Difference between revisions of "Humpback Chub Page"

Humpback chub numbers at the Little Colorado River appear to be stable. Humpback chub numbers in Western Grand Canyon are at an all-time high and numbers are increasing in upstream reaches (up to RM 180-200).

There are between 10,000 and 15,000 adult humpback chub at the LCR (2025 Annual Reporting Meeting).

There are between 50,000 and 120,000 adult humpback chub in Western Grand Canyon (2025 Annual Reporting Meeting).

Most humpback chub are found in Grand Canyon. Populations in the upper basin are considered stable with the exception of the Yampa River population which disappeared in the early 2000's.

Reintroducing Humpback Chub in Dinosaur National Monument
A White Paper
Approved by Biology Committee: July 14, 2021

Page 4: The need to restore the DNM population was identified in the Humpback Chub SSA (USFWS 2018), and was considered in the Federal Register proposed rule to reclassify the species (85 FR 3586, January 22, 2020): “By 1998, humpback chub were absent or rare in habitats where the species was likely common in the 1940s (Tyus 1998, p. 192), and the decline in the Dinosaur National Monument population likely was the result of the construction of the Flaming Gorge Dam. Humpback chub in the Green River portion of the Dinosaur National Monument population were negatively affected by the cold releases from the Flaming Gorge Dam starting in 1963, and the Yampa River portion was negatively affected by low river flows, especially in the early 2000s. Operational changes since 2006 at Flaming Gorge Dam have improved the water temperature and flow conditions in the Green River, and releases from Elkhead Reservoir since 2006 support improved flow conditions in the Yampa River. Furthermore, the rocky canyon habitats that the humpback chub rely on in Dinosaur National Monument are still present. Although management actions have improved resource conditions in Dinosaur National Monument, immigration from other humpback chub populations is too low for the species to recolonize naturally, and the population is considered extirpated. Because habitats could potentially support a population, the Upper Basin Recovery Program is considering translocation or stocking to restore humpback chub to Dinosaur National Monument. Dinosaur National Monument may now have suitable resource conditions to support a re-establishment effort.”

Page 7: The cause(s) for the decline and functional extirpation of the humpback chub in the Yampa River is unclear. The last few specimens were observed at a time when river discharge was exceedingly low, with a concurrent proliferation of smallmouth bass (Haines and Modde 2007). In August of 2002, the lowest daily flow in 100 years occurred for the Yampa River at 1.8 cfs near Maybell; a flow of 2 cfs had previously been recorded in 1934. It is believed that the low flow of 2002 was the stressor that eliminated an already declining population of humpback chub in the Yampa River. Possible reasons for decline are the compounded effects of low flow and nonnative predaceous and competing fishes, including channel catfish and smallmouth bass, although other native fish species have persisted, including the roundtail chub (Smith 2019).

After Scientific Review, the U.S. Fish and Wildlife Service to Propose Reclassification of the Humpback Chub from Endangered to Threatened

Things are looking up for a rare Colorado River fish, the endangered humpback chub. The U.S. Fish and Wildlife Service (Service) recently completed a species status assessment (SSA) and a 5-year status review that concluded the current risk of extinction is low, such that the species is not in danger of extinction throughout all of its range. The SSA explained that the largest population of humpback chub, which is found in the Colorado and Little Colorado rivers in the Grand Canyon of Arizona, is a stable population of about 12,000 adults.

Our SSA also explained that four smaller populations in the Green and Colorado rivers of the upper Colorado River basin have persisted and do not appear to be in immediate danger of extinction. All five populations are wild, persisting without the need for hatchery stocking. These population-monitoring results, when coupled with ongoing flow management and nonnative predatory fish control, mean that the humpback chub will be considered for reclassification from endangered to threatened in the next year.

Although this unique fish is making a big step toward recovery it still needs help. Conservation work by a diverse group of stakeholders has been one of the key contributions in recovering this native fish. State, tribal, federal, and private stakeholders collaborate via the Upper Colorado River Endangered Fish Recovery Program (established in 1988) and the Glen Canyon Dam Adaptive Management Program (established in 1997) to continue the monitoring programs and to reduce threats to this species’ recovery. “Endangered species recovery in altered and heavily managed ecosystems like the Colorado River is a complicated endeavor,” said Service Mountain-Prairie Regional Director Noreen Walsh. “Our best chance for continued success rests in the power of these collaborative partnerships.”

The humpback chub, which was first described as a unique species from collections in the Grand Canyon in the 1940’s, was not discovered in the upper Colorado River basin until the 1970’s. It was placed on the original list of endangered species in 1967. Humpback chub prefer canyon-bound reaches of river where they complete their life cycle in swift, turbulent currents. The species gets its name from the fleshy hump behind its head. That adaptation coupled with large, curved fins allows the species to maintain position in the turbulent flows. Habitat alterations (from changes in river flows and inundation of canyon reaches), and competition and predation from invasive species are the greatest threats to the humpback chub.

In the 5-year review, the Service also recommends that the species recovery plan be revised to incorporate the best available scientific information on the species needs and actions that will be necessary to eventually delist humpback chub. Efforts to propose reclassification and to revise the recovery plan will be ongoing in the coming year. The proposed reclassification rule and the revised recovery plan will be made available for public comment in the future.

• To review the SSA visit: Species Status Assessment for the Humpback Chub
• To review the 5-year review please visit: 5-Year Review of the Humpback Chub

Ongoing actions:

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:

• 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.

• 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 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 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 population at a federal hatchery (Reclamation has assisted the FWS in creating a humpback chub refuge at the Southwestern Native Aquatic Resources and Recovery Center [SNARRC]) or other appropriate facility by providing funding to assist in annual maintenance (including the collection of additional humpback chub from the Little Colorado River for this purpose). In the unlikely event of a catastrophic loss of the Grand Canyon population of humpback chub, the refuge would provide a permanent source of sufficient numbers of genetically representative stock for repatriating the species.

Reclamation would continue to assist the FWS, NPS and the GCDAMP to ensure that a stable or upward trend of humpback chub mainstem aggregations can be achieved by:

• Continuing to conduct annual monitoring of the Little Colorado River humpback chub aggregation (e.g., juvenile chub monitoring parameters). Periodically, an open or multistate model should be run to estimate abundance of the entire Little Colorado River aggregation inclusive of mainstem fish.

• Supporting annual monitoring in the mainstem Colorado River to determine status and trends of humpback chub and continuing to investigate sampling and analytical methods to estimate abundance of chub in the mainstem.

• Conducting periodic surveys to identify additional aggregations and individual humpback chub.

• Evaluating existing aggregations and determining drivers of these aggregations, for example, recruitment, natal origins, spawning locations, and spawning habitat (e.g., consider new and innovative methods such as telemetry or the Judas-fish approach) (Kegerries et al. 2015).

• Exploring means of expanding humpback chub populations outside of the Little Colorado River Inflow aggregation. Evaluate the feasibility of mainstem augmentation of humpback chub that would include larval collection, rearing, and release into the mainstem at suitable areas outside of or within existing aggregations.

Reclamation would, through the GCDAMP, conduct disease and parasite monitoring in humpback chub and other fishes in the mainstem Colorado. The GCMRC is currently conducting parasite monitoring in the Little Colorado River. However, in order to better understand how/if disease and parasites (primarily Asian tapeworm) are affecting chub and how temperature differences may affect parasite occurrence, this work would be expanded to include investigations of parasites in humpback chub (and surrogate fish if necessary) in the mainstem. Ensuring adequate protection from diseases and parasites is an identified management action needed in the Humpback Chub Recovery Goals (USFWS 2002a) and Razorback Sucker Recovery Goals (USFWS 2002b).

New actions:

Reclamation would collaborate with the FWS, GCMRC, NPS, and the Havasupai Tribe to conduct preliminary surveys and a feasibility study for translocation of humpback chub into Upper Havasu Creek (above Beaver Falls). The implementation of surveys and translocations, following the feasibility study, would be dependent on interagency discussions, planning and compliance, and resulting outcomes of tribal consultation. As stated above, translocations of chub into currently unoccupied habitat aid in expanding the area occupied by the species. In addition, using a tributary to the Colorado River, such as Upper Havasu Creek, protects translocated fish from the effects of dam operations in the mainstem, but still allow for chub in Havasu Creek to contribute to the mainstem population.

Reclamation would, in cooperation with the FWS, NPS, GCMRC, and AGFD, explore and evaluate other tributaries for potential translocations.

Tier 1 Trigger – Early Intervention Through Conservation Actions:

• 1a. If the combined point estimate for adult HBC (adults defined ≥200 mm) in the Colorado River mainstem LCR aggregation; RM 57-65.9) and Little Colorado River (LCR) falls below 9,000 as estimated by the currently accepted HBC population model (e.g., ASMR, multi-state).

-OR-

• 1b. If recruitment of sub-adult HBC (150-199mm) does not equal or exceed estimated adult mortality such that:

1. Sub-adult abundance falls below a three-year running average of 1,250 fish in the spring LCR population estimates, or
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 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.

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:

• 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:

Mechanical removal of nonnative aquatic predator will ensue:

• If the point abundance estimate of adult HBC decline to <7,000, as estimated by the currently accepted HBC population model.

Mechanical removal will terminate if:

• Predator index (described below) is depleted to less than 60 RBT/km for at least two years in the JCM reach (RM 60.0-64.5) and immigration rate is low (the long term feasibility of using immigration rates as a metric still needs to be assessed),

-OR-

• Adult HBC population estimates exceed 7,500 and recruitment of sub-adult chub exceed adult mortality for at least two years.

If immigration rate of predators into JCM reach is high, mechanical removal may need to continue. These triggers are intended to be adaptive based on ongoing and future research (e.g., Lees Ferry recruitment and emigration dynamics, effects of trout suppression flows, effects of Paria River turbidity inputs on predator survival and immigration rates, interactions between humpback chub and rainbow trout, other predation studies).

• GCMRC Annual Reports page
• Upper Colorado River Endangered Fish Recovery Program
• USFWS ECOS humpback chub site
• Grand Canyon NPS humpback chub site
• USGS humpback chub site
• MSCP humpback chub site
• 2019 National Park Service Expanded Non-native Aquatic Species Management Plan
• 2013 National Park Service Comprehensive Fisheries Management Plan
• 2016 Fish Protocol Evaluation Panel (PEP)

• Little Colorado River (LCR) Projects
• Translocation Projects
• Aggregations Projects
• Bioenergentics Studies
• Predation Studies
• Parasite Monitoring
• Genetic Studies
• The 2009-2012 Fall Steady Flow Experiment and the Near Shore Ecology (NSE) Study
• The 2000 Low Steady Summer Flow Experiment

• 2021 Five-year Review of Action Triggers for the Management of Humpback Chub for the LTEMP BiOp
• 2020 Humpback chub downlisting FRN
• 2018 Humpback Chub Species Status Assessment
• 2018 Humpback Chub 5-Year Review
• 2016 LTEMP Biological Opinion (BO)
• 2016 LTEMP Biological Assessment (BA)
• 2011 Biological Assessment for Nonnative Fish Control Downstream from Glen Canyon Dam for the HFE protocol
• 2011 Humpback Chub 5-Year Review
• Humpback chub downlisting criteria
• 2008 Biological Opinion for HFEs, the fall steady flow test, non-native fish removal, and trout suppression flows
• 2007 Biological Opinion on the Shortage Guidelines
• Judge dismisses 2002 Humpback Chub Recovery Goals in Grand Canyon Trust vs USBR Ruling
• 2002 Humpback Chub Recovery Goals
• 1995 Biological Jeopardy Opinion for implementation of the MLFF alternative
• 1990 Humpback Chub Recovery Plan
• 1979 Humpback Chub Recovery Plan

2025

• Monitoring Humpback Chub in the Little Colorado River and Colorado River, Grand Canyon
• Project A: Streamflow, Water Quality, and Sediment Transport and Budgeting in the Colorado River Ecosystem

2024

• Humpback Chub Recovery Team Update
• Fisheries Review: Annual Reporting FY2023
• Monitoring Humpback Chub in the Little Colorado River and Colorado River, Grand Canyon
• Humpback chub growth becomes resource dependent when released from temperature limitation

2023

• Fish Propagation Program
• Dzul et al., 2023, Vital rates of a burgeoning population of humpback chub in western Grand Canyon: Transactions of the American Fisheries Society
• Monitoring Humpback Chub in the Little Colorado River and Colorado River, Grand Canyon
• Grand Canyon National Park Fisheries Program Updates, FY 2022

2022

• Fisheries review: Annual Reporting FY2021
• Monitoring Humpback Chub in the Little Colorado River and Colorado River, Grand Canyon

2021

• Projected Climate and Geomorphic Changes in the Little Colorado River Watershed and Potential Links to Humpback Chub Habitat
• Update on 5-year Review of Management Triggers for Humpback Chub
• Proposed Action Triggers for the Management of Humpback Chub Colorado River, Grand Canyon
• Long-Term Experimental & Management Plan Biological Opinion – Humpback Chub Trigger Review & Current Status Update
• GCDAMP Annual Reporting Meeting Update: Fishes
• Long-Term Experimental and Management Plan Biological Opinion Conservation Measures Update
• Fish Populations and Aquatic Ecosystems in Lees Ferry through the Little Colorado River

2020

• GCMRC 2019 Annual Reporting Meeting Overview – Part 1
• Humpback Chub Proposed downlisting with 4(d)
• Fish in Grand Canyon - podcast
• Ward and Ward, 2020, What's in the hump of the humpback chub? Western North American Naturalist

2019

• Yackulic, C.B., and Hull, J.B., 2019, Effects of water temperature, turbidity, and rainbow trout on humpback chub population dynamics: U.S. Geological Survey Fact Sheet 2019–3049, 4 p.
• Proposed Downlisting of the Humpback Chub and Razorback Sucker Update
• Humpback Chub Population Dynamics throughout the Colorado River Ecosystem
• Long-term Monitoring

2018

• USFWS Activity Update June 2018 PPT
• Brizendine et al., 2018, Effectiveness of ultrasonic imaging for evaluating presence and maturity of eggs in fishes in remote field locations: North American Journal of Fisheries Management
• Van Haverbeke et al., 2017, Population expansion of humpback chub in western Grand Canyon and hypothesized mechanisms. The Southwestern Naturalist
• Spring 2018 Monitoring of Humpback Chub (Gila cypha) and other Fishes in the Lower 13.57 km of the Little Colorado River, Arizona Trip Report for: April 17-27, 2018 and May 15-25, 2018
• Spring 2018 Monitoring of Humpback Chub (Gila cypha) and other Fishes above Lower Atomizer Falls in the Little Colorado River, Arizona Trip Report for May 15-24, 2018
• AIF: Proposed USFWS Downlisting of Humpback Chub from Endangered to Threatened and PPT
• Humpback Chub Gila cypha SSA & 5-Year Review PPT
• Modeling humpback chub, adaptive management and LTEMP experiments PPT
• Drivers of humpback chub population dynamics PPT
• LTEMP Biological Opinion Conservation Measures Update PPT
• Yackulic et al., 2018, Inferring species interactions through joint mark-recapture analysis: Ecology

2017

• Van Haverbeke et al., 2017, Population expansion of humpback chub in western Grand Canyon and hypothesized mechanisms: The Southwestern Naturalist
• Pine et al. 2017. Growth of Endangered Humpback Chub in Relation to Temperature and Discharge in the Lower Colorado River. USU Watershed Sciences Faculty Publications
• Dibble et al. 2017. Does Bioelectrical Impedance Analysis Accurately Estimate the Physiological Condition of Threatened and Endangered Desert Fish Species?
• Humpback Chub – Range Expansion in the Lower Grand Canyon or Better Sampling?

2016

• Recovery: Humpback Chubs, New Values and New Hope for Endangered Native Fish
• Grand Canyon Monitoring and Research Center Science Updates (BO Compliance, Trout Updates, Green Sunfish, Fisheries PEP, Partners in Science)
• Effects of Turbidity on Predation Vulnerability of Juvenile Humpback Chub to Rainbow and Brown Trout
• Recovery Plan update for Humpback Chub
• Factors that Influence Juvenile Humpback Chub Survival
• Use of Ultrasonic Imaging to Evaluate Egg Maturation of Humpback Chub (Gila cypha) in Grand Canyon

2015

• Native-nonnative Interactions; Factors Influencing Predation and Competition
• Humpback chub triggers for nonnative fish control in the 2011 Biological Opinion (2015 status update)
• Early Life History of Humpback Chub: Patterns and Potential Drivers
• Biological Opinion Trigger Update: January 2015

2014

• HBC Downlisting and Kanab Ambersnail Delisting
• Science Updates - Recent Research on Sand, Bugs, and Fish
• Results from Colorado River Site and ongoing population modeling

2013

• GCMRC Update - Status of Resources and Sediment Conditions
• Science Update: Fisheries
• Fact Sheet: Native and Nonnative Fish Populations of the Colorado River are Food Limited--Evidence from New Food Web Analyses
• GCMRC Science Update on Sediment and Fisheries
• Humpback Chub and Non-native Fish Control Update
• Humpback Chub Refuge and Hatchery Planning Update
• Effects of Water Temperature on Predation Vulnerability of Humpback Chub
• Recent Advances in Population Modeling, Preliminary Estimates, and Relevance to BO Triggers

2012

• Grand Canyon Monitoring and Research Updates
• GCMRC Updates and Sediment Update PPT
• Update on Native and Non-Native Fish Populations PPT
• Grand Canyon Monitoring and Research Center Updates
• Trends and Status of the Little Colorado River Population of Humpback Chub: 1989-2011 (ASMR Update) PPT
• Humpback Chub 5-Year Status Review and Cultural Resources Ad Hoc Group Report PPT
• GCMRC Updates and PPT
• AIF: Grand Canyon National Park Fishery Management Process and PPT
• Humpback Chub 5-Year Review: Summary and Evaluation
• Discussion Paper, Western's Concerns with Humpback Chub 5-Year Status review
• U.S. Fish and Wildlife Service's Response to Western's Concerns over the Humpback Chub 5-Year Review
• USFWS Humpback Chub 5-year Review PPT presentation
• 2011 Annual Report on Native Fish Monitoring
• Tutorial on Grand Canyon Fish Population Dynamics
• HBC Status and Trends

2011

• Humpback Chub 5-Year Review: Summary and Evaluation
• AIF: GCMRC Updates and PPT
• BIO 2 Rxx: Mainstem Juvenile Humpback Chub Monitoring
• A Genetic Management Plan for Captive and Translocated Endangered Humpback Chub in the Lower Colorado River Basin dated November 2010
• Genetics Management Plan PPT

2010

• Evaluating the Relationship Between Capture Probability and Uncertainty in Estimates of Humpback Chub Abundance Using ASMR
• Evaluating the Relationship Between Capture Probability and Uncertainty in Estimates of Humpback Chub Abundance Using ASMR Corresponding PPT
• USGS/GCMRC Biology Program Updates - 2010 Biological Monitoring Summary
• AIF: 1) GCMRC Updates; 2) HBC Comprehensive Plan Implementation Ad Hoc Group Update

2009

• Memo from Clayton Palmer and submission of the Final Report for the "Annotated Bibliography for the Humpback Chub (Gila cypha) with Emphasis on the Grand Canyon Population" prepared by Argonne National Laboratory
• Grand Canyon Monitoring and Research Center Updates
• Humpback Chub Comprehensive Plan: "Draft Comprehensive Plan for the Management and Conservation of Humpback Chub and Science Advisors' Comments and the responses of SA comments
• Humpback Chub Comprehensive Plan PPT
• Humpback Chub Translocation and Refuge Development and Chute Falls Translocation PPT
• Shinumo Translocation PPT
• June 2009 Monitoring of Humpback Chub (Gila cypha) and Other Fishes above Lower Atomizer Falls in the Little Colorado River, Arizona (Trip Report by Dennis M. Stone)
• AIF: Humpback Chub Comprehensive Plan and Report Dated June 16, 2009
• Open File Report 2009-1075, "Abundance Trends and Status of the Little Colorado river Population of Humpback Chub: An Update Considering Ddata from 1989-2008
• Fact Sheet 2009-3035: Status and Trends of the Grand Canyon Population of Humpback Chub Dated April 2009
• AIF: Grand Canyon Monitoring and Research Center (GCMRC) Update
• USGS Fact Sheet: Status and Trends of the Grand Canyon Population of Humpback Chub
• USGS Open File Report: Abundance Trends and Status of the Little Colorado River Population of Humpback Chub: An Update Considering Data from 1989-2008 (prepared by Lew Coggins)
• AIF: 2007 and 2008 Biological Opinions Conservation Measures Update
• Chute Falls Translocation 2003-2008 PPT
• Shinumo HBC Translocation Site PPT
• News Release: Salazar and Locke Restore Scientific Consultations under the Endangered Species Act to Protect Species and their Habitats
• Grand Canyon Monitoring and Research Center updates by Program Managers

• Genetic Evaluation of Upper Basin Colorado River Gila cypha with Comparisons to G. robusta and G. elegans
• Genetic Structure of Humpback Chub (Gila cypha) and Roundtail Chub (G. robusta) in the Colorado River Ecosystem

• AZDGF: Protecting Grand Canyon's Endangered Humpback Chub, Lower 1200
• AZDGF: 2013/2014 Arizona Wildlife Views - Show 1
• AZDGF: Humpback Chub Fish
• AZDGF monitoring in the LCR: Protecting Grand Canyon's Endangered Humpback Chub
• NMSU Student Researches Humpback Chub in Grand Canyon
• USFWS: Colorado River Humpback Chub Aggregation Monitoring 2015
• USFWS: Humpback Chub Monitoring Little Colorado River 2015
• USFWS: Humpback Chub Translocation in Little Colorado River 2015
• USFWS: Conservation Connect: Humpback Chub
• GCWC: Humpback Chub Translocation Grand Canyon National Park
• GCWC: Humpback Chub
• NPS: 2010 Humpback Chub Translocation to Shinumo Creek
• Helicopter delivers 300 endangered humpback chub to Shinumo creek in Grand Canyon

• U.S. Fish and Wildlife say endangered fish on the upswing in Colorado River basin
• Photos of talus shoreline habitat used by humpback chub
• Lower Colorado River Multi-Species Conservation Program (LCR MSCP)
• Songs of the humpback chub (NPR interview)
• Audio
• Script

The interaction of fish, foodbase, and temperature

Fish occupying warmer water have higher metabolic demands than individuals in cooler water, and if these demands increase concurrently with a seasonal decline in prey availability, then growth rates may be reduced. [4]