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<br />should continue to assess extent of infestation, risk of warmer <br />water from a TCD, and possibly treatment for reducing infestation <br />to the population. <br /> <br />4.0 STRATEGY FOR IMPROVING CONDITIONS FOR HUMPBACK CHUB <br /> <br />Our goal is to remove jeopardy and assist in achieving recovery goals for humpback chub <br />, <br />in Grand Canyon by expanding the population size and reducing threats to the humpback <br />chub. This will be accomplished by (I) expanding the range of spawning and rearing in <br />Grand Canyon for humpback chub, (2) increasing survival and recruitment of humpback <br />chub, and (3) reducing the threat of catastrophic events or unintended consequences that <br />may negatively affect the wild population of humpback chub. <br /> <br />4.1 Expanding the Range of Spawning and Rearing for Humpback Chub <br /> <br />The primary mechanism for expanding range would be to increase the suitability of the <br />mainstem for reproduction and recruitment of humpback chub. This would be <br />accomplished by warming dam releases and providing flows necessary for spawning and <br />rearing. <br /> <br />Until the TCD is approved and constructed, actions such as the translocation of young <br />humpback chub from the LCR into Grand Canyon tributaries and/or mainstem could <br />provide safe refugia for wild fish and possibly expand the current range of humpback <br />chub. To be successful, translocations would need to occur concurrently with non-native <br />control efforts, and with consideration of other factors such as water quality, flows, and <br />tribal concerns. Use of a grow-out facility may be considered to increase growth and <br />survival of wild fish to be translocated. Ifthere are genetic concerns, these would need to <br />be addressed, perhaps through establishing connectivity between the tributary populations <br />and the mainstem population or other actions. These genetic concerns will be evaluated <br />by conservation geneticists. <br /> <br />4.2 Increasing Survival and Recruitment of Humpback Chub <br /> <br />This would be accomplished through a combination of temperature modification, non- <br />native control, dam operations, turbidity management, control of disease and parasites, <br />reduction of impacts of scientific and recreational activities, and preventing invasion of <br />new non-native species. These actions may include: <br /> <br />(I) Construct and test a temperature control device with the intent of improving <br />spawning and rearing habitat in the mainstem for humpback chub. Providing <br />adequate temperatures for mainstem spawning and rearing may increase other threats <br />such as non-native predation and parasitic infestation. <br />(2) Control non-native predators and competitors to reduce impacts to humpback chub <br />and other native species. This would also help ensure that any negative impacts from <br />temperature modification would not be on top of an already high predator/competitor <br />load. Additional research may be needed to determine which non-natives have the <br /> <br />~2S00 <br /> <br />7 <br /> <br />/[,17 <br />I <br />("\v <br />1 /I)') <br />~ I Y 1/ <br />c:, '.0"':\ <br />? ,J<>' / <br />\,y .,' <br />~~ ~A.-j\' <br /> <br />c- ) <br />-",'I.,'" <br />evc. "I' (' <br />\ ~v 5/ <br />,z-" \ <br />,( <br />\f\ -' <br /> <br />