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<br />There is no evidence that current operations are causing food <br />base to become limiting for adults, impacts to earlier life <br />stages are unknown. <br /> <br />Because highly fluctuating flow have the highest amount of drift, <br />moderately fluctuating have less, and steady flow conditions <br />further decrease availability of drifting food, the decrease may <br />create potentially limiting conditions. <br /> <br />Temperature <br /> <br />The Little Colorado River (LCR) is probably at carrying capacity. <br /> <br />The production of humpback chub in the LCR may be sufficient to <br />maintain current population levels in the mainstem, but only <br />temperature modification can significantly increase population <br />numbers in the mainstem. <br /> <br />~ <br /> <br />Flow manipulation ~ affect population, but temperature is a <br />more important factor. Cannot remove jeopardy without <br />temperature modification. <br /> <br />, <br />", <br />" <br /> <br />, <br />t';: <br /> <br />Some meeting participants recommended water for controlled floods <br />should come off the top of the reservoir, not through bypass <br />tubes, to achieve higher temperatures, which would require a full <br />reservoir. This type of release may transport some pelagic <br />species from the reservoir, but that should not be problematic as <br />these fish usually do not survive in riverine environments. <br /> <br />Further study of a multi level intake structure is warranted, <br />including further examination of the effects of warmer <br />temperatures on non-natives. <br /> <br />,~. <br />~-" <br /> <br />C' <br /> <br />11.', <br />[::: <br /> <br />'.:" <br /> <br />~:; <br /> <br />k: <br /> <br />Plow Variability <br /> <br />to. <br />'~~.' <br />,'t: <br /> <br />Flood flows should have some degree of randomness. <br /> <br />Fish are energetically disadvantaged if daily fluctuations <br />require movement. Habitat should be stabilized has much as <br />possible. <br /> <br />Minimal diurnal fluctuations is a desired goal. Daily <br />fluctuations of 5000 cfs occurred 5% of the time during pre-dam <br />flows. <br /> <br />".{e;: <br /> <br />:'.-:, <br />~ <br />~_i <br />r..-:: <br />~::~~ <br />:.-,~; <br /> <br />BaCkwaters/Sediment <br /> <br />Backwaters are important to native fish so operations should be <br />designed to ensure these habitats do exist. The relative <br />importance of backwaters may be increased in Grand Canyon due to <br />post-dam temperature lowering. <br /> <br />3 <br />