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<br />e <br /> <br />A. Stocking of nonnative fish in the Upper Colorado River Basin should be done only in <br />accordance with the proposed non-native stocking procedures. Streamside ponds should <br />be cleared of competing and preying nonnatives and leased for grow out of endangered fish <br />species. <br /> <br />Rationale: Control of non-native fish stocking and leasing of streamside ponds for grow out ponds <br />for endangered fishes, with landowner permission, will both reduce numbers of non-native fishes <br />competing with and preying upon endangered fishes and provide grow out space for endangered <br />species. (Data from the San Juan basin shows that the larger the fish when stocked, the greater <br />the opportunity for survival (pfeifer, personal communication, 1996)). <br /> <br />B. The Program should immediately initiate large scale removal of nonnative !ish from <br />critical habitat, and areas acting as a source of nonnative fishes. <br /> <br />Rationale: While curtailment of nonnative stockings in ponds will help alleviate the problem over <br />the long tenn, the immediate need is to eliminate, to the maximum extent possible, nonnative <br />fishes in the occupied habitat of endangered fish. The recently published nonnative control <br />strategy (Saunders and Tyus, 1996) recommends large scale mechanical removal of nonnatives, <br />through use of barriers, traps, weirs, seines, electro-fishing, mechanical harvesting and removal of <br />creel limits. These recommendations should be immediately implemented. No further research is <br />needed. <br /> <br />e 7. Habitat for endangered fish: <br /> <br />A. The Recovery Program should immediately begin development of streamside ponds as <br />grow out habitat for endangered !ish. <br /> <br />Rationale: The initial 1987 Recovery Implementation Plan recommended development of <br />artificial backwater habitat and rearing of endangered fish in grow out ponds, including gravel <br />pits near Grand Junction. The document cited the fact that Colorado squawfish have been raised <br />in one year to a size that would take three years in the wild (USFWS, 1987). Implementation of <br />these activities would enhance the nonnative control procedures being developed as part of the <br />Program (see 6.A. above). These recommendations should be implemented immediately. <br /> <br />B. The Recovery Program should immediately begin development of predator free <br />backwater habitat to provide for additional recruitment of endangered species. <br /> <br />e <br /> <br />The Recovery Program (USFWS, 1987) recognizes that backwater habitat can be developed <br />artificially by either connecting existing gravel pits or ponds to the river, or by physical <br />construction to simulate depths, velocity, and substrate characteristics found in naturally <br />occurring backwaters. Developing predator free backwater habitat should be implemented <br />immediately. Until nonnatives are controlled. these backwaters must be artificially protected from <br />predator intrusion. Backwaters are recognized as severely limiting recruitment of endangered <br />species when they are filled with nonnative fishes that prey upon larvae and young endangered <br />fish. Protected artificial backwater habitats should be developed, and stocked if necessary, to <br />increase recruitment of endangered fish to the maximum extent possible. <br /> <br />5 <br />