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Fake Fish Recovery for Real Jeopardy

July 27, 2014
by John Weisheit

This fact sheet written by the US Geological Survey in April of 2009 states that the population of humpback chub in Grand Canyon stabilized in 2002 and the doubled by 2008.

 This sounds like good news, but is it really? Has removing jeopardy toward this native fish been accomplished? The answer to this question is no. What about the other natives species that vanished in the Grand Canyon once Lake Powell began to fill in 1963, some 51-years ago? Have they been reintroduced back into their historic habitat, and are they reproducing without human interference? The answer to this question is no.

What actually is the criteria for delisting an endangered species? Here is the answer to that question:restoring and establishing self-sustaining populations and protecting sufficient habitat to support them.

To achievethis goal it is necessary todevelop management programs to minimiz or remove the threats posed by non-native fish competition and predation;


The 2008 population assessment is still 30% lower than it was in 1989 when the Environmental Impact Statement for operations at Glen Canyon Dam was ordered by Secretary of Interior Lujan.

Habitat conditions to successfully reintroduce extirpated fish have yet to be to achieved in the Colorado River below Glen Canyon Dam. Extirpated fish include: razorback sucker, Colorado pikeminnow, bonytail chub, and roundtail chub.

 The report acknowledges the increase in humpback chub population may be attributed to prolong drought lowering the elevation of Lake Powell, which increases the temperature of the water released through the generators at the power plant at Glen Canyon Dam; Lake Powell storage was at 50% in 2003 (Monthly Reservoir Summary). 

Lake Mead has been below 50% capacity since


It has been reported that razorback suckers are spawning where the Colorado River meets Lake Mead and in 2012, scientists captured razorbacks in the Colorado River in Western Grand Canyon. In April of 2014, the park service (and others) released nine, sonic-tagged adult razorback suckers into the Colorado River below Lava Fall in Western Grand Canyon and in June of 2014 discovered larval razorbacks.


3) From 2003 to 2006 non-native fish were captured and euthanized by boat crews in the mainstem of the Colorado River near the mouth of the Little Colorado River. The plan to mechanically remove non-native fish was approved in 2002 (FONSI).

$) The experimental steady low flow of 2000 (June through September) may have provided a habitat advantage to newly hatched and juvenile fish; another experiment that has not been repeated in 14-years.(Trammell, 2002) (Ralston, 2011)

3d) Low and steady flows (~8,000 cfs) in the months of September and October begain in 2002 (data base), but this is not a mandate and is not held to with consistancy.


Contrarily, the mission of the Glen Canyon Dam Adaptive Management Program is to:

1) Repopulate the mainstem with extirpated fish species.

Things it cannot do, but are essential to remove jeopardy

1) Provide genetic diversity because these fish are gentically isolated and disconnected from the rest of the basin because of high dams.

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