Laserfiche WebLink
<br />* The proposed five year study is expected to take 10 years <br />to complete but may take longer while waiting for the right <br />conditions. Again, the validity of measuring long-term <br />effects by such a fragmented, short-term approach seems <br />inefficient and burdensome to other resource users. <br /> <br />* Cold water releases from dams are usually too cold for <br />nonnative warmwater fish to successfully spawn and recruit <br />near the dams and are likely responsible for stunting <br />populations of warmwater nonnative fish which prey upon or <br />compete with native fish. <br /> <br />* Success in creating ideal habitats for native fish hinge on <br />precluding increased use of these habitats by nonnative fish. <br /> <br />'" <br /> <br />I <br />~ <br />~ <br />t <br />~ <br /> <br />* Native fish responses to existing dam operations may be <br />better than nonnative fish responses. Channel catfish, for <br />example, have higher temperature ranges than chub and may be <br />disproportionately impacted by the colder temperatures. <br /> <br />* Nonnative fish may be more vulnerable to present conditions <br />and mimicking pre-dam flows may enhance their survival chances <br />disproportionately to that of native fish. <br /> <br />* All efforts to provide better habitat for young native fish <br />would be for naught if predatory and competing nonnative fish <br />are able to take better advantage of the improved habitat. <br /> <br />* Body condition of humpback chub appears better than those <br />in other parts of the Colorado River system and their <br />population under normal fluctuating flows was relatively <br />stable and self-sustaining. <br /> <br />'I <br /> <br />,,' <br />;- <br /> <br />* Backwaters also are areas where nonnative use would be <br />highest and susceptibility to predation and competition the <br />greatest. Under steady flow conditions, the backwaters would <br />become less turbid thereby further enhancing a predators' <br />chances. <br /> <br />" <br /> <br />~ <br />- <br /> <br />* No evidence exists that the research flow proposal (or any <br />other flow) would affect the ability of fish to access <br />tributaries for spawning. This hypothesis has never been <br />tested in the Grand Canyon yet continues to be offered as a <br />condition which should be anticipated. <br /> <br />The effort to conduct endangered fish research sounds reasonable <br />but the effort should be compared with: 1) the system's capacity to <br />handle more chub; 2) the potential for a catastrophic event <br />damaging the present population; and 3) the potential for the <br />efforts to yield damaging increases in nonnative predatory and <br />competing fish. <br /> <br />"i <br /> <br />~, <br /> <br />.. <br /> <br />'/~ <br />" <br /> <br />14 <br />