Difference between revisions of "FISH"

Other Native Fish

Grand Canyon was once home to eight species of native fish. Only five of these species are found in the park today. Following the completion of Glen Canyon Dam in 1963, the fish assemblage in the Colorado River in Grand Canyon has shifted to a non-native rainbow trout fishery in the stretches of river closest to the dam and above the Little Colorado River. Of the canyon's native fish species, only speckled dace remain truly common in the park, and they live primarily in tributaries which retain their natural characteristics more than the Colorado River.

Two species of Grand Canyon's native fish are listed under the Endangered Species Act. Humpback chub, which used to be abundant in Grand Canyon, has been listed as an endangered species since 1967. Razorback Suckers are very rare in the canyon, and were listed as endangered in 1991.

Grand Canyon has a very distinctive collection of native fish. All eight native species belong to only two families: minnows (Cyprinidae) and suckers (Catostomidae). Six of the eight native species are found only in the Colorado River basin. This very high percentage of endemic fish species likely results from the geographic isolation of the Colorado River system, and the highly variable natural environments, flow and temperature regimes of the river and its tributaries. The Colorado River has the lowest diversity of native fish and the highest level of endemism of any river system in North America. The river's unusual native fish assemblage is as iconic a characteristic of Grand Canyon as its towering cliffs and spectacular scenery.[1]

Desired Future Condition for Native Species and Biotic Communities

Native Species:
Native fish species and their habitats (including critical habitats) sustainably maintained throughout in each species’ natural ranges in the CRE.
• A healthy, self-sustaining populations of other remaining native fish with appropriate distribution (flannelmouth sucker, bluehead sucker, speckled dace, so that listing under the ESA is not needed.