On the Waiting List... for Extinction?
(Reprinted here from the Lewis Center's "Knightly News" October & December 2007 issues)If the High Desert was still in its wild undisturbed state, the
Mojave River would support a surface flow roughly 2 to 3 times what it does now and that water would be providing a home for only one kind or species of fish, the Mohave
tui chub. The reality, however, is that the river is often dry, flowing below ground only, from its origin in the foothills of the San
Bernardino Mountains to its terminus near Baker, its wet backwaters and mountain tributaries supporting more then 18 non-native species of fish, introduced by humans. The chub's habitat, provided by time, geologic forces, climatic change, and now man, was reduced to a Jacuzzi sized pond, 10 feet in width and 4-5 feet in depth, fed by an spring, itself an anomaly of geology, on the shore of an ancient lake, a
playa, now called Soda Dry lake near Baker.
Today the Mohave
tui chub, classified by state and federal biologists as endangered, is in imminent danger of extinction. Currently its small, restricted population is considered
stable to declining. For this reason, biologists are trying to establish additional artificial, non-river based sanctuaries, or what conservation biologists call “
refugia”, to encourage population growth. In 2003, Molly Estes and Amanda Pearson (class of 2005) discovered these facts while working on
an applied science project in my biology class and committed their final two years at the
AAE to find a solution, what they called “a wish for a fish”. Molly and Amanda’s (click on the image at right to view the workshop participants) efforts resulted in an invitation to a three-day
workshop of experts in desert fish conservation biology, at
Zzyzx, just feet from the spring that some believe was the chub’s last true refuge on earth (click on the image at right to view the workshop participants). At that workshop, Molly and Amanda
proposed that an refugia be constructed on LCER’s Mojave River campus, adjacent to the Upper Narrows, one of the few sections of the river that support semi-perennial surface flow. Their proposal was accepted pending a review of acceptable sites by fishery biologists.
Last spring (2007), Judy Holman and Michael Glenn from the United States Fish and Wildlife Service (
Ventura office), Steve
Parmenter from the California Department of Fish and Game (Bishop office), and Debra
Hughson from the United States National Parks (Mojave Desert Preserve) visited the campus’s ponds, slough’s, and the river and reviewed water quality data collected by past and present Mojave River Student Scientists (
Hastin Zylstra – ‘05, Eddie
Stauffer – ‘08, Aidan
Fahnestock – ‘10). Their conclusion was that
Deppe Pond would provide and acceptable first phase of a two phase plan to introduce about 1000 chub in the late spring of 2008, providing the majority of the cattails are removed, the addition of an aeration device (to promote mixing and oxygenation of the pond’s waters) and that the pond was managed to maintain a depth of 4-4.5 feet at the deepest to provide cool water during hot summer days. The second phase involves the construction of an additional pond below the first. This pond will be called “
Tui Slough” and will be the one of first of its kind that has been constructed solely for the chub. In June a $25,000 dollar grant from the
USFW was funded to help with the preparation of
Deppe Pond and the construction of “
Tui Slough”.
Cattail removal began in early August. A technique researched by Molly Estes and Steve
Parmenter was used. Molly’s research earned her a 6
th place in the 2004 State Science Fair, just a couple places away from the “Big Bucks”. Soon an aerator will be added (turned on in Feb. 2008), and the pond level will be raised. Plans are currently in place to drill a multipurpose about 200 feet from
Deppe Pond and
Tui Slough (completed Jan. 2008). Water from this well will be used to augment pond and slough levels while providing the school with an emergency water source in the case of emergency (
ie. earthquake). The well will also be used in the school’s efforts to promote groundwater awareness education in public school across the Victor Valley.
To most people, the Mohave
tui chub (
Siphateles bicolor mohavensis), looks like a goldfish, carp or golden cousin of the
Koi. Well it should, it belongs to the same family of fishes known as the
Cyprinidae (minnows and carps). Although some of its cousin species, found in other watersheds across the Pacific north and southwest and around the world, are numerous, the Mohave
tui chub is not. Why its not is another story.
Until the mid 1800’s, only one fish was native to the
Mojave River and its tributaries. The downfall began when a sportsman’s whimsy became reality through the introduction of brown and rainbow trout to Deep Creek’s swift cool waters. To provide prey for these predatory fish,
bait fish soon followed. One species of
bait fish in particular, the Arroyo Chub, provided a seductive and genetic demise for the
Tui Chub.
The Mohave
tui chub, as it is known among today’s ichthyologists, is believed to be a refugee, forced from its preferred habitat due to a changing climate during an earlier era of our desert home’s prehistory. Fossil remains of our watershed’s present Chub ancestors have been found in the
dry playa sediments of
Manix and
Lake Mojave, two former “Pleistocene Era” lakes between
Barstow and Baker.
The end of the “
Pleistocene Era” was punctuated by a change in our hemisphere’s climate that ushered in the end of the last major ice age about 19,000 years before the present (
BP) and the
“dewatering” of our desert. By about 9,000 years
BP, these lakes began to dry, as the declining flow of the Mojave River retreated toward their mountain head-waters. Before the lakes began to dry, however, it is believed that a small population of the ancestral Mohave
Tui Chub found refuge in the retreating waters of the Mojave River. It was this remnant of the population that 8,000 years later faced a new challenge to their existence as a unique species.
Remember the Arroyo Chub (Gila
orcutti), an introduced
bait fish, it just so happens to be a “kissing cousin” to the Mohave
tui chub (
Siphateles bicolor mohavensis, formerly known as
Gila bicolor mohavensis). By 1946, years after the Arroyo Chub had been artificially introduced to the headwaters of the Mojave River, fishery biologists noticed that the Arroyo Chub readily cross bred with the native Mohave
tui chub. In 1968, it was observed that the resulting “hybrid” chub species was rapidly replacing the native chub population. By 1970, the only pure genetic strain of Mohave
tui chub were found in that small spring mentioned earlier in this article, called MC Spring, and a nearby man-made impoundment called Lake Tuendae .
Since 1968, after attempting to establish self-sustaining populations in streams, lakes and ponds across the Southwest, today only four locations (a lake, a pond, a spring and a seep) in the Mojave Desert provide the Mohave
tui chub refugees with their only viable non-native habitats. These locations are collectively called
refugia by conservation biologists.
In 1971, the one to three-inch, largely plankton eating Mohave
tui chub had been listed as a species in danger of becoming extinct. If more viable
refugia can be established along the headwaters of the Mojave River, south of the river’s Upper Narrows, this endangered species can be “down-listed” to threatened. In the future, fish from these new ponds might provide fishery and conservation biologists the stock to reintroduce the
Tui chub back into a MojaveRiver, its former refuge. However, another invader, the Asian tapeworm, may now also threaten two of these
refugia. This tapeworm is carried by Mosquito fish.
Therefore, one of the final obstacles to providing the chub with optimal habitat is the management and or removal of Mosquito fish from
Deppe Pond. These non-native, guppy sized, live bearing fish prefer to eat the eggs and larval of other native fish and amphibians that share the water with them; they eat mosquito larva only when nothing else is available. And to make things worse, they carry parasitic tapeworms that are believed to infect members of the goldfish family of fishes. At present (Fall 2007), a small group of Mojave River Student Scientists are taking on the task of designing a trap to reduce their numbers in
Deppe pond so if you see their creative two and three liter bottle traps floating on and below the waters of the pond then you know their research is underway. Future plans include allowing the pond level to drop and freeze in the winter once
Tui Slough is up and stocked.
As we can make for information available, we will. Stay tuned for more exciting news as we help the
Mojave River's only native fish get off the “waiting list for extinction”. If you want to join Molly and Amanda’s fight for this little fish, let me know at mhuffine@lcer.org or 760-946-5414 ext. 238. For more information about the Chub go on line to
http://www.lewiscenter.org/local/tuichub.php
to complete and fill the Tui Slough extension of the Lewis Center Refuge for Mohave tui chub were completed. For the details visit this link to view the "picture progress" of our efforts. But it took a snow storm on December 17th to provide the water. 
to complete and fill the Tui Slough extension of the Lewis Center Refuge for Mohave tui chub were completed. For the details visit this link to view the "picture progress" of our efforts. But it took a snow storm on December 17th to provide the water. 
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