9586

• UCREFRP Catalog Number: 9586
• Author: Desert Fishes Council.
• Title: Proceedings of the Desert Fishes Council Volume XXVI 1994 Annual Symposium.
• USFW Year: 1994.
• USFW - Doc Type: Furnace Creek, CA.
• Copyright Material: NO

DFC PROCEEDINGS - ABSTRACTS AND CONTRIBUTED PAPERS IN ORDER PRESENTED
was only 5% of the reservoir's total capacity. Populations in small reservoirs above Clear Lake may have been
eliminated due to desiccation during the summer of 1992. Some of these populations may have been reestablished
via spawning runs in the spring of 1993, but significant upstream migration may have been precluded by low
downstream discharge in Willow Creek, a major tributary. Suckers captured in 1992 and early 1993 exhibited signs
of stress, possibly due to low lake levels. The condition factors improved by late summer 1993.
The Department contracted with the National Biological Survey (Gary Scoppettone) to determine the
population density, food habits, age class structure, daily and seasonal movement patterns and seasonal limnological
conditions in Clear Lake Reservoir and the other major California population site, Tule Lake.
The Department also let a contract to determine the genetic status and taxonomic relationships of suckers in
the Klamath basin. Dr. Don Buth at UCLA has presented the following preliminary results:
1. A set of loci has been determined that will identify the four species and allow recognition of putative
hybrids.
2. To date, no allozyme evidence for hybridization between shortnose suckers and Klamath largescale suckers
has been revealed in the Clear Lake Reservoir sample. More specimens need to be examined.
3. To date, no allozyme evidence for hybridization between shortnose suckers and Klamath smallscale suckers
has been revealed in the Copco Lake sample. More specimens need to be examined. Final results are not available
due to administrative delays.
LAHONTAN AND PAIUTE CUTTHROAT TROUT - Within the last five years the Department has
successfully restored Lahontan cutthroat trout (Oncorhynchus clarki henshawi) to five streams with the California
portion of the Lahontan Basin. This effort has increased the amount of occupied or restored habitat from 17 stream
miles to 36, and the total number of populations to 14. A century ago, this federally- listed threatened fish occupied
an estimated 1,000 miles of habitat in California. The closely related Paiute cutthroat trout (Oncorhynchus clarki
seleniris), a federally-listed threatened subspecies, has been adversely affected by introgression with introduced
rainbow trout (Oncorhynchus mykiss). This has resulted in the loss of Paiute cutthroat trout from all but two tiny
tributaries of itc endemic habitat, Silver King Creek. Repeated chemical treatments have eradicated introgressed
fish from the Silver Creek drainage. As a result, pure Paiute cutthroat trout have been restocked or restored to eight
stream miles within the drainage.
UNARMORED THREESPINE STICKLEBACK - The Recovery Plan for the unarmored threespine stickleback
(Gasterosteus aculeatus williamsoni) indicates that this state- and federally listed subspecies is restricted to the
Santa Clara River drainage in Los Angeles County and the San Antonio Creek drainage in Santa Barbara County
and an introduced population in San Felipe Creek, San Diego County. Recent allozyme analysis by Dr. Don Buth
at UCLA further restricts the range of G. a. williamsoni to the Santa Clara River drainage. The San Antonio Creek
form may be unique. The Santa Clara River population suffered losses due to an oil spill after the January 1994
Northridge earthquake. Development pressures are increasing as is the number of water rights applications.
The recently discovered undescribed Shay Creek unarmored threespine stickleback is still restricted to one
pond at Shay Meadow and an introduced population at Sugarloaf Meadow, both in the San Bernardino National
Forest, San Bernardino County. The Shay Meadow population is highly vulnerable to water withdrawals, so the
Recovery Team is actively pursuing another transplant site. Juniper Springs, also in the San Bernardino National
Forest, was identified as a potential site by Dr. Jonathan Baskin while under contract to the Department.
OWENS VALLEY FISHES - In 1983, the Department, BLM and the USFWS funded a contract to produce a
recovery plan for listed aquatic, wetland and riparian species of the Owens Valley floor, including the Owens tui
chub (Gila bicolor snyderi) and Owens pupfish (Cyprinodon radiosus). A management plan will also be produced
to include non-listed species of concern such as Owens speckled dace (Rhinichthys osculus ssp.), Owens sucker
(Catostomus fumeiventris) and springsnails (Hydrobiidae). The Los Angeles Department of Water and Power, the
valley's major landholder, is cooperating with the contractors to date. The contractors (Sada et al.) expect to have
a draft recovery plan completed by late spring 1995.
Existing populations of Owens pupfish are again in bad shape. Due to ongoing problems with habitat
maintenance and non-native piscivores, numbers have plummeted at all but two refugium locations. Desert Pupfish
Spring and summer monitoring found most natural and refugium populations of desert pupfish (Cyprinodon
macularius) to be thriving. However, monitoring of Salton Sea tributary irrigation drains by the Department and
the local irrigation district found fewer pupfish than 1993 and higher numbers of non-native fishes like mollies and
tilapia.
OTHER PUPFISHES - Collections and laboratory work continue for the Department's contract with Dr. Bruce
Turner, who is assessing the molecular genetics of Death Valley drainage Cyprinodon, with emphasis on the
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