January 6, 2008

Local fish species on the rebound

Bob Hilburn, a Bureau of Land Management volunteer site steward and educator, checks the water temperature of an aquarium full of Mohave tui chub on Saturday. Photo by David Heldreth

By David Heldreth, staff writer
Desert Dispatch

BARSTOW — The Mohave tui chub is just looking for a home.

The Mohave tui chub is the only fish that is native to the Mojave River system, but it can’t be found there anymore. They were even one of the first animals protected when the Endangered Species Act was passed in 1973.

However, you can get a glimpse of the rare fish at the Desert Discovery Center on Barstow Road. While there you might even catch Bob Hilburn, a volunteer site steward and educator for the Bureau of Land Management, during a feeding.

“We have three aquariums at the Discovery Center,” Hilburn said. “Two have the Mohave tui chub and one has the Arroyo. I just do what the scientists tell me to, feed them and take the water temperature.”

The Mohave tui chub lost their original home to predators, competition with introduced fish species and possibly hybridization according to Debra Hughson a science advisor for the Mojave National Preserve. Hughson and a group of scientists are working on a new study at the DDC. The goal of the study is to create a stable Mohave tui chub population and determine if they could hybridize. The study has several steps and could take more than seven years.

“We’re in the first stages now,” Hughson said. “We need to see if the Mohave can create hybrids, and if they do are the hybrids viable. They could be sterile like other hybrids such as a mule. If so it would be easier to reintroduce the Mohave.”

The Mohave tui chub were thought to have bred with the Arroyo Chub, an introduced species, and no longer exist in a pure form. However, a little luck and the development of the field of genetics have proven that to be untrue. A small population of fish were discovered by Curtis Springer, the founder of the Zzyzx Mineral Springs and Health Spa, in the nearby waters in the 1940s. Springer then introduced some of those fish into his manmade Lake Tuendae at Zzyzx. Sixty years later genetic testing proved that the fish Springer found were pure Mohave tui chub.

It is believed that one of the times the Mojave River flooded a group of Mohave tui chub were carried into the Zzyzx area, and were stranded there as the waters receded creating the refuge. All Mohave tui chub in existence today are descendants of the fish Springer found.

“It is pure chance that Springer took care of the Mohave,” Hughson said. “The introduction of the Arroyo chub pushed them out of the river. Curtis Springer saved them from complete extinction without knowing what he was doing.”

The study being done at the DDC is also part of the first step toward down listing the Mohave tui chub from endangered to threatened. A species needs to have at least six stable populations for five years before it can be down listed. There are currently three populations in existence with one at Zzyzx, one at Fort Cady and one at Naval Air Weapons Station China Lake. Hughson said as the study at the DDC expands it should produce enough Mohave tui chub to be considered a population and only two more would be needed.

Having the study at the DDC also allows for the public to get to know the Mohave tui chub better. Hilburn has been part of that effort. Hilburn said the DDC has been working on a curriculum to teach elementary kids about the fish to try and instill the importance of preservation.

The Desert Discovery Center is open Tuesday through Saturday 11 a.m. to 4 p.m.