Native Fish In Fossil Creek, East Verde River Need Protection Say Scientists


The U.S. Fish and Wildlife Service’s plans to protect endangered native fish in Fossil Creek and the East Verde River “fail to meet any standard of good science or even common sense,” according to a letter written by four experts.

The letter expressed deep frustration in the long delay in responding to a previous plea to list as endangered the roundtail chub and the headwater chub and to update information on other species, like the flannelmouth sucker, Little Colorado sucker, bluehead suckers and Zuni bluehead sucker.

Much of the letter focused on the status of several native fish in the resurrected Fossil Creek, as well as the East Verde River, where heavy recreational use and the weekly stocking of non-native rainbow trout endangers the small populations of native fish.

“In the year and a half since our petition, the status of the headwater chub has further deteriorated. Threats to these species are high, increasing and imminent and federal protection is urgently needed to address those threats before it is too late,” concluded the letter signed by Sally Stefferud, Paul Marsh, Jerome Stefferud and Thomas Dowling. All of those fish experts have federal contracts to monitor populations of native fish in both Fossil Creek and the East Verde River.

The Fish and Wildlife Service did not return calls seeking comment on the letter.

Fossil Creek has become one of the premier refuges for half a dozen native fish in the five years since Arizona Public Service agreed to remove a century-old power generating plant and returned the flow of a spring to the creek bed.

After the creek won designation as a Wild and Scenic River, the Forest Service started work on a management plan that focuses on intensive recreational use of a key middle reach of the river, complete with a shuttle bus during the season.

The Arizona Game and Fish Department also now supports a catch-and-release fishery in Fossil Creek for roundtail chub, also known as Verde trout.

The Arizona Game and Fish Department stocks the East Verde River weekly, having extended the season in the past two years as a result of the annual release of about 11,000 acre-feet of water into the creek from the Blue Ridge Reservoir.

The fish biologists maintain that their data shows populations of native fish found in both creeks have declined sharply statewide in the past century and that the species all should top the endangered species list. Such a designation would require the federal government to take the survival of those species into account any time it approves a federally supported activity — which could include both stocking the East Verde with rainbows and adopting a management plan for the East Verde.

However, the U.S. Fish and Wildlife Service (USFWS) has routinely refused to undertake the scientific studies needed to actually list dwindling species, citing a lack of money to do the studies, say the letter writers. Some 253 species have been consigned to the limbo of USFWS’s “warranted but precluded” category. That means preliminary studies show the species is probably endangered, but USFWS can’t afford to do a study that would establish what areas are critical to the survival of that species.

The USFWS maintains that Congress each year has refused to give it enough money to undertake the studies required by law.

The four fish biologists waited for more than a year for a response to their plea to move quickly to list several native fish before writing the most recent letter in evident frustration.

“The purpose of the letter was to get them to answer the question: what is the status of each of these species?” said Dowling, a professor at Arizona State University.

Fossil Creek

Many of the questions about Fossil Creek focus on the complicated and still mysterious relationship between two native fish — the roundtail chub and the headwater chub. Both are dwindling, bug- and fish-eating members of the minnow family who grow to trout size and appear almost identical to the eye.

Biologists didn’t realize that both species lived in the spring-fed Fossil Creek when they removed all the fish, eliminated the non-native fish and returned all the surviving native fish to the creek once the full flow of water had returned.

Biologists set up a system to monitor the status of those native fish in the restored creek. That’s when genetic tests revealed that the headwater chub dominated in the upper reaches of the creek and the roundtail chub dominated in the reaches closer to the Verde River.

Dowling’s work has concentrated on those relationships. Biologists don’t know if they’ll interbreed and form a new hybrid species or divide up the creek based on some still mysterious attribute of the stream. On the other hand, one species may simply overwhelm the other.

So far, Dowling said he’s found signs that they do mingle and produce hybrid offspring in some stretches of the creek, but that they mostly seem to divide up the creek — with roundtail chubs dominating in the lower reaches and headwater chub dominating closer to the gush of the warm spring that sustains the creek.

Other native fish whose populations have boomed in Fossil Creek include the desert sucker, speckled dace, longfin dace and Sonoran sucker.

Biologists have also attempted to reintroduce Gila topminnows and razorback suckers, with uncertain success.

Virtually all non-native fish have been removed and even crayfish have disappeared since the return of the travertine-rich water to the streambed.

The biologists worry about the impact of the catch-and-release fishery on roundtail and headwater chub, also known as Verde trout. They worry about the impact of heavy recreational use, especially on the deep pools that draw the most swimmers and cliff jumpers.

Under the proposed management plan “most of the creek would be designated for recreational use with a natural resource emphasis only in two short reaches that exclude the highest value headwater chub habitats.”

The letter expressed concern about “water pollution from pharmaceuticals and personal care products introduced on bodies of swimmers and waders and through bodily fluids, dust pollution from unpaved roads, changes in wildlife behavior from noise, human presence and scattering of garbage, filth and direct harassment of fish from swimmers and divers.”

East Verde River

The letter said the Fish and Wildlife Service has never assessed the number of headwater chub in the stream nor studied the impact of stocking about 2,000 rainbow trout each week into the stream.

A previous environmental assessment call the status of the native fish in the East Verde “essentially unknown.”

Earlier assessments indicated people fishing for Verde trout sometimes catch chub, which they’re supposed to release. About 10 percent of the chub released die as a result of the stress of the capture, according to the assessment.

Despite 10 years of stocking the creek with rainbow trout and five years after issuing a management plan, the USFWS has never studied the health of the native fish population in the stream.

The letter complained that the studies and management plan were “ineffectual and discredited” and that the federal biologists continue to rely on “secondhand anecdotal information.”

The independent biologists objected to emerging federal policy that suggested the Fish and Wildlife Service didn’t need to maintain different, genetically distinct populations of the two chub species. Studies show that the DNA of different populations of chub vary sharply, so a genetic test can easily determine which stream a fish came from.


Use the comment form below to begin a discussion about this content.

Requires free registration

Posting comments requires a free account and verification.