APPCOR13192 - Laserfiche WebLink

Home Browse Search

humpback chub known to exist in the Upper Colorado River Basin (UCRB) are • located in Black Rocks and Westwater Canyons on the Colorado Rivet. Conservation measures outlined below will contribute to increasing our knowledge of humpback chub in the Green River aubbaein and providing proper habitat conditions for humpback chub, thus offsetting the likelihood of jeopardy for the apecies. BONYTAIL CHUB Little is known about the biological requirements of the bonytail chub, as the species greatly declined in numbers in the upper basin ehoctly after 1960. The last known stronghold for bonytail chub was at the confluence of the Yampa River with the Green River. Until recently, the U.S. Fish and Wildlife Service (FNS) considered the apecies extirpated from the upper basin; however, a recently collected specimen which exhibits many bonytail characteristics could indicate a small, extant population. It ie thought that, should this apecies persist in the Colorado River, the preferred habitat would be larger river reaches in the Colorado River. Conservation measures outlined below will contribute to conservation efforts for the bonytail chub,.thue offsetting the likelihood of jeopardy for the species. 1~ASURES The FWS believes that any further water depletions from the UCRB may have detrimental effects on listed fishes. However, it ie believed that certain management techniques can be implemented to offset harmful effects from additional development, particularly in the case of small depletions such as this. Impacts resulting from seemingly small water developments may be subtle, but harmful in a cumulative sense. The fact that water 1s depleted from the rivers reduces the flexibility of the eyetem to withstand additional water losses without detrimental impacts to endangered fishes. Creation of habitat favorable [o introduced apecies ie an example of how seemingly minor changes in flow regimes may shift the balance between survival and extinction for one or all of these listed fishes. Depletions that bring present day flows down to lower levels can occur 1f enhancement meaeuree contained in active research and management plane are funded by the project sponsor or proponent. FWS has identified certain conservation meaeuree that are currently considered necessary to maintain the survival of the fish and contribute toward their conservation. These measures include monitoring known populations and attempting to locate new areas containing the fish; further analyzing the potential effects of water depletions and associated flow regime modifications, locating existing and potential spawning and rearing areas; researching and constructing various fish passage and habitat restoration features; and producing the fish in a hatchery facility for research and restocking of individuals in existing and historical habitat. 3