The Little Kern Golden trout (Oncorhynchus mykiss whitei ),is native to high elevation
streams and lakes in the Little Kern River, a major tributary to the Kern River in the southern Sierra
Nevada. In the early 1900's anglers and the Department of Fish and Game, eager to improve fishing,
unwittingly threatened the Little Kern golden trout when they moved non-native rainbow, brown, and brook
trout to golden trout habitat. The introduced fish hybridized with the goldens, making an offspring that
was not a pure golden trout. This "genetic contamination" threatened the continued existence of the Little
Kern golden trout. Cattle grazing in the high country impacted the fish as well - as cattle trampled
stream banks - soil erosion clogged the streams, and vegetation that provided food, shade, and cover for
aquatic life disappeared. By the 1970's, the Little Kern golden trout occupied only about 10% of its original habitat, and
only a few thousand golden trout still existed.
The California Department of Fish and Game stopped planting non-native rainbow trout, and removed
introduced fish from the Kern drainage to make room for the pure native Little Kern golden trout. Stream
habitat was recovered little by little every year. Biologists removed non-native fish with an organic,
biodegradable fish poison, constructed impassable barriers to prevent non-goldens from moving back, then
restocked the waters with Little Kern Goldens. By 1990, after almost 20 years of conservation efforts,
the Little Kern golden trout has been restored to about 60% of its range in the drainage. The Little Kern
golden trout is still found only in the Little Kern River drainage, inhabiting about 80 miles of stream.
Distinguishing Characteristics:
The Little Kern Golden closely resembles the Volcano Creek Golden except that it has many more spots over
the back and onto the head. The body is a more subdued golden yellow with a copper or brassy back. White tips exist on
the pelvic, anal, and dorsal fins. Just in front of the tail, the spots are larger and rounded.
A good article by Daniel P. Christenson in
Outdoor California:July/August 1994
DFG biologists Daniel P. Christenson and Stan Stephens are the principal managers of the Little Kern River golden trout recovery program.
The Little Kern
River is a western tributary of the Kern River, lying at 6,000-10,000 feet of
elevation, primarily in the Sequoia National Forest and Sequoia National Park in
eastern Tulare County. There are about 100 miles of stream suitable for trout
and 11 small lakes in this drainage. Most Little Kern tributaries flow about one
cubic foot per second after the heavy winter snow-pack has melted, with a total
of about 25 cubic feet per second for the drainage.
The Little Kern
golden trout originally occupied most of this drainage and was found nowhere
else on earth. According to old records, transplanting of Little Kern golden
trout to nearby waters, including the South Fork Kaweah River to the west, began
before the turn of the century. Only one of these transplanted populations is
known to exist in its pure state. This population is in Coyote Creek, another
tributary of the Kern River (to the east of the Little Kern) in Sequoia National
Park. It has played an important part in the recovery of the
species.
Barton Warren Evermann, a biologist with the U. S. Bureau of
Fisheries, "discovered" the Little Kern golden trout in the South Fork Kaweah
River, in some Little Kern River drainage locations and in Coyote Creek while on
a wilderness scientific expedition in 1904. He recognized the distinctiveness of
this species and was concerned about its protection.
About 20 years
later, as increasingly greater numbers of people came to the Little Kern
drainage, some anglers thought certain populations were being "fished out" and
recommended that additional trout be planted. For the next couple of decades,
the state provided hatchery trout (rainbows, brooks and browns) to sportsmen's
groups and individuals for replenishing the streams and lakes in the Little Kern
drainage. Some of these non-native trout established populations and hybridized
or competed with the native Little Kern golden trout.
William Dill. a
fisheries biologist with the California Department of Fish and Game. surveyed
some of the streams and lakes in the Little Kern drainage in 1940 and 1945. He
found the over harvest claims to be invalid, but recognized the threat to native
golden trout from competition with brook trout and hybridization with non-native
rainbow trout. He recommended against further introduction of non-native fish in
order to reduce the possibility that the native golden trout would become
extinct. At that time, he was not certain that any pure Little Kern golden trout
remained. About 10 years later, the introduction of non-native fish was finally
stopped.
In 1965, Fish and Game became interested in the fate of the
Little Kern golden trout. With Evermann's original descriptions, a survey began
to find if remnants of the species existed. Trout in the headwaters of several
isolated tributaries were examined. A population was located in the uppermost
one mile section of Soda Spring Creek in Sequoia National Park which closely fit
Evermann's original description.
In other streams, DFG fishery biologists
found trout which appeared to be hybridized with rainbows. Based on the presumed
purity of the trout in upper Soda Spring Creek, the DFG prepared a plan to
develop an artificial barrier near the mouth of that stream and expand the pure
population to the balance of its drainage.
By 1971, in coordination with
Sequoia National Forest and Sequoia National Park biologists. Fish and Game used
explosives to modify a bedrock stream section near the mouth of Soda Spring
Creek. This prevented the upstream migration of trout from below and was the
first step in the process to eradicate non-native fish from the drainage. Thus
began the process which has led to the recovery of the species, which is very
close to realization.
Several attempts to genetically test Little Kern
trout populations yielded little or no new insights into their status. In 1973,
Fish and Game contracted with Graham A. E. Gall of the University of California
at Davis to tackle the problem. In his laboratory, researchers analyzed physical
characteristics, chromosome counts and electrophoretic separation of tissue
proteins (gene products) of samples collected from Little Kern golden trout. The
latter technique proved to be the most valuable tool in defining genetic
characteristics.
Interestingly, the chromosome studies indicated varying
numbers occurring in trout within an individual population, a presumed genetic
impossibility, which demonstrated the "plasticity" of trout genetics and
confounded geneticists.
The initial electrophoretic work was done by John
Gold and it demonstrated distinctive characteristics of the upper Soda Spring
Creek population and their close relationship to the golden trout of the South
Fork Kern River. This verified Evermann's discovery, confirmed earlier visual
observations and inspired greater confidence that researchers were on he right
track.
Further genetic testing of more than 30 isolated populations in
the Little Kern drainage resolved the issue of which populations were pure
Little Kern golden trout. Final results indicated pure golden trout still
existed in upper Soda Spring Creek, Deadman Creek, lower Wet Meadows Creek,
Willow Creek drainage, Fish Creek and Coyote Creek. This included a total of
merely 10 miles of stream with only a few thousand Little Kern golden trout
remaining.
It was determined that populations in the balance of the
drainage had been influenced by non-native trout. At this point, natural
disasters or illegal introductions of non-native trout in any of these streams
would have further reduced the remaining populations or caused extinction of the
species.
Along with the initiation of genetic studies in 1973, there was
sampling for rare species of aquatic invertebrates and a basin-wide stream
survey. No other species of concern, other than the other native fishes, were
identified during this process. The stream surveys identified natural barrier
locations and defined the scope of the recovery project. Initial experimental
chemical treatments were conducted in 1975 and 1976 by the DFG at lower Deadman
Creek, upper and lower Bullfrog Lakes and the upper Little Kern River, where
non-pure populations existed. These treatments verified that the target species
(non-native trout) could be eliminated without any long term effects on the
other natural resources of the area.
Fish and Game recognized the Little
Kern golden trout was threatened primarily because of loss of genetic integrity
due to breeding with introduced non-native rainbow trout. This species has been
a subject of Fish and Game's Threatened Salmonid Committee since its inception
in 1972. The U.S. Fish and Wildlife Service officially listed the Little Kern
golden trout as a threatened species in 1978 and designated its critical habitat
as the entire Little Kern River drainage above a barrier about one mile
downstream from its lowermost tributary, Trout Meadow Creek. In that same year,
almost all of the critical habitat was designated as part of the Golden Trout
Wilderness.
In 1978, in cooperation with Sequoia National Forest, Sequoia
National Park and the U. S. Fish and Wildlife Service, "The Little Kern Golden
Trout Fishery Management Plan" (revised in 1984) laid out a strategy for
recovery of the species. Sequoia National Forest biologist Richard Standage
prepared an environmental analysis report for the plan which was approved by the
USFWS in 1983. Under the authority of these documents, restoration efforts began
in 1979.
Restoration was to proceed by piecemeal reclamation of lakes and
stream sections isolated by barriers (sometimes artificially developed) at a
slow and methodical pace so that no large portion of the drainage would be
without fish at any one time. No more stream mileage was chemically treated than
could be transplanted without jeopardizing remaining native donor stocks. Each
of the remaining pure stocks was to be protected by establishing one or more
additional isolated populations and the maximum genetic diversity was developed
in the lower reaches where all stocks would be allowed to mix
freely.
Each year, proposed project activities are reviewed by the
agencies involved. Public notification of planned activities, including time and
location of chemical treatments, is provided periodically through the season to
concerned individuals and the media. A leaflet is also prepared to inform
wilderness users of proposed activities in the areas they may be visiting. Local
posting of trails is done to notify travelers of the dates and location of
chemical treatments. An annual report of restoration activities is prepared for
distribution to those interested in the project.
Before chemical
treatments are conducted, visual and fly rod fish population inventories are
made to provide baseline estimates so that it can be determined when a restored
population has been fully recovered. When feasible, non-native trout in stream
sections to be treated are salvaged by electrofishing and transplanted to
non-recovered stream sections to augment recreational fishing. While this effort
has little biological benefit, it does make it possible for these trout to make
a contribution to fishing recreation.
Stream distance flagging, stream
flow determination, downstream chemical travel time estimates and volume
measurements help to facilitate treatments and control the amounts of chemical
applied. Live-net test fish are placed at strategic locations to monitor the
progress and effectiveness of the toxicants.
Lake treatments are done
using an inflatable boat to apply enough chemical to the surface to treat the
water. The chemical of choice was initially antimycin because of its
effectiveness and rapid break down. Unfortunately, antimycin is no longer
available for use. Rotenone is currently used in the chemical treatment process.
Rotenone is a naturally produced, biodegradable product obtained from the
tropical cube root. In the concentrations used, it is not harmful to plants,
birds or mammals, including humans. Detoxification is by dilution and oxidation,
or application of potassium permanganate.
Live-net tests show when the
water is non-toxic so that the lake or stream can be restocked with Little Kern
golden trout. Restocking can be done by backpack, horse, llama, airplane or
helicopter.
Stream treatments are done by placing five-gallon drip cans,
usually at 400 meter intervals, for rotenone with timed releases of 1-8 hours to
provide a continuous block of toxic water moving downstream. Backwaters and side
pools are sprayed by hand in conjunction with the stream treatment. To verify
the effectiveness of a treatment, it is repeated to ensure that no fish
remain.
If time allows, or if there is a possibility of eggs incubating
in the gravels where they may survive the treatment, a period of several weeks
or months is allowed before the final treatment. Detoxification can be done by
dilution downstream or from a tributary or by the application of potassium
permanganate at the lower end of the section. Restocking with Little Kern golden
trout can take place within a day or two after the treatment as the chemical is
rapidly diluted and flushed from the section. Periodic inventories of a restored
population are done to monitor its recovery rate.
In 1982, the Fish and
Game began an experimental effort to artificially propagate Little Kern golden
trout to provide more fish to restock reclaimed waters. This has developed into
a temporary golden trout hatchery at Fish and Game's Kern River Planting Base
near Kernville, which now produces several thousand golden trout fingerlings
each year. Stocking of these fish, along with those transplanted from native and
restored pure populations has resulted in this threatened species' restoration
to over 70 percent of its critical habitat.
Complete restoration is
expected in 1995. It is anticipated the Fish and Wildlife Service endangered
species status delisting process could begin soon thereafter. *
*The Little Kern Golden continues to be placed upon the Threatened list since the remaining population is derived from a very small population with a low genetic diversity. This low genetic diversity can impact the species in dealing with habitat change and disease.
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