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Home , Fauna of California, Game fish, Lahontan redside, Mountain whitefish, Paiute sculpin, Richardsonius

Basin‐wide Native Non‐ Assessment 2011 Annual Report Revised on February 21, 2013 USDA Forest Service, Basin Management Unit

Written by Christopher Lemmers (Biological Science Technician) and Maura Santora (Aquatic Biologist)

Reviewed by Sarah Muskopf (Acting Forest Aquatic Biologist) and Shana Gross (Forest Ecologist)

Approved by Holly Eddinger (Biological Program Leader)

Original Version: April 19, 2012 Revised Version: February 21, 2013 1

TABLE OF CONTENTS

Summary ...... 2 Introduction ...... 3 Methods ...... 5 Results ...... 7 Discussion ...... 11 Recommendations ...... 13 Works Cited ...... 14 Appendix ...... 17

Summary

The Lake Tahoe Basin Management Unit (LTBMU) is conducting a fish assessment survey on state and federal lands within the basin to determine species presence, distribution, and relative abundance. These baseline conditions will provide information for future watershed and ecosystem level management decisions. To date 26 streams within the Lake Tahoe basin have been surveyed. In 2011, the Lake Tahoe Basin Management Unit aquatics field crew, with help from partner agencies, surveyed the Upper (UTR) from the mouth at Lake Tahoe upstream 19.3 kilometers. Over 12,500 fish were sampled, 53 non‐native warm water fish were removed, and an estimated 330 invasive crayfish (Pacifastacus leniusculus) and 1,589 native western pearlshell mussels (Margaritifera falcata) were counted. Of the 12 species found, seven native species were documented: ( egregious), speckled dace (Rhinichthys osculus), Tahoe sucker ( tahoensis), mountain sucker (Catostomus platyrhynchus), Paiute sculpin ( beldingi), mountain whitefish ( williamsoni), and Lahontan cutthroat (Oncorhynchus clarki henshawi). With the exception of speckled dace and Paiute sculpin, native fish species were a small percentage of fish sampled while non‐native brown and accounted for nearly 25% of the total fish sampled. In general, native species were limited in distribution and relative abundance, with the greatest species diversity found in the lower reaches of the UTR.

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Introduction

Historically, eight fish taxa were known to be native to the Lake Tahoe Basin including: Lahontan (Richardsonius egregious), speckled dace (Rhinichthys osculus), Paiute sculpin (Cottus beldingi), Tahoe sucker (Catostomus tahoensis), mountain sucker (Catostomus platyrhynchus), Lahontan tui chub (Gila bicolor pectinifer), mountain whitefish (Prosopium williamsoni), and Lahontan (Oncorhynchus clarki henshawi) (Miller 1951, Frantz and Cordone 1970, and Vander Zanden et al. 2003). Lake Tahoe’s pre‐1900 was dominated by a single predator, the Lahontan cutthroat trout (LCT). Mountain whitefish and LCT were abundant and provided ample food for the Native Americans living around Lake Tahoe. LCT were extirpated from Lake Tahoe by 1939 (Cordone and Frantz 1968, Moyle 2002), and the population of mountain whitefish now occur in very low numbers (Murphy and Knopp 2000). Several factors have contributed to the decline or extinction of native fish and the degradation of fish habitat in the Lake Tahoe Region. Over‐, logging, mining, dams, water diversions, intense grazing, road building, urban development, and the introduction of non‐native fish and other aquatic organisms are believed to have cumulatively contributed to the change in Lake Tahoe’s fish composition and degradation of fish habitat (SNEP 1996, Murphy and Knopp 2000, Cordone and Frantz 1968, Moyle 2002). In aquatic ecosystems modified by human disturbance, non‐native fish species often become dominant and out‐ compete native fish species (Deacon and Minckley 1974; Shepard et al. 1997; Brandenburg and Gido 1999; Schindler 2000; Knapp et al. 2001).

During the last 130 years, numerous non‐native species have been introduced intentionally and unintentionally to the Tahoe Basin, altering its biological assemblage. The first series of introductions included nine species of salmonids thought to be suited to Tahoe’s environment. Only rainbow trout (Oncorhynchus mykiss), (Salmo trutta), ( namaycush), (Salvelinus fontinalis), and kokanee (Oncorhynchus nerka) survived and persist in the basin today. Non‐native salmonids, which dominate streams within the Lake Tahoe basin, have adverse effects on the distribution and abundance of native species in Sierra streams (Moyle and Vondracek 1985; Moyle and Williams 1990). Non‐native warm water fish have also been introduced into Lake Tahoe streams and near shore environment, including: brown bullhead (Ameiurus nebulosus), ( macrochirus), largemouth ( salmoides), (Micropterus dolomieu), black (Pomoxis nigromaculatus), and goldfish (Carassius auratus) (Basinwide Native Non‐ game Fish Assessment 2007‐2010; Kamerath et al. 2008). With the illegal introduction of non‐ native warm water fish and other aquatic species, such as signal crayfish (Pacifastacus leniusculus), the aquatic food web has drastically changed. These changes have been negatively correlated with the percent of native fish present (MacRae and Jackson 2001; Betolli et al. 1992; Vander Zanden et al. 2003; Moyle and Nickols 1973; Findlay et al. 2000).

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Although several of Lake Tahoe’s tributary streams are still known to contain native fish, information about the historical and current status of native non‐game fish communities in the Lake Tahoe basin was almost non‐existent before this survey. The most recent comprehensive document about was compiled by the Tahoe Regional Planning Agency (TRPA) and U.S. Forest Service (USFS) in 1971 called “Fisheries of the Lake Tahoe and its Tributary Waters” (TRPA 1971). However, most of the information pertained to sport fisheries, while information pertaining to native non‐game species was presumed in most cases. This lack of current native species status and distribution triggered the initiation of the Basin‐wide Native Non‐game Fish Assessment (referred to as Fish Assessment) in 2007.

Most inlet streams on the west and north shore of Lake Tahoe have been surveyed in the Fish Assessment. More recently, surveys have focused on the south shore of Lake Tahoe and in perennial streams where LTBMU projects are being planned. Originally, field crews were trained to record only the fish species found, but in 2011 two other aquatic species were noted when detected: Western pearlshell mussel (Margaritifera falcata) and signal crayfish. Western pearlshell mussel will likely be listed on the next update of the USFS Region 5 Sensitive Species List, which is currently in review. Also, local river restoration activities have started relocating current populations when old channel sections are be dewatered. Signal crayfish are a non‐ native aquatic species which alter the aquatic ecosystem by preying on fish and other native aquatic dependent species.

Western pearlshell mussel is a freshwater mussel native to western . The mussels are long‐lived species (individuals may live for ~100 years) (Bauer 1992, Hastie et al. 2000a, b). Like most freshwater mussels, Western pearshell mussel has an obligate parasitic larval stage on . After completing larval development, juvenile mussels drop from their fish hosts onto the river bed and become minute (~60‐μm) free‐living bivalves. Many historical populations throughout its range appear to have been severely reduced in size from dense beds to a few isolated individuals in flow refugia at many historical sites (Vannote and Minshall 1982, Hovingh 2004, Strayer et al. 2004, Howard 2008, 2010). In recent years, it was discovered that the Upper Truckee River (UTR) is home to one of the only known populations of Western pearshell mussel in the Lake Tahoe Basin. However, the extent and distribution of this species in the UTR and other streams in the Tahoe Basin is not well documented. Currently, this species is only known to occur in the lower and middle reaches of the UTR.

Signal crayfish is a from the , , and were introduced into Lake Tahoe in 1916 by Department of Fish and Game (CDFG) officials (Riegel, 1959) and have spread from the lake into its tributaries. While their ecology has been studied in Lake Tahoe and nearby Donner Lake (e.g. Abrahamsson & Goldman, 1970; Flint & Goldman, 1975; Flint, 1977; Goldman & Rundquist, 1977), little is known about their importance, abundance or even occurrence within streams in the region. Crayfish are abundant in the littoral zone of Lake Tahoe and most large inlet streams to the lake. They have been linked to increased algae blooms, a decrease in native invertebrates and are believed to be detrimental to Lake Tahoe's

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clarity. Non‐native warm‐water fish, such as and bluegill, are nearly the only predators that feed on the crayfish.

In previous survey efforts (2007 – 2010), multiple streams were surveyed as part of the Fish Assessment; however, 2011 efforts were focused only in the UTR. The UTR is the largest tributary entering Lake Tahoe. The headwaters are located in Meiss Meadows, at about 2750 meters, and flow approximately 40 kilometers north where it empties into Lake Tahoe near the Tahoe Keys housing development. A self‐sustaining population of LCT has been restored in the headwaters and expansion efforts are underway to increase the range of this population. Due to the size and complexity of the UTR, including multiple land ownership, 2011 survey efforts were conducted in collaboration with multiple partners including California Tahoe Conservancy (CTC), CDFG, CalTrout, California State Parks, City of South Lake Tahoe, U.S. Bureau of Reclamation (BOR), Lahontan Regional Water Quality Control Board, University of California at Davis (UCD), University of Nevada at Reno (UNR), and Tahoe Regional Planning Agency (TRPA). Multiple reaches of the UTR are slated for restoration efforts by the various state, federal, and local agencies. The goal of the 2011 survey was to determine current distribution and relative abundance of native and non‐native species to be used as a comparison for post restoration activities.

Methods

Between 2007 and 2011, 26 perennial streams were surveyed for species relative abundance, distribution, and size class breakdowns as part of the Lake Tahoe Basin Management Unit’s (LTBMU) Basin‐wide Native Non‐game Fish Assessment. Streams were surveyed from the mouth to headwaters where possible. Exceptions to this occurred when the terrain was too difficult, when permission was not granted to be on non‐FS land, or when surveys detected only one species in the reaches approaching the headwaters. A survey was considered complete when only one species was found for 500m.

The 2011 survey was initiated in early August when stream discharge reached a safe wadeable level and continued through the end of September. Due to stream conditions and high water levels some sections of the stream, specifically deep pools, could not be effectively surveyed. Beyond these portions of stream, the UTR was sampled continuously from the mouth at Lake Tahoe upstream approximately 19.3 kilometers, (coordinates N: 4302458, E: 758781) (Figure 1). Surveys were conducted using backpack electro‐fishers and an electro‐fishing boat, courtesy of CDFG.

The electro‐fishing boat was used to survey from Lake Tahoe, from the mouth of the UTR, upstream 1800m. This was the only feasible way to survey this section due to the depth and width of the channel. The electro‐fishing boat surveyed upstream along the right bank and then back downstream on the left bank. Two netters stood on the bow of the boat to capture any

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shocked fish (Figure 2). Fish were placed into a live well until the reach was complete at which point they were identified, measured, and released. Reaches were delineated based on how many fish were being caught. When too many fish were being held in the live well, the crew ended the reach.

When the river became too shallow to use the boat, backpack electro‐ fishers were used to continue survey efforts. The backpack electro‐ fishers were adjusted as necessary to accommodate for electrical conductivity to prevent injury to fish while still being effective. During backpack electro‐fishing, crew members carefully walked through the stream with the electro‐ proceeding first and the Figure 1. Electro‐fishing method breakdown. netter/processor following closely behind to capture any stunned fish. All fish captured were placed in a recovery bucket full of water until they could be processed. During the height of summer when water temperatures were highest and dissolved oxygen in the recovery bucket was depleted quickly, especially when large quantities of fish were captured in a reach, the water in the recovery bucket was refreshed frequently to improve survival.

Reach breaks were approximately 100m. Prior to initiation of survey efforts, 102 reaches were pre‐flagged to improve efficiency and accuracy of survey efforts (Figure 1). Flagging started at the Hwy 50 bridge in South Lake Tahoe, CA, (Reach 1. N: 4312470, E: 760912) and ended in the Lake Tahoe Golf Course in the Washoe Meadows State Park (Reach 93. N: 4306438, E: 758605). A 100m tape was dragged along the stream bank to estimate the 100m lengths. During boat electro‐fishing, reach breaks (reach 500 – 507) were farther apart and chosen at random stopping points because 100m reaches were too short for the boat to sample effectively. Reach 508‐516 Figure 2. LTBMU crew member, Ulysses Tapia 6 (right) boat electro‐fishing with CDFG.

(downstream of the Hwy 50 crossing) and 1‐143 (upstream of the Hwy 50 crossing in town past Elks Club Rd and to above the most upstream Hwy 50 crossing in Meyers) were sampled using a backpack electro‐fisher. Reach lengths for 508‐516 and 94‐143 were estimated during the survey due to time constraints. These reach length estimates were determined in the field; as crews worked upstream they stopped at changes in habitat type or at reasonable distance breaks. Sometimes reaches were longer than 100m because few fish were sampled, or the reach was surveyed very quickly, and stopping was not efficient. UTM coordinates were taken at the beginning and end of the reach survey with a Trimble GeoXH handheld GPS unit. Actual reach lengths were calculated in ArcGIS by snapping the UTM coordinates to the USFS NHD flowline and manually measuring them.

Species and size classes (0‐5cm, 5‐10cm, 10‐20cm, 20‐30cm, 30+cm) were counted and recorded at the end of each survey reach. Fish were released downstream into a previously sampled reach. All crayfish were counted when observed or captured, and western pearlshell mussel abundance was estimated when detected. All field data was entered into an Excel spreadsheet and checked for accuracy. In 2011, the data was also entered into the USFS corporate Natural Resource Information System (NRIS) geodatabase in the Aquatic Surveys (AqS).

Crew members were trained to safely and appropriately operate backpack electro‐fishers. Field safety precautions were discussed and all members of the field crew reviewed and signed an electro‐fishing and stream wading Job Hazard Analysis (JHA). All members of the crew were trained in identification of native and non‐native fish species in both adult and juvenile stages.

Results

One hundred and sixty nine reaches were surveyed in the 2011 Fish Assessment. Over 12,500 fish composed of 12 species were sampled during the eight week survey effort. Seven of the 12 species were native, including the Lahontan redside shiner, Paiute sculpin, speckled dace, Tahoe sucker, mountain sucker, mountain whitefish, and Lahontan cutthroat trout. Five species were non‐native including brook trout, brown trout, rainbow trout, bluegill, and brown bullhead. Native species accounted for 76% of fish surveyed while non‐native fish accounted for 24% of fish surveyed (Figure 3). An estimated 330 invasive crayfish and 1,589 native western pearlshell mussels were counted.

Smaller size classes had a greater number of native and non‐native fish compared with larger size classes. No native fish species were identified that were larger than 30 cm (Figure 4, Table 1, and Appendix A). Speckled dace, followed by Paiute sculpin, were the most abundant native fish in 0‐5 cm and 5‐10 cm size classes (Figure 4, Table 1, and Appendix A). Tahoe sucker, followed by mountain sucker, were the most abundant fish in the 10‐20 cm size class, while Tahoe sucker, followed by mountain white fish, were the most abundant fish in the 10‐20 cm

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size class (Figure 4, Table 1, and Appendix A). Brown trout, followed by rainbow trout, were the most abundant non‐native fish in all size classes (Figure 5, Table 1, and Appendix A). The most common non‐native fish to other basin streams, brook trout, only accounted for 0.05% of fish sampled (Figure 3).

Figure 3. Percentage of each species caught of the total fish sampled in the UTR.

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10000 (log)

Fish 1000 of

100 Number

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1 0‐5 cm 5‐10cm 10‐20cm 20‐30cm 30+cm Lahontan redside shiner 1101600 speckled dace 4603 2921 4 0 0 Tahoe sucker 5 3863120 Lahontan cutthroat trout 00020 Paiute sculpin 728 873 12 0 0 mountain sucker 10 58 49 2 0 mountain whitefish 01290 unknown sucker 020170 0 Figure 4. Native fish community composition by size class in the Upper Truckee River (note that the Y axis is log (10)).

1000 (log) 100 Fish

of

Number 10

1 0‐5 cm 5‐10cm 10‐20cm 20‐30cm 30+cm brown bullhead 01620 rainbow trout 421 246 247 47 10 brook trout 02400 brown trout 537 969 338 64 46 bluegill 133100 0

Figure 5. Non‐native fish community composition by size class in the Upper Truckee River (note that the Y axis is log (10)).

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Fish mortality was 1.65% during the survey efforts. This was mostly attributed to the high voltage and frequency level needed to stun fish in such a large volume of water. Though this was not a fish removal project, non‐native warm water fish captured during survey efforts were sacrificed to contribute to warm water fish removal efforts initiated by CDFG in other parts of Lake Tahoe. Within the UTR, 44 bluegill and 9 brown bullheads were intentionally removed. One bullfrog found in the golf course section was also sacrificed.

Table 1. Distribution of size classes for fish sampled in Upper Truckee River, summer 2011.

Species 0-5cm 5-10cm10-20cm 20-30cm 30+cm Total Mortalities

brown bullhead 0 1 6 2 0 9 9

Lahontan redside shiner 1 101 6 0 0 108 5

speckled dace 4603 2921 4 0 0 7528 46

Tahoe sucker 5 38 63 12 0 118 0

rainbow trout 421 246 247 47 10 971 60

brook trout 0 2 4 0 0 6 0

brown trout 537 969 338 64 46 1954 94

Lahontan cutthroat trout 0 0 0 2 0 2 0

Paiute sculpin 728 873 12 0 0 1613 1

mountain sucker 10 58 49 2 0 119 0

mountain whitefish 0 1 2 9 0 12 1

bluegill 1 33 10 0 0 44 44

unknown sucker 0 20 17 0 0 37 0

TOTAL 6306 5263 758 138 56 12521 260

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Discussion The UTR currently has numerous river restoration efforts in various stages of planning and implementation. Given the lack of historic distribution data, it is unknown what the species assemblages looked like prior to the river’s current state in both the physical and biological aquatic components. Although current conditions are providing some fish habitat, it is assumed that following restoration efforts, habitat components needed for a variety of fish species and life stages will improve.

Preliminary results from the Fish Assessment survey in other creeks in the Lake Tahoe basin (2007‐2010) indicate that the greatest species diversity (including both natives and non‐natives) tends to be found in low gradient downstream reaches in proximity to Lake Tahoe. This trend is expected because many of Lake Tahoe’s native non‐game species prefer slow and/or deep waters, and some species only occur in streams temporarily when they leave the Lake Tahoe near shore environment to . Additionally, the source populations of non‐native warm water fish occur in near shore environments of Lake Tahoe, and have not expanded upstream in great numbers at this point. Results from the UTR surveys display similar trends; the lower four restoration sections of the UTR had greater native fish diversity than the two most upstream portions surveyed (Appendix B &C). The UTR habitat begins to change in the upper two sections, with a more constricted valley type, slightly higher gradient, and shallower pools. Distribution and abundance of native species were higher in Meeks, Tallac, Taylor, Trout, and Ward creeks (Appendix E). Similar to the UTR, these streams are relatively large, with slow water meadow/marsh areas, deep pools, and a low gradient creating a good habitat structure for various life stages of native non‐game species.

A full analysis will still have to be done to parse apart true differences in fish assemblages between different watersheds in the Lake Tahoe basin, or between different reaches within a river. Species distributions in the tributaries which feed Lake Tahoe vary significantly by season as different species migrate to spawn or rear. Fish Assessment sampling doesn’t always occur in similar flows and seasonal conditions, and sampling in some creeks did not occur throughout the whole creek. This makes it difficult to make comparisons.

Out of the 26 streams surveyed since 2007, 15 have been dominated by non‐native trout (approximately 61% of total fish surveyed have been non‐native trout). Non‐native trout have occupied nearly every habitat in all tributaries surveyed throughout the Fish Assessment. Paiute sculpin, speckled dace, and Lahontan redside shiner make up 38% of total fish surveyed, while the other native species and introduced warm‐water fish make up the remaining 1%.

The native mountain whitefish and tui chub have been nearly absent in Fish Assessment survey efforts throughout the basin. It is unknown if this is due to declining numbers, the time of year surveys are performed, or the seasonal flow present when surveying occurs. Mountain whitefish are fall spawners, while tui chub spawn in late spring through summer. The population of mountain whitefish is considered fragmented and poorly documented in the Lake Tahoe basin (Moyle 2002). One mountain whitefish was detected in Taylor Creek in 2007 and 11

eight were detected in the UTR in 2011 during Fish Assessment surveys; while the CDFG detected at least 100 individuals near the mouth of the UTR in the lake (pers. com. Mike Maher of CDFG). Tui chub will use lagoon and marsh habitat in Lake Tahoe for spawning and rearing. Tui chub were detected in McKinney (2007) and Griff Creek (2008) during Fish Assessment surveys, but there have been no additional detections since that time. Although this species is not known to utilize fast moving streams, it is unknown why no detections have been documented in the mouths of tributaries other than Griff Creek since it is not a slow water or low gradient stream. Additionally, the tui chub sampled on McKinney Creek was found roughly 1,650 meters upstream.

This is the first time during the Fish Assessment that LCT have been recorded. Approximately 1,000m upstream from the lake (Appendix D), two LCT were captured as part of the survey effort. Both were missing adipose fins and it was determined that they were hatchery fish, most likely stocked by Nevada Department of Wildlife at Cave Rock in the summer of 2011. Both LCT appeared injured, presumably assaulted by another fish (Figure 6).

Figure 6. Injured LCT captured 1000m from Lake Tahoe on the UTR. Note wound near tail.

In 2011, two species were added as presence / absence data collection efforts by visual estimates: western pearlshell mussel and signal crayfish. Presence / absence data and initial visual estimates of abundance of the native western pearlshell mussel will aid in future mussel relocation activities where river restoration occurs. Crayfish are considered an invasive species in the Lake Tahoe basin, and recording presence / absence data could be used to show positive or negative interaction with fishes and the extent of invasion. Visual detection estimates are presumably lower than actual abundance and at this time no formal protocol has been established for abundance estimates.

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Recommendations

Approximately 4 more miles of stream in the UTR needs to be surveyed in order to complete the survey effort in the lower portion of the UTR, where there is a natural 40 foot waterfall /fish barrier in Christmas Valley. Upstream of the waterfall to the headwaters (approximately 14.5 km) LCT recovery efforts are occurring. These efforts involve manual removal of non‐native brook and rainbow trout to open up habitat for the LCT population to expand into from Meiss Meadows.

Further surveys efforts across the Lake Tahoe Basin are necessary to provide a complete dataset of relative abundance and distribution of all fish species in tributaries to Lake Tahoe. Fish Assessment is currently only realistic for the LTBMU if surveys are performed during summer when seasonal employees are working, and during low flow conditions when electro‐ fishing is practical. In order to capture a complete picture of fish assemblages, survey efforts should be considered for all seasons. Additionally, snorkel surveys could be considered in order to assess the deeper pools where electro‐fishing is not achievable. Lastly, to increase effectiveness of sampling in larger rivers, two electro‐fishers are recommended.

Annual training on proper electro‐ is recommended in order to ensure sampling effort is similar between crew members. Additionally, a field guide to Lake Tahoe basin fishes was completed by the LTBMU field crew in 2011, with complete descriptions and photos of species, to help ensure proper identification by all crew members. Included in this guide are pictures of fry and juvenile trout, which are difficult to identify. Additional identification training is recommended for species of suckers due to both the mountain and Tahoe sucker’s similar habitat use and similar morphological characteristics.

Delineating reach breaks before sampling began in early June when the water level was very high did not correlate to consistent reach breaks during electro‐fishing efforts in August. It is recommended to use GPS way points in future survey years to delineate reaches as electro‐ fishing efforts are underway. This will also ensure reach lengths and UTM’s are written on the data sheet for every sample unit. Another option could be to have the crew drag a 100m tape (or use a hip chain) to measure reach lengths as they walk behind the electro‐fisher. However, issues with catching any fish the point netter may have missed could be problematic.

Finally, to improve data collection accuracy the seconds of electro‐fishing should be recorded to document effort, and mortalities should be clearly noted.

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Works Cited

Abrahamsson S.A.A. & Goldman C.R. (1970) Distribution, density, and production of the crayfish Pacifastacus leniusculus Dana in Lake Tahoe, California‐Nevada. Oikos, 21, 83–91.

Bauer, G. 1992. Variation in the life span and size of the freshwater pearl mussel. Journal of Ecology 61:425–436.

Betolli PW, Maceina MJ, Noble RL, Betsill RK. 1992. Piscivory in largemouth bass as a function of aquatic vegetation abundance. North American Journal of 12: 509‐516.

Brandenburg, W.H, and K B. Gido.1999. Predation by Nonnative Fish on Native Fishes in the San Juan River, New Mexico and . The Southwestern Naturalist, Vol. 44, No. 3: 392‐394.

Cordone, A.J., and T.C. Frantz. 1968. An evaluation of trout planting in Lake Tahoe. California Department of Fish and Game 54:68‐69.

Deacon J.E. and W.L. Minckley.1974. Desert fishes. Desert biology. Academic Press, (1974), pp. 385–488.

Decker, L.M. 1989. Coexistence of two species of sucker, Catostomus, in Sagehen Creek, California, and notes on their status in the western Lahontan Basin. Natur. 49:540‐551.

Frantz, T.C., and A.J. Cordone. 1970. Food of Lake Trout in Lake Tahoe. California Fish and Game 56:21‐35.

Flint R.W. & Goldman C.R. (1975) The effects of a benthic grazer on the primary productivity of the littoral zone of Lake Tahoe. Limnology and Oceanography, 20, 935–944.

Flint R.W. (1977) Seasonal activity, migration and distribution of the crayfish, Pacifastacus leniusculus, in Lake Tahoe. American Midland Naturalist, 97, 280–292.

Goldman C.R. & Rundquist J.C. (1977) A comparative ecological study of the California crayfish, Pacifastacus leniusculus (Dana), from two subalpine lakes (Lake Tahoe and Lake Donner). Freshwater Crayfish, 3, 51–80.

Hastie, L. C., M. R. Young, AND P. J. Boon. 2000a. Growth characteristics of freshwater pearl mussels, Margaritifera margaritifera. Freshwater Biology 43:243–256.

Hastie, L. C., M. R. Young, P. J. Boon, P. J. Cosgrove, and B. Henninger. 2000b. Sizes, densities, and age structures of Scottish Margaritifera margaritifera (L.) populations. Aquatic Conservation: Marine and Freshwater Ecosystems 10:229–247.

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Hovingh, P. 2004. Intermountain freshwater mollusks, USA (Margaritifera, Anodonta, Gonidea, Valvata, Ferrissia): geography, conservation, and fish management implications. Monographs of the Western North American Naturalist 2:109‐135.

Howard, J. 2008. Strategic inventory of freshwater mussels in the northern Province. Final Report by Western Mollusk Sciences, , CA to PSW Regional Office, Vallejo, CA. 65 pp.

Howard, J. 2010. Sensitive freshwater mussel surveys in the Pacific Southwest Region: Assessment of Conservation Status. Final Report by Western Mollusk Sciences, San Francisco, CA to U.S. Forest Service, PSW Regional Office, Vallejo, CA. 60 pp

Kamerath, M., S. Chandra and B.C. Allen. 2008. Distribution and impacts of warm water invasive fish in Lake Tahoe, USA. Aquatic Invasions 3(1):35‐41.

Knapp, R.A., K.R. Matthews, O. Sarnelle. 2001. Resistance and resilience of alpine lake fauna to fish introductions. Ecological Monographs. 71:401‐421.

MacRae, P.SD. and D.A. Jackson. 2001. The influence of smallmouth bass (Micropterus dolomieu) predation and habitat complexity on the structure of littoral zone fish assemblages. Canadian Journal of Fisheries and Aquatic Sciences, 2001, 58 :(2) 342‐351.

Miller, R.G. 1951. The natural History of Lake Tahoe Fisheries. Master’s thesis, Stanford University, California.

Moyle, P. B. 2002. Inland fishes of California, revised and expanded. University of California Press, Berkeley, California, USA.

Moyle, P. B., R.M. Yoshiyama,J. E. Williams, and E.D. Wikramanayake. 1995. Fish species of special concern of California. 2nd edition. California Department of Fish and Game, Sacramento, California.

Moyle PB, Nickols RD. 1973. Ecology of some native and introduced fishes of the Sierra Nevada foothills in . Copeia 3: 478‐490.

Moyle, P.B., and B. Vondracek. 1985. Persistence and Structure of the Fish Assemblage in a Small California Stream. Ecology, Vol. 66, No. 1: 1‐13.

Moyle, P. B. and J.E. Williams. 1990. Biodiversity Loss in the Temperate Zone: Decline of the Native Fish . Conservation Biology, 4: 275–284.

Murphy, D. D. and C. M. Knopp. 2000. Lake Tahoe Watershed Assessment: Volume 1. Pacific Southwest Research Station, USDA Forest Service. Albany, CA.

Murphy G. 1942. Relationship of the freshwater mussel to trout in the Truckee River. California Fish Game 28:89–102.

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Olson, M.D. 1988. Upstream changes in native fish abundance after reservoir impoundment in California streams of the Lahontan Basin. Unpubl. M.S. Thesis, University of California, Berkeley. 34 pp.

Olson, M.D. and D.C. Erman. 1987. Distribution and abundance of mountain sucker, Catostomus platyrhynchus,in five California streams of the Western Lahontan Basin. Calif. Dept. Fish and Game Rep. Contract C‐2057.

Riegel J.A. (1959) The systematics and distribution of the crayfishes in California. California Fish and Game, 45, 29–50.

Schindler, D.W. 2000. Aquatic problems caused by human activities in Banff National Park. Ambio 29: 401‐407.

Shepard, B.B., B. Sanborn, L. Ulmer, and D.C. Lee. 1997. Status and risk of extinction for westslope cutthroat trout in the upper basin. North American Journal of Fisheries Management 17: 1158‐1172.

SNEP [Sierra Nevada Ecosystem Project] 1996. Status of the Sierra Nevada. Sierra Nevada Ecosystem Project, final reports to Congress, Vols I–III and Addendum. Sierra Nevada Ecosystem Project. http://ceres.ca.gov/snep/pubs/; accessed on 16 May 2004.

Strayer, D.L., J.A. Downing, W.R. Haag, T.L. King, J.B. Layzer, T.J. Newton, and S.J. Nichols. 2004. Changing perspectives on pearly mussels, North America’s most imperiled . BioScience 54: 429‐439.

Tahoe Regional Planning Agency (TRPA). 1971. Fisheries of Lake Tahoe and Its Tributary Waters: A Guide for Planning. Tahoe Regional Planning Agency and USDA Forest Service. South Lake Tahoe, California.

Vander Zanden, J., S. Chandra, B.C. Allen, J.E. Reuter, and C.R. Goldman. 2003. Historical Food Web Structure and Restoration of Native Aquatic Communities in the Lake Tahoe (California‐Nevada) Basin. Ecosystems 6: 274‐288.

Vannote, R.L., and G.W. Minshall. 1982. Fluvial processes and local lithology controlling abundance, structure, and composition of mussel beds. Proceedings of the National Academy of Sciences 79:4103‐4107.

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Appendix

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Appendix A. Species and size class distribution by restoration area.

Rainbow Trout 250

200

150 fish

of

# 100

50

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley 0‐5 16076119226 5‐10cm 371850184 10‐20cm 37 10 6 24 52 122 20‐30cm 19 2 0 5 5 18 30plus 900001

Brown Trout 400

350

300

250 fish 200 of

# 150

100

50

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley 0‐5 6 45 78 303 77 29 5‐10cm 49 180 33 351 204 154 10‐20cm 57 39 48 83 43 69 20‐30cm 10 2 3 16 10 24 30plus 27 2 0 5 4 11

18

Tahoe Sucker

30

25

20 fish 15 of

# 10

5

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley 0‐5 010400 5‐10cm 8118821 10‐20cm 24 10 14 11 3 1 20‐30cm 901200 30plus 000000

Mountain Sucker 25

20

15 fish of

# 10

5

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley 0‐5 800100 5‐10cm 221491300 10‐20cm 16 5 9 19 0 0 20‐30cm 100100 30plus 000000

19

Brook Trout

5

4

3 fish

of

# 2

1

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley

0‐5 000000 5‐10cm 000020 10‐20cm 000004 20‐30cm 000000 30plus 000000

Mountain Whitefish 6

5

4 fish 3 of

# 2

1

0 Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley 0‐5 000000 5‐10cm 001000 10‐20cm 200000 20‐30cm 500000 30plus 000000

20

Appendix B. Species relative distribution and abundance by restoration reaches* from 2011 Fish Assessment.

Species Marsh UTR 1 & 2 Airport Sunset Golf Course Xmas Valley

bluegill 8 9 25 3 ‐ ‐

brook trout ‐ ‐ ‐ ‐ 2 4

brown bullhead ‐ ‐ 1 3 3 2

brown trout 149 268 162 758 338 287

crayfish 4 73 ‐ 135 63 55

Lahontan cutthroat trout 2 ‐ ‐ ‐ ‐ ‐

Lahontan redside shiner 43 25 21 20 ‐ ‐

mountain sucker 47 19 18 34 ‐ ‐

mountain whitefish 7 ‐ 1 ‐ ‐ ‐

Paiute sculpin 2 20 30 109 429 1023

rainbow trout 69 25 7 113 226 551

speckled dace 2732 1586 1259 1647 324 7

Tahoe sucker 41 12 33 25 5 2

unknown sucker ‐ ‐ 36 1 ‐ ‐

Western Pearlshell Mussel ‐ 133 ** 1340 86 ‐

# of species 11 10 12 12 9 8

Native species 7 6 8 7 4 3

Non‐native species 4 4 4 5 5 5 *Species distribution numbers in this table were calculated based on river reaches. River reaches do not necessarily start or end at land ownership boundaries, but are instead approximate to land ownership delineations.

** Western Pearlshell mussels were identified in the Airport Reach in 2011 by the consultants implementing the restoration project in this reach.

21

Appendix C. Map of 2011 Fish Assessment survey area by land ownership.

22

Appendix D. Species Distribution Maps

Distribution of Western Pearlshell Mussel

23

Distribution of the signal crayfish

24

Distribution of invasive bluegill and brown bullhead

25

Distribution of non‐native salmonids

26

Distribution of Tahoe and Mountain Suckers

27

Distribution of speckled dace and Lahontan redside shiner

28

Distribution of Lahontan cutthroat trout and mountain whitefish

29

Distribution of Paiute sculpin

30

Appendix E. Distribution of fishes in Lake Tahoe basin streams that were surveyed between 2007‐2011.

Creek/River/ Lahontan Lahontan Lahontan brook brown brown mountain mountain Paiute rainbow speckled Tahoe bluegill goldfish cutthroat redside Lake tui trout bullhead trout sucker whitefish sculpin trout dace sucker Stream trout shiner chub

Angora X X X X X

Blackwood X X X X

Burton X

Cascade X X X X

Cold X X X X X

Eagle X X X X X X X

General X X X X X X X

Glen Alpine X X X X X X

Griff X X X X X

Homewood X

Incline Lake area X X X

Incline Creek X X X X

Madden X X X

McKinney X X X X X X X X

Meeks X X X X X X

Quail X X X X

Rubicon X

31

Saxon X X X X

Tallac X X X X X X X

Taylor X X X X X X X X X X X

Third X

Trout X X X X X X X X X

Upper Truckee X X X X X X X X X X X X

Ward X X X X X

Watson X

32