Current Refuges
Background Information: There are already three established refuges for the Mohave tui Chub. They are located in China Lakes, Lake Tuendae, and Camp Cady (currently dry, as of 6/2004). Unlike the other refuges, MC Springs can be considered a true refugia, a protected habitat for a species created by nature (or so we think is the case for MC Spring. If you are interested in understanding the conventional wisdom surrounding the difference between a man-made "refuge" and a natural "refugia" follow this link.
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In order for the Chub
to be down-listed from endangered to threatened, three more permanent
refuges must be established. In order for a refuge to be considered
permanent it must have a viable population of Chub. Several different
locations have been used to try to establish a permanent refuges.
These locations include both private and public lands. There are
still a few more areas that have not yet been tried and are under
consideration. |
One
of these is located on the campus of the Academy for Academic
Excellence, a charter school in Apple Valley, California.
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MC Spring and Lake Tuendae:
MC Spring, or Mohave Chub Spring, is a naturally occurring spring. However, it has been excavated to form a cylindrical shape. No one really knows how the Chub got there, but there is supposition they arrived after the Mojave River flooded. Because This population of Mohave tui Chub has proven to be genetically pure. Chub from this population were initially used to populate the Lake Tuendae refuge, which in turn is used to provide fish for any other refuge(s) that has been established or may be in the future.
This is MC Spring. It is maintenance to keep down the cattail population and is located in the Mojave National Preserve.
In 1944, Curtis Howe Springer established Zzyzx Mineral Springs and Health Resort at Soda Springs. For ten years he built an extensive infrastructure to support his operation. Around 1955, Springer excavated an artificial pond about 125 wide by 500 feet long, calling it Lake Tuendae. It has a surface area of 1.4 acres and maximum depth of 3.3 feet (prior to dredging the westerly end in 2001). Lake Tuendae lies about four feet above the dry surface of Soda Lake and is surrounded by Mexican fan palms. A fountain in the middle of the lake, dubbed the “Enrico Caruso Fountain,” runs when groundwater is being pumped into the lake. The Lake has no protection from evaporation. It sustains an annual evaporative loss of about 410,000 cubic feet (9.4 acre-feet), five times its volume. Lake Tuendae is connected to the Soda Lake aquifer by seepage, which has probably prevented a long-term buildup of salinity. It gradually fills in with sediments and cattails that must be dredged about every 10 years. Springer or his associates most likely introduced the Mohave tui Chub into Lake Tuendae, which now provides one of its few remaining habitats.
In the fall of 2001 the National Park Service dredged Lake Tuendae, which was becoming filled with silt and cattails. Some fish were killed accidentally when an inflatable dam that was holding water in one half of the lake while the other half was being dredged slipped. Ten dead fish were sent to San Diego State University (research conducted by Victoria Matey and the late Boris Kuperman,) for necropsy and all were found to be infected with Asian tapeworm (Bothriocephalus achelognathii). The Asian tapeworm is a parasite believed to have entered the U.S. in shipments of grass carp and spread to California by live bait fish. It is known to have deleterious effects on fish of the Cyprinid (minnow) family, of which the Mohave tui Chub is a member. The Mohave tui Chub shares Lake Tuendae with the Saratoga Springs pupfish (Cyprinodon nevadensis nevadensis) and the exotic mosquitofish (Gambusia affinis), which is native to southeastern U.S. Gambusia has traditionally been introduced to control mosquitoes but also may consume eggs and larvae of endemic fish. Gambusia affins was first observed in Lake Tuendae around the time of the dredging. Spring 2003 saw an anomalous plankton bloom, perhaps related to the dredging, perhaps related to the mosquitofish. Predation on zooplankton by mosquitofish could allow ecological release of phytoplankton in the lake and exacerbate an ecological imbalance. Tests of the water in the fall of 2003 showed alkaline pH (9.5), total dissolved solids of 2130 mg/L, and salinity of 2.2 ‰, all within the range tolerated by the Chub.
This is Lake Tuendae. It is a man-made lake located at the Mojave National Preserve in Zzyzx, California.
[The above descriptions for the MC Spring and Lake Tuendae Refugias were adapted from "Report on a Workshop to Revisit the Mohave tui Chub Recovery Plan, September 3-4, 2003 at Zzyzx, California, Mojave National Preserve"]
China Lake Naval Air Weapons Station
Mohave tui Chub were introduced at China Lake Naval Air Weapons Station in 1971. From the point of their initial placement, beginning with Lark Seep, Chub naturally immigrated into a series of channels and seeps that had been constructed to drain wastewater away from residential developments. Chub have been surveyed in Lark Seep, G1 Channel, G1 Seep, George Channel, and North Channel.
The Lark Seep habitat started out as a sewage problem. The city of Ridgecrest had grown up to serve China Lake Naval Air Weapons Station (NAWS), a 1.1 million acre military reserve managed by the Department of Defense (DOD) for the purpose of testing Navy air weapons and training troops. Disposal of wastewater lead to the mounding of a shallow groundwater table. In 1945 the City of Ridgecrest built a wastewater treatment facility and the treated wastewater discharge became Lark Seep. As the area of surface water increased and channels were excavated to drain water away from the facilities (G1 Channel, G1 Seep, George Channel, and North Channel) habitat for the tui Chub increased. From MC Spring, 425 Mohave tui Chub immigrated into Lark Seep in 1971, and demonstrated a remarkable ability to migrate between seeps. Cattails are removed annually and DOD has widened a channel in an attempt to maintain open water. Populations have been surveyed since 1979, with large confidence intervals due to low recapture rates, and the mosquito fish is widely abundant.
For more information about the China Lake refuge check out this on-line resource.
Once the traps are collected, the Chub are measured. weighed, and tagged. They are then released back into the area where they were caught.
[The above description for the China Lake Refuge was adapted from "Report on a Workshop to Revisit the Mohave tui Chub Recovery Plan, September 3-4, 2003 at Zzyzx, California, Mojave National Preserve"]
Camp Cady:
Camp Cady is a designated State Wildlife Area in the Mojave River drainage northeast of Barstow, California. Around 1986, the California Department of Fish and Game excavated two ponds to a maximum depth of 2.75 meters, lined them with clay, and stocked them with Mohave tui Chub. The east pond suffered water loss problems and was eventually drained and lined with plastic in 1991. Each pond continues to support approximately 500 Mohave tui Chub. One pond is in poorer condition, and the population suffers from problems similar to Lake Tuendae.
This is a picture of Camp Cady just as the river approaches the Cady Mountains. This is where the water of the Mojave River that flows underground begins to well to the surface.
[The above description for the Camp Cady Refuge was adapted from "Report on a Workshop to Revisit the Mohave tui Chub Recovery Plan, September 3-4, 2003 at Zzyzx, California, Mojave National Preserve" Picture and text credit http://water.usgs.gov/pubs/of/ofr01-245/html/campcady.html]
A Possible Site for a Future Refuge
Oxbow Lake on the Mojave River:
On the campus of the Academy for Academic Excellence there exists an oxbow lake. It is actually an extension of the Mojave River itself and exists because of the beaver dams that encircle one side of it. Besides receiving occasional runoff, it is uncertain as to how much water "seeps" into the oxbow depression from the local river aquifer. It is known that the marsh has not been dry since it and the land surrounding it was purchased by the High Desert Partnership in Academic Excellence Foundation in 1999. The marsh-oxbow lake occasionally receives direct surface flow from the Mojave River as was the case during the Winter of 2005-2006 rainy season. This kind of event would provide Chub the opportunity to be reintroduced to the main course of the Mojave River. Using this site as a refugia would enable students to become part of the solution at no additional cost to any number of government programs. Through a partnership with state and/or federal agencies, guidance could be provided which would enable students the opportunity to be actively involved in the management of this proposed refugia, conduct fish surveys to keep track of how Chub populations are responding to this proposed new setting conduct research as opportunities present themselves.
