Laserfiche WebLink
<br />. <br /> <br />. <br /> <br />and low survival, or (4) Adequate reproduction and survival but reduced <br />carrying capacity. <br /> <br />We hypothesize that the availability of food (native, fusiform, soft-rayed <br />fishes) for adult squawfish has been reduced since historic times because of <br />a combination of two factors: (1) an altered flow regime allowing <br />sedimentation of coarse substrates and a reduction in allochthonous energy <br />input, together resulting in lowered primary (algal) and secondary <br />(invertebrate) production, and (2) the introduction of nonnative fishes that <br />compete with native food fishes but are themselves unavailable as food to <br />squawfish. This in turn has resulted in a lowering of the carrying capacity <br />of the Colorado River to support a large population of piscivorous fish <br />(squawf1sh) . <br /> <br />The proposed study will incorporate a systems approach to assess the effect <br />of factor No. I (above), utilizing an interdisciplinary team of fluvial <br />geomorphologists, fish biologist.s and systems ecologists. The goal will be <br />to determine if food availabilit.y is indeed an important limiting factor, <br />and if so, provide recommendations for flow regimes that would increase <br />carrying capacity of the Colorado River. These flow recommendations would <br />be important for the Aspinall consultation process as well as ongoing <br />refinement of IS-mile reach recommendations. Thus, management would be <br />geared toward improving conditions for the entire river-wide native fish <br />community, which in turn would benefit the community's top predator, the <br />Colorado squawfish. <br /> <br />10 <br />