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Daily Rules, Proposed Rules, and Notices of the Federal Government

DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2011-0089 MO 92210-0-008]

Endangered and Threatened Wildlife and Plants; 12-Month Finding for a Petition To List the California Golden Trout as Endangered

AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 12-month petition finding.
SUMMARY: We, the U.S. Fish and Wildlife Service, announce a 12-month finding on a petition to list the California golden trout (Oncorhynchus mykiss aguabonita) as endangered under the Endangered Species Act of 1973, as amended (Act). After review of all available scientific and commercial information, we find that listing the California golden trout is not warranted at this time. However, we ask the public to submit to us any new information that becomes available concerning the threats to the California golden trout or its habitat at any time.
DATES: The finding announced in this document was made on October 11, 2011.
ADDRESSES: This finding is available on the Internet athttp://www.regulations.govat Docket Number FWS-R8-ES-2011-0089. Supporting documentation we used in preparing this finding is available for public inspection, by appointment, during normal business hours at the U.S. Fish and Wildlife Service, Sacramento Field Office, 2800 Cottage Way, Sacramento, CA 95825. Please submit any new information, materials, comments, or questions concerning this finding to the above address.
FOR FURTHER INFORMATION CONTACT: Karen Leyse, Field Office Listing/Critical Habitat Coordinator, Sacramento Field Office (seeADDRESSES); by telephone at 916-414-6600; or by facsimile at 916-414-6712. If you use a telecommunications device for the deaf (TDD), please call the Federal Information Relay Service (FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION: Background

Section 4(b)(3)(B) of the Act (16 U.S.C. 1531et seq.) requires that, for any petition to revise the Federal Lists of Endangered and Threatened Wildlife and Plants, to the maximum extent practicable, within 90 days after receiving the petition, we make a finding as to whether the petition presents substantial scientific or commercial information indicating that the petitioned action may be warranted. In addition, within 12 months of the date of the receipt of the petition, we must make a finding on whether the petitioned action is: (a) Not warranted, (b) warranted, or (c) warranted but precluded by other pending proposals. Section 4(b)(3)(C) of the Act requires that we treat a petition for which the requested action is found to be warranted but precluded as though resubmitted on the date of such finding, that is, requiring a subsequent finding to be made within 12 months. Such 12-month findings are to be published promptly in theFederal Register. This notice constitutes our 12-month finding on the October 23, 2000, petition to list the California golden trout as endangered.

Previous Federal Actions

On October 23, 2000, we received a petition dated October 13, 2000, from Trout Unlimited, requesting that the California golden trout be listed on an emergency basis as endangered under the Act, and that critical habitat be designated. Included in the petition was supporting information on the subspecies' taxonomy, distribution, and ecology, as well as information regarding factors considered by the petitioners to threaten the subspecies. We acknowledged receipt of the petition in a letter to Trout Unlimited, dated November 7, 2000. In that letter, we also stated that we would be unable to address the petition until fiscal year 2002 or later due to court orders and judicially approved settlement agreements for listing and critical habitat determinations under the Act, which required nearly all of our listing and critical habitat funding for fiscal year 2001. The petitioner filed a complaint in Federal District Court on November 29, 2001, resulting in a ruling on June 21, 2002, ordering us to complete the 90-day finding by September 19, 2002. We completed the finding by the requisite date, and published it in theFederal Registeron September 20, 2002 (67 FR 59241). In the finding we determined that the petition presented substantial scientific or commercial information to indicate that listing the California golden trout may be warranted. We also determined that an emergency rule to list was not warranted at the time of the 90-day finding. We concurrently initiated a status review on which to base our eventual 12-month finding regarding whether listing of the California golden trout is warranted. On September 22, 2003, Trout Unlimited sent a Notice of Intent to sue the Service for violating the Act by failing to make a 12-month finding within the statutory timeframe. This 12-month finding resolves that issue.

Subspecies Information Taxonomy and Subspecies Description

The California golden trout (Oncorhynchus mykiss aguabonita) (formerly known as Volcano Creek golden trout) is one of three subspecies of rainbow trout (O. mykiss) native to the Kern River basin in Tulare and Kern Counties, California (Behnke 1992, p. 191; Behnke 2002, p. 105; Moyle 2002, p. 283). The two other subspecies native to this basin are the Little Kern golden trout (O. mykiss whitei), which is found in the Little Kern River and its tributaries, and the Kern River rainbow trout (O. mykiss gilberti), which is found in the Kern River. All three subspecies most likely originated from successive invasions of primitive redband trout (ancestral rainbow trout) of the Kern River approximately 10,000 to 20,000 years ago (Behnke 1992, p. 189; Behnke 2002, p. 107; Moyle 2002, p. 283). These fish gained access to the Kern River drainage during glacial cycles and short-term interglacial wet cycles that allowed Lake Tulare to overflow and connect the Kern River drainage to the San Joaquin River and Pacific Ocean (Behnke 2002, p. 109). These primitive forms of rainbow trout that became isolated in the Kern River watershed gave rise to the California golden trout, Little Kern River golden trout, and the Kern River rainbow trout due to local selective factors in their environment (Behnke 2002, p. 111; Moyle 2002, p. 283).

The taxonomy of golden trout in the Kern River basin has been revised several times. Originally, four species of trout were described:Salmo aguabonitafrom the South Fork Kern River,S. rooseveltifrom Golden Trout Creek,S. whitei(Little Kern golden trout) from the Little Kern River, andS. gairdeneri gilberti(Kern River rainbow trout) from the lower Kern River (Moyle 2002, p. 284). Trout from the South Fork Kern River and Golden Trout Creek were later recognized as color variants ofS. aguabonita(Schreck and Behnke 1971, p. 994). More recently, rainbow trout were reclassified asOncorhynchus mykissto reflect their relationship to Pacific salmon, and California golden trout in both the South Fork Kern River and Golden Trout Creek became recognized as the same subspecies of rainbow trout,Oncorhynchus mykissaguabonita(Behnke 1992, pp. 163, 172). Similarly, Little Kern golden trout becameO. mykiss whitei,and Kern River rainbow trout becameO. mykiss gilberti.

California golden trout are well known for their bright coloration, red to red-orange belly and cheeks, bright gold lower sides, a central lateral band that is red-orange, and a deep olive-green back (Moyle 2002, p. 283). Typically, 10 parr marks (oval colorations) are present along the lateral line on both young fish and adults, but may be lost in older fish under some conditions (Behnke 2002, p. 106). The pectoral, pelvic, and anal fins are orange with a white to yellow tip preceded by a black band; dorsal fins may also have a white to yellow tip (Moyle 2002, p. 283). Body spotting is highly variable, but spots are usually scattered across the dorsal surface with a few below the lateral line (Moyle 2002, p. 283). California golden trout from Golden Trout Creek have few spots on the body, primarily concentrated on and near the caudal peduncle (the muscle before the tail fin), whereas California golden trout in the South Fork Kern River typically have small dark spots present over most of the length of the body above the lateral line, although a few spots can be found below the lateral line (Fisk 1983, p.1; Stephens 2001a, p. 4). Golden trout are rainbow trout, so the basic rainbow trout characteristics apply to the subspecies (Moyle 2002, p. 283); however, golden trout have the lowest number of vertebrae (59 to 60) and pyloric caeca (finger-like projections of the intestine (30 to 32)), and the highest number of scales along the lateral line (170 to 200) of any rainbow trout (Behnke 2002, p. 106). California golden trout in streams can obtain lengths of 19 to 20 centimeters (cm) (7.5 to 7.9 inches (in)) (Knapp and Dudley 1990, p. 168). California golden trout remain geographically isolated from Little Kern golden trout and Kern River rainbow trout, but historical planting of nonnative hatchery trout (O. mykiss irideus) has resulted in hybridization in most of the range (see the Hybridization section under Factor E below).

California golden trout also present behavioral and life-history characters that help distinguish them from other subspecies of rainbow trout (see also discussion under the Habitat and Life History section below). These include smaller home ranges (Matthews 1996a, p. 84; Matthews 1996b, p. 587), remaining active during both day and night (Matthews 1996a, pp. 82, 84-85), a relatively long lifespan (Knapp and Dudley 1990, p. 169), and the construction of redds (depressions in the substrate for eggs) using relatively small-grained substrate (Knapp and Vredenburg 1996, pp. 528, 529).

For purposes of this finding, we have considered California golden trout to be those trout within the native range of the subspecies (see Distribution section below) that present the morphological and behavioral characters listed above. We do not rely on genetic tests indicating levels of genetic introgression (infiltration of genes from one species into the gene pool of another species through repeated backcrossing of a hybrid with one of its parent species) with nonnative trout (see Factor E—Hybridization section below) to determine what constitutes a member of the subspecies because the most recent genetic analysis of introgression in California golden trout populations specifically cautioned against the use of strict cutoffs of introgression levels in determining management categories based on any single genetic test (Stephens 2007, p. 55). According to this study, the algorithm used by one genetic test may result in an estimation of low levels of introgression where none actually exist, essentially not allowing for an unambiguous determination between low levels of introgression and genetically “pure” populations (Stephens 2007, p. 56). This caution against using single methods for determining cutoffs was due in part to considerable differences in introgression estimates for certain populations of California golden trout, which were generated by the different methodologies and assumptions of the various genetic tests that have been used to test those populations (Stephens 2007, p. 72), as well as to the general need for an adequate understanding of the variance surrounding introgression estimates (Stephens 2007, p. 57). However, while we do not rely on genetic tests of introgression levels to distinguish California golden trout populations from nonnative trout, we do consider such genetic information useful for evaluating the effectiveness of measures taken to prevent further introgression.

Hybridization between California golden trout and nonnative rainbow trout is sometimes displayed by an increased number and location of body spots, especially below the lateral line, and a more rainbow trout-like body coloration; however, not all hybrid trout display rainbow trout characteristics (CDFGet al.2004a, p. 24). We have anecdotal information that suggests there are trout that exhibit changed coloration and spotting patterns from those ascribed to the California golden trout (Trout Unlimited 2000, pp. 18, 19) and that these intergrades may predominate in the lower reaches of the South Fork Kern River (Sims 2011a). Such reports have not been substantiated with systematic measures of, or comparison with, introgression levels or with other morphological or behavioral attributes described above, and there are no studies that have measured the morphological or behavioral changes in introgressed California golden trout as compared to “pure” golden trout. Furthermore, there is no documentation that we are aware of that indicates that additional meristic measures used to describe California golden trout (such as number of vertebrae, scale counts, and pyloric caeca) have changed with introgression levels.

Distribution

The historical range of the California golden trout included only the South Fork Kern River and Golden Trout Creek in the upper Kern River basin. Golden Trout Creek and upper portions of the South Fork Kern River were once part of the same stream, which became separated by volcanic activity in the region approximately 10,000 years ago (Cordeset al.2003, p. 20). This led to Golden Trout Creek and the South Fork Kern River as known today (Evermann 1906, pp. 11-14) in two adjacent watersheds draining the Kern Plateau of the southern Sierra Nevada.

The Golden Trout Creek watershed is 155 square kilometers (km2) (60 square miles (mi2)). Golden Trout Creek drainage begins around 3,292 meters (m) (10,800 feet (ft)) elevation near Cirque Peak and extends to 2,135 m (7,000 ft) elevation at the confluence of Golden Trout Creek and the Kern River. The headwaters are in the northern section of the Kern Plateau, and several lakes (Chicken Spring, Johnson, and Rocky Basins lakes) drain into the watershed. With the exception of headwater lakes, and the probable exception of upper reaches of some tributary streams, Golden Trout Creek was historically occupied by the California golden trout from the headwaters to a series of waterfalls near the confluence of the creek with the Kern River (Evermann 1906, pp. 12-14; 28, 30). The waterfalls are impassable and thus isolate California golden trout in Golden Trout Creek from fish found in the Kern River. Within Golden Trout Creek, California golden trout currently maintain the same distribution as they did historically.

The South Fork Kern River watershed covers 1,380 km2(533 mi2). The South Fork Kern River begins southeast of Cirque Peak at approximately 3,170 m(10,400 ft) in elevation and continues until it reaches Isabella Reservoir at 794 m (2,605 ft) in elevation. The headwaters are in the eastern section of the Kern Plateau, starting at South Fork and Mulkey Meadows. California golden trout were historically known in the South Fork Kern River from the headwaters to the southern boundary of the Domeland Wilderness (CDFGet al.2004a, p. 8). The subspecies currently maintains the same distribution as it did historically within the South Fork Kern River; however, the degree of genetic introgression from nonnative rainbow trout increases as one proceeds downstream from Templeton Barrier (Stephens 2007, pp. 42, 72). There is no evidence to suggest that the degree of introgression has been sufficient to remove morphologically and behaviorally distinct California golden trout from the southern portion of its historical range. Therefore, we are considering the subspecies to be present in its entire historical range for purposes of this finding. The range is completely within the Inyo and Sequoia National Forests, which are administered by the U.S. Forest Service.

Range Expansion

California golden trout have been widely transplanted outside of their historical range, but the history of these transplants is poorly documented. Most of these transplanted fish came from hybridized Cottonwood Lakes stock that was derived from Golden Trout Creek (Stephens 2007, pp. 54, 55). Fish were transplanted into fishless lakes and streams within the Golden Trout Creek watershed, the South Fork Kern River watershed, and other areas throughout the Sierra Nevada (such as adjacent to the Kern Plateau, including Ninemile Creek, Cold Creek, Salmon Creek, many of the lakes and streams to the north in Sequoia National Park, and all tributaries to the Kern River). In California, planting records and historical documents indicate that California golden trout have been stocked in Alpine, El Dorado, Nevada, Placer, Sierra, Fresno, Inyo, Madera, Mono, Siskiyou, Trinity, Tulare, and Tuolumne Counties (Fisk 1983, p. 11). Outside of California, golden trout were sent to England, Colorado, Utah, Montana, New York, and Wyoming between 1928 and 1937 (McCloud 1943, p. 194).

For the purposes of this finding, we are analyzing a petitioned entity that includes populations of California golden trout considered native to the South Fork Kern River and Golden Trout Creek in the upper Kern River basin. We do not consider introduced populations present elsewhere as part of the listable entity because we do not consider them to be native populations. Neither the Act nor our implementing regulations expressly address whether introduced populations should be considered part of an entity being evaluated for listing, and no Service policy addresses the issue. Consequently, in our evaluation of whether or not to include introduced populations in the potential listable entity we considered the following:

(1) Our interpretation of the intent of the Act with respect to the disposition of native populations;

(2) A policy used by the National Marine Fisheries Service (NMFS) to evaluate whether hatchery-origin populations warrant inclusion in the listable entity; and

(3) A set of guidelines from another organization (International Union for Conservation of Nature (IUCN)) with specific criteria for evaluating the conservation contribution of introduced populations.

Our interpretation is that the Act is intended to preserve native populations in their ecosystems. While hatchery or introduced populations of fishes may have some conservation value, this does not appear to be the case with introduced populations of California golden trout in California and elsewhere in the United States. These introduced populations were apparently established to support recreational fisheries without any formal genetic consideration to selecting and mating broodstock (group of mature fish kept for breeding purposes), and are not part of any conservation program to benefit the native populations. Consequently, we do not consider the introduced populations of California golden trout in California, England, Colorado, Utah, Montana, New York, and Wyoming to be part of the listable entity.

Habitat and Life History

California golden trout reach sexual maturity when they are 3 to 4 years old and begin spawning during the spring or early summer when maximum water temperatures consistently exceed 15 to 18 degrees Celsius (°C) (59 to 64 degrees Fahrenheit (°F)) and average stream water temperatures exceed 7 to 10 °C (45 to 50 °F) (Stefferud 1993, pp. 139-140; Knapp and Vredenburg 1996, p. 528). Spawning begins with female California golden trout moving fine gravel substrate to construct a shallow depression, known as a redd, to lay their eggs. Although California golden trout can construct redds using gravel of smaller average diameter than other trout species or subspecies, they still select the largest substrates available (Knapp and Vredenburg 1996, pp. 528, 529).

Growth of California golden trout shows a negative correlation with fish density and a positive correlation with several factors, including the stability of the stream bed and banks, and the presence of aquatic and streamside vegetation (Knapp and Dudley 1990, pp. 165, 170, 171). Aquatic vegetation provides habitat for small invertebrates preyed on by the trout, while overhanging streamside vegetation provides habitat for terrestrial invertebrates that can serve as a food source when they fall in the water (Knapp and Dudley 1990, p. 170; Moyle 2002, p. 285). Streamside vegetation also tends to stabilize banks and to provide cover for young trout from potential predators such as birds (Moyle 2002, p. 277). Overhanging vegetation, steep or undercut banks, and deeper streambeds are all needed by trout (Moyle 2002, p. 286), in part because they provide shade and cooler water during the day. Average daily water temperatures can fluctuate from 2 to 22 °C (Knapp and Dudley 1990, p. 163), while optimal temperatures for trout range from 15 to 18 °C (59 to 64 °F) (Moyle 2002, p. 276). Deeper streambeds and steeper banks are associated with greater stream stablity, thus helping to explain the positive correlation between stream stability and trout growth found by Knapp and Dudley (1990, pp. 165, 171). Stream stability is also likely important because erosion of unstable streams produces higher sediment loads that can cover redds and interfere with feeding by clouding the water (Moyle 2002, p. 278).

California golden trout have been known to live as long as 9 years, and commonly reach 6 to 7 years old (Knapp and Dudley 1990, p. 169). This long lifespan is likely due to a short growing season, high fish densities, and a low food abundance, all of which promote slow growth rates and old ages of trout (Knapp and Dudley 1990, p. 169).

California golden trout adapted to the South Fork Kern River and Golden Trout Creek in the absence of competitors, although they probably did coexist with Sacramento suckers (Catostomus occidentalis) in the South Fork Kern River (Moyle 2002, p. 284). Long isolation of California golden trout from other species has likely resulted in a lack of competitive ability, making them vulnerable to replacement by other trout species (Behnke 1992, p. 191). Likewise, the subspecies is thought to have evolved without substantial interspecific predation risk; the birds and mammals that might have beenlikely predators of the California golden trout occur infrequently in high alpine areas where California golden trout are found (Moyle 2002, p. 285). One possible indication that California golden trout adapted without predators is the trout's active behavior during both day and night (Matthews 1996a, pp. 82, 84-85).

California golden trout home ranges were calculated as the linear distance that encompasses 90 percent of trout locations, based on movements recorded using radio-telemetry during the months of July and September (Matthews 1996a, p. 84; Matthews 1996b, p. 587). California golden trout were found to have small home ranges that average 5 m (16 ft) (Matthews 1996a, p. 84; Matthews 1996b, p. 587). Movements of 26 to 100 m (86 to 328 ft) were observed, but these constituted less than 1 percent of all observations (Matthews 1996b, p. 587).

The Conservation Strategy

Since publication of the 90-day finding in 2002 (67 FR 59241; September 20, 2002), the California Department of Fish and Game (CDFG), the Forest Service, and the Service (hereafter referred to collectively as the Agencies) completed a revisedConservation Assessment and Strategy for the California Golden Trout(Conservation Strategy) dated September 17, 2004 (CDFG et al. 2004a). The Conservation Strategy replaced a previous guidance document known as theConservation Strategy for the Volcano Creek (California) Golden Trout(1999 Conservation Strategy), which had been in effect since April 22, 1999. The Agencies also signed a Memorandum of Agreement (MOA) on September 17, 2004, to implement the Conservation Strategy (CDFG et al. 2004b); both the Conservation Strategy and MOA are currently in effect. The purposes of the Conservation Strategy are to:

(1) Protect and restore California golden trout genetic integrity and distribution within its native range;

(2) Improve riparian and instream habitat for the restoration of California golden trout populations; and

(3) Expand educational efforts regarding California golden trout restoration and protection.

The Agencies' intent has been to encourage ongoing nongovernmental stakeholder coordination and consultation throughout the implementation phase of the Conservation Strategy. The Conservation Strategy is based on adaptive management, with tasks being removed, added, or adjusted annually as new information becomes available. The Agencies, through the MOA, agreed to formally implement and collaborate on the Conservation Strategy and make any necessary adaptive management changes as the primary mechanism for the conservation of the California golden trout. Implementation of many tasks described in the Conservation Strategy began while it was under development, and have continued since its finalization. Those tasks and other conservation efforts implemented in prior years are summarized below throughout the five-factor analysis.

Summary of Information Pertaining to the Five Factors

Section 4 of the Act (16 U.S.C. 1533) and implementing regulations (50 CFR 424) set forth procedures for adding species to, removing species from, or reclassifying species on the Federal Lists of Endangered and Threatened Wildlife and Plants. The Act treats subspecies such as the California golden trout as species for these purposes (16 U.S.C. 1532(16)). Under section 4(a)(1) of the Act, a species may be determined to be endangered or threatened based on any of the following five factors:

(A) The present or threatened destruction, modification, or curtailment of its habitat or range;

(B) Overutilization for commercial, recreational, scientific, or educational purposes;

(C) Disease or predation;

(D) The inadequacy of existing regulatory mechanisms; or

(E) Other natural or manmade factors affecting its continued existence.

In considering what factors might constitute threats, we must look beyond the mere exposure of the species to the factor to determine whether the species responds to the factor in a way that causes actual impacts to the species. If there is exposure to a factor, but no response, or only a positive response, that factor is not a threat. If there is exposure and the species responds negatively, the factor may be a threat and we then attempt to determine how significant a threat it is. If the threat is significant, it may drive or contribute to the risk of extinction of the species such that the species warrants listing as threatened or endangered as those terms are defined by the Act. This does not necessarily require empirical proof of a threat. The combination of exposure and some corroborating evidence of how the species is likely impacted could suffice. The mere identification of factors that could impact a species negatively is not sufficient to compel a finding that listing is appropriate; we require evidence that these factors are operative threats that act on the species to the point that the species meets the definition of threatened or endangered under the Act.

In making this finding, information pertaining to the California golden trout in relation to the five factors in section 4(a)(1) of the Act is discussed below. In making our 12-month finding on the petition, we considered and evaluated the best available scientific and commercial information. We reviewed the petition, information available in our files, and other available published and unpublished information.

Factor A. The Present or Threatened Destruction, Modification, or Curtailment of the Species' Habitat or Range

The petition and our subsequent investigations have identified several habitat-related activities relevant to the conservation status of California golden trout, including: Livestock grazing management, pack stock use, recreation, artificial fish barriers, and beavers. We address each activity below.

Livestock Grazing Management

The combined effect of current livestock grazing activities in the Golden Trout Wilderness and legacy conditions from historically excessive grazing use have the potential to impact habitat and the range of the California golden trout. The following subsections discuss the effects of excessive historical grazing, current grazing management practices, and habitat restoration and monitoring efforts within the basins in which the native stream habitat of the California golden trout occurs.

Historical Effects of Excessive Grazing

Grazing of livestock in Sierra Nevada meadows and riparian areas began in the mid-1700s with the European settlement of California (Menkeet al.1996, p. 909). Following the gold rush of the mid-1800s, grazing rose to a level that exceeded the carrying capacity of the available range and caused significant impacts to the grazed ecosystems (Meehan and Platts 1978, p. 275; Menkeet al.1996, p. 909). Approximately 95 percent of the California golden trout's native stream habitat has been subjected to varying intensities of grazing for more than 130 years (CDFGet al.2004a, p. 31). Livestock grazing within the national forests in the southern and high Sierras has continued with gradual reductions since the 1920s, except for an increase during World War II (Menkeet al.1996, pp. 909-910, 916-919).

Livestock can contribute to the destabilization of stream banks byaccelerating erosion and increasing bank disturbance (Kauffmanet al.1983, pp. 684-685; Marlow and Pogacnik 1985, p. 279). Livestock grazing in meadows and on stream banks can compact soils, which reduces water infiltration rates and the soil's ability to hold water, thereby increasing surface runoff rates into adjacent streams, downcutting streambeds, and lowering the watertable (Meehan and Platts 1978, pp. 275-276; Kauffmanet al.1983, pp. 684-685; Kauffman and Krueger 1984, pp. 433-434; Bohn and Buckhouse 1985, p. 378; Armouret al.1994, pp. 7-10). In some cases, excessive livestock grazing has resulted in the conversion of wet meadows into dry flats and in diminished perennial stream flows (Armouret al.1994, p. 7). Erosion from trampling causes stream bank collapse and an accelerated rate of soil movement from land into streams (Meehan and Platts 1978, pp. 275-276). Accelerated rates of erosion lead to elevated instream sediment loads and depositions, and changes in channel morphology, which alter the structure of the aquatic environment used by fish for spawning (Meehan and Platts 1978, pp. 275-276; Kauffman and Krueger 1984, pp. 433-434; Bohn and Buckhouse 1985, p. 378). These effects to the aquatic ecosystem increase with increases in the intensity of grazing (Meehan and Platts 1978, pp. 275-276).

Livestock grazing can cause a nutrient loading problem due to urination and defecation in or near the water, and elevate bacteria levels in areas where cattle are concentrated near water (Meehan and Platts 1978, p. 276; Stephenson and Street 1978, p. 152; Kauffman and Krueger 1984, p. 432). The nutrient status of streams can create a cause and effect relationship between nutrient levels, bacterial growth, and insect mortality (Lemly 1998, p. 234). Growth of filamentous bacteria on the bodies and gills of aquatic insects was demonstrated to be an effect of nutrient loading in livestock-use pastures, significantly lowering the density of insect occurrences at downstream sites (Lemly 1998, pp. 234-235). Aquatic insects suffered extensive mortality because of this bacterial growth in laboratory and field studies, indicating that elevated bacteria levels can negatively influence stream insect populations (Lemly 1998, pp. 234-235, 237), which can result in detrimental effects to prey species important to fish.

Several studies have documented the environmentally detrimental impacts of historical grazing practices in areas within the range of the California golden trout. Albert (1982, pp. 29-47) studied factors influencing the riparian condition of streams in the Golden Trout Wilderness and adjoining watersheds in Sequoia National Park. Her results showed that stream zones in the South Fork Kern River and Golden Trout Creek were less stable, had more livestock damage, and were generally in poorer condition than those in Sequoia National Park, which had not been grazed for the preceding 50 years. Stream reaches with light cattle use had channel bottoms that were more stable (less subject to erosional and depositional changes) than heavily used reaches (Albert 1982, pp. 48-51).

Odionet al.(1988, pp. 277-289) examined the effects of cattle grazing and recovery potential in Templeton and Ramshaw Meadows along the South Fork Kern River. Vegetation change was monitored inside and outside of exclosures that were established along riparian areas within the range of California golden trout. Odionet al.(1988, pp. 277-289) concluded that livestock trampling and defoliation caused a breakdown of the protective sod layer in the meadows, allowing streams to incise (where the streambed channel downcuts in elevation, reducing habitat quality and quantity), produce gullies, and lower the water table. Subsequently, plants adapted for a dry habitat, such as sagebrush, invaded the altered meadows. Results of density monitoring indicated that cattle trampling impaired colonization of plant species important in stabilizing substrate on stream banks, thus reducing the natural revegetation potential of bare stream bank habitat (Odionet al.1988, p. 283).

Matthews (1996b, pp. 579-589) used radio transmitters to determine habitat selection and movement patterns of California golden trout in two stream reaches with different levels of habitat recovery on Mulkey Creek. The study areas were differentiated by high and low coverage ofCarex rostrata(beaked sedge) along the stream banks. Low coverage areas were typically associated with signs of cattle degradation, such as widened stream channels, collapsed banks, and a reduction in areas with undercut banks. In both low and high sedge reaches, California golden trout more often selected undercut banks, aquatic vegetation, and sedge while avoiding bare and collapsed banks caused by livestock grazing. They were most commonly found in pools and runs (slow moving areas in a stream), where they used habitat features such as undercut banks, aquatic vegetation, and sedges, all of which typically can be damaged by excessive cattle grazing along stream banks.

Knapp and Matthews (1996, pp. 816-817) examined the effects of excessive livestock grazing on California golden trout and their habitat inside and outside of grazing exclosures in the South Fork Kern River watershed. In the 2-year study, most physical parameters of the stream channels showed large differences between grazed and ungrazed sites, with ungrazed sites displaying greater canopy shading, stream depth, bank-full height, and narrower stream width. Densities and biomass of California golden trout per unit area were significantly higher in ungrazed versus grazed areas in three out of four comparisons, but differences were less consistent when density and biomass were calculated using stream length. Other findings of this study indicate a significant decrease in stream width in the upper Ramshaw Meadows exclosure between 1984 and 1993, and a greater number of willow plants inside exclosures than outside.

Not all studies found differences in grazed and ungrazed areas. Sarr (1995, pp. 97, 104) did not find significant differences in stream morphology in his study between grazed and ungrazed reaches on the South Fork Kern River. In a movement and habitat use study, California golden trout were monitored with radio transmitters inside and outside of grazing exclosures on the South Fork Kern River (Matthews 1996a, pp. 78-85). No differences in distance moved or home range were found between California golden trout inside and outside exclosures, and most fish were found within 5 m (16.4 ft) of their previously recorded location.

Current Levels of Grazing Use

Many grazing impacts to the Kern Plateau were originally caused by unmanaged grazing practices dating back to the late 1800s, during which tens of thousands of cattle were grazed over long periods of time (CDFGet al.2004a, p. 31). Grazing use has been greatly reduced since then in order to restore natural habitat conditions (CDFGet al.2004a, p. 34). Additionally, during the past decade the Inyo National Forest has completely restricted grazing on two of its four grazing allotments. In February of 2001, a Decision Notice was signed that implemented a 10-year period of rest on the Templeton and Whitney grazing allotments to facilitate recovery of watershed and channel conditions. The notice indicated that grazing on the two allotments would be reconsidered at the end of the 10-year period (USFS 2001a, p. 5). The USFS expects to reach a decision on this issue in June of 2012 (USFS 2011, p. 10).

Within the Sequoia National Forest from 2001 to 2004, two of the three available grazing allotments had little or no grazing, while the third utilized up to 65 percent of the total livestock permitted (CDFGet al.2004a, p. 19). Grazing use levels in the Sequoia National Forest are lower than permitted largely because of remoteness and inaccessibility (Anderson 2006), whereas in the Inyo National Forest, a 1995 amendment (typically referred to as Amendment 6, discussed below) to the Forest-wide grazing utilization standards of the Forest's Land and Resource Management Plan (LRMP) has apparently resulted in reduced cattle use (CDFGet al.2004a, p. 34).

Current Grazing Management Practices

In 1995, Amendment 6 to the Inyo National Forest LRMP was developed to establish forest-wide grazing utilization standards, which are requirements in addition to existing utilization standards contained in grazing permits (USFS 1995, pp. 13, 14). The forest-wide standards were designed, in part, to improve the existing condition of streams supporting California golden trout in grazed watersheds (USFS 1995, pp. 27, 28). The Amendment allows Forest Service personnel to tailor grazing utilization standards to maintain or improve hydrologic and meadow conditions. Grazing utilization standards establish an upper limit of forage that grazing cattle may consume before being moved to a new area (Sims 2011b, p. 1). Inyo National Forest personnel conduct annual monitoring of representative meadows to determine whether utilization standards have been exceeded. If they do find that standards have been exceeded they adjust the standards downwards in following years to allow recovery. The utilization standards themselves are reassessed every 5 to 10 years to ensure that they avoid habitat degradation (including the degradation of stream habitat) (Sims 2011b, p. 1).

The Inyo National Forest LRMP also restricts trampling of streambanks to 10 percent of the streambank length along State trout waters (which include most of the streams supporting California golden trout), and to 20 percent along other waters (USFS 1988a, pp. 78-79). As with utilization standards, annual monitoring of representative streambanks helps assure these standards are not exceeded, and allows grazing prescriptions to be adjusted to promote recovery of the streambanks if the standards are exceeded (Sims 2011b, p. 1). Additionally, salt provided for cattle must be located at least 0.25 mi (0.4 km) away from riparian areas, and additional requirements may apply to specific management areas with unique characteristics. For example, range management direction for the Golden Trout Management Area (#19) amends grazing allotment plans to include necessary mitigation measures and corrective actions if grazing is significantly impacting fish habitat (USFS 1988a, p. 236).

On the Sequoia National Forest, LRMP grazing standards and guidelines applicable to all streams within the habitat of the California golden trout were amended in 2004 (subsequent to the October 13, 2000, petition to list the California golden trout) by the adoption of the Sierra Nevada Forest Plan Amendment (SNFPA) (CDFGet al.2004a, p. 23). The new standards and guidelines, established for the protection of rare aquatic populations such as the California golden trout, require habitat managers to implement the following conservation measures:

(1) Prevent disturbance to meadow-associated streambanks and natural lake and pond shorelines caused by resource activities from exceeding 20 percent of stream reach or 20 percent of natural lake and pond shorelines.

(2) Limit livestock utilization of grass and grass-like plants to a maximum consumption of 30 percent of each plant by volume (or minimum 6 in (15 cm) stubble height) for meadows in early seral status; limit livestock utilization of grass and grass-like plants to a maximum consumption of 40 percent of each plant by volume (or minimum of 4 in (10 cm) stubble height for meadows in late seral status).

(3) Determine ecological status on all key areas monitored for grazing utilization prior to establishing utilization levels.

(4) Limit browsing to no more than 20 percent of the annual leader growth of mature riparian shrubs and no more than 20 percent of individual seedlings (CDFGet al.2004a, pp. 23, 84, 87).

Habitat Restoration and Monitoring Efforts

The Inyo National Forest has installed several exclosures in riparian areas within the range of the California golden trout to protect and restore portions of the South Fork Kern River, Mulkey Creek, Ninemile Creek, and Golden Trout Creek from grazing impacts (see also Historical Effects of Excessive Grazing section above). Livestock exclosures totaling several miles exist on numerous stream reaches in all four grazing allotments within Inyo National Forest. Exclosures in the Monache and Mulkey allotments, where grazing is currently allowed, are currently excluding cattle from areas where they would otherwise be grazing. Exclosures in the Whitney and Templeton allotments, which are currently being rested from grazing, will only begin to actively exclude cattle if and when grazing is resumed on those allotments.

Research by Knapp and Matthews (1996, pp. 816-817) in Mulkey and Ramshaw Meadows showed that areas within exclosures display greater canopy shading, stream depth, bankful height, and narrower stream width. Studies by Odionet al.(1988, p. 277) in Ramshaw and Templeton Meadows indicated that exclosures allowed significantly more pioneer species to colonize areas that were bare from disturbance. Photo-points recorded between 1989 and 2005 within a number of these exclosures indicate recovery in many areas that were once degraded by grazing (Sims 2006a). For these reasons, livestock exclosures have contributed to restoring habitat, reducing the effects of grazing, and preventing future damage to these habitats for the subspecies. Because exclosures require maintenance, activities conducted pursuant to annual work plans within the Conservation Strategy have included annual maintenance of cattle exclosure fencing (McGuire and Sims 2006, p. 17; Sims and McGuire 2006, p. 12).

In addition to monitoring and cattle exclusion efforts, Inyo National Forest has completed numerous projects to stabilize soil and prevent erosion (USFS 2005inMcGuire and Sims 2006, p. 35). In addition to preventing further degradation, such treatments can direct stream flows to reestablish stream characteristics beneficial to California golden trout, such as overhanging banks and vegetation. These restoration and stabilization projects generally involve placing materials such as rocks or logs at key points of eroding streams in a given area to catch sediments and prevent further erosion. Since 1996, such projects have been completed at 19 sites (USFS 2005inMcGuire and Sims 2006, pp. 35, 37). Between 1933 and the mid-1980s, approximately 800 erosion control structures were installed in the Golden Trout Wilderness (USFS 1988a, p. 236; CDFGet al.2004a, p. 34).

Conservation activities that have been conducted for the benefit of the California golden trout are described in the report titled, “Watershed Restoration and Monitoring Accomplishments on the Kern Plateau” (Kern Plateau Report) (USFS 2005inMcGuire and Sims 2006, pp. 32-42), which summarizes watershed improvement and monitoring projects within the grazing allotments on theKern Plateau since the 1930s. For example, from 2002 to 2003, the Forest Service implemented intensive monitoring and data collection over a wide area of the South Fork Kern River and Golden Trout Creek watersheds to assist in determining watershed condition trends (USFS 2005inMcGuire and Sims 2006, p. 32). A wide-scale headcut monitoring effort was initiated in 2003 at various parts of the Kern Plateau on both active and rested grazing allotments. Photo-points have been established at various locations on the Kern Plateau to monitor trends in stream bank stability, headcut migration, and vegetation patterns, with data collected indicating recovery in many areas that were affected by grazing (Sims 2006a, p. 1). The Kern Plateau Report also identifies opportunities for monitoring and evaluating the effectiveness of management practices. Recent results from these monitoring efforts showed significant improvement in meadow condition and streambank stability for the two allotments rested from grazing (Templeton and Whitney), and a positive trend in meadow and streambank conditions for the Mulkey allotment (Weixelman 2011, p. 12). No sites were shown to decline in condition (Ettema and Sims 2010, p. 63). Overall, 64 percent of sites in grazed allotments and 74 percent in ungrazed allotments are now meeting desired conditions (good to excellent) (Weixelman 2011, pp. 3, 12).

The Conservation Strategy also includes monitoring of the effectiveness of best management practices (BMPs) to determine their effectiveness in protecting California golden trout habitat, with an annual report completed for inclusion in the annual accomplishment reports (CDFGet al.2004a, p. 54). BMPs are a practice or combination of practices that are the most effective and practical means of preventing or reducing water pollution from non-point sources. We also note that the MOA commits the signatories of the Conservation Strategy to meet annually to evaluate the effectiveness of the strategy, determine whether the goals and objectives are being adequately achieved, and discuss whether the strategy requires any adaptive changes to better conserve the California golden trout (CDFGet al.2004b, p. 3). This means that changes in management can occur if conditions or results of monitoring indicate there is a negative change to the California golden trout's habitat or range. The MOA also contains a provision that if any element of the Conservation Strategy is determined infeasible, or if any new threat is identified, then the Agencies will be notified within 30 days and a meeting will be held to determine the course of action (CDFGet al.2004b, p. 4). Thus, in the event of a change in future conditions that result in an unacceptable level of impacts due to excessive grazing, appropriate changes in management can occur.

Summary of Livestock Grazing Management

In summary, historical excessive grazing practices have affected the stream habitat in nearly the entire native range of the California golden trout. Habitat degradation has been addressed in recent decades with numerous conservation efforts, such as reducing the season of use and number of cattle allowed to graze on an allotment, implementing grazing standards and guidelines in the LRMPs, resting of grazing allotments, implementing watershed monitoring, and completing restoration projects. Monitoring of Golden Trout Creek and upper South Fork Kern watersheds has found that implementing these conservation efforts has improved meadow and streambank conditions for three of four grazing allotments, and has stabilized conditions in the fourth grazing allotment (Ettema and Sims 2010, p. 63; Weixelman 2011, p. 12). Based on our evaluation of current practices and of recent and ongoing restoration activities, we do not consider livestock grazing to present a significant threat to the California golden trout now or into the future.

Pack Stock Use

Similar to cattle, horses and mules may significantly overgraze, trample, or pollute streamside habitat if too many are concentrated in riparian areas too often or for too long. Commercial pack stock trips are permitted in national forests within the Sierra Nevada, providing transport services into wilderness areas with the use of horses or mules. Use of pack stock in the Sierra Nevada increased after World War II as road access, leisure time, and disposable income increased (Menkeet al.1996, p. 919). The Inyo National Forest has permitted commercial pack operators since the 1920s (USFS 2006a, p. 1). Current commercial pack stock use is approximately 27 percent of the level of use in the 1980s reflecting a decline in the public's need and demand for pack stock trips. From 2001 to 2005, commercial pack stock outfitters within the Golden Trout and South Sierra Wilderness Areas averaged 28 percent of their current authorized use (USFS 2006b, p. 3-18).

Currently, pack stock use within Golden Trout and South Sierra Wilderness Areas overlaps with historical and current livestock grazing locations, thus making it difficult to identify impacts to vegetation that are due specifically to pack stock use (USFS 2006b, p. 3-13). Monitoring of pack stock grazing impacts on meadows within the California golden trout's range shows a general trend of decreasing impacts to stream bank stability. This trend is believed to be due to restoration efforts and the cancellation of cattle grazing permits (USFS 2006b, p. 3-12).

Allowable pack stock uses are limited in the Inyo National Forest by the same restrictions discussed above for cattle, such as the Amendment 6 forest-wide grazing utilization standards and the 10 percent limit to bank trampling along State trout waters (USFS 200b, p. 3-353). Pack stock grazing is also prohibited in specific meadows, including Volcano Meadow, South Fork Meadow (at the headwaters of the South Fork of the Kern River), and parts of Ramshaw Meadow. As discussed above, these restrictions have resulted in improved conditions for the majority of monitored habitat for which we have monitoring results, and stabilized conditions for the remainder of that habitat (Ettema and Sims 2010, p. 63; Weixelman 2011, p. 12). Accordingly, we consider current habitat management practices sufficient to prevent pack stock use from posing a significant threat to the California golden trout.

Recreation

Recreational activities that include hiking, camping, and off-road vehicle (ORV) use take place throughout the Sierra Nevada and can have impacts on fish and wildlife and their habitats (impacts from fishing are discussed below under Factor B—Overutilization for Commercial, Recreational, Scientific, or Educational Purposessection). Impacts to wilderness areas can vary in their extent, longevity, and intensity (Cole and Landres 1996, pp. 169-170). In easily accessible areas, heavy foot traffic in riparian areas can trample vegetation, compact soils, and physically damage stream banks (Kondolfet al.1996, pp. 1014, 1019). Human foot, horse, bicycle, or ORV trails can replace riparian habitat with compacted soil (Kondolphet al.1996, pp. 1014, 1017, 1019), lower the water table, and cause increased erosion.

Recreation is the fastest growing use of national forests (USFS 2001b, p. 453). Because of an increasing demand for wilderness recreational experiences,wilderness land management now includes standards for wilderness conditions, implementing permit systems, and other visitor management techniques to reduce impacts to habitat, including riparian habitat (Cole 2001, pp. 4-5). These wilderness land management techniques are currently being used on the Inyo and Sequoia National Forests where they are expected to benefit California golden trout by reducing impacts on its habitat.

All of the current range of the California golden trout, with the exception of the Monache Meadow and Kennedy Meadow areas, is encompassed within the federally designated Golden Trout, South Sierra, and Domeland Wilderness areas, where access is difficult and impacts from recreation are lower than in easily accessible areas. Recreational use currently is low and well-dispersed in these areas. The Forest Service monitors wilderness use levels and limits wilderness use if recreation levels are determined to be high (Sims 2006a, p. 1). Recreational impacts are ameliorated by the implementation of various management actions, such as camping restrictions, wilderness ranger presence, and permit requirements. Camping within the Golden Trout Wilderness is not allowed within 100 ft (30 m) of lakes or streams, and a permit is required by the Sequoia National Forest for overnight use. These measures minimize impacts to the fish's habitat. Additionally, Federal designation of an area as Wilderness prohibits the use of motorized or mechanized equipment by the public, with limited exceptions, and therefore provides protection from ORV impacts within these areas.

On National Forest lands outside of federally designated wilderness areas, California golden trout stream habitat occurs in high-use areas, such as Monache and Kennedy Meadows. In these areas, recreational impacts are occurring and are expected to continue. Recreational use occurs primarily on the South Fork Kern River through Monache Meadows on the Inyo National Forest and Kennedy Meadows on the Sequoia National Forest. Motorized access in Monache Meadows is restricted to use of a single 4-wheel-drive road that enters to the south of the meadow. Camping, fishing, and hunting are the primary uses, as well as access for pack stock (CDFGet al.2004a, p. 21). Kennedy Meadows is easily accessed by road and receives heavy use during the trout season for fishing and camping activities. Easily accessible and popular fishing areas, such as Monache and Kennedy Meadows, are being impacted by anglers, whose use of the stream banks can lead to collapsed undercut banks, compacted soils, and disturbed riparian vegetation (Stephens 2001a, p. 64).

Although recreational impacts are expected to continue, they are localized to a few areas within the native range of the California golden trout. In addition, the Forest Service and CDFG have implemented measures identified in the Conservation Strategy to offset recreational impacts to the subspecies. Restoration and stabilization projects were implemented adjacent to and within the Monache Allotment in 2004 to address ORV impacts to the meadow habitat in the South Fork Kern River drainage. A brochure for recreational users was produced in 2005 and 2006 that informed the public about fishing and requested help with restoration projects aimed at protecting the California golden trout; it is available for recreational users at area ranger stations, visitor centers, and local flyfishing shops. Information regarding volunteer field activities, opportunities for public involvement, subspecies information, and agency contacts is also posted on the California Trout and Trout Unlimited web pages. Through these volunteer field activities, Trout Unlimited, California Trout, and the Federation of Flyfishers have assisted CDFG and the Forest Service to protect and restore California golden trout and their habitat.

In summary, recreational activities have the potential to negatively impact the habitat and range of the California golden trout through trampling and vegetation loss due to use by pack stock, humans, and ORVs. We believe that some adverse effects to the California golden trout from recreation at high-use areas outside of federally designated Wilderness Areas will continue; however, these effects are expected to remain localized and not rise to a level that would significantly affect the subspecies as a whole. We conclude that current wilderness land management standards afford considerable protection from a variety of potential recreational impacts to habitat of the California golden trout in wilderness. Implementation of management activities by the Forest Service and CDFG have offset recreational impacts to California golden trout habitat in several high-use recreational areas outside of designated wilderness. Activities such as public outreach and stakeholder involvement have been, and continue to be, conducted to help limit potential recreational impacts over the native range of the California golden trout. Consequently, we conclude that habitat loss due to recreational activity does not currently present a significant threat to the California golden trout, and we do not expect it to become a significant threat in the future.

Artificial Fish Barriers

Three barriers have been constructed on the South Fork Kern River to prevent upstream migration of nonnative trout species, and thereby to reduce their introgression and competition with California golden trout. Between 1970 and 1973, the Ramshaw Barrier was constructed in a gorge at the upper end of Ramshaw Meadows; it is located farthest upstream from the other barriers on the South Fork Kern River. In 1973, the Templeton Barrier was constructed of rock, chain-link fencing, and filter fabric at the head of Templeton Gorge, located approximately 11.3 km (7 mi) downstream of the Ramshaw Barrier at the eastern end of Templeton Meadows. In 1980, Templeton Barrier was replaced with a rock-filled gabion structure across the river that resembled a small dam. In 1981, the Schaeffer Barrier was constructed 11.3 km (7 mi) downstream from the Templeton Barrier at the upper end of Monache Meadows.

Although the Ramshaw Barrier has been impassable to fish since 1973, both the Templeton and Schaeffer barriers were determined in 1994 to be on the verge of collapse (Stephens 2001a, p. 33; CDFGet al.2004a, p. 36). In 1996, the gabion dam at Templeton was replaced with a rock and concrete dam immediately downstream and in contact with the existing structure (CDFGet al.2004a, p. 37). In 2003, Schaeffer Barrier was replaced with a reinforced concrete dam that is 2 ft (0.6 m) higher than the old barrier and includes a concrete apron below the spillway to prevent the formation of a jump pool below the barrier (CDFGet al.2004a, p. 37). As a result of these modifications, all three barriers now effectively prevent upstream fish passage (CDFGet al.2004a, p. 37; Lentz 2011, p. 1).

The construction of these fish barriers and subsequent modifications likely have had some negative effect on California golden trout by altering their stream habitat. Dams, water diversions, and their associated structures can alter the natural flow regime both upstream and downstream of dams. However, because the barriers have been constructed to prevent passage of nonnative fish and to protect the California golden trout rather than to impound water, we expect that their effect on stream conditions and hydrology are limited to localized areas where the barriers are placed. The barriers have the potential to fragmentthe California golden trout's stream habitat because they generally prevent the upstream movement of fish, including California golden trout. However, California golden trout may be somewhat insulated from these effects because they generally do not move far from where they were hatched, except under unusually high flood flows (Stephens 2003, p. 5). The barriers also facilitate the restoration of natural prey and competitor conditions in the California golden trout's stream habitat by preventing population of the streams by nonnative brown trout (Salmo trutta). The effects of artificial fish barriers on movement of brown trout are discussed below under Factor C—Disease or Predation.Effects on movement of hybridized trout are discussed under Factor E—Other Natural or Human Factors.

In summary, the three artificial fish barriers that have been placed on the South Fork Kern River are expected to have localized effects to the stream habitat of the California golden trout, and are also expected to benefit the subspecies in the future by allowing restoration of natural predator and prey relationships within the habitat. We conclude that the barriers do not constitute a significant threat to California golden trout at this time or in the future.

Beavers

Beavers (Castor canadensis) currently exist within the native range of the California golden trout. Although beavers were native to California's Central Valley in the early 19th century, they were not generally known from the Sierra Nevada except where introduced by humans (Tappe 1942, pp. 7, 8, 13, 14, 20). Native beaver populations experienced great declines during the early exploration of California by traders and trappers (Tappe 1942, p. 6). Subsequent reestablishment and introductions have extended their original range (CDFG 2006, p. 1). In the Sierra Nevada and Cascade Mountain ranges, beavers inhabit streams, ponds, and lake margins from Modoc County south to Inyo County (CDFG 2006, pp. 1, 2). Beavers commonly inhabit riparian areas of mixed coniferous-deciduous forests and deciduous forests containing abundant beaver forage and lodge-building material, includingSalixspp. (willows),Alnusspp. (alders), andPopulusspp. (cottonwoods) (Allen 1983, p. 1; CDFG 2006).

There is debate over whether beavers are native to the Kern River basin (Townsend 1979, pp.16-20; CDFGet al.2004a, p. 33). Beavers were introduced by CDFG in the 1940s and 1950s as a tool to restore meadow habitat degraded by livestock grazing. Beavers can have positive and negative effects on trout habitat. Beaver ponds can provide pool habitat for fish, reduce severe ice conditions, and increase populations of bottom-dwelling invertebrates suitable for trout to eat (Gard 1961, p. 240). However, siltation resulting from beaver dams can also degrade spawning habitat for California golden trout, which require gravel for spawning (Knapp and Vredenburg 1996, pp. 528, 529). In a study conducted on Sagehen Creek on the eastern slope of the Sierra Nevada, Gard (1961, pp. 240-241) concluded that beavers were a benefit to trout in this high-elevation creek because they improved fish habitat, forage, spawning activities, and population numbers.

Currently, large beaver populations occur in upper and lower Ramshaw Meadows. Additional populations of unknown size also exist at other locations within the Kern River Plateau (CDFGet al.2004a, p. 33). As of 2004, negative effects of beaver activity within the native range of the California golden trout have not been documented (CDFGet al.2004a, p. 33). Additionally, we are currently unaware of any additional information that document negative effects of beaver within the range of the California golden trout. The Conservation Strategy discusses the beaver as a potential issue for the California golden trout; therefore, CDFG and the Inyo National Forest monitor and evaluate the effect of beaver activity within the native range of the California golden trout. For example, beaver populations were monitored in 2004, 2005, and 2008 at areas on Golden Trout Creek and Ramshaw Meadow that are considered to have the highest potential impacts from beaver on golden trout habitat (CDFG and USFS 2006a, pp. 16-17; CDFG and USFS 2006b, p. 11; McGuireet al.2009, p. 11). At Ramshaw, two active dams were observed in 2008 and the beaver population appeared stable since the previous monitoring in 2005. At Golden Trout Creek, a single beaver dam had been maintained since 2003. No negative impacts from the beaver populations were documented. Therefore, we conclude that beaver activity does not currently constitute a threat to the California golden trout, nor do we expect it to in the future.

Summary of Factor A

California golden trout stream habitat has historically been adversely affected by livestock grazing and, to a lesser degree, pack stock use, recreational activities, and artificial fish barriers. Conservation efforts rela