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Little Kern Golden Trout Restoration
For
more information contact: jfcordes@ucdavis.edu
Collaborators
This study is being done in collaboration with Dr. Graham A. E. Gall at UC Davis, The California Department of Fish and Game (CDFG), and the U.S. Forest Service (USFS). Funding is provided by the CDFG and the USFS.
Background
and Significance of Study
The Little Kern golden trout (LKGT) is
one of two golden trout subspecies designated as the California State fish. Both
subspecies were endemic to the Kern River watershed prior to European
settlement, with the Little Kern form restricted to the Little Kern River above
a natural barrier (Evans et al. 1973). Extensive stocking of non-native rainbow
trout in the basin during the first half of this century led to the near extinction of the
LKGT due to
hybridization. Planting of non-native trout ceased in the
1950’s, and the California Department of Fish and Game (CDFG) began surveys in 1965 to initiate restoration efforts.
Allozyme electrophoretic analyses begun in 1976 at UC Davis ultimately identified six pure populations of
GT-LK occupying only ten miles of stream out of the 100 miles of historic range
(Gall and May 1997 and references therein).
Restoration efforts began in 1975 with the first rotenone treatment by the California Department of Fish and Game. In addition to chemical treatments, restoration measures have included restocking of treated waters with pure LKGT, construction of barriers to the upstream movement of non-native trout, habitat improvement of streams damaged by cattle grazing, public education, and continued monitoring of fish populations, their genetic integrity, and habitat conditions.
Although restoration was believed complete in 1996, subsequent genetic
analyses identified a number of streams and lakes within the system that had
been stocked with one strain of LKGT that contained hybridized
trout (S. Stephens, CDFG, pers. comm.). These populations are in the headwaters of streams
in the southwest portion of the drainage and could contaminate 35% of the basin
with hybridization.
The purpose of this study is to use highly variable microsatellite
markers to identify hybridized populations of GT-LK that will be targeted
for chemical treatment. After treatment, waters will be restocked with pure
GT-LK and periodically monitored for the presence of non-native trout and/or
evidence of hybridization.
Materials and Methods Sample Collection. Fin clips samples of Little Kern golden trout will be collected by California Department of Fish and Game personnel from ten different sites within the Little Kern River Basin. Genetic
Analysis. Whole genomic DNA will be isolated from fin clip samples using standard
protocols. Microsatellite loci previously shown to
differentiate between various lineages of the rainbow trout (O. mykiss spp.)
complex will then be amplified from the isolated DNA samples via the polymerase
chain reaction (PCR). Differences in the presence/ absence and frequencies of
alleles will be used to identify hybrid populations to be targeted for chemical
treatment. Recent Results
We have recently developed the microsatellites and a single copy nuclear (scnDNA) marker that will abe used in this study, and are currently seeking funding to complete the project.
Literature Cited Evans, W.A., R.C. Smith, and M. Bell. 1973. A reconnaissance survey of the fish resources of the Little Kern River drainage, California. U.S. Dept. Agriculture Forest Ser., Region 5, and Ca. Dept. Fish Game Draft (Prelininary Report). 41 p. Gall,
G.E., and B. May. 1997.
Trout of the Kern River Basin: A genetic analysis of Little Kern River and
Golden Trout Creek populations. Report to California Department of Fish and
Game, Threatened Trout Committee. September 1997. 55 pp.
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Last Updated: 11/04/02
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