7731 - Laserfiche WebLink

Home Browse Search

and flooded bottomlands have been shown to contain large numbers of zooplankton and benthic organisms. When these habitats are available, razorback suckers use them extensively for feeding prior to and after spawning, and may also have spawned in such sites. Colorado squawfish also use these areas for feeding prior to migrating to spawning areas. The Recovery Action Plans contain tasks to identify and restore important bottomland habitat. The Recovery Program is conducting an inventory of all bottomlands adjacent to mainstem upper basin rivers and will classify them according to their perceived value to endangered fish recovery. Five bottomland sites in the upper basin already have been identified for restoration (two on the Green River, two on the Colorado River, and one on the Gunnison River). Conceptual management plans for restoring these sites are being developed and baseline data are being collected. Where land and/or water rights are needed, the Recovery Program is working to acquire them (via lease, purchase, etc.). Once management plans are finalized and access secured, restoration and construction activities will begin, and these will be followed by monitoring and evaluation to determine their success in contributing to recovery. Additional sites may be identified for restoration as a result of the bottomland inventory. Passage barriers have fragmented endangered fish populations and their habitats, resulting in confinement of the fishes to 20 percent of their former range. Blockage of Colorado squawfish movement by dams and water-diversion structures has been suggested as an important cause of the decline of this species in the upper basin {Tyus 1984, USFWS 1991). Restoring access to historically-occupied habitats via fish passage ways has been identified in the Colorado squawfish Recovery Plan as one of several means to aid in Colorado squawfish recovery (USFWS 1991). The Recovery Action Plans contain tasks to assess and make recommendations for fish passage at various dams and diversion structures. The need for passage already has been- determined at some sites and activities are under way to restore passage at agricultural diversions in the Yampa River and at the Redlands Diversion Dam on the Gunnison River, and several diversions on the mainstem Colorado River near Palisade, Colorado. The Green River directly downstream of Flaming Gorge Dam formerly provided habitat for all four of the endangered fishes. However, after the dam was closed, these warmwater species disappeared in the reach between the dam and the confluence with the Yampa River. Cold water temperatures {resulting from- release of cold reservoir water) are presumed to be unsuitable and may be the primary reason for the absence of the endangered fishes there. Modifying water temperature by releasing warm surface water or otherwise manipulating flows from Flaming Gorge Reservoir has been suggested as a strategy to restore this habitat. . 8