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The Endangered Fish of the Colorado River Basin
January 01, 2009
By improving the quality of life for wild creatures, we improve the quality of life for people. This is the intent of the Endangered Species Act (ESA). It is a legislative act of hope to preserve our heritage and a marker that society has a responsibility toward community and stewardship.
Aldo Leopold recognized in 1949 what the distraction is against the preservation ethic, "the land-relation is still strictly economic, entailing privileges but not the obligations."
President Eisenhower might have said it best, "A people that values its privileges above its principles soon loses both."
Since Congress passed the ESA in 1973, recovery programs on the Colorado River have yet to stabilize a single imperiled species. Because there is no honest enforcement from federal and state agencies, the ESA has become a legislative embarrassment to the nation and lawsuits abound.
The Department of Interior currently boasts that the endangered humpback chub population in Grand Canyon is improving under their tuteluge, but fails to mention that the razorback sucker and other species were simultaneously lost.
The dialogue of the privileged to reform the ESA is more about their greed, inconvenience, and zookeeping remedies. The hope is turning into despair.
Besides throwing blame on the government, we need to look at the whole of society, as Leopold observed. Specifically our acute consumption of natural resources to fuel the growth economy theory, which is impossible to sustain in perpetuity despite the cheerleading.
Achieving a steady-state population and economy for humans is indeed desirable, if not absolutely essential to reverse the struggle toward extinction, because it otherwise mirrors the inclusion of the human race.
Our society must face the fact that for too long, we have consumed too much, and this carelessness does not offer a final reward.
Read: Prosperity without growth.
The native fish populations in the southwestern United States have the highest rate of jeopardy toward extinction in the nation.
If not for the undeveloped tributary streams of the Colorado River basin, where natural habitat still exists, these fish would have become extinct long ago. 2001 - Tyus and Saunders.
Click here to watch a movie clip of native fish (either humpback chub or bluehead sucker) spawning at the mouth of Havasu Creek, a spring-fed tributary of the Colorado River in Grand Canyon National Park.
Historically, the native fish fauna of the Colorado River Basin was dominated by the minnow (cyprinids) and sucker (catostomids) families. Of the 34 known native species to the Colorado River basin, 74% are found nowhere else in the world, or endemic.
Fish ladders have been constructed at small diversion dams in the upper basin river reaches, which increase the range of habitat for a few dozen miles. Fish ladders at high dams, such as Glen Canyon and Hoover dams, are probably impossible to construct. Whereas removing Glen Canyon Dam, which is not essential water infrastructure, would increase river habitat by 500 miles on the Colorado, San Juan, and all the convergent tributaries of Canyon Country.
Glen Canyon Dam exists solely for reasons of delaying the downstream movement of water at a fixed geographical location (Lee's Ferry, Arizona), a function that Hoover Dam is able to perform. Also, of course, to provide hydropower revenue (a federal subsidy) to pay for the dams and water projects of the basin, a function that farmers and cities are able to perform.
In other words, bureaucratic bean counting is essentially why these fish suffer.
Note: Includes 100-year river floodplain and full pool elevation of reservoirs. Lake Powell is not critical habitat except for the uppermost arms of San Juan and Colorado rivers. Total river mileage is 1,980.
Upper Colorado River
2001 - Comments on the recovery goals for endangered fish. Coggins and Gloss; GCMRC.
SIGNIFICANT PROGRESS REPORTS
The Colorado pikeminnow is a long-distance migrator and historically ranged from Wyoming to Mexico; moving hundreds of miles to and from spawning areas. Adults require pools, deep runs, and eddy habitats maintained by high spring flows. These high spring flows maintain channel and habitat diversity, flush sediments from spawning areas, rejuvenate food production, form gravel and cobble deposits used for spawning, and rejuvenate backwater nursery habitats. Spawning occurs after spring runoff when the temperature reaches 64 -73° F. After hatching and emerging from spawning substrate, larvae drift downstream to nursery backwaters that are restructured by high spring flows and maintained by relatively stable base flows (non-fluctuating).
Historically ranged from below present-day Hoover Dam in the Colorado River upstream into Colorado, and in the larger portions of Colorado River tributaries in Arizona, Utah, Colorado, and Wyoming. The humpback chub is restricted to deep, swift, canyon-bound regions of the mainstem and large tributaries of the Colorado River. This specialized habitat, as it were, is probably why the species was unknown to the world until 1946. Adults require eddies and sheltered shoreline habitats maintained by high spring flows for spawning. High spring flows maintain channel and habitat diversity, flush sediments from spawning areas, rejuvenate food production, and form gravel and cobble deposits used for spawning. Eggs are dispersed when the water temperature reaches 61-72° F. The young require low-velocity shoreline habitats, including eddies and backwaters, that are more prevalent under base-flow (non-fluctuating) conditions.
Historically, razorback sucker were widely distributed in warm-water reaches of larger rivers of the Colorado River Basin from Mexico to Wyoming. Habitats required by adults in rivers include deep runs, eddies, backwaters, and flooded off-channel environments in spring; runs and pools often in shallow water associated with submerged sandbars in summer; and low-velocity runs, pools, and eddies in winter. Spring migrations of adult razorback sucker were associated with spawning in historic accounts, and a variety of local and long-distance movements and habitat-use patterns have been documented. Spawning in rivers occurs over bars of cobble, gravel, and sand substrates during spring runoff at widely ranging flows and water temperatures (typically greater than 57°F). Spawning also occurs in reservoirs over rocky shoals and shorelines. Young require nursery environments with quiet, warm, shallow water such as tributary mouths, backwaters, or inundated floodplain habitats in rivers, and coves or shorelines in reservoirs.
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