Lower Colorado River Area Report

Authors: Anthony T. Robinson, Aaron J. Bunch, Kelly J. Meyer, David R. Van Haverbeke, Mary Richardson, Stephanie Coleman, Codey Carter, Heidi B. Blasius

Year: 2012 (xliv)

Abstract

A wide variety of native fish conservation activities were completed in the Lower Colorado Area during the last year. In the Grand Canyon area, Arizona Game and Fish Department (AGFD) conducted annual native fish monitoring between Lees Ferry and Lake Mead. The typical species were captured: flannelmouth sucker, Catostomus latipinnis, bluehead sucker, C. discobolus, speckled dace, Rhinichthys osculus, and humpback chub, Gila cypha. The AGFD also monitored native fishes in the lower 1,200 meters of the Little Colorado River using hoop nets. The humpback chub and other native fish populations appear to be stable. Results of the U.S. Fish and Wildlife Service (USFWS) mark-recapture effort in the Little Colorado River also indicated that the humpback chub population has remained stable since spring 2008; the 2012 spring estimate was 5,327 (SE = 379) humpback chub >199 mm total length. The USFWS and National Park Service (NPS) also translocated about 200 juvenile humpback chub from the lower portion of the Little Colorado River upstream to above Chute Falls. An additional 700 juvenile humpback chub were transported to Dexter National Fish Hatchery and Technology Center to augment the captive population and to hold for grow-out and translocation to Havasu and Shinimo creeks in 2013. The Shinumo Creek humpback chub translocation project continued; so far 902 chub have been translocated into Shinumo Creek. Growth rates of juvenile chub in the creek exceed those in the mainstem Colorado River and meet or exceed those in the Little Colorado River. Emigration of chub from Shinumo Creek is high (>40%). The NPS and FWS also continued trout removal efforts in Shinumo Creek. Havasu Creek is the other humpback chub translocation project and 543 chub have been translocated to the creek since 2011. Growth rates of juvenile chub exceed those for the Little Colorado River, Shinumo Creek, and Colorado River. Some male chub released in 2011 were in spawning condition during the May 2012 monitoring trip, and high numbers were re-captured. The NPS continued to implement native fish conservation measures in Bright Angel Creek including installation of a weir at the mouth of the creek and three-pass backpack electrofishing depletion to capture and remove spawning trout. Weir captures were lower than previous years. During backpack electrofishing, 120 brown trout and 87 rainbow trout were removed, and 87 bluehead suckers and 3199 speckled dace were captured. In the Virgin River drainage, the Virgin River Program continued annual fall monitoring efforts in the Virgin River drainage and prepared for renovation of the Virgin River Gorge. With regard to monitoring, red shiner, Cyprinella lutrensis, were the most abundant species captured, followed by western mosquitofish, Gambusia affinis, speckled dace, flannelmouth sucker, desert sucker, C. clarki, Virgin River spinedace, Lepidomeda mollispinis, Virgin River chub, Gila seminude, black bullhead, Ameiurus melas, common carp, Cyprinus carpio, green sunfish, Lepomis cyanellus, largemouth bass, Micropterus salmoides, channel catfish, Ictalurus punctatus, and fathead minnow, Pimephales promelas. No woundfin were captured. The number of red shiners captured was relatively low compared to past sampling events. The Bunkerville diversion was again washed out during a flood. The diversion continues to be an area of vulnerability in the Lower Virgin River because it is not functioning as a barrier to upstream migration of nonnative fish. The renovation of the Virgin River Gorge was postponed because of AGFD concerns. The AGFD had a 15-month long moratorium on all piscicide applications in Arizona, which was lifted on June 6, 2012. The moratorium was put in place because of attempted state legislation to regulate the use of rotenone. During the moratorium a Rotenone Review Advisory Committee was formed which provided recommendations that were later accepted by the Arizona Game and Fish Commission. A new Arizona Game and Fish Commission policy governing use of piscicides was established, and the AGFD developed and adopted a Piscicide Treatment Planning and Procedures Manual. Immediately after lifting of the moratorium, administrative work began on two piscicide projects: the Virgin River and Fossil Creek. Because of the intense scrutiny by the state legislature, AGFD was very cautious in implementing these two projects. The Virgin River treatment called for treating at concentrations and durations that would have required a Special Local Needs permit, and the AGFD was unwilling to seek the permit for the first renovation project after lifting of the moratorium. As a result, the Virgin River Gorge treatment was postponed. In Lake Mead, razorback sucker, Xyrauchen texanus, monitoring was continued by BioWest. Downstream of Lake Mead, the Lower Colorado Multispecies Conservation Program partners stocked thousands of razorback suckers into three reaches of the Colorado River; 7,342 were stocked into Lake Mohave, 7,683 into the Colorado River to Lake Havasu, and 6,027 in the Colorado River below Lake Havasu. In the Gila River Basin a wide variety of activities occurred. With regard to repatriations, the AGFD, FWS, and BLM stocked Gila topminnow, Poeciliopsis occidentalis, into eight new sites (Buckhorn Spring in the Agua Fria drainage, Road Canyon Tank, Nogales Spring, and Little Nogales Spring in the Cienega Creek drainage southeast of Tucson, Ben Spring, Murray Spring, and Horse Thief Draw in the San Pedro drainage southeast of Tucson, and Usery Mountain Regional Park in Maricopa County). Gila topminnow were detected during the first post-stocking monitoring at each of these sites. Several previously repatriated sites were also stocked with additional Gila topminnow: Fossil Creek, Bonita Creek, Redrock Wildlife Area in New Mexico, and the Phoenix Zoo. Gila topminnow were present detected at each of those sites in subsequent monitoring. Desert pupfish, Cyprinodon macularius, were stocked into one new site (Road Canyon Tank in the Cienega Creek drainage east of Tucson), two other sites were stocked in summer 2011: Murray Spring and Horse Thief Draw in the San Pedro River drainage southeast of Tucson. Desert pupfish were detected at each of these sites during post-stocking monitoring. Spikedace, Meda fulgida, and roundtail chub, Gila robusta, were stocked into a new site: the Blue River in eastern Arizona. And roundtail chub were also stocked into one other new site: Gap Creek a tributary to the Verde River. A number of the sites stocked in previous years are now considered to have established populations. For instance, Gila topminnow are now considered established in several locations: two ponds at Robbins Butte Wildlife Area, Spur Cross Conservation Area, Morgan City Wash, and Chalky Spring, and Fossil Creek. Desert pupfish are now considered established in two ponds on Robbins Butte Wildlife Area and two ponds in McDowell Mountain Regional Park. For a number of other sites, it is still unclear whether or not the repatriated native fish have established populations: spikedace, and loach minnow, Tiaroga cobitis, in Fossil Creek, Redfield Canyon, Hot Springs Canyon, and Bonita Creek, Gila chub, Gila intermedia, in the Lower San Pedro River Preserve pond, roundtail chub in Roundtree Canyon. The largest nonnative fish removal effort was the renovation of Fossil Creek during September 2012. Smallmouth bass, Micropterus dolomieu, invaded Fossil Creek in 2011, and numerous attempts to mechanically remove them were conducted, but then in spring of 2012 young of year smallmouth bass were detected in the stream, indicating that they had spawned. In September 2012 the portion of Fossil Creek between the two barriers was treated with rotenone twice. Native fish from upstream began colonization soon afterward, and a few of the threatened and endangered species were to be stocked into the renovated section. Two other nonnative fish removal efforts were conducted by AGFD and The Nature Conservancy in Redfield Canyon. One mechanical removal effort was conducted in March 2012, but only one green sunfish was observed and it eluded capture. During the second mechanical removal effort in June 2012, 45 green sunfish were removed. AGFD completed surveys of multiple Mogollon Rim streams for headwater chub, Gila nigra. Twelve of 16 streams sampled were considered to have stable headwater chub populations. AGFD also surveyed many of the Apache trout, Oncorhynchus gilae apache, streams in the White Mountain area of Arizona that were impacted by the 2011 Wallow Fire. During 2012 AGFD surveyed the South Fork, West Fork, and East Fork of the Little Colorado River, the Black River and Fish, Bear Wallow, Conklin, Soldier, Coyote, and Maime creeks. Two replicated Apache trout populations were lost, but Apache trout persisted, albeit in variable numbers, in the other streams. AGFD also mechanically removed nonnative trout from Conklin Creek. In addition, the Forest Service contracted out post-Wallow Fire surveys for loach minnow in the East Fork of Little Colorado River and Blue River. Few fish were found in the Blue River. The FWS uplisted spikedace and loach minnow to endangered status and critical habitat was designated in February 2012. The five-year review for both spikedace and loach minnow was completed. A spikedace and loach minnow recovery team was formed and began drafting a revised recovery plan. Bureau of Land Management (BLM) completed a variety of actions within the Gila River basin. They fenced out the upper end of Buckhorn Springs in 2012, and repaired fencing around Chalky Spring and Tule Spring. BLM also conducted fish surveys in Lousy Canyon, Larry Creek, Indian Creek and Silver Creek. The Safford Field Office continued efforts to mechanically remove green sunfish from lower Bonita Creek. They also conducted annual monitoring in Bonita Creek, the Gila River, Cold Spring Seep, Howard Well, and one site on the Little Colorado River. BLM and students from the local college, High School, and elementary school removed sedges from Howard Well and constructed a railroad tie stairway down the bank to improve habitat conditions in Howard Well. The BLM, Bat Conservation International, and Center for Wetlands and Stream Restoration also enhanced four wetland habitats and created a wetland habitat at Porter Wash. The BLM is also working to restore four acres of native grassland that borders a future native fish refuge in the San Simon River valley. The Bureau of Reclamation (BOR) funded a fish barrier was completed in the lower Blue River in eastern Arizona. After the barrier was completed, non-native piscivores were mechanically removed from the lower section of the river using snorkeling and spear-poles; 9 channel catfish and 1 green sunfish were removed. After the removal effort, 539 spikedace, 217 loach minnow, and 222 roundtail chub were stocked. Post-stocking surveys were scheduled for October 2012. Surveys of 49 of the tanks in the Blue River drainage were completed May thru July 2012, and fish (nonnative) were found in three; these three will be targeted for removal efforts. In New Mexico, New Mexico Game and Fish Department (NMGFD), the Forest Service, Kansas State University, and University of New Mexico surveyed warm-water reaches of the Gila River during August 2012, after some significant post-fire ash flows. Both loach minnow and spikedace were collected in the Gila River forks area and bird area. NMGFD and partners also salvaged Gila chub out of Turkey Creek, and loach minnow and from the San Francisco River; fish are being held at Dexter National Fish Hatchery. In addition, Gila trout, Oncorhynchus gilae, were salvaged from Spruce Creek and Whiskey Creek. Gila trout were also translocated from Langstroth Creek to McKenna Creek. Gila chub collected from Harden Cienega Creek in Arizona during March 2012 were stocked into Mule Creek in June 2011.