Establishment of a Reproducing Population of Endangered Humpback Chub through Translocations to a Colorado River Tributary in Grand Canyon, Arizona

A successful translocation effort has established a reproducing population of endangered Humpback Chub (Gila cypha) in Havasu Creek, Grand Canyon National Park. The study, conducted from 2010 to 2018, involved annually relocating 243–509 juvenile Humpback Chub—reared in a hatchery for 8–12 months—to this Colorado River tributary. Mark-recapture sampling revealed that the translocated fish exhibited survival and growth rates comparable to or exceeding those of the established population in the Little Colorado River (LCR). Reproductive maturity was observed as early as May 2012, with untagged juveniles appearing annually thereafter, indicating successful in situ reproduction. By 2016, recruitment to maturity from locally produced fish was evident, and population abundance continued to grow through 2018. This study demonstrates the potential for tributaries to play a critical role in the recovery of large-river fishes, offering valuable insights for future conservation strategies.

Healy, B. D., Omana Smith, E. C., Schelly, R. C., Trammell, M. A., & Nelson, C. B. (2019). Establishment of a Reproducing Population of Endangered Humpback Chub through Translocations to a Colorado River Tributary in Grand Canyon, Arizona. North American Journal of Fisheries Management, 40(1), 278–292. https://doi.org/10.1002/nafm.10408