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<br />6 <br /> <br />Recovery Factor E.-other Natural or Manmade Factors for which Protection Has <br />Been Provided <br />12. Non-source pollutants in the LCR watershed <br />. A number of potential sources of hazardous materials exist in the <br />LCR watershed. Collectively, these affect water quality in <br />occupied and critical habitat in the LCR and could affect <br />reproduction and survival of all life stages of humpback chub <br />13. Hazardous materials spills at the Cameron Bridges <br />. A spill from an overturned tanker truck at one of the Camejron <br />Bridges could be transported downstream to occupied and critical <br />habitat, resulting in possible losses of all ages of humpback chub at <br />the only spawning location for the species in Grand Canyon <br /> <br />Threats to the species and corresponding recommended management actions are <br />provided in the strategy section 4.0 and the project timeline shown in Appendix D. Of <br />the 13 threats previously identified, addressing some requires more immediate attention <br />than others. The immediate threats to humpback chub in Grand Canyon and current <br />actions are linked to the following: <br /> <br />. Flow regimes from dam releases: The effects of dam releases are <br />not fully understood, but experimental flows continue to provide <br />infonnation under adaptive management. <br /> <br />. Water temperature: Cold water releases are known to inhibit <br />mainstem reproduction, swimming ability, and growth of <br />humpback chub. A risk assessment is currently being conducted <br />by Bureau of Reclamation for a temperature control device on <br />Glen Canyon Dam. If environmental compliance proceeds on <br />schedule, a temperature control device (TCD) could be in place by <br />spring of 2007 to provide a tool for wanning downstream releases. <br />Meantime, some aspects of experimental flows (i.e., low steady <br />releases) could provide for some longitudinal and near-shore <br />warming that may benefit survival and growth of humpback chub. <br /> <br />. Predators: Predator control was implemented in 2003 for rainbow <br />trout and brown trout in the mainstem near the LCR inflow and for <br />brown trout in Bright Angel Creek. These efforts should be <br />continued, since predation is perceived as a major threat to <br />humpback chub in Grand Canyon. . <br />e6>.J1fJ.~.l'll.,,'\.V"'.. #u;J V<,-t-(lt(t<.-.{.....) ?L-t ~h:S' +'v....-t <br /> <br />. Hazardous materials spills: The risk of hazardous materials spills <br />continues to loom over the LCR. Immediate actions are needed to <br />implement a plan to minimize the risk and for cleanup. <br /> <br />. Parasites: Asian tapeworms and Lernaea anchor copepods are the <br />two parasites of most concern for humpback chub; investigations <br />