Status Review vation. Colorado and New Mexico have active conservation plans that outline strategies and The U.S. Fish and Wildlife Service (USFWS) implementation schedules. received a petition in 1998 to list the Rio Grande Cutthroat Trout (RGCT) under the Sportfishing Status of the Endangered Species Act. In a 90-day find- ing, the agency concluded that listing was not Rio Grande Cutthroat Trout warranted. However, in 2001 a candidate status review was initiated in response to litigation Rio Grande Cutthroat Trout are considered a appealing this decision and new informa- sport fish by all state, federal and tribal agencies tion, particularly regarding the presence of that manage this subspecies. Harvest restric- whirling disease within the native range of tions are in place for most conservation popula- the sub- species (USFWS 2002). The results tions (usually catch and release, flies and lures of this review were published in 2002, and it only) but there are also many RGCT non-con- was again determined that listing of this taxon servation populations managed for recreational was not warranted (USFWS 2002). In 2005, a fishing where standard regulations and bag petition for Review of Agency Action regard- limits apply. RGCT recreational fishing waters ing the ‘not warranted’ decision was denied. are frequently located in high- elevation lakes That decision was appealed to the 10th Circuit where cold water temperatures and lack of Court. After briefs were filed, USFWS settled spawning habitat is expected to prevent natural the case and agreed to conduct a new status trout reproduction. Some of these recreation review. In 2014, USFWS determined that that populations have the potential to act as ‘genetic listing under the Endangered Species Act was refugia’ for pure historic populations, but many not warranted. The subspecies is recognized as also contain other Oncorhynchus taxa that are a species of special concern in both Colorado expected to hybridize with RGCT where op- and New Mexico, and as a sensitive species portunities for natural reproduction occur. Rio within USFS Regions 2 and 3 and the Bureau Grande Cutthroat Trout are considered to be of Land Management. In 2006, the RGCT easily captured by anglers, which could suggest Conservation Team adopted the Inland Cut- its vulnerability to excessive harvest. throat Trout Protocol as a tool for assessing However, over-harvest is not considered a the rangewide status of RGCT. The first draft problem to RGCT at this time. Special regu- of a Rio Grande Cutthroat Trout Rangewide lations requiring catch-and-release, limited Database was completed by the RGCT Con- harvest, and terminal tackle restrictions have servation Team in March, 2007. The RGCT demonstrated effectiveness in maintaining Conservation Team created a 2008 Rangewide trout populations in the face of a wide range Status Report for RGCT; another is sched- of fishing pressure, and have been applied to uled for completion in 2016. In addition, there native cutthroat trout waters in the two states. is a signed Conservation Agreement (2013) Core RGCT populations are protected by fish- and Conservation Strategy (2013) in place to ing closures in some instances. The tendency identify partners and goals for RGCT conser- RIO GRANDE CUTTHROAT TROUT (Oncorhynchus clarkii virginalis) | iii

for these populations to be composed largely Rio Grande Cutthroat Habitat of small-sized fish may also reduce interest by anglers wishing to harvest fish. Requirements Rio Grande Cutthroat Trout Rio Grande Cutthroat Trout habitat prefer- ence is consistent with typical cutthroat trout Distribution habitat. Cutthroat trout, in general, prefer clear, streams and lakes. Population densities are reg- Rio Grande Cutthroat Trout are native to ulated mostly by stream size and morphology, the Rio Grande and Pecos River drainages over-wintering habitat, stream productivity, and of Colorado and New Mexico. They are also summer cover for predator avoidance. Optimal believed to be native to the Canadian Riverd- cutthroat trout stream habitat is characterized rainage of Colorado and New Mexico, but no by clear, cold water, a silt free rocky substrate in early historic specimens or written accounts are riffle-run areas; an approximately 1:1 pool-riffle available to verify this. ratio with areas of slow, deep water; well veg- etated stream banks; abundant in-stream cover; Range and GMUs of the RGCT and relatively stable water flow and tempera- ture regimes.

Optimal lacustrine habitat is characterized by clear, cold, deep lakes that are typically oli- gotrophic, but may vary in size and chemical quality, particularly in reservoir habitats. Rio Grande Cutthroat Trout are stream spawners and require gravel substrates for reproduction to occur. Growth depends primarily on food availability, size of prey, competition, water temperatures, and the length of the growing season. Rio Grande Cutthroat Trout popula- tions inhabiting small streams typically range in size from 2 inches at age 1 to 12 inches at age 7. However, RGCT inhabiting productive lakes can grow considerably larger.

RGCT Rangewide Database 2013 iv | Western Native Trout Status Report - Updated May 2016

Concerns and Issues Relative stock of pure RGCT has been developed at Haypress Lake, in addition to a back-up brood to the Conservation and Im- stock at the Pitkin Hatchery. New Mexico has also developed brood stock at Seven Springs provement of RGCT State Hatchery for restoration and recreational stocking. Habitat degradation, hybridization, and com- petition with non‐native trout are the primary threats to the security of RGCT populations. Habitat Concerns Other concerns include lack of connectivity to A wide variety of land management practices maintain genetic diversity, potential for angler have been suggested to threaten the continued over‐ harvest, impacts of whirling disease, and existence of populations of RGCT, including catastrophic threats such as drought and forest overgrazing, heavy metal pollution, and water fire. depletion and diversion. Some of these practic- es have served to isolate upstream populations Genetic Considerations of RGCT and protect them from invasion by nonnative salmonids, but they also serve Extensive genetic testing of RGCT has been to fragment streams and isolate populations. conducted rangewide. Results of genetic analy- In addition, natural climatic events such as sis will be used to guide management decisions drought, floods, and fires can threaten popula- for the conservation of RGCT and where tions of RGCT, especially when stream popula- possible, the subspecies will be managed on the tions remain fragmented, small and isolated. basis of each geographic unit. Genetic evalua- Fires also provide conservation opportunities tion has been conducted, and will continue to for re-establishing RGCT in areas previously be conducted, in order to make genetic distinc- inhabited by non-native trout. Temporary habi- tions between populations from the various tat loss due to drought and/or water extrac- geographical units. tion in certain years also appears to be a threat Some isolated RGCT populations currently to RGCT populations in Colorado. Habitat exhibit population sizes smaller than those problems are viewed as site specific and not an recommended for optimum population vi- overall threat throughout the range. ability and occupy shorter stream lengths than those recommended. However, all of these Disease Concerns populations remain important elements in the conservation of the subspecies. For some of Rio Grande Cutthroat Trout are susceptible to these populations, there may be opportunities common salmonid diseases, including whirling to increase carrying capacity and the chance of disease, which is caused by the myxosporidian long- term persistence by improving habitat Myxobolus cerebralis (MC). Native cutthroat quality, expanding available habitat down- trout, including RGCT, exposed to MC in stream, and linking them with other isolated sentinel fish experiments suffered greater mor- populations. Within Colorado, a blended brood tality from the infection than other non-native RIO GRANDE CUTTHROAT TROUT (Oncorhynchus clarkii virginalis) | v

salmonid species like brown trout. Transmis- harvest, and terminal tackle restrictions have sion of diseases to wild cutthroat popula- demonstrated effectiveness in maintaining tions from non-native trout is recognized as a trout populations in the face of a wide range of potential threat. Physical barriers (both natural fishing pressure, and have been applied to na- and man- made) that serve to isolate RGCT tive cutthroat waters throughout Colorado and populations also provide significant protection New Mexico. Scientific collection of wildlife from transmission of fish diseases. Both Colo- is regulated through permit systems in both rado and New Mexico have statewide policies Colorado and New Mexico requiring formal and regulations that address fish health status, applications stating project objectives, sampling disease certification of stocked and imported methodologies, sampling sites, and need for fish, and stocking protocols, which are designed collecting. to reduce disease threats. Opportunities to Improve the Introduced Species Threats Status of RGCT Stocking of non-native salmonids was wide- The goal of the Conservation Strategy for the spread since before 1900, and has been consid- RGCT is to assure the long-term persistence ered a primary threat to inland native cutthroat of the subspecies within its historic range by subspecies. Brook trout are known to replace facilitating restoration projects, preserving its most subspecies of inland cutthroat trout when genetic integrity, reducing habitat fragmenta- in sympatry. Rainbow trout and other nonna- tion, and providing sufficient suitable habitat tive cutthroat trout subspecies hybridize with to support adequate numbers of viable, self- RGCT and produce fertile offspring. In New sustaining populations. The conservation and Mexico, only infertile triploid rainbow trout enhancement of RGCT will depend on an are stocked by the Department of Game and approach that reduces threats to the subspecies. Fish to prevent hybridization with RGCT. The specific approaches are described in both The competition from non-native trout means state and federal agency plans. Actions will that pure RGCT populations require protec- need to be prioritized and implemented within tion by natural or artificial migration barriers. the five RGCT GMUs. Typically the actions Construction, monitoring, and maintenance of fall within these categories: such barriers are management priorities for all relevant agencies. Illegal stocking of non-native • Fish population inventory (surveys and trout into RGCT populations and movement analysis including genetics) of fish by anglers are also a concern. • Restoration projects (non-native removal, reintroduction, supplemental stocking, Overutilization Concerns spawn-taking, maintaining broodstock) Over-harvest is not considered a threat to • Habitat manipulation (barrier placement this subspecies at this time. Special regula- or removal, in-stream structure, flows, tions requiring catch-and-release, very limited increasing connectivity) vi | Western Native Trout Status Report - Updated May 2016

• Regulatory actions (fishing regulations, netic analyses to measure introgression or water use, land management) purity. • Developing educational and outreach ef- • Expand RGCT populations through res- forts toration, reintroductions, and non-native RGCT Restoration Potential fish control in priority watersheds. • The Agencies agree to summarize exist- In 2007, the RGCT Conservation Team ing distribution, population, genetics, and completed the final component of the Inland habitat data; and to summarize conserva- Cutthroat Trout Protocol, which was to iden- tion accomplishments in a common and tify potential restoration and expansion oppor- consistent format to allow range-wide, tunities for RGCT. Increasing the number of integrated data analyses, summaries and pure RGCT populations in streams and lakes comparisons. by restoring them within their historic range is • Identify potential, unoccupied habitat for a key component of improving their conserva- restoration with RGCT. tion status. Sources of RGCT for restoration will include replication of currently identified RGCT Habitat Manipulations pure populations, if possible, and development of appropriate genetically-mixed stocks from Land use management considerations as part of pure populations based on genetic information, this plan include: riparian buffer maintenance and concepts of “nearest neighbor” and “similar and protection, sedimentation abatement, min- ecological niche” for selecting genetic donors. ing and logging restrictions, proper placement Either of these approaches will be accom- of recreational trails, minimal impact grazing plished via transfers of fish from neighboring strategies, quantitative habitat monitoring, and drainage basins or use of progeny from captive development of in-stream and riparian habitat broodstocks of desired genetic heritage for restoration projects. Coordination between the restoration stocking of progeny. An additional U.S. Forest Service, Bureau of Land Manage- goal of these restoration projects is to promote ment, and state wildlife agencies to develop and restore connectivity of existing and re- best management practices in regard to habitat stored populations where feasible to enhance concerns for the RGCT is an ongoing practice. metapopulation function. Key actions include: Population Surveys, Genetic Analyses, and • Inventory, maintain, protect and improve Fish Restoration Projects existing aquatic and riparian habitats. • Improve hydrologic and fluvial processes Key actions include: associated with RGCT populations at a • Continue to locate and assess RGCT watershed scale. populations. • Address public and private land manage- • Conduct standardized surveys and ge- ment, forestry, mining, agriculture and RIO GRANDE CUTTHROAT TROUT (Oncorhynchus clarkii virginalis) | vii

O&G development practices to protect Highest Priority Objectives for habitat. • Monitor and evaluate natural catastrophic the 5 GMU’s for RGCT impacts like fire and drought; implement controlled burns and forest thinning to Rio Grande Headwaters mitigate wildfire risks. • Secure and protect existing populations. Regulatory Actions to enhance RGCT status For example, construct fish movement barriers at Wolf Creek, Miners Creek, and Maintaining the sportfish status of RGCT Alamosito Creek. and utilizing regulations to manage angling • Expand the distribution of RGCT pressure will be an important component of populations through chemical reclama- maintaining the health of these populations. In tion projects, electrofishing removal addition, working with others to maintain ap- projects and stocking of vacant waters. propriate regulations for prevention of disease, For example, complete chemical reclama- water quality impairment, and habitat distur- tion projects at Trinchera Creek, Roaring bance are important considerations. Fork/Haypress Lake, and Sand Creek. Key actions include: • Restore degraded habitat. For example, • Maintain or enhance regulatory actions to evaluate fish passage at culvert crossings prevent destruction of habitat. on USFS and BLM roads, and install new diversion structures on Medano Creek • Enforce regulatory mechanisms that pre- that prevent emigration into irrigation vent impacts associated with recreational ditches. angling. Lower Rio Grande GMU • Enhance and maintain regulatory mecha- nisms that prevent diseases or illegal • Secure and protect existing populations. introduction of nuisance species. • Construct barrier on Costilla Creek and evaluate effectiveness of existing barriers. Expand Education and Outreach programs to garner public support for RGCT • Expand range of RGCT through chemi- cal reclamation projects, electrofishing Key actions include: removal, and stocking of vacant waters. Conduct chemical reclamation projects • Expand public education efforts regard- in the Rio Costilla watershed. Conduct ing RGCT restoration actions to increase electrofishing removals on streams. public awareness of specific restoration ac- tions as well as responsibilities in conserv- • Restore degraded habitat. For example, ing RGCT habitat and fish populations. install riparian exclosures on Cañones and Polvadera Creeks. viii | Western Native Trout Status Report - Updated May 2016

Pecos GMU Funding Needs • Expand range of RGCT through chemi- • Rio Grande Cutthroat Trout genetics cal reclamation projects, electrofishing analysis. $15,000 per year is needed for removal and stocking of vacant waters. genetic analysis of fish tissue specimens Site, design and construct barriers as from known or suspected populations of needed. Evaluate subdrainages within the RGCT in New Mexico. Pecos watershed for chemical restoration potential. Continue electrofishing remov- • Purchase piscicides and supplies for als where RGCT are sympatric with stream/lake reclamation projects. $25,000 non-native trout. Replicate Pecos drainage per year is needed for RGCT restora- populations into fishless waters. tion projects in New Mexico and another $25,000 is needed per year in Colorado. Canadian GMU • Construct fish migration barriers. $100,000 per year is needed to construct • Secure and protect existing populations. at least one manmade barrier per year Construct barriers on streams where within RGCT historic range in Colorado RGCT exist such as Luna Creek and the and another $100,000 in New Mexico. Vermejo River. • Habitat restoration and protection. • Expand range of RGCT through chemi- $30,000 per year is needed to implement cal reclamation projects, electrofishing riparian best management practices and removal, and stocking of vacant waters. construct grazing exclosures. Site, design and construct barriers as needed. Evaluate subdrainages within the Likely Future RGCT Joint Canadian watershed for chemical restora- tion potential. Ventures • Restore degraded habitat. For example, implement post-fire recovery actions to • Rio Grande Cutthroat Trout GIS data- expedite post-fire revegetation in Ponil base management services. $15,000 per Creek system. year is needed to hire consultant services to complete annual updates to the range- Caballo GMU wide RGCT database.

• Expand range of RGCT through chemi- cal reclamation projects, electrofishing removal and stocking of vacant waters. Stock RGCT into Las Animas Creek wa- tershed when habitat affected by wildfire improves. RIO GRANDE CUTTHROAT TROUT (Oncorhynchus clarkii virginalis) | ix

WNTI Completed/Ongoing References Projects 1. Rio Grande Cutthroat Status Assessment (2008). • 2008: La Garita Creek (CO) native fish restoration project ($63,000) 2. Conservation Agreement for Rio Grande Cutthroat Trout (2013). • 2008: Wolf Creek Barrier Repair (CO) ($22,500) 3. Conservation Strategy for Rio Grande Cut- throat Trout (2013). • 2008: Protection of Alamitos Creek (NM) population of Rio Grande cutthroat trout 4. Conservation Plan for Rio Grande Cut- ($75,000) throat Trout in Colorado (2004). • 2009: Restoration of Rio Grande Cut- 5. Long Range Plan for the Management of throat trout in the headwaters of Santa Rio Grande Cutthroat Trout in New Mexico Clara Creek (NM) ($87,100) (2002). • 2010: Renovation of Barrier to Protect 6. Rio Grande Cutthroat Trout Rangewide Rio Grande Cutthroat Trout in Tio Database, Rio Grande Cutthroat Trout Con- Grande Creek, NM ($64,000) servation Team (2013). • 2011: Tanques Creek, NM, barrier reno- vation ($65,000) • 2011: Rio Ruidoso, NM, watershed native trout restoration ($80,000) • 2011: Surviving Climate Change: Build- This publication was funded (or partially ing Resilience for the Rio Grande Cut- funded) by Federal Aid to Sportfish Restora- throat Trout ($3,000) tion Funds through the Multistate Conser- • 2012: Genetic assessment of extant Rio vation Grant Program (Grant WY M-8-P), Grande CT populations in Colorado a program supported with funds from the ($23,800) Wildlife and Sport Fish Restoration Program • 2012: Barrier construction on tributaries of the U.S. Fish and Wildlife Service and to the Rio Hondo, NM, for Rio Grande jointly managed with the Association of Fish and Wildlife Agencies, 2006-9. cutthroat trout ($20,000) • 2013: Rio Grande cutthroat trout angler survey and educational materials ($3,000) • 2015: Get to Know your Native ($3,000)