State's native fish in struggle for life

TEMPE - They're not cute. They're neither warm nor fuzzy. Fish, in fact, are cold, slimy and scaly. Their champions are few.

Scientists have identified 33 native Arizona fish species and 29 of the remaining 32 are in trouble - serious trouble.

But there is no public clamor for action.

"Fish are very difficult for a human to understand. They might as well be on Mars," said W.L. "Mink" Minckley, an Arizona State University zoology professor and a leading advocate for native Arizona fish.

"Fishes are extremely alien. They breathe water and generally are thought of only as something to catch or eat," Minckley said.

Minckley, who has studied native Arizona fish since 1963, said one species is extinct, two are confined to the Pacific Ocean and 29 of the other 30 are listed as endangered or threatened, or are under study for listing.

"Clearly, there's a problem," he said.

"Native Arizona fish probably are in the most trouble of any group of species in the Southwest," said Tom Gatz, endangered species coordinator in the U.S. Fish and Wildlife Service's Phoenix office.

Many of the fishes' rivers have been dammed or drained by ground-water pumping.

But Minckley said the greatest native fish losses have been due to aggressive, non-native predator or competitor fish - which were introduced for sport, food or for a specific purpose such as mosquito control.

Gatz said the blame for releasing the hordes of non-native fish in Arizona goes to local, state and federal agencies as well as individuals. "We've all been involved over the years," he said.

Why should anyone care if the native Arizona fish species survive or perish?

"The idea that a fish is part of a systemwide process is difficult to comprehend," Minckley said. "But native fishes are major components of unique Arizona ecosystems."

Fish eat insects, algae, organic material, microscopic water animals and other aquatic organisms, keeping streams and rivers clean, he said.

Birds, amphibians and mammals also eat fish as an essential part of their diets, he said.

Kirk Young, native fish biologist in the Arizona Game and Fish Department in Phoenix, said there are other reasons to hope the fish survive.

He said the endangered Gila and Yaqui topminnows are subjects of medical research because their skin pigmentation appears to prevent cancers. Other medicinal uses might be discovered in the future.

Minckley said many of the native Arizona fish are unique because of their isolation - more than 90 percent of the state's waterways drain into the Colorado River.

Only small creeks in the far southeast corner of the state, east of Douglas, flow south into Mexico - and they also are home to rare species, he said.

"The Colorado River Basin is very old - millions rather than thousands of years - and these fish were isolated, stuck in the waters," Minckley said. "As little as three feet of dry land would prevent them from moving."

The great fluctuations in the depth, speed and courses of Arizona's desert rivers left many fish species trapped in pools for periods of time, awaiting the next high-flow period, he said.

"There clearly has been strong selection," he said. "Native Arizona fish, in general, are able to exist under high temperatures and very high salinity.

"And many native fishes are strong swimmers that can disperse rapidly when they get an opportunity."

Some native Arizona fish are long-lived, he said. Colorado squawfish can live for 75 years, razorback suckers can live 50 years and boneytail chubs have exceeded 40 years of age, Minckley said.

But their longevity makes it hard for them to reproduce quickly and grow large enough to defeat predatory fish, he said.

And the Colorado River system had few fish species, and few predator species, compared to other U.S. river systems, he said.

"In the lower Colorado (south of Lee's Ferry), there were only nine kinds of fishes, and only five were abundant," Minckley said.

But transplants from places like the Mississippi River system - home to hundreds of kinds of fish - brought species that "had vast experience with competition for food and many predators," he said.

Since transplanting became widespread in the 1930s, it's been no contest.

"Below Parker Dam, there are no native fishes left," he said. "It's the only river in the world where natives were wiped out."

Despite all the problems, only one native Arizona fish - the Monkey Spring pupfish - has become extinct. That happened in 1971, under scientists' noses.

"We thought it was secure and were lulled into a little apathy," Minckley said. "We all kind of ate crow."

The Monkey Spring pupfish was found only in water flowing from an isolated spring on a ranch in Santa Cruz County.

Minckley said that in 1968, ranch hands put six adult largemouth bass in Monkey Lake, an irrigation pond the rancher had formed with spring water. Scientists got the bass out with nets.

But in late 1970 or early 1971, ranch hands again put some adult largemouths in the pond - and scientists did not visit the site until the summer of 1971, he said. It was too late.

Among remaining fish, the bonytail chub is the most endangered, Minckley said. The species, once abundant in the entire Colorado River system, now is found only in Lake Mohave, he said.

Minckley's brother Chuck, a native fish biologist in Fish and Wildlife's Parker office, is working to revive the bonytail chub and the razorback sucker.

"The bonytail chub is probably the most endangered vertebrate in the United States," Chuck Minckley said. "It took ASU and Fish and Wildlife 25 years to catch 30 wild adults."

Chuck Minckley and his crews are creating predator-free coves on the edges of lakes Mohave and Havasu to allow bonytails and razorbacks to grow to 12 inches in length, he said.

The fish are then released into one of the lakes or in protected golf course ponds, he said. The suckers, which are endangered, also are released in the Colorado and some of its tributaries, he said.

The largest of native Arizona fish is the Colorado squawfish. Once abundant, it is endangered - extinct in Arizona. It survives in the upper Colorado system.

The Colorado squawfish is in the minnow family. But it was the Colorado River system's top predator and at the turn of the century was found at up to six feet long and 75 to 100 pounds.

Commercial fishermen pulled them from the Salt River in Phoenix before and just after the turn of the century. A tasty fish, locals called them "salmon."

They were so abundant that Phoenix-area farmers pitchforked them out of the Salt and its canals for use as fertilizer.

"We have the technology and knowledge to save these fish," he said. "We'll have to change fishing regulations to manage for natives and non-natives. It will take a lot of compromise and education."

Chuck Minckley said an angler caught the last wild Colorado squawfish seen in Arizona in the Grand Canyon in 1972.

But in recent years, hatchery-bred Colorado squawfish have been planted in the Salt and Verde rivers, he said.

"There's quite an effort to save these fish," he said. "They're like aquatic eagles, but you can't see them as easily."

"Mink" Minckley said Colorado squawfish and razorback suckers were once common in the San Pedro River. Commercial fishermen sold them for food in Tombstone in the 1870s and 1880s.

The San Pedro then was a significant river that was home to the same array of native Arizona fish species that lived in the larger Gila River into which it fed, he said.

The Santa Cruz River through Tucson flowed year-round decades ago, but never compared with the San Pedro or Gila and couldn't support the larger species, Minckley said.

The Santa Cruz was home, however, to the desert pupfish, the Gila topminnow, the Gila chub, longfin and speckled dace, and two types of suckers, he said.

The desert pupfish and Gila topminnow are listed as endangered. The status of the other species is under study.

Minckley is convinced Arizona's remaining native fish can be restored to healthy populations.

"We have the technology and knowledge to save these fish," he said. "We'll have to change fishing regulations to manage for natives and non-natives. It will take a lot of compromise and education.

"Will people give up fishing for rainbow trout in some rivers to save a sucker? They need to realize these fish are useful and valuable."

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