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Decision Memo Island Lake Fish Removal Project USDA Forest Service Eldorado National Forest Pacific Ranger District El Dorado County, California

Background The Sierra Nevada yellow-legged frog (Rana sierrae) is a California endemic amphibian that is threatened with extinction. Recent efforts to compile conservation information on R. sierrae suggest introduced aquatic predators (primarily salmonid fishes) are one of the principle reasons behind the decline of this species (CDFW 2011; USFWS 2014; Brown et al. 2014). The negative impacts of introduced trout on R. sierrae are well-documented in the Sierra Nevada (Bradford 1989; Bradford et al. 1993; Bradford et al. 1998; Knapp and Mathews 2000b; Knapp et al. 2003; Vredenburg 2004; Knapp et al. 2007). Direct predation on the vulnerable larval (tadpole) stage is likely the primary cause of population declines (Vredenburg 2004), but other aspects of introduced fish represent challenges for population persistence. R. sierrae grow slowly in their high mountain environments and must overwinter underwater in their larval stage. Overwintering requires deep water that does not freeze completely. As a consequence R. sierrae and trout are both typically restricted to large, deep water bodies where bottom waters remain fluid (unfrozen) during the winter. However, the majority of lentic water bodies within the Sierra Nevada are relatively small and shallow which means the critical habitat necessary for both R. sierrae and trout to overwinter is relatively uncommon. The presence of predatory fish can also interfere with dispersal and recolonization routes which, in turn, can fragment and isolate populations and increase local extinction risk (Knapp and Matthews 2000a, 2000b).

Fish were absent from nearly all high elevation habitats in California until the mid-1800s, (Moyle et al. 1996; Knapp 1996; Moyle 2002). Stocking trout into high elevation lakes became a common practice during the early 1900s (Knapp 1996) and targeted larger, perennial lakes and streams. As a result, most historically fishless lakes large enough to support fish currently have introduced trout populations. With the widespread introduction of non-native trout, nearly all large, deep lakes that could provide suitable breeding and overwintering habitat for R. sierrae are now occupied by introduced trout. The presence of fish in optimal habitat (i.e., larger lakes) means R. sierrae are often restricted to marginal habitats, including ephemeral streams and shallow meadow ponds. These smaller waterbodies often do not provide sufficient breeding or overwintering habitat and can be particularly vulnerable to prolonged drought.

The CDFW (2011) and the USFWS (Draft Conservation Strategy, 2016) identify and recommend critical actions necessary for the recovery of the R. sierrae. Top priority recovery actions are: 1) remove non-native fish that threaten existing frog populations and 2) establish additional populations of frogs. Both of these actions are fundamental to the USFWS Conservation Strategy that is in administrative draft.

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Figure 1. Island Lake and associated drainage within the Desolation Wilderness.

Island Lake (Figures 1 and 2) is part of a group of small alpine lakes and ponds that harbor a small population of R. sierrae. However, Island Lake, its outlet stream, a nearby unnamed pond, and Twin Lakes all contain persistent non-native brook trout (Salvelinus fontinalis) which likely negatively impact native frogs in the area. Recent monitoring evidence suggests this frog population is in decline and the combination of prolonged drought and the presence of non-native predatory fish is likely contributing to the decline (Sarah Musselman per. com). In 2012 the California Department of Fish and Wildlife identified this small complex of lakes as a Native Species Reserve (NSR) for R. sierrae (CDFW 2012). In accordance with management objectives developed in their Aquatic Biodiversity Management Plan for the Desolation Wilderness Management Unit (CDFW 2012) the CDFW proposes to remove fish from Island Lake to benefit the extant R. sierrae population. In 2014 CDFW completed a restoration assessment for Island Lake and its tributaries down to a fish passage barrier about 200 meters below the Island Lake dam. CDFW believes fish removal can be accomplished using gill nets, backpack electrofishers and hand tools to temporarily remove riparian vegetation in order to access fish removal sites. The proposed action will significantly increase fishless deep water habitat in the area which is crucial for R. sierrae breeding, rearing, and overwintering habitat.

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Figure 2. Close view of Island Lake detailing the distribution of nonnative trout and historic observations of R. sierrae. Note, the single observation of R. sierrae near the upper end of Island Lake occurred in 2005 and is in a small unmapped pond adjacent to the lake and not in the lake proper where fish removal operations will occur. Deci_sion I have decided to implement the Island Lake Fish Removal Project within the Desolation Wilderness on the Pacific Ranger District of the Eldorado National Forest. This action has been categorically excluded from documentation under the Environmental Policy and Procedures Handbook, FSH 1909.15, Section 32.2, category 6, "Timber stand and/or wildlife habitat improvement activities that do not include the use of herbicides or do not require more than 1 mile of low standard road construction" (36 CFR 220.6(e)(6)." This category is applicable because the purpose of the Island Lake Fish Removal Project is to remove non-native fish and restore critical breeding and overwintering habitat for the endangered Sierra Nevada yellow- . legged frog (R. sierrae). The Island Lake Fish Removal Project would recreate fish-free deep­ water habitat that is vital to the reproductive success of R. sierrae and contribute to the preservation of this state and federally listed endangered species. In addition, since R. sierrae populations play an extremely important ecological role in alpine and sub-alpine systems - R. sierrae functions as a predator species on invertebrates, and prey species for birds, mammals, and reptiles - this project is expected to restore historic ecosystems processes in Island Lake and the surrounding environment. Restoring lakes to a fishless condition not only directly benefits populations of R. sierrae, but also improves ecological conditions for native species that utilize

Decision Memo - Island Lake Fish Removal Project Page 3 of 12 USDA =:::::-:;;;;;; fishless mountain lakes, such as Sierra gartersnake (Thamnophis couchii), mountain gartersnake (Thamnophis elegans elegans), long-toed salamander (Ambystoma macrodactylum), and invertebrate species, such as mayflies (Amaletus spp.). The project will indirectly benefit small mammals, such as the Mt. Whitney pika (Ochotona princeps albata) and predators like the northern goshawk (Accipiter gentilis), which rely on a natural functioning ecosystem.

Project Actions Field work would be conducted by CDFW biologists and seasonal CDFW field staff. Non-native fish would be removed from Island Lake and its tributaries down to a natural fish passage barrier approximately 200 meters below a small dam on the lake outlet channel. A majority of the fish removal would take place under a passive approach utilizing monofilament gill nets. A smaller portion of fish would need to be removed using a mechanical backpack electrofishing unit. Fish removal would be occurring at about 8,000' and therefore must be implemented during the summer months between spring thaw and fall freeze. This window is typically from early June to late October, although significant variation can occur, depending on weather and snow pack. All surveys for R. sierrae would be conducted using CDFW' s visual encounter survey protocol.

Specific project methods include: 1) Two to six CDFW employees (depending on project needs) would hike to the site and be camped for four days at a time every other week. CDFW staff would obtain a wilderness permit, and ensure that all wilderness regulations would be followed including camp site location, leave no trace principles, and waste handling. 2) After ice out (July or August of 2017), field staff would deploy multiple monofilament gill nets in Island Lake perpendicular to shore in an effort to capture adult-sized fish. A backpack electrofisher would be used to target smaller fish, shallow habitat, and tributaries. If necessary, hand tools such as loppers and pruners would be used to remove a minimal number of branches from willows to access wetted habitat. Net fragments would be deployed in large pools associated with tributaries and the fringes of Island Lake. All fish caught would be identified, counted, and measured. The initial work is expected to require 15 to 18 person­ days of effort. Signs will be posted at the major entrances to the wilderness to alert visitors to the fish removal efforts underway at Island Lake. Smaller signs will be posted at the locations of gill nets sets to alert visitors to the presence of gill nets in the water. 3) Captured fish will be sacrificed, have their swim bladders punctured, and be sunk in the middle of the lake. Disposing of fish in this manner utilizes the natural decay process to retain nutrient in the lake system and make them available to the rest of the trophic web. 4) Gill nets would be left in the water fishing for two to three weeks, after which time field staff would return to the site, retrieve, clean, repair, and re-deploy the nets. Shallow habitat and tributaries would be fished again with th_e backpack electrofisher. The work will demand 4 to 8 person-days of effort and will occur every two to four weeks, depending on catch rates. CDFW expects the catch rate to drop dramatically during the active season of 2017, possibly to levels where brook trout are unable to breed in the fall . Regardless, these visits will repeat through summer 2017 until fall freeze. 5) As fall approaches and the lakes begin to freeze, 'over-winter' gill nets will be deployed off shore and at sufficient depth to fish under ice throughout the winter.

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6) In early summer 2018, over-winter nets will be retrieved. CDFW expects that a few brook trout will be caught; depending on the size of the population and the water year, breeding may have occurred in fall. By August, it will be clear if breeding occurred in 2017. Catch rates may drop to zero during this season; regardless, work will continue at a similar level to year one and overwinter nets will again be deployed. Additional pruning of riparian vegetation with hand tools will occur, as needed. 7) In 2019, it is likely that catch rates will either be very low or zero. Gill nets and net pieces will continue to be deployed to ensure no fish remain. Tributaries often require additional effort and backpack electrofishing will continue. Gill netting will continue at a lower effort level: 8-12 person days per month will be required. Depending on catch rates in tributaries during this third summer, fish removal and monitoring in the tributaries may continue for summer 2020 - ensuring that all fish have been removed is vital to the success of the project, and a full year without capturing or observing a fish is considered proof that no fish remain in the system. 8) In each summer during which habitat restoration is undertaken, field staff will perform one to three visual encounter surveys to monitor the response of the frog population. Applicable Design Criteria Work would be conducted in accordance with the Wilderness Minimum Requirements Analysis developed by the Pacific Ranger District and on file at the Eldorado National Forest Supervisors Office. CDFW staff will follow all Desolation Wilderness regulations when traveling and camping. Project activities, such as electrofishing, should occur mid-week to minimize impacts to the public. Any gill nets and associated signage within wilderness will be as unobtrusive as practicable to minimize visual impacts. Environmental Analysis It has been determined that there are no identified extraordinary circumstances or conditions associated with this project that would have a significant effect on the environment (FSH 1909.15, section 31.2; 05/23/2014). The following describes the contributing information that led to this conclusion: a) Federally listed threatened or endangered species or designated critical habitat, species proposed for Federal listing or proposed critical habitat, or Forest Service sensitive species. Botany A Forest Service Botanist visited Island Lake in the summer of 2016 and determined that there are no known federally threatened or endangered plant species or designated critical habitat within or adjacent to the project area. A species of moss (Bruchia bolanderi) designated as a Forest Service sensitive species has been documented alone the trail near Twin Lakes, but no plants were found during this site visit. Because past surveys cannot positively state the absence of a sensitive plant species it is possible that the proposed project could affect undetected individuals in the project area. However, the project includes no ground disturbing actions. Furthermore, accessing the lake and executing project actions is not expected to increase impacts to the area over what would be expected under normal recreational use. Therefore, the proposed project may affect undiscovered individuals but is not likely to result in a trend toward Federal listing or loss of viability for Bruchia bolanderi.

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Terrestrial Wildlife Species There are no known federally threatened or endangered terrestrial wildlife species or designated critical habitat within or adjacent to the project area. There is only one Forest Service sensitive species, the Bald Eagle (Haliaeetus leucocephalus), that occurs within the project area. No bald eagles have been recorded at Island Lake, but records in the Forest Service database (NRIS) indicate they have been recorded approximately 2.5 miles to the southwest at Wrights Lake. Fish bearing lakes provide foraging areas for bald eagles, thus the removal of fish from Island Lake may reduce the foraging opportunities for bald eagles in the Desolation Wilderness. However, surrounding lakes including Wrights Lake, Aloha Lake, _Lake of the Woods, and Lake Tahoe provide sufficient foraging areas for bald eagles which may forage in the Desolation Wilderness. Bald eagles are carrion eaters and birds found soaring over Island Lake during the fish removal process could try to take dead fish caught in the gill nets. Therefore, there is a theoretical possibility that bald eagles could be entangled in nets and possibly injured or killed. However, a thorough review of the available gillnet literature produced no recorded instances of bald eagles being trapped in gillnets. In fact, several studies designed to quantify the availability of prey for local bald eagle populations have utilized gillnets (Gerrard and Bortolotti, 1988; Mersmann, 1989; Vondracek et al., 1989; Hunt et al., 1992) and gillnetting is one of the recommended approaches for bald eagle prey base assessment in the state of California (Jackman and Jenkins, 2004). While the potential for bald eagles to be trapped in gill nets may exist, all available evidence suggests the probability of such an occurrence is quite low. Therefore, the proposed project may affect individuals but is not likely to result in a trend toward Federal listing or loss of viability for the bald eagle. Aquatic Wildlife Species A few small ponds in the vicinity of Island Lake contain one federally listed endangered aquatic species, the Sierra Nevada yellow-legged frog (Rana sierrae). In addition, the project will occur within Designated Critical Habitat for R. sierrae. No Forest Service sensitive aquatic wildlife species or other federally listed threatened or endangered aquatic species exist within the project area. Island Lake represents approximately 20.4 acres of potential habitat for R. sierrae all of which is situated within the Crystal Range Critical Habitat Unit. Therefore, the Island Lake Fish Removal Project has been analyzed for its potential to directly or indirectly effect R. sierrae and Designated Critical Habitat. The actions with the most potential to directly affect R. sierra individuals are associated with fish removal utilizing gill nets and electrofishing equipment. These techniques are not expected to adversely impact frogs. Gill nets are designed to trap and entangle fish and have a relatively poor reputation in marine research because of their potential for by-catch (capture of non-target species; Read et al., 2006). The limited amount of published information addressing bycatch in freshwater fisheries stresses the impacts to non-target fish species and air breathing vertebrates (turtles, crocodiles, otters, and platypus), but makes no mention of effects to frogs (Raby et al., 2011). Gill nets have been used to eradicate non-native fish from other high alpine lakes in California (Vredenburg, 2004; Knapp et al., 2007) and are generally considered safe for non-target frog species (Knapp and Matthews, 1998). While there is no research that specifically addresses the issue of bycatch of frogs in gill nets in freshwater lakes, no freshwater fish removal projects that

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utilized gill nets have reported frog by-catch (Knapp and Matthews, 1998; Parker et al., 2001; Vredenburg, 2004; Knapp et al., 2007; Muskopf et al., 2011). However, anecdotal accounts provided by CDFW personnel with experience in fish removal in high alpine lakes in California (Isaac Chellman per. com.; Sarah Musselman per. com.) indicate bycatch of frogs may occur if high density frog populations exist in fish removal lakes. Ultimately, the potential for impacts to frogs by gill netting in Island Lake may depend on the presence and density of frogs in the lake. The California Department of Fish and Wildlife has monitored Island Lake over the course of the last 12 years and no R. sierrae have ever been observed in the lake (Sarah Musselman per. com.; Figure 2). Taking into account 1) the general lack of literature documenting bycatch of frogs in gill nets, 2) the absence of frogs from Island Lake, and 3) the anecdotal accounts of bycatch effects occurring only in high density populations, the potential for gill netting to injure or kill individual R. sierrae is considered minimal in Island Lake. The potential for bycatch of R. sierrae may increase if frogs move into the lake as fish are depleted, but the long-term impact of the Island Lake Fish Removal Project on R. sierrae would be highly beneficial - helping to ensure the persistence of a breeding population in critical habitat. Electrofishing involves applying an electrical current to the water to temporarily immobilize fish and other aquatic vertebrate organisms. The technique, if conducted properly, is considered safe for amphibians and is, in fact, used in the non-destructive sampling of amphibians (Strain and Raesly, 2012). Fish removal via electrofishing is only effective in shallow relatively simple habitat and will only be used to capture smaller fish in the lake shallows and fish bearing tributaries. Frogs and tadpoles would be relatively easy to see in these shallow clear water environments which would help technicians avoid stressing the animals by electrofishing in their presence. Again, given the lack of frog presence in Island Lake and its tributaries, the level of control available to avoid shocking frogs, and the low impact electrofishing has on amphibians, the potential to injure or kill individual SNYLF via electrofishing is expected to be minimal. Some minor pruning of willow along the shoreline may need to occur to facilitate placement of gill nets. Given the extent of riparian willows present at the site, the potential effects from the minor amount of willow pruning would be negligible. No other impacts to critical habitat are expected from the project. The Island Lake Fish Removal Project is not expected to have significant impacts on any Threatened, Endangered, or Sensitive species or have significant impacts on designated Critical Habitat for these species. The probability of impacting individuals is low and alterations to critical habitat (i.e., removal of fish from Island Lake) would be beneficial. As a consequence, the presence of an endangered species and designated critical habitat within the project area is not considered to constitute an extraordinary circumstance per FSH 1909 .15, section 31.2. b) Flood plains, wetlands, or municipal watersheds. The project occurs within the South Fork Silver Creek Watershed, which contributes to a downstream municipal watershed. However, the project includes no ground disturbing actions outside of pruning some willow branches. Dead fish will have their swim bladders punctured and will be sunk in the lake. This action will slowly return nutrients to the lake as dead fish decay, but would not result in a net increase of nutrients to the system. There are no impairments to the South Fork Silver Creek or the larger 5th order watershed (Silver Creek), including sediment, turbidity or nutrient loading that might be cumulatively impacted by the proposed project. Such impacts as they

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might occur would be negligible and immeasurably small in either the South Fork Silver Creek or the larger Silver Creek watershed.

c) Congressionally designated areas such as wilderness, wilderness study areas, or national recreation areas. The Island Lake Fish Removal Project would take place within the Desolation Wilderness. Forest Service Manual directives guiding management of Wilderness state the following objective, "Provide protection for known populations and aid recovery in areas of previous habitation, of federally listed threatened or endangered species and their habitats." (FSM 2323.31) In the situation of aiding recovery for the R. sierrae, it would be difficult to achieve without some trammelling action. The proposed project would result in temporary negative impacts to the untrammeled character of Desolation Wilderness with human intervention in biological processes. However, the project would aid in the mitigation of the past human-induced impacts of non-native fish on the natural character of Desolation Wilderness. The long term recovery of the R. sierrae, considered a species that is a part of the wilderness ecosystem, is considered to be essential to the protection and enhancement of the natural character of Desolation Wilderness in the long-term. The Desolation Wilderness Management Plan provides direction, "To provide protection for known populations and aid recovery in areas of previous habitation, of federally listed threatened or endangered species and their habitats, so long as the action is for correcting an undesirable condition resulting from human activity or authorized uses." Although the proposed project would result in some short-term and localized negative impacts on the untrammelled and undeveloped character of Desolation, the project will result in long term benefit to the natural character and will assist the Forest in meeting the species recovery objectives for R. sierrae. d) Inventoried roadless areas or potential wilderness areas. The project would not occur within an Inventoried Roadless Area or Potential Wilderness Area. e) Research natural areas. The project will not occur within a Research Natural Area. f) American Indians and Alaska Native religious or cultural sites - There are no American Indians and Alaska Native religious or cultural sites within the project area. g) Archaeological sites, or historic properties or areas - This project complies with Section 106 of the National Historic Preservation Act of 1966, as amended in accordance with provisions of the Programmatic Agreement among the U.S.D.A. Forest Service, Pacific Southwest Region (Region 5), the California State Historic Preservation Officer, the Nevada State Historic Preservation Officer, and the Advisory Council on Historic Preservation Regarding Processes for Compliance with Section I 06 of the National Historic Preservation Act for Management of Historic Properties by the National Forest of the Pacific Southwest Region (Regional PA 2013). Under the provisions of the Regional PA 2013 "activities that do not involve ground or surface disturbance, and that do not have the potential to affect access to or use of resources by Native Americans based on the nature of the undertaking or prior or current consultation with Native American tribes" are considered Screened Undertakings (Class B). The Island Lake Fish Removal Project was reviewed by the Pacific District Archaeologist and certified as a Screened Undertaking (Class B) according to the provisions of the Regional PA 2013. No Standard Protection Measures are required and the project may be implemented without further review or consultation.

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In addition, the project has limited context and intensity (40 CFR 1508.27), and this action will produce little or no individual or cumulative environmental effects, to either biological or physical components of the human environment (40 CFR 1508.14). Public Involvement On April 28, 2017, a letter initiating scoping and requesting comments on the proposed action was mailed to special use permittees, environmental organizations, wilderness organizations, and private landowners with interest in fisheries and wilderness management on the Eldorado National Forest. On May 6, 2017 representatives from the Eldorado National Forest and The California Department of Fish and Wildlife (CDFW) attended the Wrights Lake Homeowner's Association meeting to provide information and answer questions about the proposed project. On June 22, 2017 CDFW gave a presentation about the project to a diverse stakeholder group at the Sacramento Municipal Utilities District (SMUD) meeting. In July 2017 the project was listed as a proposal on the Eldorado National Forest Schedule of Proposed Actions (SOPA). The SOPA is mailed to individuals, organizations, and agencies that have asked to be notified of proposed actions on the Eldorado National Forest. The SOPA is also posted on the Eldorado National Forest website. The Forest Service and California Fish and Wildlife received several comments regarding the project at the Wrights Lake Homeowner's Association and SMUD meetings, the majority of which were requests for more information or clarification of project goals and scope. All questions arising during the meetings were addressed verbally at the meetings. The Forest Service received one written request for more information in relation to the scoping letter and the response to that request is on file at the Eldorado National Forest Supervisor's Office in Placerville CA. No follow up comments were received. Tribal consultation for this project was initiated during the scoping process and included mailing a notice to the Tribal Historic Preservation Officer (THPO) for the Washoe Tribe of Nevada and California. The Washoe THPO replied that brook trout are not a culturally sensitive species and that the Washoe have concurred with CDFW efforts to remove non-native species in the past and are collaborating with CDFW and USFWS to restore native species where applicable. Findings Required by Other Laws and Regulations This action is found to be consistent with all applicable laws and the Eldorado National Forest Land and Resource Management Plan (1989), as amended by the Sierra Nevada Forest Plan Amendment (2004). Administrative Review (Objection) Opportunities This decision is not subject to legal notice and comment procedures of 36 CFR 218.22, and is not subject to the pre-decisional administrative review process pursuant to 36 CFR 218. Implementation Date This decision may be implemented immediately.

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Contact For additional information concerning this decision, contact: Jeffrey Mabe, Fisheries and Aquatic Biologist, Eldorado National Forest, 100 Forni Road, Placerville, CA 95667; Phone 530-621- 5240.

Date

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References Bradford, D. F. (1989). Allotopic distribution of native frogs and introduced fishes in the high Sierra Nevada lakes of California: implication of the negative effects of fish introductions. Copeia, 1989, 775-778. Bradford, D. F., Cooper, S. D., Jenkins, T. M., Kratz, K., Sarnelle, 0 ., & Brown, D. A. (1998). Influences of natural acidity and introduced fish on fauna! assemblages in California alpine lakes. Canadian Journal of Fisheries and Aquatic Sciences, 55, 2478-2491. Bradford, D. F., Graber, D. M., & Tabatabai, F. (1993). Isolation of remaining populations of the native frog, Rana muscosa, by introduced fishes in Sequoia and Kings Canyon National Parks, California. Conservation Biology, 7, 882-888. Brown, C., Hayes, M. P., Green, G. A., & MacFarlane, D. C. (2014). Mountain yellow-legged rag conservation assessment for the Sierra Nevada mountains of California, USA. Vallejo, CA: RS­ TP-038. USDA Forest Service, Pacific Southwest Region. CDFW (California Department of Fish and Wildlife). (2011 ). A Status Review of the Mountain Yellow­ legged Frog (Rana sierrae and Rana muscosa). Sacramento, CA: State of California, Department of Fish and Wildlife. CDFW (California Department of Fish and Wildlife). (2012). Aquatic Biodiversity Management Plan for the Desolation Wilderness Management Unit. Sacramento, CA: State of California, Department of Fish and Wildlife.

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Gerrard, J. M., & Bortolotti, G. R. (1988). The Bald Eagle, Haunts and Habits of a Wilderness Monarch. Washington D.C.: Smithsonian Institute Press. Hunt, W. G., Jenkins, J. M., Jackman, R. E., Thelander, C. G., & Gerstell, A. T. (1992). Foraging ecology of bald eagles on a regulated river. Journal of Raptor Research, 26, 243-256. Jackman, R. E., & Jenkins, J.M. (2004). Protocol for evaluating bald eagle habitat and populations in California. Sacramento, CA: U.S. Fish and Wildlife Service, Endangered Species Division. Knapp, R. A. (1996). Non-native trout in natural lakes of the Sierra Nevada: an analysis of their distribution and impacts on native aquatic biota. Sierra Nevada Ecosystem Project: Final Report to Congress. Vol. Ill: Assessments, commissioned reports, and background information (pp. 363-407). Davis, CA: University of California, Davis, Centers for Water and Wildlind Resources. Knapp, R. A. (2005). Effects of nonnative fish and habitat characteristics on lentic herpetofauna in Yosemite National Park, USA. Biological Conservation, 121, 265-279. Knapp, R. A., & Matthews, K. R. (1998). Eradication of nonnative fish by gill netting from a small mountain lake in California. Restoration Ecology, 6, 207-213. Knapp, R. A., & Matthews, K. R. (2000a). Effects of nonnative fishes on wilderness lake ecosystems in the Sierra Nevada and recommendations for reducing impacts. Proceedings: Wilderness Science in a Time of Change. 5, pp. 312-317. Ogden, UT: U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station. Knapp, R. A., & Matthews, K. R. (2000b). Non-native fish introductions and the decline of the mountain yellow-legged frog from within protected areas. Conservation Biology, 14, 428-438. Knapp, R. A., Boiano, D. M., & Vredenburg, V. T. (2007). Removal of nonnative fish results in population expansion of a declining amphibian (mountain yellow-legged frog, Rana muscosa). Biological Conservation, 135, 11-20. Knapp, R. A., Matthews, K. R., Preisler, H.K., & Jellison, R. (2003). Developing probabilistic models to predict amphibian site occupancy in a patchy landscape. Ecological Applications, 13, 1069-1082. Mersmann, T. J. (1989). Foraging ecology of Bald Eagles on the north Chesapeake Bay with an evaluation of techniques used in the study of Bald Eagle food habits. Blacksburg, VA: M.S. Thesis, Virginia Polytechnic Institute. Moyle, P. B. (2002). Inland Fishes of California. Revised and Expanded. Berkeley, CA: University of California Oress. Moyle, P. B., Yoshiyama, R. M., & Knapp, R. A. (1996). Status offi shes and fisheries. Sierra Nevada Ecosystem Project:Final Report to Congress. Vol. II: Assessment and scientific basis for management options. Davis, CA: University of California, Davis, Centers for Water and Wildland Resources. Muskopf, S., Santora, M., Bind!, M., & Lemmers, C. (2011). Sierra Nevada yellow-legged frog habitat restoration project in the Desolation Wilderness, annual reprotfor 2011. South Lake Tahoe, CA: U.S. Forest Service, Lake Tahoe Basin Management Unit. Parker, B. R., Schindler, D. W., Donald, D. B., & Anderson, R. S. (2001). The effects of stocking and removal of a nonnative salmonid on the plankton of an alpine lake. Ecosystems, 4, 334-345. Raby, G.D., Colotelo, A.H., Blouin-Demers, G., & Cooke, S. J. (2011). Freshwater commercial bycatch: an understated conservation problem. BioScience, 61 , 271-280. Read, A. J., Drinker, P., & Northridge, S. (2006). Bycatch of marine mammals in U.S. and global fisheries. Conservation Biology, 20, 163-163. Strain, G. F., & Raesly, R. L. (2012). Amphibian sampling techniques along the Maryland coastal-plain streams. Northeastern Naturalist, 19, 229-248. USFWS (US Fish and Wildlife Service). (2014). Endangered and Threatened Wildlife and Plants; Endangered Species Status for Sierra Nevada Yellow-Legged Frog and Northern Distinct Population Segment of the Mountain Yellow-Legged Frog, and Threatened Species Status for Yosemite Toad; Final Rule. Federal Register, 79(82), 24256-24310. Vondracek, B., Baltz, D. M., Brown, L. R., & Moyle, P. B. (1989). Spatial, seasonal, and die! distribution of fishes in a California reservoir dominated by native fishes. Fisheries Research, 7, 31-53. Vredenburg, V. T . (2004). Reversing introduced species effects: experimental removal of introduced fish leads to rapid recovery of a declining frog. Proceedings of the National Academy of Sciences of the United States ofAm erica, 101, 7646-7650.

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