fall 11 / 24:3 - Grand Canyon River Guides

A previously translocated humpback chub underwater in Shinumo Creek.Photo by M. Trammell.origins of these humpback chub.Logistics of the fisheries work in Havasu Creekwere designed to minimize interference with boatersat the mouth of Havasu Creek and with the wildernesscharacteristics of the area. Crews will either bedropped off at the mouth by an already-scheduledriver trip and hike out to Hualapai Hilltop, or hike inand out of the field site. Helicopter transport of thehumpback chub and fisheries equipment was determinedto have the least impact to park resources andvisitor experience, while minimizing stress to the fish.Shinumo Creek TranslocationThe third translocation of 300 humpback chub toShinumo Creek occurred on June 21, one week priorto the Havasu translocation. This translocation is thethird in a three-year project. A total of 902 humpbackchub have been released in Shinumo Creek to date.Data are currently being analyzed, providing earlyinsights into the success of the translocations sofar. Based upon data from the pit tag antenna, approximatelyhalf of the released chub have left thecreek since translocation. Most leave within the firstten days, and most leave at night. Humpback chubtranslocated at smaller sizes seem more likely to remainin the creek than larger ones. While the barrierwaterfall keeps non-native predatory fish from theColorado River out of Shinumo Creek, it also preventshumpback chub that go over the falls from returning.Emigration and losses due to predation by non-nativerainbow trout in Shinumo Creek remain a concern forlong-term success of the project.Growth rates of translocatedhumpback chub are higher in ShinumoCreek than in either the Little ColoradoRiver or the Colorado River. Hahnsaid, “I was with the field crew duringthe monitoring in Shinumo Creek inJune. It was heartening to see that someof the chub translocated in 2009 and2010 were already starting to developlittle humps! The next milestone thatwe hope to see in Shinumo Creek isspawning behavior by the translocatedfish.”Data collected last fall also suggestthat fish translocated to ShinumoCreek have added to the number ofhumpback chub found in the ColoradoRiver. In September 2010, GrandCanyon Research and Monitoring Center(gcmrc) and usfws found that 28percent of all tagged humpback chubcaptured in the river were from the Shinumo Creektranslocations. Some translocated humpback chubthat leave the tributary are surviving, and potentiallyadding to the number of humpback chub in the mainstembelow the Little Colorado River. They also seemto maintain the higher growth rate of Shinumo Creek,even after they have entered the mainstem.While monitoring activities and data analysiscontinues, the nps is determining the next steps forShinumo Creek. One important tool in this processwill be a model recently developed by researchers fromthe University of Florida, working with personnelfrom nps, bor, usfws, agfd, usgs, and swca, to evaluatetranslocation protocols as well as other managementactivities. This model, together with results fromShinumo Creek and Havasu Creek monitoring, willassist the nps’ efforts to restore the canyon’s native fishcommunities.Emily Omana Smith, Allyson Mathis,and Brian HealyNote: Emily Omana Smith and Brian Healy are fisheries biologistsand Allyson Mathis is the Outreach Coordinator for the Divisionof Science and Resource Management for Grand CanyonNational Park. Emily can be reached at Emily_Omana@nps.gov.A podcast video about the 2010 translocation to Shinumo Creekis on YouTube at http://www.youtube.com/watch?v=R9I6D_PdTTs.page 18grand canyon river guides