Humpback Chub Page

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Description The humpback chub (Gila cypha) is an endangered, native fish 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. The humpback chub uses its large fins to “glide” through slow-moving areas, feeding on insects that become trapped in water pockets. 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 inhabited the swift and turbulent waters in canyons 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 discovered in 1946. Before that time, few people ventured into these treacherous regions – 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 known population of humpback chub is in the Lower Colorado River (LCR) Basin in the Grand Canyon -- primarily in the LCR and its confluence with the main stem of the Little 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 individuals.

---	Fish Species of the Colorado River in Lower Glen Canyon and Grand Canyon	---

Updates This is an estimate of humpback chub coming into the LCR to spawn. The decline in 2015 coincides with a decline in chub condition and a decline in the trout population (remember trout and chub eat the same things and are considered competitors). This may be an indication of skip-spawning in 2015 and remaining in the mainstem, not an actual decline in population. Body condition of humpback chub has been declining with the decline in macroinvertebrates in the drift. Note that most of the drift occurs in the summer when macroinvertebrate production is high. This decline in macroinvertebrate production coincides with the population expansion and subsequent decline in the rainbow trout population indicating competition between rainbow trout and humpback chub. Humpback chub numbers in Grand Canyon have been increasing since the early 2000s. The Multistate Population Model separates the LCR chub from the mainstem chub in estimating population size. LCR remote PIT tag arrays *Paper on how talus shoreline habitat is used by humpback chub

INFORMATION Humpback chub triggers for nonnative fish control in the 2011 Biological Opinion (2015 status update) Humpback chub triggers for nonnative fish control in the 2011 Biological Opinion 2011 Biological Assessment for Nonnative Fish Control Downstream from Glen Canyon Dam as a result of the new HFE protocol 2011 Humpback chub 5-year Review: Summary and Evaluation Humpback chub downlisting criteria Near Shore Ecology (NSE) Study of the fall steady flow test 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 Presentations and Papers 2016 Spring 2016 Chute Falls humpback chub sampling trip report Spring 2016 Lower LCR humpback chub sampling trip report Mark-Recapture and Fish Monitoring Activities in the Little Colorado River in Grand Canyon Colorado River in Grand Canyon from 2000 to 2015 Effects of Turbidity on Predation Vulnerability of Juvenile Humpback Chub to Rainbow and Brown Trout Recovery Plan update for Humpback Chub Humpback chub in the Little Colorado River, Monitoring of Juveniles, Sub-Adults, and Adults and Translocations Humpback Chub Translocations to Havasu and Shinumo Creeks, Grand Canyon National Park Humpback chub (Gila cypha) that Spawn in the Little Colorado River: Status and Potential Drivers Factors that Influence Juvenile Humpback Chub Survival Use of Ultrasonic Imaging to Evaluate Egg Maturation of Humpback Chub (Gila cypha) in Grand Canyon Monitoring Humpback Chub Aggregations in the Mainstem, 1991-2015 2015 Havasu Creek Translocation Update Native-nonnative Interactions; Factors Influencing Predation and Competition Chute Falls Translocation Update Humpback Chub Translocations to Shinumo and Havasu Creeks, Grand Canyon National Park Humpback Chub in the Colorado river: Status and Trends of Aggregations, Changes in Range Early Life History of Humpback Chub: Patterns and Potential Drivers Biological Opinion Trigger Update: January 2015 2014 HBC Downlisting and Kanab Ambersnail Delisting 2014 Shinumo Creek Flood Modeling Long Term Effects of HFEs on Trout and HBC Colorado River fish monitoring in Grand Canyon, Arizona: 1990-2013 humpback chub, Gila cypha, aggregations Results from Colorado River Site and ongoing population modeling 2013 K. E. Limburg, T. A Hayden, W. E. Pine, III, M. D.Yard, R. Kozdon, and J. W. Valley. 2013. Of Travertine and Time: Otolith chemistry and microstructure detect provenance and demography of endangered humpback chub in Grand Canyon USA. PLoS One 8(12), E84235 2011 GCMRC Update - Chub, Temperature, and Sediment Other Stuff Humpback Chub Translocation in Little Colorado River 2015 Colorado River Humpback Chub Aggregation Monitoring 2015 AZDGF monitoring in the LCR Grand Canyon National Park translocations (more information) https://www.youtube.com/watch?v=tzHvHvViCuU%7C NMSU Student Researches Humpback Chub in Grand Canyon] Lower Colorado River Multi-Species Conservation Program (LCR MSCP) Songs of the humpback chub (NPR interview)