Difference between revisions of "Humpback Chub Page"
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Ongoing actions: | Ongoing actions: | ||
− | Reclamation would continue to support the NPS, FWS, GCMRC, and GCDAMP in | + | Reclamation would continue to support the NPS, FWS, GCMRC, and GCDAMP in funding and implementing '''translocations''' of humpback chub into tributaries of the Colorado River in Marble and Grand Canyons, and in monitoring the results of these translocations, consistent with agencies’ plans and guidance (e.g., NPS Comprehensive Fisheries Management Plan [CFMP], FWS Humpback Chub Genetics Management Plan and Translocation Framework, and GCMRC Triennial Work Plan). Translocations allow for opportunities to expand the area occupied by humpback chub and improve the overall status of the species. Specifically, the following would occur: |
− | funding and implementing '''translocations''' of humpback chub into tributaries of the | + | |
− | Colorado River in Marble and Grand Canyons, and in monitoring the results of these | + | |
− | translocations, consistent with agencies’ plans and guidance (e.g., NPS Comprehensive | + | |
− | Fisheries Management Plan [CFMP], FWS Humpback Chub Genetics Management Plan | + | |
− | and Translocation Framework, and GCMRC Triennial Work Plan). Translocations allow | + | |
− | for opportunities to expand the area occupied by humpback chub and improve the overall | + | |
− | status of the species. Specifically, the following would occur: | + | |
*Humpback chub would be translocated from the lower reaches of the Little Colorado River to areas above Chute Falls in an effort to increase growth rates and survivorship. | *Humpback chub would be translocated from the lower reaches of the Little Colorado River to areas above Chute Falls in an effort to increase growth rates and survivorship. | ||
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*Monitoring would be conducted annually, or as needed, depending on the data required, to determine survivability, population status, or genetic integrity of the Havasu Creek humpback chub population. Intermittent translocations of additional humpback chub in Havasu Creek would be conducted if the FWS and NPS determine it is necessary to maintain genetic integrity of the population. | *Monitoring would be conducted annually, or as needed, depending on the data required, to determine survivability, population status, or genetic integrity of the Havasu Creek humpback chub population. Intermittent translocations of additional humpback chub in Havasu Creek would be conducted if the FWS and NPS determine it is necessary to maintain genetic integrity of the population. | ||
− | Reclamation would continue to fund a '''spring and fall population estimate''' annually, or at | + | Reclamation would continue to fund a '''spring and fall population estimate''' annually, or at a different frequency as deemed appropriate in consultation with FWS, using a mark recapture based model for the Little Colorado River or the most appropriate model developed for the current collecting techniques and data. Monitoring the chub population allows us to determine its status (whether it is stable, increasing, or decreasing). |
− | a different frequency as deemed appropriate in consultation with FWS, using a mark | + | |
− | recapture based model for the Little Colorado River or the most appropriate model | + | |
− | developed for the current collecting techniques and data. Monitoring the chub population | + | |
− | allows us to determine its status (whether it is stable, increasing, or decreasing). | + | |
− | Reclamation would continue to fund '''control or removal of nonnative fish''' in tributaries | + | Reclamation would continue to fund '''control or removal of nonnative fish''' in tributaries prior to chub translocations depending on the existing fish community in each tributary. Reclamation, NPS, and FWS would lead any investigation into the possibility of using a chemical piscicide, or other tools, as appropriate. Tributaries and the appropriate control methods would be identified by the FWS, NPS, Reclamation, and GCMRC, in consultation with the Arizona Game and Fish Department (AGFD). Depending on the removal methods identified, additional planning and compliance may be necessary. Removal of nonnative fishes improves the status of chub and other native fishes by reducing competition and predation. The regulation and control of nonnative fish is a management action identified in the Humpback Chub Recovery Goals (USFWS 2002a) and Razorback Sucker Recovery Goals (USFWS 2002b). |
− | prior to chub translocations depending on the existing fish community in each tributary. | + | |
− | Reclamation, NPS, and FWS would lead any investigation into the possibility of using a | + | |
− | chemical piscicide, or other tools, as appropriate. Tributaries and the appropriate control | + | |
− | methods would be identified by the FWS, NPS, Reclamation, and GCMRC, in | + | |
− | consultation with the Arizona Game and Fish Department (AGFD). Depending on the | + | |
− | removal methods identified, additional planning and compliance may be necessary. | + | |
− | Removal of nonnative fishes improves the status of chub and other native fishes by | + | |
− | reducing competition and predation. The regulation and control of nonnative fish is a | + | |
− | management action identified in the Humpback Chub Recovery Goals (USFWS 2002a) | + | |
− | and Razorback Sucker Recovery Goals (USFWS 2002b). | + | |
Reclamation would continue to fund the FWS in maintenance of a '''humpback chub refuge''' | Reclamation would continue to fund the FWS in maintenance of a '''humpback chub refuge''' | ||
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# Sub-adult abundance falls below a three-year running average of 810 fish in the mainstem Juvenile Chub Monitoring reach (JCM annual fall population estimate; RM 63.45-65.2). | # Sub-adult abundance falls below a three-year running average of 810 fish in the mainstem Juvenile Chub Monitoring reach (JCM annual fall population estimate; RM 63.45-65.2). | ||
− | Tier 1 Trigger Response: | + | ===Tier 1 Trigger Response: === |
*Tier 1 conservation actions listed below will be immediately implemented either in the LCR or in the adjacent mainstem. Conservation actions will focus on increasing growth, survival and distribution of HBC in the LCR & LCR mainstem aggregation area. | *Tier 1 conservation actions listed below will be immediately implemented either in the LCR or in the adjacent mainstem. Conservation actions will focus on increasing growth, survival and distribution of HBC in the LCR & LCR mainstem aggregation area. | ||
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+ | It is expected that the conservation actions proposed below will assist in ameliorating HBC adult losses or recruitment failures from predation. First, ongoing translocations in the LCR above Chute Falls (~300 fish/year) as well as outside the LCR population (e.g., to Havasu Creek, etc.) will continue, regardless of Tier 1 triggers are met or not. New conservation actions will include expansion of existing activities coupled with experimental actions: | ||
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+ | *LCR - Expand translocation actions in the LCR by collecting an additional 300-600 young of the year (YOY) HBC and move to above Chute Falls in October. | ||
+ | *LCR - Assess efficacy of transporting larval HBC (April/May) into Big Canyon and above Blue Springs in the LCR system. Evaluate growth and survival of these transplants; | ||
+ | *Mainstem LCR Aggregation - Larval fish will be removed from LCR (April/May) and head-started at Southwest Native Aquatic Resources and Recovery Center (SNARRC). Once fish reach 150-200 mm they will be translocated to the mainstem LCR reach the following year (currently grow-out space at SNARRC is limited to 750 HBC, use of fish for this purpose would reduce numbers available for other actions, e.g. Havasu, Shinumo.); | ||
+ | *Additional conservation actions as identified and evaluated. | ||
=== '''Tier 2 Trigger - Reduce threat using mechanical removal if conservation actions in Tier 1 are insufficient to arrest a population decline:''' === | === '''Tier 2 Trigger - Reduce threat using mechanical removal if conservation actions in Tier 1 are insufficient to arrest a population decline:''' === |
Revision as of 15:42, 13 July 2018
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DescriptionThe humpback chub (Gila cypha) is an endangered, native endemic of the Colorado River that evolved around 3-5 million years ago. The pronounced hump behind its head gives this fish a striking, unusual appearance. It has an olive-colored back, silver sides, a white belly, small eyes and a long snout that overhangs its jaw. Like the Colorado pikeminnow and bonytail, the humpback chub is a member of the minnow family. The humpback chub is a relatively small fish by most standards – its maximum size is about 20 inches and 2.5 pounds. By minnow standards it is a big fish, though not like the giant of all minnows – the Colorado pikeminnow. Humpback chub can survive more than 30 years in the wild. It can spawn as young as 2 to 3 years of age during its March through July spawning season. Although the humpback chub does not have the swimming speed or strength of the Colorado pikeminnow, its body is uniquely formed to help it survive in its whitewater habitat. The hump that gives this fish its name acts as a stabilizer and a hydrodynamic foil that helps it maintain position and also probably helped it escape predation by making it difficult to be swallowed by all but the largest pikeminnow. The humpback chub uses its large fins to “glide” in eddy complexes, feeding on insects that become trapped in pockets of slow-moving water. [1] Status and distribution
The humpback chub was listed as endangered by U.S. Fish and Wildlife Service in 1967 and given full protection under the Endangered Species Act of 1973. Historically, humpback chub were probably limited to the eddy complexes of several canyon reaches of the Colorado River and three of its tributaries: the Green and Yampa rivers in Colorado and Utah, and the Little Colorado River in Arizona. The species was first described in 1946. Before that time, few people ventured into these treacherous canyons – including fishery biologists. Today, five self-sustaining populations of humpback chub occur in the Upper Colorado River Basin. Two to three thousand adults can occur in the Black Rocks and Westwater Canyon core population in the Colorado River near the Colorado/Utah border. Several hundred to more than 1,000 adults may occur in the Desolation/Gray Canyon core population in the Green River. Populations in Yampa and Cataract canyons are small, each consisting of up to a few hundred adults. The largest population of humpback chub is found in the Grand Canyon -- primarily in the Little Colorado River (LCR) and its confluence with the main stem Colorado River. In 2009, the U.S. Geological Survey announced that this population increased by about 50 percent from 2001 to 2008 to between 6,000 and 10,000 adults. [2] The 2017 5-Year Status Review concluded that the humpback chub is not in danger of extinction throughout all of its range, but is likely to become so in the foreseeable future; that is, it is a threatened species throughout all of its range. Therefore, the USFWS made a recommendation to downlist the humpback chub to threatened status. [[3] LTEMP Resource Goal for Humpback ChubMeet humpback chub recovery goals, including maintaining a self-sustaining population, spawning habitat, and aggregations in the Colorado River and its tributaries below the Glen Canyon Dam. Desired Future Condition for Humpback Chub• Achieve HBC recovery in accord with the Endangered Species Act (ESA), the HBC comprehensive management plan, and with the assistance of collaborators within and external to the AMP. |
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Fish of the Colorado River below Glen Canyon Dam - GCDAMP training prepared by AZFGD |
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