p s f F2srtot tr 1992 S-' 3r:''- miE DOCUMENTS COLLECT/GfJ CEC u 1992 MONTANA STATE LIBRARY Lirr, ni?15 E. Sth AVE. WELENA, MONTANA 59620 STATUS REPORT: BULL TROUT IN MONTANA AUGUST, 1992 y^-'- ^=^4 'i'^J i^ ■ g i, ■.; ;■•• *. . '1 ;- Prepared by: Ginger Thomas, Consultant 502 Livingston Avenue Mi^ula, MT 59801 Prepared ton Montana Department of Fish, Wildlife and Parks 1420 E. 6th Ave Helena, MT 59620 J«^ t 3 t993 ■??'■ ff ^:m. AUG a FEB 4 2002 ACKNOWLEDGEMENTS I would like to thank the many people who generously donated their time, effort, and knowledge to this project. Thanks to Tom Weaver, Janet Decker-Hess, Scott Rumsey, Don Peters, Rod Berg, Eric Priest, Ron Pierce, Doug Perkinson, L^e Brundm, Len Walch, Wayne Hadley, Chris Clancy, Dale Hoth, Dick Kramer, Kate Walker, Robbin Wagner, Robb Leary, Kathy Knudsen, Kevin Sage, Rick Stowell, Brad Shepard, Leo Marnell, Brian Marotz, Mike Enk, Laney Hanzel, Jim Vashro, Joe DosSantos and Denise Vore. Special thanks to Chris Hunter for making this project happen. TABLE OF CONTENTS Introduction Life history of bull trout * • ■ } Life history patterns ^ Reproduction ^ Spawning site preferences • Spawning behavior ^ Fecundity ^ Egg deposition to emergence ^ Sources of mortality ^ Juvenile behavior and habitat needs • ^ Habitat preferences ^ Food habits Migration ^ Sources of mortality ■ • • ^ Adult behavior and habitat needs ^ Habitat preferences in rivers ^ Habitat preferences in lakes ^ Migration ^ Age and growth ^ Food habits Parasites Sensitivity to environmental disturbance ^ Genetic factors ^ Environmental and life history characteristics 1" Introductions of non-native species 1^ Intentional and unintentional eradication . 12 Status of bull trout in Montana - overview of the state 13 Historic distribution 1^ Current distribution 1^ Methods • 1^ Distribution of bull trout in Montana 28 Status of bull trout in Montana - by hydrologic unit 31 Hydrologic unit # 17010101 - The Kootenai River (not including the Yaak drainage or the Fisher River) 31 Historic distribution 31 Current distribution 31 Hydrologic unit # 17010102 - the Fisher River 33 Historic distribution 33 n 33 Current distribution Hydrologic unit # 17010103 - the Yaak River ^^ Historic distribution . Current distribution ," v ' u Hydrologic unit # 17010104 - Kootenai River from Idaho to the Yaak River ^^ Historic distribution • Current distribution • • •. Hydrologic unit # 17010201 - the Clark Fork River from Warm Spnngs Creek to the Blackfoot River, not including Rock Creek and Flmt Creek - . Historic distribution Current distribution • Hydrologic unit # 17010202 - Rock Creek and Hint Creek dramages 34 Historic distribution Current distribution Hydrologic unit # 17010203 - the Blackfoot River dramage ^^ Historic distribution Current distribution ' ' ' * V." u * J Hydrologic unit # 17010204 - the Clark Fork River from the Flathead River to the Blackfoot River ^' Historic distribution Current distribution Hydrologic unit # 17010205 - the Bitterroot River drainage ^» Historic distribution Current distribution The Upper Flathead River system above Kerr Dam ^^ Status of bull trout in Glacier National Park ^^J Bull trout management on the Flathead National Forest 41 Hydrologic unit # 17010206 - the North Fork of the Flathead River 42 Historic distribution Current distribution '''' '^ ^.' " ' An Hydrologic unit # 17010207 - the Middle Fork of the Flathead River 43 Historic distribution Current distribution r^' J ' a' " ' Hydrologic unit # 17010208 - Flathead Lake and the mainstem Flathead ^^ River above Flathead Lake Historic distribution Current distribution ". * ' ' "t^ .' ao Hydrologic unit # 17010209 - the South Fork of the Flathead River 49 Historic distribution Current distribution Hydrologic unit # 170101210 - the Stillwater River drainage ^^ Historic distribution ni Current distribution ^^ Hydrologic unit # 17010211 - the Swan River drainage 51 Historic distribution 51 Current distribution 51 Hydrologic unit # 17010212 - the Flathead River below Flathead Lake ..... 54 Historic distribution 54 Current distribution 55 Hydrologic unit # 17010213 - the Clark Fork River below the Flathead River ^^ Historic distribution 55 Current distribution 56 Hydrologic unit #10010002 - St Mary's River drainage 56 Historic distribution 56 Current distribution ^ ' en Summary and conclusions -^ ' Literature Cited ^^ Appendix A ^ IV T JST OF TABLES Table 1. Relative abundance of bull trout, by hydrologic unit. Numbers refer to the number of reaches Table 2. # Stream Reaches With Use Codes: 19 Table 3. # Reaches With Genetic Codes: 21 Table 4. # Reaches With Habitat Codes: 23 Table 5. Criteria For The Risk Of Extinction 25 Table 6. Risk Of Extinction, By Hydrologic Unit 26 Table 7. Number of reaches and number of miles of stream containing bull trout 29 in Montana Table 8. Summary of the North Fork of the Flathead River bull trout spawning site inventories from 1979-1991 in the stream sections monitored annually. . . 44 Table 9. Summary of the number of bull trout redds observed in the U.S. portion of the North Fork of the Flathead drainage during basin-wide survey years. . 45 Table 10. Summary of Middle Fork of the Flathead River bull trout spawning site inventories from 1979-1991 in the stream sections monitored annually 47 Table 11 - Results of basinwide bull trout redd counts conducted in the Middle Fork of the Flathead River ^^ Table 12. Summary of Swan drainage bull trout spawning site inventories from 1982-1991 in the stream sections monitored annually (Rumsey 1991) • • 53 Table 13. Bull trout redd counts from Swan drainage randomly monitored streams (Rumsey 1991) Introduction In October, 1991, the Montana Department of Fish, Wildlife, and Parks contracted with Ginger Thomas, a fisheries consultant, to prepare a status report on bull trout r Salvelinus confluentus Suckley) within the state of Montana. The purpose of this report is to summarize the life history and habitat requirements of bull trout. In addition, Montana bull trout populations are identified and characterized as to life history, status, habitat needs, and limiting factors. The report also includes a discussion of historic vs current occurrence and the genetics of bull trout. Increasing concern about the status of bull trout was the impetus for this report. Bull trout are listed as a species of special concern by the Montana Department of Fish, Wildlife, and Parks and the American Fisheries Society and as a "sensitive species" by the U.S. Forest Service. They are also listed as a Category 2 species by the U.S. Fish and Wildlife Service. This indicates that a proposal to list the species as threatened or endangered may be appropriate, but that evidence is inconclusive. The Oregon Chapter of the American Fisheries Society recently voted to petition the U.S. Fish and Wildlife Service for a status review of the bull trout in the state of Oregon under the provisions of the Endangered Species Act. Life history of bull trout Life history patterns The bull trout in Montana is identified as having three life history patterns - resident, fluvial, and adfluvial. (Anadromous bull trout have been reported in coastal streams, but none are found in Montana). Resident bull trout spend their entire lives m the same (or nearby) streams in which they were hatched. Resident bull trout adults and juveniles generally confine their migrations to their natal streams. In fluvial and adfluvial populations, the aduhs spawn in tributary streams where the young rear for one to four years (Fraley and Shepard 1989). The juvenile bull trout then migrate to either a lake (adfluvial fish) or a river (fluvial fish), where they grow to maturity. Resident bull trout populations may be isolated from others by some physical barrier. Members of resident stocks tend to mature at an early age, are smaller in size than migratory populations, and have low fecundity (Willamette National Forest 1989). Most of the published information on bull trout has been gathered on migratory populations. Details of the life history of resident bull trout are largely unreported. The following life history description refers to adfluvial and fluvial bull trout unless otherwise stated. Reproduction Bull trout spawning generally takes place during September and October. Initiation of spawning is correlated with declining water temperatures. The threshold temperature appears to be 9°C. When the daily maximum temperature drops below this level spawning begins (Fraley and Shepard 1989, McPhail and Murray 1979). Spawnmg takes place primarily at night (Heimer 1965, Weaver and White 1985) although m the upper Flathead system, spawning has been observed in the daylight hours later m the spawning run (Weaver pers. comm. 1992). Not all adult bull trout spawn annually. Fraley and Shepard (1989) reported that approximately 57% of the aduh bull trout population left Flathead Lake each spring and summer to spawn. However, repeat spawning has also been documented for bull trout. In the upper Flathead system, Montana, bull trout have been observed spawning every year, every other year, and every third year (Weaver pers. comm. 1992). Spawning site preferences Bull trout spawners select areas in the stream channel characterized by loose gravel substrates and low gradient. Groundwater inflow and proximity to cover are also significant factors influencing spawning site selection (Fraley and Shepard 1989). Runs or tails of pools with water 0.2 - 0.8 m deep may be used for spawning. Water velocities associated with redds are 0.2 - 0.6 m/s. Eggs are buried 100 - 200 mm in the gravel (Pratt 1992). Bull trout spawners tend to use larger, higher order (3rd - 5th order) tributaries. These specific requirements tend to limit the available spawning area for bull trout In the upper Flathead system, only 28% of the 750 km of available salmonid spawning habitat is used for bull trout spawning (Fraley and Shepard 1989). In the Swan River drainage over 75% of the bull trout spawning takes place in 8.5% of the available habitat (Leathe and Enk 1985, Rumsey 1991). Again, this information was collected on fluvial and adfluvial populations. Resident bull trout may have different spawning site preferences. Spawning behavior Female bull trout choose the spawning site and construct the redd, while the male defends the area. The female digs the redd with an up and down tail action, moving m an upstream direction (Scott and Grossman 1973). Redd super-imposition has been noted in several areas (Heimer 1965, Ratliff 1987). After spawning, the spent adults of migratory populations move out of the tributaries downstream to either a large nver or lake (Fraley and Shepard 1989). Precocious males, "jacks", have been recorded in several localities. In the Upper Arrow Lakes, British Golumbia, "jack" bull trout entered tributary streams while still green and left without spawning (McPhail and Murray 1979). Shepard and Graham (1983) noted precocious males actively spawning with larger females and eating eggs. Fecundity Fecundity of females varies with fish size. Fraley and Shepard (1989) reported an average of 5,482 eggs per female in the Flathead drainage of Montana, with one 6.8 kg bull trout containing over 12,000 eggs. Bull trout in Arrow Lakes, British Columbia were smaller with an average of less than 2,000 eggs per female (McPhail and Murray 1979). Egg deposition to emergence Incubation time and survival to emergence are partially dependent on temperature. McPhail and Murray (1979) reported the best survival of bull trout embryos at temperatures of 2 - 4°C. They found the lowest survival rates at temperatures of 8 to 10°C (0 to 20% survival). Weaver and White (1984) also observed increased incubation mortality above 8°C in laboratory tests. Survival to emergence was higher in 4 - 6°C water. Bull trout require 350-440 temperature units (°C) to hatch (Weaver and White 1984, Gould 1987). In general, bull trout eggs hatch within 100 - 145 days after deposition, usually by the end of January. Fraley and Shepard (1989) reported that bull trout fry emerged from the gravel 635 temperature units (223 days) after deposition. The alevins remain in the gravel and absorb the yolk sac, with the first fry appearing in mid-April. Weaver (pers. comm. 1992) reports that in three years of study, bull trout time to emergence has ranged from 219 - 225 days, with first emergence occurring in late April - early May. In the upper Flathead system, Montana, when bull trout emerge from the gravel they range in size from 23 - 28 mm, and more than double their length in their first summer of growth (Fraley and Shepard 1989). Bull trout are found to feed while still in the gravel (McPhail and Murray 1979). Sources of mortality The amount of fine materials in the substrate and extreme streamflows are common causes of mortality to bull trout eggs and alevins . Weaver and Fraley (1991) found a significant inverse relationship between the percent of the substrate < 6.35 mm in diameter and emergence success. Approximately 33% survival to emergence can be expected in situations where 35% of the substrate is < 6.35 mm. The authors concluded that any increases in fine materials in spawning areas could significantly reduce the emergence success of bull trout fry. Extreme high flows can scour out gravels and cause egg mortality. Conversely, high flows may liberate fry that would otherwise be entombed by fines (Weaver pers. comm. 1992). Low flows can expose redds and result in freezing (Weaver and White 1985). Juvenile behavior and habitat needs Habitat preferences The distribution of juvenile bull trout is influenced by temperature. They are rarely found in streams with maximum summer water temperatures exceeding 15°C (Fraley and Shepard 1989). In the Pend Oreille basin, bull trout were found in highest density in streams with cold spring influences and a closed forest canopy, resulting in cooler temperatures (Pratt 1985). Juvenile bull trout have been observed in cold tributaries where no spawning has ever been documented. It has been speculated that they may migrate to these streams during high spring flows (Weaver pars. comm. 1992). Fraley and Shepard (1989) found young-of-the-year bull trout were generally in side channel areas and along the stream margins. McPhail and Murray (1979) found young-of-the-year bull trout in areas of low velocity near stream edges. Pratt (1984, 1985) studied microhabitat preferences of bull trout in the Flathead drainage, Montana, and found that juvenile bull trout (<100 mm) usually remained near the stream bottom, close to streambed materials and submerged debris. They tend to seek out small pockets of slow water velocity (0.1 mps). Juveniles larger than 100 mm also remained near cover, including larger instream debris. As the juvenile bull trout grew, they became less associated with the streambed. The cover used by juveniles was submerged, particularly unembedded substrate and woody debris. Juvenile bull trout densities decline when the spaces between the substrate fill with fine materials (Enk 1985). Weaver and Fraley (1991) found a significant positive relationship between the substrate score (Crouse et al 1981) and juvenile bull trout density. The substrate score is an index of streambed particle size and embeddedness. Food habits During stream residence, juvenile bull trout are opportunistic feeders ingesting aquatic invertebrates in similar percentages as they are available in the stream. Bull trout larger than 110 mm in the Flathead system also eat small fish (Fraley and Shepard 1989). Fish identified in juvenile bull trout stomachs include sculpins (Cottus sp,), salmon fry, and other bull trout (Pratt 1992). In Lake Pend Oreille, bull trout 100 - 300 mm ate insects and bull trout over 300 mm ate fish (Jeppson and Platts 1959). Migration Juveniles in most river systems have been reported to migrate at two to three years of age, ahhough in the upper Flathead system 18% of the migrants were age I (McPhail and Murray 1979, Fraley and Shepard 1989). The timing of emigration vanes by age, size, and habitat availability (Willamette National Forest 1989). In the Flathead River system, emigration of juveniles from the tributaries takes place largely from June to August. The peak outmigration was in June in the Middle Fork tributaries, and July m the North Fork tributaries (Fraley and Shepard 1989). Oliver (1979) reported that juvenile bull trout migrated continuously throughout the summer and fall m the Wigwam drainage. The young bull trout appear to move quickly along the margins of the larger rivers (Willamette National Forest 1989, Fraley and Shepard 1989). Sources of mortality Outmigrating juveniles are sometimes harvested by anglers when they are large enough (200 - 250 mm). Juveniles are also vulnerable to predation, particularly dunng migration. In the upper Flathead River system of Montana, outmigrating juveniles may be preyed upon by adult bull trout, lake trout, northern squawfish ( Ptychocheilus oregonensis), and some northern pike (Esoxjudus) (Vashro pers. comm. 1992). Adult behavior and habitat needs Habitat preferences in rivers The adult bull trout, like its young, is a bottom dweller, showing preference for deep pools of cold water rivers, lakes, and reservoirs (Moyle 1976). In Oregon's upper Klamath River, summer habitat for stream resident adults included water temperatures from 9 to 15°C, gradients of 10 to 20%, moderate to fast currents, and stream widths of two to five meters (Bond and Long 1979). Another resident population, found m Crater Lake National Park, occupied a stream with summer temperatures of 5C, velocities of 0.6 to 1.8 meters per second, a stream width of three meters, and a gravel-rubble substrate. It was fed by groundwater seeps (Wallis 1948). Habitat preferences in lakes Bull trout in Flathead Lake are distributed throughout all areas of the lake in all seasons. They have been found at depths of 79 m., although it is almost certain that they exist in the deepest areas of the lake (Hanzel 1985). In the summer in Flathead Lake bull trout remain below the thermocline. In the spring when the lake is isothermal, bull trout will use shallow waters (generally less than 30 m., more likely less than 16 m.) and feed on yellow perch (Shepard pers. comm. 1992, Vashro pers. comm. 1992). However, bull trout in Flathead Lake appear to move in response to temperature, and will eat what prey is available (Hanzel 1985). In Priest Lake bull trout occupy the lower thermocline in the summer, using depths from 12 to 18 meters and temperatures from 7.2 to 12.8°C. In the spring and fall, these fish moved to near surface waters when temperatures were below 12.8°C (Bjomn 1961). Shepard (1985) listed the thermal preference of bull trout (8 - 14°C) as a major influence on their vertical distribution in Libby Reservoir, Montana. Migration Adfluvial adult bull trout generally mature for two to three years in lakes and reservoirs before undertaking spawning migrations (Willamette National Forest 1989). The general migratory pattern in the Flathead system is as follows: bull trout maturing in Flathead Lake begin their spawning migration into the river system as early as April, with the peak migration occurring during the high flows of May and June. They move slowly upstream, arriving in the North and Middle Forks of the Flathead River during late June and early July. Spawning migrations in the Flathead range from 88 - 250 km in length (Fraley and Shepard 1989). Adult bull trout remained at the mouths of the tributaries for two to four weeks before entering the tributary streams at night from July through September. It appears that bull trout in the Flathead form pairs while staging at the mouths of the tributaries. Bull trout are generally not in final spawning condition when they enter the tributaries. They hold in the tributaries for up to a month or more in deeper holes or in debris cover before spawning (Fraley and Shepard 1989). Downstream movement after spawning is very fast (Willamette National Forest 1989). Females generally leave the tributaries prior to the males in the Flathead system (Fraley and Shepard 1989). Several authors have recorded two spawning runs. The earlier run was made up of the smallest and youngest individuals. These fish tended to remain in the tributaries for longer periods than the older, second run adults (Oliver 1979, McPhail and Murray 1979). Some incidental tagging information suggests that bull trout spawning migrations may be more complex and variable than is indicated above. For example, a spawning bull trout tagged in the North Fork of the Flathead moved downstream then upstream into the Middle Fork, through a large lake, and was recaptured in a tributary of McDonald Lake (Pratt 1992). Leathe and Enk (1985) tagged one spawning bull trout in Goat Creek, a tributary of the Swan River, which moved downstream through Swan Lake and over Bigfork Dam into Flathead Lake and then was recaptured 9 months later 55 km up the Flathead River. The total length of this movement was 119 km. Another complex migration was noted in the Blackfoot River system. A 400 mm bull trout was tagged in a spring creek system on August 8, 1990. This fish moved downstream 0.8 km to the North Fork of the Blackfoot, then downstream 9.6 km to the Blackfoot, then 31.2 km downstream to the Clearwater River. It was recaptured 9.6 km up the Qearwater River on June 16, 1991, for a total migration of 51.3 km. Age and growth The annual growth increment for bull trout in Flathead I^ke ranged from 60 - 132 mm. Growth of fish residing in lakes was relatively constant after age IV. Growth rates of bull trout in Flathead Lake were similar to those reponted for Priest and Upper Priest Lakes, Idaho (Bjomn 1961), Hungry Horse Reservoir, and Lake Koocanusa (Huston 1974, May et al 1979). The average length at age for bull trout in the Flathead system ranged from 52 - 75 mm for age I, 98 - 129 mm for age II, 139 - 204 mm for age III, 228 - 360 mm for age IV, 384 - 440 mm for age V, 472 - 538 mm for age VI, 566 - 574 mm for age VII, 655 - 658 mm for age VIII, and 731 mm for age IX, depending on the water body (Fraley and Shepard 1989). Bull trout growth rate was slower in the Middle Fork tributaries than in the North Fork tributaries, despite higher productivities and warmer water temperatures (Shepard et al 1984). Juvenile bull trout in the Swan River drainage grew relatively slowly in tributary streams, but growth accelerated rapidly after these fish emigrated from tributary streams, primarily as one and two year old fish. Fish longer than 700 mm total length are not uncommon in Swan River spawning runs. The growth and condition of Swan Lake bull trout was better than that reported for nearby Flathead Lake by Leathe and Graham (1982). Growth of repeat spawners in Goat Creek, (tributary to the Swan River) was nearly 50 mm during the period between spawning (Leathe and Enk 1985). In general, the maximum period of growth appears to occur between the third and fourth years of age. Most individuals by this time have reached a sufficient size to switch to a piscivorous diet. Adfluvial populations average a 90 mm increase per year (Willamette National Forest 1989). The maximum size published for an adfluvial bull trout is 1025 mm and 14.5 kg, for a fish taken from Pend Oreille Lake (Willamette National Forest 1989). Food habits The food habits of juvenile bull trout were discussed eariier. Adult bull trout are generally opportunistic piscivores. In Flathead Lake, whitefish species and yellow perch r Perca flavescensl were the most important food items, followed by kokanee r Oncorhvnchus nerka') and non-game fish. Small bull trout also feed incidentally on Mvsis (Fraley and Shepard 1989). Kokanee was the major food item for bull trout in Pend Oreille Lake, Idaho (Jeppson and Platts 1959), while whitefish were the major food in Upper Priest Lake, Idaho (Bjornn 1961). In Hungry Horse Reservoir, approximately 32% of the stomachs examined were empty. Over 99% of the biomass of the stomach contents was fish. Juveniles ate primarily northern squawfish and mountain whitefish (Prosopium williamsoni) while adults ate suckers, northern squawfish, and mountain whitefish. Cutthroat trout were found in stomachs as well in varying amounts. Overall, the juveniles and the adults had similar food habits, except the adults consistently ate more suckers than the juveniles (May et al 1988). Bull trout in Lake Koocanusa ingested at least 10 different species of fish. Over 99% of the biomass consumed by bull trout was fish. Collectively, salmonids were the most important species consumed. Kokanee appeared to be the species of most importance to bull trout, followed by Oncorhvnchus trout species, largescale suckers r Catostomus macrocheilus l and peamouths rMylncheilus caumiusV The only species not taken by bull trout were burbot (Lotajota) and bull trout (Chisholm et al 1989). Cavender (1978) reported that sculpins predominated in the bull trout stomachs he examined, but salmonids were found as well. Some bull trout had eaten gastropods, and one 380 mm bull trout had swallowed a 215 mm individual of its own species. Two bull trout from northern British Columbia had eaten small mammals. They are also reported to feed on other vertebrates of suitable size such as frogs, snakes, mice, and ducklings. Several unique populations of bull trout with unusual food habits have been reported There are three lakes in Glacier National Park which support non-piscivorous populations of bull trout. In Upper Kintla Lake, bull trout are the only fish species. In Upper and Lower Isabel Lakes, bull trout and cutthroat trout seem to have developed a rather peculiar association, with the cutthroat trout being larger and more robust than the bull trout. The bull trout are not piscivorous (Marnell 1985). Resident bull trout populations in Bitterroot National Forest streams are also often smaller than the cutthroat trout in the same streams (Clancy pers. comm. 1992) Parasites In Oregon, Shaw (1947, cited in Willamette National Forest 1989) reported bull trout infected with the cestode Ahnthrium crassum . the nematode Dachnitis truttae , and the trematodes Crepidostum cooperi and Aponunus sp. Wallis (1948) found roundworms, nematodes, and tapeworms in fish from a stream resident population. Patches of Saproleenia covered some individuals. Hanzel (1985) listed the tapeworm Dibothriocephalus latum and the external copepod Salmicola edwardsonii from Flathead Lake. Hanzel (1985) cited Elrod (1926) as stating that out of 121 bull trout stomachs examined from Flathead Lake, all but three had tapeworms in the stomach and intestines. The cestode Fubothrium salvelini, the acanthocephalan Neoechinorhynchus rutili. and the trematode Crepidostomum farionis were found in bull trout from British Columbia (Bangham and Adams 1954). At the Kootenai Hatchery in British Columbia, 8 Brown (1985) noted eggs and fry were infected with mxyobacteria, flexibacteria (similar to cold water disease), and gill disease. The bacterial gill disease Costia was reported at the Wallowa Hatchery in Oregon (Oregon State Game Commission 1968). Sensitivity to environ ineiital dis turbance Genetic JEactors Relatively few studies have been done to date on the genetics of bull trout. In fact, it has only been since 1980 that bull trout have been officially recognized as a separate species, distinct from its relative the Dolly Varden (Salvelinus malma) (Cavender 1978, Robins et al 1980). Leary (1985) reported electrophoretic data indicate the bull trout, arctic char r Salvelinus alpinus \ brook trout ( S. fontinalisi and lake trout (S. namaycush) are all genetically very distinct. The bull trout and arctic char are the Iwo most similar taxa. In order to develop a sound conservation plan for bull trout, the population genetic structure of the population needs to be understood. Leary et al (1991) found that the population genetic structure of bull trout in the Columbia and Klamath River drainages is typical of salmonid fishes inhabiting interior waters. There is relatively little genetic variation within populations, but substantial genetic differences among populations. Preservation of the genetic variation of the bull trout will require continued existence of many populations throughout the area. Leary et al (1991) found that bull trout from the Klamath and Columbia drainages are reproductively isolated and are evolutionarily distinct. These two groups of bull trout would qualify as separate "species" under the United States Endangered Species Act according to criteria established for anadromous salmonid fishes. One of the difficult problems biologists are facing with regard to the conservation of bull trout is the widespread distribution of the non-native brook trout throughout the bull trout range. Hybridization between brook trout and bull trout has been reported m Montana (Leary et al 1983), Alberta (Scott and Grossman 1973), and Oregon (Markle 1992). The hybrids are almost completely sterile (Leary et al 1991). The frequent production of sterile interspecific hybrids is an unstable situation that should lead to the loss of one of the two parental types. Life history differences between bull and brook trout tend to favor the brook trout in this situation (Leary et al 1991). Brook trout become sexually mature at age two or 3, are relatively short-lived, and tend to "overpopulate" small streams. In contrast, bull trout do not reach sexual matunty until 3-6 years, and are long lived (Scott and Grossman 1973). Leary et al (1991) present data from Montana which tends to confirm this hypothesis. Bull trout have been largely replaced by brook trout in a stream where hybridization was first detected in the early 1980's. They expect this trend to continue until bull trout are extirpated from the stream or brook trout meet an upstream dispersal barrier. On the Bitterroot Forest, bull trout are not usually found together with brook trout in large numbers, it is either one or the other in large dominance with a few of the minority species present (Clancy pers. comm. 1992). Given the wide distribution of brook trout throughout the range of bull trout and the increasing frequency with which hybrids are being reported, this is a dangerous situation for bull trout. Bull trout populations which are exposed to brook trout are at an increased risk of extinction. Several interesting questions about bull trout genetics remain. Is there a genetic difference between populations that spawn in differem streams, but utilize the same habitat as adults? For example, are the bull trout that reside in Flathead Lake members of one population, or two (Middle Fork and North Fork) or 26 (the number of spawning tributaries)? Leary (pers. comm. 1992) feels that if bull trout are similar to other interior salmonids then each spawning tributary is probably a separate population. If so, this could complicate the management of the Flathead Lake fishery. Another unanswered question is: are there genetic differences between the adfluvial, fluvial, and resident forms? Or is the life history mode determined by a combination of the growth rate of the individual fish and environmemal factors? We have a large number of small resident bull trout populations in Montana which are isolated from the larger rivers and lakes. Frequently, the isolation is the result of environmental disturbance and habitat degradation. If these habitats could be restored, and the connections made between the isolated, resident populations and the bigger bodies of water, could we restore some migratory bull trout runs? Clearly there are some important questions remaining concerning bull trout population genetics. Environmental and life history characteristics Bull trout share several features of their life history with other far- northern species such as lake trout, Arctic char (Salvelinus alpinus), grayling ( Thymallus arcticus ) whitefish ( Prosopium sp.\ and ciscoes (Coregonus sp.). These features include advanced age at maturity, alternate year spawning, extensive migrations, and separation of juvenile and adult segments of the populations. These general characteristics are adaptive in relatively unstable periglacial and northern environments, but some of them, particularly advanced age at maturity, render fish populations sensitive to the effects of human exploitation (McCart 1985). 10 Bull trout seem to be particularly vulnerable to overharvest. Because the spawners are relatively large and their spawning tributaries are relatively small, buU trout are easily observed and targeted. In addition, bull trout are weU known for their voracious appetites, making them easily taken by anglers. Finally, they have a tendency to congregate at the mouths of key tributaries or in favored spawnmg areas, further increasing their vulnerability to angling. In many areas, the bull trout's slow rate of maturation subjects them to substantial angling mortality before they have a chance to spawn. In a fluvial population of the Muskeg River, Alberta, Boag (1987) found that the majority of bull trout harvested by anglers were immature individuals less than five years old In the Flathead River system, Montana, anglers harvest some of the largest outmigrating juveniles as they exceed 200 - 250 mm (Vashro pen. comm. 1992). Stories of anglers taking loads of bull trout with their bare hands or with pitch forks abound. Frequently these stories concern locales where bull trout are no longer found This may not be a coincidence. Proposals are being considered to lower or eliminate harvest of bull trout in many parts of Montana. Unfortunately, lower bag limits or closed seasons alone do not effectively protect bull trout when poaching is a problem. On the Wenatchee National Forest illegal harvest and outright vandalism (wanton killmg and wastage of adult bull trout) has been observed Avith disconcerting regularity (Brown 1992). The long overwinter incubation and development phase for bull trout embryos and alevins leaves them particularly vulnerable to fine sediments and degradation of water quality (Fraley and Shepard 1989). Embryos and alevins need both security and cold, oxygenated water. Any physical or water quality changes that alter the delicate balance among water quality, flow, and stream bottom composition can have disastrous effects on these early life stages. Data from the Flathead and Bitterroot National Forests are indicating a clear connection between logging activity, sediment levels, and bull trout production (Weaver pers. comm. 1992, Clancy pers. comm. 1992). Increased sediment loads in tributary streams can also impact juvenile bull trout because of their close association with the substrate and their use of the interstitial spaces for cover. In addition, juvenile bull trout feed on aquatic insects which are also sensitive to changes in streambed composition. Declining reanng habitat due to sediments and/or reduced stream flows could force juveniles to migrate at a youngw age and smaller size, thus increasing susceptibility to predation (Vashro pers. comm. 1992). Adult bull trout will only spawn in streams meeting narrow physical and temperature criteria during their limited spawning season. Changes in environmental conditions at spawning areas could lead to unsuccessful spawning or could cause a failure of the stimulus that triggers final spawning behavior. Adults are also sensitive to environmental changes in the river system which they inhabit for five to six months during spawning runs. 11 Bull trout are especially sensitive to modifications of water temperature. They seem to require warmer temperatures in the winter and colder temperatures in the summer. Any human activity, including local impacts such as reduced npanan vegetation, or large scale impacts such as global warming, which change water temperatures could impact bull trout production. Finally, fluvial and adfluvial bull trout are a highly migratory fish. Construction of passage barriers can block migration and isolate populations, resulting in loss of spawnmg habitat and genetic isolation. In addition, bull trout can be lost to unscreened imgation diversions or killed by hydroelectric turbines. Bull trout are thus a species with narrow environmental tolerances, and are highly sensitive to disturbance. Bull trout are dependent on the quality of the habitat and on population management in rivers, lakes, and tributaries. Introductions of non-native species In addition to the problems bull trout face from brook trout (see section on genetics), bull trout are also faced with competition from a wide range of other non- native species. Nelson (1965) referred to introductions of brown trout Salmo trutta and possibly non-native suckers Catostomus sp. as factors in the decline of bull trout m the Bow River. The introduction of brown and brook trout may have been a factor contributing to the decline of bull trout in the McQoud River (Moyle 1976, Rode 1990). Marnell (1985) mentioned the introduction of lake trout as a possible factor contributing to the decline of bull trout in some areas of Glacier National Park. The Montana Department of Fish, Wildlife, and Parks (1992) also suspects that lake trout predation on bull trout may impact bull trout populations in the upper Flathead River system. In the late 1980's, juvenile lake trout began to appear in the Flathead River. Their presence has been documented as far upstream as West Glacier on the Middle Fork of the Flathead and the Canadian border on the North Fork of the Flathead. A 1991 survey of 23 lake trout stomachs from the Flathead River produced eight westslope cutthroat trout and one juvenile bull trout. The overall impact of lake trout predation of bull trout abundance is not known, but lake trout limits were liberalized m 1991 m an attempt to reduce predation, among other things (Vashro pers. comm. 1992). Intentional and unintentional eradication In the early 1900's, attempts were made to eradicate bull trout due to their voracious habits. A commercial fishery using nets was permitted in Montana m 1913 - 1914 (Brown 1971). Other states had bounties on bull trout, and Montana may have had a bounty as well (Simpson and Wallace 1978, Vashro pers. comm. 1992). 12 Ratliff and Howell (1992) list chemical rehabilitation projects as one of the causes of decline for bull trout in Oregon. In the 1950's and 1960's a number of waters, some of which contained bull trout, were treated with rotenone to remove rough fish. There was little concern at the time about bull trout. Similar projects may have been done in bull trout waters in Montana. For example, in the 1960's there was a basin-wide lake rehabilitation effort in the Clearwater chain of lakes, Blackfoot River drainage. Tributaries and lakes were thoroughly poisoned with rotenone to remove competitive threats from non-native species. However, bull trout appear to have survived in all the Qearwater lakes and populations appear to have improved in the last decade based upon limited gill net and angler reports (Peters pers. comm. 1992). Status of bull trout in Montana - overview of the state Historic distribution Bull trout are distributed in a north-south belt along the Rocky Mountain and Cascade ranges of northwestern North America. The area stretches from latitude 41°N, to latitude 60°N or slightly beyond. Bull trout are distributed on both sides of the continental divide between latitude 50 and 60°N, but primarily west of the continental divide south of this zone. The bull trout likely originated in the Columbia River basm (Cavender 1978). The bull trout is one of the four species of salmonid native to western Montana (westslope cutthroat trout, mountain whitefish, and redband rainbow trout being the other two). There is limited information available on the historic distribution of this fish. However, for this report it is assumed that they were generally distributed throughout western Montana. Possible exceptions are areas where migration was blocked by natural barriers or areas where the geology of the area may have created adverse conditions for bull trout. This is a reasonable assumption given the current distribution of bull trout m Montana. Almost every drainage has examples of bull trout populations in small headwater tributaries. In order for bull trout to have dispersed so widely, they must also have existed in all the major drainages. In addition to their distribution west of the continental divide, bull trout are native to the St. Mary's River drainage (Saskatchewan River drainage), east of the continental divide (Brown 1971, Marnell 1985). 13 Current distribution Methods Personal interviews were conducted of state, tribal, and federal fisheries biologists working in bull trout waters around the state. Based on information gathered in these interviews, the Montana Interagency Fisheries Database was updated and corrected to reflect the current status of bull trout in Montana waters. In addition, information was recorded on a data form devised by Region 1 of the Forest Service for a regional bull trout status review. Published and unpublished reports were also reviewed for information. Information collected for the Interagency Database for each water body included: a fish abundance rating, fish use rating, (including use for spawning only, rearing only, resident, or a combination of uses), a genetics ranking of the population, and a habitat value rating. Additional information collected for the regional bull trout status review included: the life history mode, whether or not the population is considered to be a remnant, the population status, the positive and negative factors influencing the population status, the type of information that is available about the population, and the contact persons. An attempt was made to document every stream where bull trout have been caught in the last 10 years, although some of the data was older and, therefore, a less reliable indicator of current status. The Environmental Protection Agency (EPA) River Reach Numbering System was used to identify stream reaches for analysis of bull trout status within each hydrologic unit (Figure 1). In this system, streams are divided into distinct reaches at tributary junctions or confluences. A "river reach number" (RRN) is assigned to each reach. Each RRN is 16 digits: 1) the first eight digits represent the USGS Cataloging Unit (CU) that identifies the hydrologic basin within which the stream reach is located; 2) the next three digits represent a unique segment number that, in combination with the CU, identifies the reach within a basin; 3) the last four digits represent the mile point number that identifies a section or sub-reach within a stream. Recently, the Bonneville Power Administration and the Northwest Power Planning Council, in cooperation with EPA, embarked on a project to revise the digital reach data and EPA Reach File to reflect hydrography on a 1:100,000 scale from the existing 1:250,000 scale. When this project by the Montana Rivers Information System is complete it will be possible to make a more complete and accurate analysis of status of bull trout in Montana. 14 Figure 1 fOUnCAL lUKMVtsaOM COM Abundance codes were assigned to every reach with bull trout (Table 1). The selection of the appropriate code was left to the field biologists who were interviewed for this report. These codes are somewhat subjective in nature. It is important to note that populations which were given the abundance code "rare" included streams with as few as one documented buU trout. In addition, some of this information is dated and may not reflect currem conditions. The abundance code E (expected but not verified) was used in situations where no data exists, but the local biologists believed that bull trout would be found. The abundance code Z (abundance unknown) was used m situations where there was documentation of bull trout in the reach, but no data on their abundance. A few reaches were coded P (species absent but could be present if introduced) when the biologist felt that was appropriate. Each bull trout water was also given a use code (Table 2). Again, this coding is based on the professional judgement of the field biologists. In most cases, the biologists had a difficult time distinguishing between adfluvial, fluvial, and resident populations. It a migration barrier exists, then the population above the barrier is known to be resident. In other situations, the distinctions are much less clear. Streams containing only sinall fish may have juvenile fluvial and adfluvial fish or resident fish or a combmation it a stream does have large fish, they could be large residem fish or migratory fish Due to the difficulties in assigning the proper use code, these data should be used with a great deal of caution. For the genetic coding (Table 3), brook trout were considered to be a contaminating species. Streams without electrophoretic data were usually coded either B or E Code B indicates a potentially pure population with no record of contaminating species, code E indicates a potentially pure population where brook trout are known to exist. Since brook trout X bull trout hybrids are apparent from visual inspection, some populations may have been classified as hybridized even though no electrophoresis has been conducted. The habitat coding (Table 4) is based on the judgement of the biologist. In the Montana Interagency Stream Database System, streams are designated as habitat code N (not applicable) when the genetic code is E (contaminating species known to exist). However, in order to get a better sense of the status of these populations, habitat ratings for as many of these streams as possible were obtained, even when the genetic code was E. Finally, a rating for the risk of extinction for each stream reach with bull trout was developed (Table 5 and Table 6). This extinction rating was based on a similar ratmg done by Ratliff and Howell (1992) in their status review of bull trout in Oregon. The rating is based on three criteria: the abundance of the fish, the rating of the habitat, and the risk of hybridization with brook trout. The rating ranges from 3, meaning Imle risk of extinction, to a risk of 12, meaning a high risk population. This rating is not meant to be an exact numeric designation but rather a technique for measuring relative risk. 16 Table 1. Relative abundance of bull trout, by hydrologic unit. Numbers refer to the number of reaches. (See below for definition of codes) Hydrounit AifeB c& D U V R E N P z 1 17010101 Kootenai R 19 2 46 33 5 9 2 16 17010102 Fisher R. 5 20 ' 17010103 Yaak R. 3 21 II 17010104 lower Kootenai R. 3 17010201 upper Clark Fork 2 8 36 4 17010202 Flint Ck, Rock Ck 6 22 15 10 12 17010203 Blackfoot 3 12 29 31 20 13 ' 17010204 middle Clark Fork 1 5 31 40 52 2 7 17010205 Bitterroot 6 31 57 31 16 36 15 17010206 NFk Flathead 10 9 6 50 3 1 8 17010207 MidFk Rathead 19 29 58 7 6 17010208 Flathead R 6 1 6 17 17010209 S. Fk. Flathead 18 18 52 5 1 1 17010210 1 Stillwater 4 23 10 13 10 17010211 Swan R. 2 9 14 46 11 1 17010212 lower Flathead 1 18 1 17010213 lower Clark Fork 1 9 37 39 10010002 St. Mary's 1 21 TOTAL 26 148 225 388 293 81 65 22 73 Definition of species abundance codes A = Abundant B = Abundant with proportion of large sized fish C = Common D = Common with proportional number of large sized fish U = Uncommon V = Uncommon with proportional number of large sized fish R = Rare E = Species expected but not verified N = Not present (mostly used in situations where the data previously entered into the database indicated bull trout were present, but current information suggests they are not present. See text for more explanation.) P = Species absent but could be present if introduced Z = Abundance unknown 18 Table 2. # STREAM REACHES WITH USE CODES: (See below for explanation of codes) HYDROUNIT L A J C F N Z R 17010101 Kootenai R 19 45 11 5 11 5 37 17010102 Fisher R. 20 5 1 17010103 Yaak R. 3 21 17010104 lower Kootenai R 3 17010201 upper Clark Fork 10 31 7 2 17010202 Flint Ck, Rock Ck 5 21 8 5 26 17010203 Blackfoot 17 35 14 3 13 29 17010204 middle Clark Fork 48 33 5 1 7 40 17010205 Bitterroot 102 12 1 36 6 35 17010206 N. Fk. Flathead 3 21 7 4 28 17010207 Mid. Fk. Flathead 1 19 60 5 1 17010208 Rathead 1 6 6 19 17010209 S. Fk. Flathead 2 11 49 8 2 1 17010210 Stillwater 4 9 17 23 7 1 17010211 Swan R. 1 7 35 31 6 2 17010212 lower Flathead 5 14 17010213 lower Clark Fork 5 24 23 18 16 10010002 St. Mary's 16 6 TOTAL 223 307 258 96 13 67 58 218 Definition of use codes L = Resident throughout life cycle A = Spawning elsewhere - spends part or most of life in reach J = Spawning and nursery to subadult (includes both fluvial and adfluvial) C = Passing through - species uses reach as a corridor to migrate F = Feeding run or avoiding poor conditions elsewhere N = No use (Used with abundance code N = not present) Z = Use undetermined R = Both resident and migratory fish utilize the reach 20 Table 3. # REACHES WITH GENETIC CODES: (See below for explanation of codes) HYDROUNIT A B C D E G H I "1 1 17010101 Kootenai R. 2 20 28 62 17 4 1 17010102 Fisher R. 25 1 17010103 Yaak R. 24 1 17010104 lower Kootenai R 3 17010201 upper Clark Fork R. 15 32 3 1 17010202 Flint Ck, Rock Ck 16 2 47 17010203 Blackfoot R. 25 3 82 1 17010204 middle Clark Fork R. 11 5 38 78 2 17010205 Bitterroot R. 43 8 3 123 9 6 17010206 N. Fk. Flathead 9 76 1 1 17010207 Mid. Fk Flathead 100 2 17 17010208 Flathead R. 6 5 1 17010209 S. Fk. Flathead 90 4 1 17010210 Stillwater R. . 6 3 52 21 1 17010211 1 Swan R. 11 36 27 8 1 1 17010212 1 lower Rathead 1 11 7 1 17010213 lower Clark Fork 6 4 37 39 10010002 St Mary's R. 1 21 TOTAL 17 425 15 167 644 2 29 19 Definition of genetic codes A = A genetically pure population as determined by electrophoresis that is isolated from contaminating species. B = A potentially pure population where there is no record of contaminating species in areas where spawning occurs. Contaminating species for bull trout is brook trout. C = A potentially pure population where no contaminating species exist, but planting records indicate that a contaminating species has been planted in the drainage or is elsewhere in the drainage and could invade. D = An especially valuable genetically pure bull trout population (determined by electrophoresis) where there are also contaminating species in the reach or drainage. E = A potentially pure population where contaminating species are known to exist. G = A genetically pure population could exist but is not present. H = A hybridized or introgressed population known to exist based on electrophoresis. For this report, this category was expanded to include populations visually identified as brook trout X bull trout hybrids. I = A genetically pure population where contaminating species could invade. Sometimes used instead of genetics rating D for bull trout in order to upgrade an especially important spawning stream. 22 Table 4. # REACHES WITH HABITAT CODES: (See below for definition of habitat codes) HYDROUNIT A B C D N 17010101 Kootenai R. 2 32 49 26 24 17010102 Fisher R. 20 5 1 1 17010103 Yaak R. 3 21 1 17010104 lower Kootenai R. 3 17010201 upper Clark Fork 1 4 45 II 17010202 Flint Ck, Rock Ck 29 9 5 22 1 17010203 Blackfoot R. 35 33 5 1 37 17010204 middle Clark Fork 25 34 12 50 17 17010205 Bitterroot R. 7 81 48 15 40 1 17010206 N. Fk. Flathead R. 52 11 2 22 17010207 Mid. Fk. Flathead 47 19 1 52 17010208 Flathead R. 12 1 17010209 S. Fk. Flathead R. 47 16 6 8 17 17010210 Stillwater R. 5 8 4 12 32 1 17010211 Swan R. 44 10 28 23 17010212 lower Rathead R. 17010213 lower Clark Fork 10010002 St. Mary's R. TOTAL 305 45 304 159 A = Best habitat B = Substantial value habitat C = Moderate value habitat D = Limited value habitat N = Not applicable, sometimes used when genetic = E 11 20 143 18 21 412 24 Table 5. CRITERIA FOR THE RISK OF EXTINCTION Category Low risk of extinction = risk factor 1 Of special concern = risk factor 2 Moderate risk of extinction = risk factor 3 High risk of extinction = risk factor 4 Abundance code Code A or B abundant Code C or D common Code U or V = uncommon Code R = rare Habitat value code Code A = best value habitat Code B = Substantial value habitat Code C = Moderate value habitat Code D = Limited value habitat Brook trout (Genetic code) Code A = pure bull trout with no brook trout in area Codes B, C, J = low risk from brook trout Codes D, I = brook trout could invade Codes E, H = hybrids exist or brook trout in reach The total risk of extinction is the sum of the three risk factors. Range is from 3 (low risk) - 12 (high risk). 25 Table 6. RISK OF EXTINCTION, BY HYDROLOGIC UNIT 3 = Minimal risk, 12 = Maximum risk. See text. HYDROUN IT 3 4 5 6 7 8 9 10 11 12 1 1 17010101 Kootenai R. 1 1 26 24 24 10 10 17010102 1 Fisher R. • 17010103 Yaak R 3 17010104 lower Kootenai R. ■ 17010201 upper Clark Fork 1 4 17010202 Flint Ck, Rock Ck 4 4 21 8 4 1 1 17010203 Blackfoot R 1 6 4 21 12 20 1 17010204 middle Clark Fork 4 8 49 5 8 2 43 17010205 Bitterroot 2 3 4 11 11 50 28 9 6 17010206 N. Fk. Flathead 6 46 9 1 17010207 Mid. Fk. Flathead R. 5 42 14 1 2 17010208 Flathead R. 11 26 17010209 S. Fk. 1 Flathead 11 37 19 2 6 2 17010210 II Stillwater R 2 3 7 4 5 ' 17010211 Swan R. 3 46 5 1 II 17010212 lower Flathead R. 1 11 1 17010213 lower Clark FkR. 1 6 37 1 3 20 10010002 St. Mary's TOTAL 6 2 24 162 143 161 110 91 46 86 1 27 Appendix A contains a printout of all the stream reaches in the Montana Interagency Database which contain bull trout. Appendix B contains the Montana information gathered for the regional bull trout status review. These datasheets contain some additional information not given in the database. Distribution of bull trout in Montana Based on the updated information in the Interagency Database, bull trout are found in 42% of the river and lake reaches in their native range in Montana (Table 7). If it is assumed that bull trout were distributed throughout western Montana historically, then this represents a loss of bull trout from 58% of their native range. This estimate may be either too high or too low, depending on the following variables: First, there are areas of western Montana that may never have been utilized by bull trout, in which case the loss has been over-estimated. On the other hand, the database is currently incomplete, especially with regard to lakes. Since most of the missing streams and lakes probably do not contain bull trout, the loss estimate may be conservative. Finally, the estimate includes populations that are designated as rare - some of which may actually be extinct. If this is the case, the estimate of loss is too low. When the ongoing update of the Interagency database is completed the length of the stream reaches will be more accurate in the database. At that time it will be possible to undertake a more complete and accurate analysis of miles of habitat lost. Of the 1,250 reaches which have information about bull trout use, 223 contain resident bull trout, 307 contain bull trout that spawn elsewhere, 258 serve as spawning and nursery areas, and 218 have both resident fish and juvenile migratory fish. In addition, 96 reaches have bull trout passing through, 13 reaches contain either a feeding run or serve as a refuge from poor conditions elsewhere. There are 58 reaches where bull trout are known to exist, but their use of the area is undetermined and 67 reaches with no bull trout use. Slightly over half the reaches containing bull trout have a genetic code E, meaning a potentially pure population where contaminating species are known to exist (Table 3). In addition, another 29 records are coded H, meaning a hybridized or introgressed population is known to exist based on electrophoresis. In total, 51% of the state's bull trout populations are at high risk for genetic contamination from brook trout. Of the 911 reaches where data on habitat quality are available, 609 have a habitat quality rating of A or B - best or substantial value habitat (Table 4). There are 143 reaches that provide only limited value habitat. While the picture could change if data on the rest of the reaches was available (those reaches with habitat value code N), it appears that a substantial portion of the remaining bull trout habitat in Montana is in good condition. Of course, this analysis does not take into consideration the condition of the habitat that historically contained bull trout, but no longer supports these fish. 28 Table 7. Number of reaches and number of miles of stream containing bull trout in Montana [HYDROUNrr # REACHES TOTAL # REACHES WITH BULL TROUT (%) #MnKS TOTAL # MILES WITH BULL 1 TROUT (%) j 17010101 Kootenai R. 353 122 (35%) 1,198.9 456.6 (38%) 1 17010102 Fisher R. 77 5 (6%) 301.3 29.4 (10%) 17010103 Yaak R. 72 24 (33%) 259.6 59.7 (23%) 17010104 lower Kootenai R. 6 3 (50%) 3L1 6.3 (20%) 17010201 upper Clark Fork R. 132 49 (37%) 812.5 234.3 (29%) 17010202 Hint Ck, Rock Ck 118 65 (55%) 516.0 243.9 (47%) 17010203 Blackfoot R 227 98 (43%) 1,001.7 460.2 (46%) 17010204 middle Clark Fork R. 264 131 (49%) 974.7 424.5 (43%) 17010205 Bitterroot R. 303 156 (51%) 1,401.8 881.2 (63%) 17010206 N. Fk Flathead 155 87 (56%) 588.0 284.7 (48.4%) 17010207 Mid Fk Flathead R. 170 119 (70%) 594.6 425.6 (72%) 17010208 Flathead R. 76 13 (17%) 425.8 174.4 (40.9%) 17010209 S Fk Flathead 286 94 (33%) 888.7 386.3 (43%) 29 17010210 Stillwater R 164 60 (37%) 514.4 217.2 (42%) 17010211 Swan R. 185 82 (44%) 557.9 300.5 (54%) II 17010212 lower Flathead R. 85 19 (22%) 565.2 114.8 (20%) 17010213 lower Clark Fork R. 232 86 (37%) 874.1 307.4 (35%) II __ 10010002 St. Mary's 50 22 (44%) 241.7 120.8 (50%) TOTAL 2957 1235 (42%) 11,759 4927.8 (42%) | • Includes reaches designated as abundance code E = bull trout expected but not verified, and also reaches designated as abundance code Z = abundance unknown 30 Because of the large number of records that did not have habitat value ratings, it was possible to calculate the risk of extinction on only 831 reaches. These ratings were skewed in the direction of moderate to high risk of extinction. Only 32 reaches had a low risk of extinction (rating 3, 4, or 5). In contrast, 86 reaches had the highest possible risk of extinction (12) (Table 6). Status of bull trout in Montana - hy hydrolopic unit Hydrologic unit # 17010101 - The Kootenai River (not including the Yaak drainage or the Fisher River) Historic distribution Historically, bull trout were distributed throughout the drainage. However, there must have been two separate populations above and below Kootenai Falls. This falls is a natural barrier which prevents upstream fish migration. Bull trout are currently found upstream of this falls, so it is assumed that they existed upstream of the falls histoncally as well. Current distribution The construction of Libby Dam created another migration block on the Kootenai River. In addition, a portion of the river has now been converted to a reservoir. As a result, there are now three separate main stem Kootenai River bull trout stocks - those below Kootenai Falls, those above the falls and below the dam, and those above the dam. The fish above the dam were fluvial fish that have now been forced into an adfluvial life history mode. The bull trout in the Kootenai River below Kootenai Falls may include some adfluvial fish from Kootenay Lake. There is some minor tributary use (Callahan Creek, and the lower Yaak River). Fish are found in Lake Creek and O'Brien Creek each year, but may not be able to spawn. Two large bull trout (762 mm and 610 mm) were caught in O'Brien Creek in July 1992 (Vashro pers. comm. 1992). Brook trout are present m the tributaries but no genetics work has been done to date (Perkinson pers. comm. 1992). The most important spawning stream for bull trout living in the Kootenai River between Kootenai Falls and Libby Dam is Quartz Creek. Trapping work done m this stream estimated that there was a population of approximately 250 fish using this spawning tributary, although only 25 - 35 spawning fish were trapped each year (Marotz pers comm. 1992). The 1991 redd survey for Quartz Creek found 32 positive, 9 possible, and 10 false redds. The West Fork of Quartz Creek is also used by spawmng bull trout. The 1991 redd count found 43 positive, 6 possible, and 2 false redds (Skaar 1992). The genetic status of this population has been tested, and a hybridization rate of 25% has been detected (Perkinson pers. comm. 1992). 31 Pipe Creek has a moderate amount of bull trout spawning activity. In 1991 five positive redds were found in a concentrated area of this stream. The 1991 survey m this drainage did not find any other streams which had bull trout redds, although some other potentially suitable areas were noted (Skaar 1992). This stock of bull trout has been cut off fi-om many potential spawning tributaries upstream by Ubby Dam. The bull trout population in Lake Koocanusa is small in number (< 5% of the fish population), although individuals are large in size. Bull trout in Lake Koocanusa show greater growth than bull trout in Hungry Horse Reservoir or Flathead Lake up to age four. After that, growth is comparable to these other waters. The data suggest that there is some feeding advantage for bull trout in Lake Koocanusa relative to these other waters (Chisholm et al 1989). Bull trout are a very minor portion of the angler harvest (0.06%) in Lake Koocanusa, based on data collected in the summer of 1985. The average buU trout creeled fi-om this reservoir was 411 mm in length and the average catch rate was < 0.01 fish/hr (Chisholm and Hamlin 1987). The Lake Koocanusa bull trout utilize Graves, Stahl, Clarence, and Blue Sky cks. for spawning. Unfortunately, they have to migrate through the Tobacco River to access these streams, making the trip difficult. In addition, some Lake Koocanusa fish move north into tributaries in Canada and the Wigwam River for spawning. Some mmor tributary use is probable in Pinkham Creek and Big Creek (Shepard, pers. comm. 1992, Marotz pers, comm. 1992, Perkinson pers. comm. 1992). Bull Lake also supports a remnant population of adfluvial bull trout. These fish are atypical in that they migrate downstream to spawning tributaries. The primary spawning tributaries are Stanley and Keeler creeks. Bull trout in this drainage are dependent on a few key tributaries to support the population. This fact alone puts the population at risk. In addition, a review of the nsk of extinction for these populations based on fish abundance, habitat value, and presence of brook trout indicates that the majority of the populations are at moderate to high nsk (Table 6) Of the 96 reaches where a risk of extinction could be calculated, 74 (77%) had a risk of extinction between 8 - 10 on a scale of 3 - 12, 12 being the highest risk. There are 20 reaches (19%) with a risk of extinction of 11 - 12 (high risk). The West Fork of Quartz Creek appears to have the most secure population in the drainage, with a risk of extinction rated at 6. As mentioned above, this is one of the most important spawning tributaries in the drainage. Waters with the greatest nsk of extinction are Camp Creek, Keeler Creek, Meadow Creek, Murphy Creek, and Pipe Creek. 32 Hydrologic unit # 17010102 - the Fisher River Historic distribution Bull trout were likely distributed throughout the Fisher River drainage historically as there are no physical barriers to migration (Perkinson pers. comm. 1992). Current distribution Biologist Doug Perkinson (pers. comm. 1992) has characterized the bull trout population in this drainage as non-viable if not extinct. There are five stream reaches where bull trout populations are expected but not verified (Table 1, Appendix A). There are 20 reaches where fluvial bull trout could be present if introduced. Brook trout are abundant in the drainage, a factor which could complicate re-introduction efforts. Most of the potential bull trout waters are rated as having moderate value habitat (Table 4). Hydrologic unit # 17010103 - the Yaak River Historic distribution It is possible that Yaak Falls was a migration barrier that prevented bull trout from colonizing the Yaak drainage above this point. Current distribution Currently, bull trout are only known to be found below Yaak Falls. The Yaak River above Yaak Falls is coded as bull trout expected but not verified. In the Yaak River below Yaak Falls fluvial bull trout are rare. These fish have a relatively high risk of extinction (Table 6) because of their rarity and the presence of brook trout. The habitat value of the lower Yaak River is considered to be substantial. Hydrologic unit # 17010104 - Kootenai River from Idaho to the Yaak River Historic distribution This small hydrologic unit encompasses the Kootenai River drainage from the Idaho border to the Yaak River. Bull trout are assumed to have been distributed throughout the drainage. Current distribution There is a population of fluvial and/or adfluvial bull trout in the mainstem Kootenai below the Yaak River. These fish are uncommon, with a proportional number of large size fish. They are assumed to be spawning elsewhere (not in the mainstem 33 Kootenai R.) (Table 2). They are considered to be the same population as is found in the Kootenai above the Yaak River and below Kootenai Falls (see discussion under hydrologic unit # 17010101). Hydrologic unit # 17010201 - the Qark Fork River from Warm Springs Creek to the Blackfoot River, not including Rock Creek and Flint Creek. Historic distribution Given the current distribution of bull trout in this drainage, it is apparent that bull trout at one time inhabited all the major streams in this drainage. Current distribution Bull trout are rare in the mainstem Clark Fork River between the Blackfoot River and Warm Springs Creek. The only portions of the Uttle Blackfoot River which still contain bull trout are the upper sections above Dog Creek. Below this point, bull trout appear to have been eliminated. Only a few tributary streams are known to contain bull trout. Harvey Creek has a population of resident bull trout, but a barrier at the mouth of the stream prevents Clark Fork River fish from utilizing this stream for spawning. The upper portion of Harvey Creek, above Eightmile Creek, appears to have the most secure population of bull trout in the drainage (risk of extinction = 6). Some sections of Warm Springs Creek contain bull trout, but they are primarily resident populations residing in the headwaters sections. Rock Creek and Schwartz Creek contain bull trout. Barker Creek and Storm Lake Creek may also contain bull trout, but their abundance is unknown. A few lakes in this drainage contain their own adfluvial populations of bull trout, specifically, Lower Twin Lake, Upper Twin Lake, and Silver Lake. Given the extensive mining impacts that have occurred in this drainage it is not surprising that bull trout are rare and primarily restricted to headwaters portions of relatively pristine tributaries. Hydrologic unit # 17010202 - Rock Creek and Flint Creek drainages Historic distribution The current distribution of bull trout in this drainage implies that bull trout were distributed throughout the drainage historically. 34 Current distribution The Rock Creek drainage may be the best bull trout drainage in the state outside of the upper Flathead River system. In general, this drainage has had relatively few human impacts, although there is some mining, logging, agriculture, and residential development. In the mainstem of Rock Creek, bull trout are uncommon below Welcome Creek and common above Welcome Creek. The habitat in all of Rock Creek is rated an A - best value habitat. However, brook trout are present in Rock Creek and a number of the important spawning tributaries. Electrofishing surveys done in 1984 noted some apparent bull trout X brook trout hybrids in several of the tributary streams, but no electrophoresis has been done to confirm this information. A few tributaries remain brook trout free - Alder Creek, Cinnamon Bear Creek, South Fork of Ross Fork, West Fork Rock Creek, Wyman Creek, and Welcome Creek. It is unknown to what degree Clark Fork River bull trout utilize the Rock Creek drainage as a spawning area. Given the excellent habitat found in this drainage, it is prudent to assume that the few remaining bull trout in the mainstem Clark Fork rely heavily on this stream for spawning. The Flint Creek drainage has had considerably more human impacts than Rock Creek and bull trout are generally in perilous condition. Bull trout are uncommon in Flint Creek and Boulder Creek. They are rare in most of Copper Creek, Douglas Creek, and Wyman Gulch Creek. A few headwaters lakes contain adfluvial populations of bull trout. They are rare in East Fork Reservoir, Kaiser L, and Moose L. Hydrologic unit # 17010203 - the Blackfoot River drainage Historic distribution Historically, bull trout were probably distributed throughout the Blackfoot River drainage. In addition, there was a connection between Clark Fork River fluvial bull trout and Blackfoot River fluvial bull trout. Moomaw et al (1952) reported that the Salish name for Missoula meant "bull trout" and the name for Bonner was like bull trout in meaning except more and larger trout were found at this place. The Flatheads were reported to have a campground at Milltown at the junction of the Blackfoot and Clark Fork Rivers which was used for fishing for bull trout (Anon 1954). The connection between the lower Clark Fork and the Blackfoot was broken by the construction of Milltown Dam in the early 1900's. Each spring, concentrations of fish are still observed at the base of Milltown Dam. In June, 1992, a 30 inch male and female bull trout died in an accidental dewatering of the middle bay area of Milltown Dam. It is assumed that these fish are attempting an upstream migration past the Dam. 35 Information from landowners and anglers indicates that Rock Creek (tnbutary to the North Fork of the Blackfoot) and Beaver Creek contained bull trout in the past. There is presently a lack of young-of-the-year (and older) bull trout in these streams, although a rehabilitation effort is underway in Rock Creek (see below). Current distribution Bull trout populations in the Blackfoot River drainage have been the subject of recent research efforts. The mainstem Blackfoot River contains populations of fluvial bull trout. The abundance of these fish varies by reach. From the mouth of the Blackfoot to the North Fork of the Blackfoot River, bull trout are considered uncommon with a proportional number of large size fish, although the habitat is rated "A" -best value habitat. From the North Fork of the Blackfoot River to Poorman Creek, Blackfoot River bull trout are rare, and the habitat is rated a "B" - substantial value. From Poorman Creek to the Landers Fork, bull trout are expected but not verified. From the Landers Fork to the headwaters, bull trout are rare and the habitat has substantial value (Tables 1 and 4) (Peters pers. comm. 1992). Surveys of the Blackfoot River tributaries have found that, in general, tributaries which flow south have bull trout, whereas tributaries which flow northward do not. Some of the most important tributaries are Gold Creek, Copper Creek, Monture Creek, Morrell Creek, the North Fork of the Blackfoot, and Belmont Creek. Some of these tributaries have brook trout and some do not (Appendix A, Table 3). No genetic work has been done to date on these streams. In 1991, redd surveys were done on the North Fork of the Blackfoot and Monture Creek. Counts were 26 and 25 redds, respectively. Rock Creek (tributary to the North Fork of the Blackfoot River) has been identified as an ancestral spawning stream for bull trout based on landowner mformation. No young-of-the-year bull trout have been captured in the 1.2 mi long stream m over a week of electrofishing effort. Brook trout, multiple passage barriers, and degraded habitat are probably reasons for the loss. A stream restoration project (completed m June, 1992) has significantly reversed degraded habitat condition. Creation of complex pool habitats and removal of grade controlling structures have cleaned the channel ot sediment. The stream has greatly increased capacity to keep itself clear of sediment m the pools and riffles as a result of the work. Mature bull trout were observed m the stream in July, 1992 (Peters pers. comm. 1992). A number of lakes in the upper Blackfoot River drainage support adfluvial populations of bull trout. The data on these populations is limited, but bull trout are known to occur in Seeley Lake, Placid Lake, Rainey Lake, Lake Alva, and Lake Inez. Rainey Lake is believed to have the most abundant bull trout population in this group (Peters pers. comm, 1992). 36 A basin-wide catch and release only season was implemented m 1990 for bull trout to reduce angler impacts. Misidentification of bull trout and compliance contmues to plague the attempt at reducing bull trout mortality (Peters pers. comm. 1992). In general, the status of bull trout in this drainage appears to be precarious. Of the 98 reaches which are believed to have bull trout, none are rated as having abundant bull trout, and in only 3 reaches are bull trout rated common. Bull trout are uncommon in 41 reaches and rare in 31 reaches (Table 1). Brook trout are common throughout the drainage, occurring in approximately 77% of the buU trout waters (Table 3). It vms possible to calculate a risk of extinction factor for 65 of the bull trout reaches. The lowest risk of extinction was a 5 (one reach - Copper Creek) and the highest was an 11 (one reach - Clearwater R. above Morrell Creek). The majority of the reaches (53) rated between 8 - 10 (moderately high risk of extinction) (Table 6). Hydrologic unit # 17010204 - The Qark Fork River from the Flathead River to the Blackfoot River Historic distribution Populations of fluvial bull trout probably occurred throughout the drainage. This portion of the Clark Fork River was probably not used by adfluvial bull trout from Lake Pend Oreille because Thompson Falls may have been a natural migration barner. It is unknown whether or not bull trout from Flathead Lake moved downstream out of the lake into the lower Flathead River and potentially into this section of the Clark Fork River. Although unusual, downstream migrations of adfluvial bull trout have been documented in other locations (e.g. Bull Lake, Upper ^^f^^ake. Cracker l^ke)._^^ construction of Kerr Dam blocked fish passage between the lower Flathead\Clark Fork River systems and Flathead Lake. The construction of MiUtown Dam blocked passage between the Clark Fork River and the Blackfoot River. Current distribution In the mainstem Clark Fork River bull trout are rated as either rare or uncommon, with a proportional number of large sized fish. The most important spawning tributaries for fluvial bull trout in this reach of river are Cache Creek and Montana Creek (tributaries of Fish Creek), the St. Regis River, and Trout Creek. Other important bull trout streams are Cedar Creek, Cement Gulch Creek, Lost Creek, Ward Creek, and the South Fk. of Little Joe Creek. It is not clear if these tributaries are supporting resident or fluvial populations of bull trout (or both). There are quite a few streams in this drainage where bull trout have been found in very low numbers (one or two fish per sample). The implication is that these streams were at one time bull trout streams which are no longer supporting healthy bull trout 37 populations. Streams in this category include Ninemile Creek, Petty Creek, Sixmile Creek, Tamarack Creek, and the South Fork of Trout Creek. The Montana Department of Fish, Wildlife, and Parks has gathered some information on bull trout densities and redd counts in some of the critical bull trout streams. This information is in draft form at this time but will be available soon on Fish Creek, Cache Creek, Montana Creek, and Straight Creek. Of these streams. Cache Creek appears to have the highest relative density of bull trout (13%) of the population, however, hybridization with brook trout was noted in this population. The construction of the Montana Water Co. Dam on Rattlesnake Creek blocked fish passage between Rattlesnake Creek and the Clark Fork River. It is not known if Clark Fork River bull trout successfully utilize the lower, accessible reaches of Rattlesnake Creek below the dam, although adult bull trout congregate below the dam annually in an attempt to migrate upstream. Above the dam. Rattlesnake Creek supports a population of large size resident bull trout. Overall, bull trout have a number of problems in this drainage. The connections between the Clark Fork River and the upper Flathead system, the Blackfoot River, and the lower Clark Fork River have been broken by dams. Many of the lower reaches of the tributary streams have been impacted by habitat degradation, or are inaccessible due to barriers. Mining activities in the headwaters of the drainage (Butte and Anaconda area) have impacted water quality in the mainstem during recent history and these impacts may be continuing into the present. Approximately 85% of the reaches containing bull trout also contain brook trout (Table 3). Given all these problems, it is not surprising that many of the bull trout populations in this drainage have a high risk of extinction. Of the 119 reaches where a risk of extinction could be calculated, 49 (41%) had a risk of extinction of 8 and 43 (36%) had a risk of extinction of 12 - the highest risk (Table 6). Streams with the highest risk of extinction include Ninemile Creek (may already be extinct in this drainage). Petty Creek, St Regis River, Sixmile Creek, Tamarack Creek, and the South Fork of Trout Creek. Hydrologic unit # 17010205 - the Bitterroot River drainage Historic distribution There are no major natural barriers to fish migration that would have excluded bull trout from any significant portions of this drainage. Bull trout were likely distributed throughout the drainage historically. There are reports of 20" bull trout being caught in the Bitterroot River in the 1920's. 38 Current distribution BuU trout appear to be extinct, or nearly so, from the mainstem Bitterroot River from the mouth of the river to Blodgett Creek. From Blodgett Creek to the East Fk. of the Bitterroot, bull trout are rare and the habitat is of substantial value (a "B" ratmg) (Table 1, Table 4). In general, the tributary streams contain small populations of small bull trout (rarely over 12" in length) which are isolated from other bull trout waters. The connections between the tributaries and the mainstem Bitterroot River have often been severed by habitat degradation, dewatering, and passage barriers. Tributaries of the east side of the valley tend to have more bull trout than on the west side of the valley. The upper East Fork of the Bitterroot and the Skalkaho Creek area are refuge areas for bull trout, while the upper West Fork has abundant brook trout. An analysis of the sediment condition of the Bitterroot National Forest streams indicates that about one third of the streams are in good shape, one third are in poor shape, and one third are in critical condition. While bull trout are found in all three types of streams, most of the healthier populations are found in the healthy dramages. There are three streams (six reaches) which were rated as having abundant bull trout: Meadow Creek, Daly Creek, and Sweathouse Creek. Bull trout are common in 31 reaches, uncommon in 57 reaches, and rare in 31 reaches. They are expected but not verified in 16 reaches (Table 1). While these figures appear to show that bull trout are widely distributed in the Bitterroot drainage, it must be considered that "rare" frequently means that one or two bull trout were found in this stream at some time. Brook trout are common in Bitterroot Valley streams. Approximately 75% of the bull trout streams also contain brook trout (Table 3) . Some genetic analysis has been done in the area. There are three streams that are known to contain hybridized brook trout X bull trout populations and eight streams that are known to contain pure strain bull trout. The majority of the Bitterroot Valley waters have a moderate risk of extinction - 72% of the reaches had an extinction risk from 8 - 10 (Table 6). Overall, the drainage has a large number of fragmented populations containing small numbers of small fish with no genetic interchange. The Upper Flathead River system above Kerr Dam There is no concrete information on the historic abundance of bull trout in the Flathead system, but it is clear that they were widely distributed throughout the drainage. Some of the smaller tributary streams have waterfalls that could have prevented bull trout colonization, but the major river systems were all open and interconnected. 39 Currently, the Flathead adfluvial bull trout population is probably one of the most viable left in the United States. The interconnectedness of the Flathead system has been disrupted by the construction of hydroelectric facilities. Bigfork Dam, built in 1902, blocked fish migration from Flathead Lake into the Swan River. Hungry Horse Dam, closed in 1953, blocked fish migration into the South Fork of the Flathead River. Kerr Dam blocks fish passage fi-om the lower Flathead River into Flathead Lake. It is estimated that Hungry Horse and Bigfork Dams cut off 40% of the historic spawning grounds for Flathead Lake. Bull trout persist above these facilities and their populations appear to be healthy. However, these remnant populations are at risk and genetic exchange with the Flathead population is essentially nil. Recent monitoring data has caused concern about the status of bull trout in the Flathead. Spawning redd counts showed major decreases in the North Fork Flathead drainage in 1991 and in the Middle Fork drainage in 1990 and 1991. North Fork tributary monitoring areas have averaged 229 redds during 12 years of annual counts (1979 - 1990). This year's total of 146 is 36% below this annual average figure. The only North Fork tributary with a higher than average figure was Big Creek Whale and Trail creeks had extremely low redd numbers. Redd counts in Middle Fork tributary areas have averaged 141 redds annually during the 1979-1990 period. The 1991 total of 97 redds is 31% below this average figure. The 1990 redd count in the Middle Fork was 46% lower than average. There is no single obvious reason to account for the low escapement over the past two years and it is not known if the decline is temporary or reflects a long term decline. Factors affecting the 1991 spawning year class could include natural population fluctuations, low water during winter 1984 - 85 (egg mortality), habitat changes both natural and management related, drought in 1987 and 1988, predation by lake trout in river and lake, overharvest of spawners, general overharvest, and changes in the food web. The Montana Department of Fish, Wildlife, and Parks and the Confederated Salish and Kootenai Tribes (who co-manage Flathead Lake) are proposing a reduction m bull trout harvest as a short-term measure to halt the decline in bull trout. Long term management strategies include habitat protection and enhancement and population supplementation. Status of bull trout in Glacier National Park Bull trout occur in about a dozen west slope lakes and streams draining from Glacier National Park to the North and Middle Forks of the Flathead River. In most cases they co-exist with other native species including the westslope cutthroat trout (Marnell pers. comm. 1992). 40 About half of these are large glacial fingers lakes lying between 3280 and 3940 ft MSL in elongated valleys. Most of these waters have been invaded by non-native species as a result of downstream fish introductions dating from around 1916. Many of these lakes now contain lake trout, lake whitefish, and kokanee. An occasional rainbow trout or brook trout is reported from Lake McDonald, the largest of these lakes (MameU pers. comm. 1992). Half a dozen small lakes in the interior of Glacier Park also harbor buU trout in sympatry with other native fish species. While these lakes are believed to contain only native species at the present time, several are vulnerable to invasion by non-native species (MameU pers. comm. 1992). Bull trout are also widely dispersed throughout the network of first and second order tributaries in both the North and Middle Fork drainages of Glacier Park. Generally, they are restricted to elevations below 4590 ft. MSL. due to natural bamers characteristic of the park's mountainous topography (MameU pers. comm. 1992). The staff of Glacier National Park are quite concerned about recent mass movements of non-native fishes in the North and Middle Forks of the Flathead River. In the falls of 1990 and 1991, large aggregations of Lake Superior whitefish and lake trout were observed in the Middle Fork of the Flathead near West Glacier. These non-native fish have the potential to impact buU trout populations which have not been previously exposed to non-native fish. The Park staff is particularly concerned about possible lake trout entry into Quartz Lake and the Camas Creek drainages in the North Fork of the Flathead (Marnell pers. comm. 1992). Bull trout management on the Flathead National Forest The bulk of the Flathead system bull trout spawn in streams in the Flathead National Forest. In February, 1990 the Flathead Forest amended the Land and Resource Management Plan (LRMP) to revise the standards for bull trout. The amended LRMP caUs for use of sediment models in 21 critical bull trout streams to evaluate the effects of proposed development on buU trout habitat. In addition, estimated increases in sediment delivery rates wiU be held to a level that does not pose a significant threat of sediment deposition in spawning and rearing habitat. Research done by the Flathead Basin Forest Practices, Water Quality, and Fisheries Cooperative Program (FBCP) in 1991 defined a "threatened stream" as those having greater than 35% fine sediment in spawning gravels and an "impaired stream" as those having greater than 40% fine sediment. The FBCP recommendation for impaired streams is for no additional sediment loading and a rigorous program of controlling sediment from previous disturbances. The Forest has pledged to abide by these fisheries recommendations and is currently working on implementation guidelines to put this policy into active use. 41 Hydrologic unit # 17010206 - the North Foik of the Flathead Rhrer Historic distribution The North Fork of the Flathead River drainage comprises one portion of the upper Flathead River system. The North Fork of the Flathead has its headwaters in Canada, then flows south bordered by Glacier National Park and the Flathead National Forest. There are no natural fish passage barriers on the mainstem of the North Fork which would have prevented bull trout from colonizing the river, although some of the tributary streams have waterfalls which are fish passage barriers. Current distribution More data on bull trout have been collected in the North and Middle Forks of the Flathead River than in any other drainage in Montana. These drainages support some of the most pristine and healthy bull trout populations in the United States. The North Fork drainage is particularly significant as it does not have brook trout. These facts are refiected in the risk of extinction ratings for the North Fork which range from 3 (low risk of extinction) to 8 (moderate risk of extinction) (Table 6). In general, streams to the west of the North Fork of the Flathead support adfluvial bull trout spawning, whereas tributaries on the east (draining Glacier National Park) do not. However, some of the Glacier Park drainages contain relatively large lakes with their own populations of adfluvial bull trout. The "crown jewels" of Glacier National Park, in terms of bull trout, are Cerulean, Quartz, Middle Quartz, and Akakola Lakes. These lakes have had no exposure to introduced fishes and still contain pristine habitat. Bull trout co-exist with westslope cutthroat trout in these lakes (Marnell pers. comm. 1992). Apparently healthy bull trout populations co-exist with cutthroat trout in Lower Quartz Lake and Trout Lake in Glacier National Park. However, there has been a recent unconfirmed report of a lake trout caught in Lower Quartz Lake which is a cause of concern in this water (Marnell pers. comm 1992). Arrow Lake was known to support bull trout in the 1960's, however no bull trout have been caught in this lake in recent surveys. There is speculation that the 1964 flood may have been a potential factor in the decline of bull trout in this lake (MarneU pers. comm. 1992). A unique population of bull trout occurs in Upper Kintla Lake in Glacier National Park. Bull trout are the only species of fish which occur in this lake. It appears that bull trout were not stocked in the lake, but rather ascended some barrier cascades, perhaps during the late stages of glacial withdrawal. The presence of anomalous biochemical 42 alleles suggests long term isolation of the population from other bull trout. These fish are lake outlet spawners (Mamell pers, comm 1992). Bull trout co-exist with lake trout in Bowman and Logging Lakes. Creel survey data and anecdotal reports suggest a decline of bull trout in Bowman Lake m recent years. Logging Lake is still in near pristine condition and bull trout are abundant (Marnell pers. comm. 1992). Kintla Lake in Glacier National Park is severely compromised and bull trout are now uncommon. This lake contains lake trout, lake whitefish, and kokanee. The most significant spawning streams for adfluvial Flathead Lake bull trout in the United States portion of the North Fork of the Flathead River drainage are Big, Hallowat, South Coal, Coal, Mathias, Red Meadow, Whale, Shorty, and Trail creeks. Streams in Canada support approximately 25% of the North Fork bull trout spawning. The most significant streams in the Canadian portion of the drainage are Howell, Cabin, Sage, and Kishenehn creeks. Bull trout densities are monitored annually in the North Fork by the Montana Department of Fish, Wildlife, and Parks through redd counts on four high density spawning streams. In addition, periodic basinwide redd counts have been conducted since 1980. Data from the annual monitoring is summarized in Table 8. Data fi-om the basinwide monitoring for the North Fork is given in Table 9. Monitoring of spawning gravel conditions has been done on three bull trout spawning streams since 1981. These data indicate that Big and Coal cks have sediment levels in excess of the 40% level recommended by the FBCP, while Trail Creek has approximately 35% sediment. The data are available from the Flathead National Forest. Surveys of juvenile bull trout densities in the North and Middle Fork found that they averaged 4.6 bull trout > 75 mm/ 100 m. The range in the North Fork tributaries was fi-om 1.7 (Red Meadow Creek) to 5.2 (Trail Creek). Hydrologic unit # 17010207 - the Middle Fork of the Flathead River Historic distribution Bull trout were likely to have been distributed widely throughout the Middle Fork drainage. 43 Table 8. Summary of the North Fork of the Flathead River bull trout spawning site inventories from 1979-1991 in the stream sections monitored annually. YEAR\STREAM BIG COAL WHALE TRAIL (TOTAL) 1979 10 38 35 34' 117 1980 20 34 45 31' 130 1981 18 23 98 78 217 1982 41 60 211 94 406 1983 22 61 141 56 280 1984 9 53 133 32 227 1985 9 40 94 25 168" 1986 12 13 90 69 184 1987 22 48 143 64 277 1988 19 52 136 62 269 1 1989 24 50 119 51 224 1990 25 29 109 65 228 1 1991 24 34 61 27 146 (AVERAGE) 19.7 41.1 108.8 52.9 221.0 ^ Counts may be low due to mco mplete sur vey High flows may have obliterated some redds 44 Table 9. Summary of the number of bull trout redds observed in the U.S. portion of the North Fork of the Flathead drainage during basin-wide survey years. fsTREAMVYEA R 1980 1981 1982 1986 1991 (AVE) 1 ®^^ 15 24 45 12 32 26 HALLOWAT 8 14 31 3 27 17 COAL 48 30 95 35 42 57 S.COAL 2 24 9 4 8 10 1 MATHIAS 10 10 17 10 8 11 RED MEADOW 6 19 10 8 15 12 WHALE 47 101 236 90 61 107 SHORTY 4 17 56 35 6 24 TRAIL 31 82 101 69 27 62 TOTAL 11 — 171 321 600 266 226 317 1 45 Current distribution The Middle Fork of the Flathead River is, along with the North Fork of the Flathead and the Swan River, the stronghold for buU trout in Montana. Unlike the North Fork, the Middle Fork does have some brook trout in a few locations. Bull trout redd counts have been conducted in the Middle Fork since 1979, using the same strategy as in the North Fork. The redd count data from the four key monitonng streams is given in Table 10, and the data from the basin-wide surveys is in Table 11. The only stream in the Middle Fork drainage where bull trout spawning gravels have been monitored is Granite Creek. In the last decade, a pulse of sediment moved through Granite Creek, raising the levels of fine materials in spawning gravel to 51% m 1986. By 1990, significant flushing had occurted and sediment levels had declined to 26%. A road induced slope failure in an upstream tributary is believed to be partly responsible for the sediment pulse in Granite Creek. Juvenile bull trout population densities ranged from 4.9 - 11.8 fish >. 75 mm/100m2 in the two Middle Fork tributaries sampled, Morrison Creek and Ole Creek. Large numbers of brook trout may pose a threat to bull trout spawning in Bear Creek (Vashro pers. comm. 1992). Upper and Lower Isabel Lakes in Glacier National Park contain some unusual bull trout. Bull trout in these lakes are more brightly colored, especially red, than is usual. In addition, they tend to be slightly smaller than the cutthroat trout which are present in these lakes. No bull trout larger than 300 mm has been collected to date. A life history study is being planned by the Park staff (Marnell pers. comm. 1992). Harrison Lake in Glacier National Park contains bull trout along with westslope cutthroat trout, brook trout, and kokanee. Very little is known about the status of this population of bull trout (Marnell pers. comm. 1992). McDonald Lake contains bull trout, although lake trout is the dominant species in the lake. Kokanee, lake whitefish, and an occasional rainbow or brook trout are also seen. Bull trout are considered to be uncommon (Marnell pers. comm. 1992). Hydrologic unit # 17010208 - Flathead Lake and the mainstem Flathead River above Flathead Lake Historic distribution The Rathead River above Flathead Lake was used as a migration cortidor for bull trout moving between Flathead Lake and their spawning areas in the tributaries. In addition, there were likely fluvial populations of bull trout residing in the river and 46 Table 10. Summary of Middle Fork of the Flathead River bull trout spawning site inventories from 1979-1991 in the stream sections monitored annually. 1 YEAR\STREAM MORRISON GRANITE LODGEPOTF, OLE TOTA 1 1979 25' 14 32 a 71* 1980 75 34 14 19 142 1981 32* 14* 18 19 83* II 1982 86 34 23 51 194 II 1983 67 31 23 35 156 1984 38 47 23 26 P' 1985 99 24 20 30 173" 1986 52 37 42 36 167 1987 49 34 21 45 149 1988 50 32 19 59 160 . 1989 63 31 43 21 158 1990 24 21 12 20 77 1991 45 20 9 23 97 (AVE) 54 29 23 32 135 * Counts may be low due to incomplete survey " High flows may have obliterated some redds 47 Table 11 - Results of basinwide bull trout redd counts conducted in the Middle Fork of the Flathead River. STREAM\YEAR 1980 1981 1982 1986 1991 (AVE) 11 NYACK 14 14 23 27 22 20 1 PARK _. 13 87 19 30 1 OLE 19 23 51 36 23 30 II BEAR 9 12 23 21 23 18 1 LONG 8 — — ~ 12 10 1 GRANITE 34 14 34 37 20 28 1 MORRISON 75 32 86 52 45 58 LODGEPOLE 14 18 23 42 9 21 SCHAFER 10 12 17 30 12 16 DOLLY VARDEN 21 31 36 42 23 31 CLACK 10 7 7 16 11 10 BOWL 29 10 19 36 14 22 — STRAWBERRY 17 21 39 41 20 28 TRAIL 31 26 30 53 37 35 TOTAL 291 233 388 520 290 344 48 spawning in the tributary streams. There may have also been resident populations of bull trout in the small streams that drain directly into the Flathead River. Flathead Lake contained bull trout historically. Current distribution The importance of Flathead Lake and the upper Flathead River to bull trout cannot be overemphasized. The upper Flathead system adfluvial bull trout population may be the healthiest such population remaining in the United States. Due to the complex life history requirements of bull trout, all parts of the system - lake, nver, and tributaries - must be maintained in a healthy condition for bull trout to contmue to thnve in these waters. According to information gathered from the Montana Interagency Database, six reaches of the Flathead River (from the mouth to the Middle Fork) and one tributary (Truman Creek) contain bull trout (Appendix A). Bull trout in the Flathead River are considered to be uncommon, with a proportional number of large size fish. The nyer is used primarily as a migration corridor, no brook trout are present, and the habitat is rated an "A" - best value habitat. Truman Creek contains a resident population of uncommon bull trout. Brook trout are also in the stream and the habitat value is not rated. Bull trout in Flathead Lake are common, with a proportional number of large sized fish, and the habitat is of the best value. Hydrologic unit # 17010209 - the South Fork of the Flathead River Historic distribution Very little data are available concerning the South Fork of the Flathead before 1958. Prior to construction of Hungry Horse Dam the South Fork drainage was considered the major spawning area for adfluvial stocks fi-om Flathead Lake. Hungty Horse Dam was built without provisions to provide for fish passage. Consequently the connection between the South Fork of the Flathead and the rest of the drainage was broken. Approximately 38% of the total drainage area available for spawning salmomds migrating upstream from Flathead Lake was permanently blocked. This habitat was estimated to have supported between 1,840 and 2,089 adult bull trout (Zubik and Fraley 1986). 49 Current distribution When Hungry Horse Dam was constructed, it trapped adfluvial bull trout destined for Flathead Lake. These fish established an adfluvial stock in Hungry Horse Reservoir. Sampling in the reservoir has found that bull trout numbers are highest in the spring, intermediate in the fall, and lowest in the summer. The mean catches in sinking gill nets ranged from 4.7 to 6.3 fish per net in May samples and fi-om 2.0 to 4.8 fish per net in the fall collections. These catch rates from the 1980's are similar to catch rates from sampling done in the early 1970's. The mean catches in the Sullivan area (upper reservoir area) were consistently higher than in the other areas sampled. Bull trout caught ranged in length from 170 mm to 910 mm (May et al 1988). A creel census conducted in the summer of 1986 found that bull trout comprised 31% of the catch in Hungry Horse Reservoir (approximately 2,168 fish). The overall angler catch rate for bull trout was 0.10 fish/hr, but this figure varied Avidely by area and by season. The highest average catch rate was in the Sullivan area (0.26 fish/hr). For the reservoir as a whole, the month of May had the highest catch rate (0.16 fish/hr) (May and Weaver 1987). Most of the spawning and rearing areas for bull trout in this drainage are located in the backcountry areas of the Bob Marshall Wilderness Area so there has not been a great deal of survey work done to date. Important spawning tributaries that are not in designated wilderness are Wheeler, Sullivan, Quintonkin, and Bunker cks. as well as portions of the Spotted Bear River. In addition to the adfluvial bull trout population in Hungry Horse Reservoir, it is likely there are also resident, fluvial, and other adfluvial populations within the drainage. Big Salmon Lake and Doctor Lake are known to have adfluvial populations of bull trout. Several other streams have bull trout as well, however many of the streams have barrier falls which prevented bull trout from colonizing the headwaters areas (Sage pers. comm. 1992). Hydrologic unit # 170101210 - the Stillwater River drainage Historic distribution Bull trout appear to have been distributed throughout the Stillwater River drainage historically. Current distribution The lower portion of the Stillwater River, from the mouth to Hellroaring Creek, is used primarily as a migration corridor for bull trout. This portion of the river has a risk 50 of extinction rating from 11 to 12 - high risk of extinction. This is due to the low numbers of bull trout, low habitat value rating and the presence of brook trout. Ihe upper portions of the Stillwater River support spawning and rearing of bull trout. However, bull trout are still uncommon, and the habitat is rated a C - moderate value habitat. Several lakes in this drainage support adfluvial populations of bull trout: Cyclone Lake Frozen Lake, Lower and Upper Stillwater Lakes, Upper Whitefish and Whitefish Lakes and Tally Lake. Cyclone and Frozen Lakes have what appear to be the most secure populations in the drainage, with best value habitat and no brook trout. However, bull trout are uncommon in these lakes. Tributary streams which contain bull trout are Logan Creek, Sunday Creek, Swift Creek, and the East and West forks of Swift Creek. Overall bull trout are relatively uncommon in this drainage probably due to the large numbers of brook trout, roading, logging, and subdivision that has occurred m the drainage. Hydrologic unit # 17010211 - the Swan River drainage Historic distribution Historically, bull trout were able to migrate freely between the Swan River drainage and the rest of the Flathead system. The construction of Bigfork Dam m 1902 blocked upstream fish passage from Flathead Lake into the Swan River. Tag^ng studies done by Leathe and Enk (1985) indicated that the Swan River bull trout population is essentially isolated. Current distribution Leathe and Enk (1985) in their survey of 74 tributary reaches in the Swan drainage estimated that there were 31,000 stream dwelling bull trout in the Swan River tributary system. They found that bull trout were not the dominant fish species m any gradient category, but tended to be more abundant in reaches with a gradient of six percent or less. Sampling of the Swan River downstream of Cygnet Lake in 1982 found no bull trout A few juvenile bull trout were captured from the Swan River between the Salmon Prairie and the Piper Creek bridges, indicating that significant use of this reach of the river by bull trout for anything other than a migration corridor was unlikely (Leathe and Enk 1985). 51 Anglers fishing in the Swan River in 1983 - 1984 harvested an estimated 564 bull trout with an average catch rate of 0.06 fish/hr. The harvest of bull trout from the tributaries above Swan Lake was estimated at 296 fish with a catch rate of 0.07 fish/hr (Leathe and Enk 1985). Gill net surveys of Swan Lake found 0.3 bull trout per floating gill net and 3.7 bull trout per sinking gill net. This latter rate is similar to catches from Flathead Lake. Most of the bull trout captured in Swan Lake were taken in the north and middle sections of the lake (Leathe and Enk 1985). Bull trout were the third most abundant fish harvested from Swan Lake in the 1983 - 1984 season. The total harvest of 739 fish was distributed relatively evenly throughout the year. The average bull trout catch rate was 0.26 fish/hr (Leathe and Enk 1985). Redd surveys done from 1982 - 1991 in the four most heavily used tributary streams located between 109 - 371 redds (Rumsey 1991) (Table 12). Seventy eight percent of all the bull trout redds occurred in approximately 29 km of habitat located in four streams - Elk, Lion, Goat and Squeezer cks (Tables 12 and 13). The most concentrated spawning use in the drainage occurs each year in Elk Creek, where 44 to 52 redds were found in the most heavily used 1 km section (Leathe and Enk 1985). Based on redd count information, spawner densities in Swan Lake appeared to be substantially higher than those in Flathead Lake or Pend Oreille Lake, Idaho (Leathe and Enk 1985). Redd counts in the Swan drainage in 1991 were 44.1% above the nine year average when comparing streams monitored annually (Rumsey 1991). The Swan River drainage also contains some isolated, resident bull trout populations. The North Fork of Lost Creek is known to contain bull trout upstream of a barrier falls. Other such resident populations may be found in the drainage in the future, but to date relatively little research has been done (Enk pers. comm. 1992). 52 TABT F 12. Summary of Swan drainage bull trout spawning site inventories from 1982- 10Q1 in the. stream sections monitored annually (Rumsey 1991). ^ 1 YEAR\STREAM ELK GOAT SQUEEZER LION TOTAL 1982 56 33 41 63 193 1 1 1983 91 39 57 49 236 II 1984 93 31 83 88 295 1 1985 19 40 24 26 109" 1 1986 53 56 55 46 210 1 1987 162 31 64 33 290 1988 201 46 9" 65 321' II 1989 186 34 67 84 371 1990 136 27 42 58 263 II 1991 140 31 101 94 366 1 (AVERAGE) 114 37 54 61 265 1 High flows may have obliterated some redds 53 TABLE 13. Bull trout redd counts from Swan drainage randomly monitored streams (Rumsey 1991). 1 STREAM 1982 1983 1984 1989 1990 1991 1 Cedar 1 — — — — 1 Cold 1 9 6 — — 5 1 Glacier 1 ~ ~ — -- Holland — — — — 30 1 — Jim __ 7 6 39 22 40 1 North Lost 9 6 7 ~ 13 5 1 South Lost 2 1 12 ~ ~ 1 Piper 1 25 — 18 —^ South Woodward ~ ~ — — ~ 8 Woodward 1 — — — 28 TOTAL 13 25 32 64 35 135 Some brook trout X bull trout hybridization has been documented in the Swan River drainage (Weaver pers. comm. 1992). More detailed information about the bull trout of the Swan River drainage is available in Leathe et al (1985a and 1985b). Hydrologic unit # 17010212 - the Flathead River below Flathead Lake Historic distribution It is clear that, historically, bull trout were found in all the major the tributary streams draining the east side of the Flathead Indian Reservation Bull trout were probably seasonally found in the Flathead River below Flathead Lake as well although natural warm temperatures in this river may have limited bull trout during the sumnjer months. In addition, bull trout may have migrated between Flathead Lake and the lower River. The connection was broken between the lake and lower nver with the construction of Kerr Dam in 1938. The construction of the Flathead Agency Irrigation Project, beginning in the 1910's, broke the connection between many of the tributary streams and the Flathead 54 River. Cross and DosSantos (1988) estimated that construction of irrigation diversions, canals, and dams on the tributaries eliminated access to more than 100 km of spawnmg and rearing habitat. The degree to which bull trout historically utilized the Little Bitterroot River drainage, on the west side of the Reservation, is unknown. Bull trout are not currently found anywhere within the drainage. It is possible that naturally warm water temperatures and high turbidity prevented much buU trout colonization of this nver. However, it is difficult to know what the natural conditions were like m this dramage. Current distribution Bull trout are the least common salmonid found in the lower Flathead River. During extensive electrofishing surveys between 1983 and 1986, 17 bull trout were captured, ranging in length from 190 to 850 mm TL. These fish averaged 480 mm TL (Age 5) in length and 1,311 g in weight. The authors noted that bull trout captured in the lower portions of the river were larger than those found in the upper portions of the river (DosSantos et al 1988). In the Jocko River, a small resident bull trout population is found upstream of the Jocko "K" Canal, 42 km upstream of the mouth. The Jocko "K" Canal is a bamer to fish movement (DosSantos et al 1988). The construction of McDonald Lake Dam, Mission Dam, and St. Mary's Dam trapped bull trout in the upper reaches of these drainages. These reservoirs now contam adfluvial populations of bull trout. These status of these populations are unknown, but these fish appear to be in a precarious situation. Research on these populations is planned for the summer of 1992 (DosSantos, pers. comm. 1992). Hydrologic unit # 17010213 - the Qark Fork River below the Flathead River Historic distribution Historically, the tributaries of this stretch of river were used for spawning by adfluvial bull trout from Lake Pend Oreille. In addition, they likely supported fluvial bull trout from the main river as well. The construction of a series of hydroelectric dams on the Clark Fork River blocked the movement of fish between Lake Fend Oreille and the upper tributaries. These dams have also isolated the fluvial bull trout stocks and changed their habitat fi-om a river to a reservoir. Echo (1954) stated that bull trout were among the game fish found in Thompson Lakes. Bull trout are not recorded as being present in these lakes today. 55 Brunson (1952) trapped bull trout in the Bull River and Prospect Creek near Thompson Falls. The traps were operated from August 1 - 8, 1950 at the mouths of the creeks. He speculated that these fish were migrants fi-om the Clark Fork River and possibly Lake Pend Oreille. The traps collected 51 breeding adults, 23 males and 28 females ranging in weight from 1 lb 10 oz to 8 lb 12 oz. Today bull trout are listed as rare in the Bull River, and uncommon in Prospect Creek. As mentioned earlier, the adfluvial run from Lake Pend Oreille can no longer access these waters. Onishuk (1959) relates catching a large bull trout in White Pine Creek. This stream is not listed in the database as containing bull trout today. Opheim (1966) collected bull trout in Twelvemile Creek in July 1963. In this study, four sections were sampled with an average of 5 - 7 bull trout/section. The average length of these fish ranged from 6.0 - 7.9". Twelvemile Creek was also sampled in 1953 and 1961. In 1953, one section was electrofished and no bull trout were found. In 1961 three sections were sampled and no bull trout were found in two sections, but 5 bull trout were collected from the third section (Opheim 1966). More recent studies m this stream have not found any bull trout, but lots of brook trout (Walker pers. comm. • 1992). A few natural barriers existed - Vermillion Falls on the Vermillion River may have been the upstream boundary for bull trout on this tributary. Thompson Falls may have prevented upstream fish migration. However, bull trout were present above Thompson Falls historically, as they are today. Current distribution Bull trout are uncommon in the mainstem of the Clark Fork River. A few fish are known or expected to use Rock Creek, the Vermillion River, Cooper Creek, and Big Spruce Creek (Table 1). Bull trout are rare in the Bull River and its tributanes. Several tributary streams go dry at the lower ends due primarily to natural factors and this could influence their usefulness to bull trout. Brook trout are present in about 85% of the bull trout reaches (Table 3). Of the 50 reaches that could be evaluated for risk of extinction, 40 (80%) had a risk of extinction of 8 - moderate risk (Table 6). Hydrologic unit #10010002 - St Mary's River drainage Historic distribution Bull trout are commonly found on both sides of the continental divide in Canada. In Montana, the St. Mary's drainage is the only drainage east of the continental divide known to have bull trout. The historic range and distribution of the species is unknown, although Brown (1971) stated that bull trout are found throughout the Saskatchewan River drainages in the state. 56 Current distribution BuU trout are found in St. Mary Lakes and the St. Mary River on the Blackfeet Indian Reservation. Spawning streams are likely Boulder Creel^ Divide Creek, Otatso Creek, Kennedy Creek, and Lee Creek. There is no upstream fish passage past the Milk River Irrigation Diversion. The status of these populations is unknovm, although they are believed to have been impacted by non-native interactions (probably brook trout) and agriculture. Within Glacier National Park, Cracker Lake is a small headwaters lake situated above several falls in the St. Mary drainage which contains a stunted population of bull trout. Although no stocking records exist, bull trout were believed to have been introduced near the turn of the century when a small copper mine was »" operation at the site The genetic data available to date support the initial diagnosis that the population was introduced (Marnell 1985). Bull trout in this lake are extremely abundant, but stunted. Fish spawn at 250 mm in length in the outlet of the lake It appears that Cracker Lake bull trout are feeding exclusively on plankton and detntus (Marnell pers. comm. 1992). Summary and conclusions Bull trout are highly sensitive to environmental disturbance. In most areas of Montana bull trout populations are clearly in decline. Only the upper Flathead dminage and the Swan River drainage still support relatively healthy populations of large adfluvial and fluvial bull trout that are able to complete long migrations to their spawning tributaries Even these two populations are not safe from the impacts of dam building, hSt degradation, over-haLst, hybridization with brook trout, and competition with other non native species. Particularly in the upper Flathead system, concern h^ been e^ressed about the status of this population given the low redd counts found the last year or two. The Rock Creek drainage (tributary to the upper Clark Fork River) seems to have relatively abundant numbers of bull trout. While man-caused habitat alterations m L drainage have been relatively minor, brook trout are found ^-^^^^^^^^^^^^^^^^ many of its tributaries. Some hybridization is suspected to have occurred. This drainage n not contain any large lakes which could support large adfluvial bull trout, such as are found in the Flathead system. In the rest of the historic range of bull trout within Montana, bull trout are largely relegated to small, isolated, resident populations. The Blackfoot River and the Kootenai Rive'r still support small populations of fluvial bull trout, but the """jf^ ^^ ;"^»*f ^^ supporting these populations is low. They appear to be at a relatively high nsk of becoming extinct Bull trout are rare in most of the other large nvers m western Montana. 57 A number of smaller lakes support adfluvial populations of bull trout. Glacier National Park contains some of the most significant and pristine populations of this type. To date, most of the research on bull trout has been concentrated on the larger, migratory populations. It is likely that there are additional resident populations in Montana that have not yet been documented. There is relatively little mformation available about the life history and limiting factors of these populations. The genetic information available makes it clear that in order to preserve genetic diversity in bull trout, every population needs to be protected. Changes m land use and fisheries management may be needed to protect this fish in its remammg habitat. 58 LITERATURE CITED Man, J.H. 1980. Ufe history notes on the Dolly Varden charr ( SaWelinus malma) in the upper Clearwater River, Alberta. Alberta Energy and Natural Resources , Fish and Wildlife Division, Red Deer, Alberta, cited in Pratt, K.L. 1^2. A review of bull trout life history, in: Howell, P.J. and D.V. Buchanan, eds. Proceedings of the Gearhart Mountain bull trout workshop. Oregon Chapter of the Amencan Fisheries Society, Corvallis, Oregon. 67 p. Anonymous. 1954. The Hellgate Survey. Anthropology and Sociology Paper Vol. 16, Montana State University, Missoula. Bangham, R.V. and J.R. Adams. 1954. A survey of the freshwater fishes from the mainland of British Columbia. J. Fish. Res. Bd. Can. 11: 673-708. Bjomn, T.C 1961. Harvest, age structure, and growth of game fish populations from Priest and Upper Priest Lakes. Trans. Am. Fish. Soc. 100:423-438. Boae T D 1987. Food habits of bull char (Salvelinus confluentus) and rainbow trout, rs«1mn pairdemi \ coexisting in a foothills stream in northern Alberta. Canadian Field Naturalist 101: 56-62. Bond, CE. and J.J. Long. 1979. Unique fish survey, Fremont National Forest Final Report. Cooperative agreement No. 237. U.S. Forest Service Pacific Northwest Range Experimem Station and Oregon State University, Corval is, Oregon, cited in: Willamette National Forest. 1989. Biology of the bull trout ( Salvelmus confluentus) : a literature review. Eugene, Oregon. Brown, C.J.D. 1971. Fishes of Montana . Big Sky Books, Bozeman, Montana. 207 p. Brown LG. 1992. Draft management guide for the bull trout Salvelinus confluentus '(Suckley) on the Wenatchee National Forest. Washington Department of Wildlife, Wenatchee, Washington. Brunson, R.B. 1952. Egg counts of Salvelinus malma from the Clark's Fork River, Montana. Copeia. 1952: 196-197. Cavender, T.M. 1978. Taxonomy and distribution of the bull trout, Salvelinus confluentus (Suckley) from the American northwest. Calif. Fish and Game 64: 139 - 174. Chisholm, I. and P. Hamlin. 1987. Libby Reservoir angler creel <^';^':-^%^l-^''^''^^' 3li 1987. Interim report. Montana Department of Fish, Wildlife and Parks, 59 Kalispell, Montana. Prepared for BonnevUle Power Administration, Portland, Oregon. Project No. 84-52. Chisholm, I., M.E. Hensler, B. Hansen, and D. Skaar. 1989. Quantification of Obby Reservoir levels needed to maintain or enhance reservoir fishenes. Methods and data summary, 1983 - 1987. Montana Department of Fish, Wildlife and Parks, Kalispell, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Agreement No. DE-AI79-83-BP 12660. Project No. 83-467. Clancy, C. 1992. Personal communication, Montana Department of Fish, Wildlife and Parks, Hamilton, Montana. Cross, P.D. and J.M. DosSantos. 1988. Lower Rathead System Fisheries Study. Executive Summary, Volume I. Final Report FY 1983 - 1987. Confederated Salish and Kootenai Tribes, Pablo, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-AI79-83BP39830. Crouse, M., C. Callahan, K. MaLueg, and S.E. Dominguez. 1981. Effects of fine sediments on growth of juvenile coho salmon in laboratory streams. Trans. Am. Fish. Soc. 110: 281-286. DosSantos, J.M. 1992. Personal communication. Confederated Salish and Kootenai Tribes, Pablo, Montana. DosSantos, J.M., J.E. Darling, and P.D. Cross. 1988. Lower Flathead Systern Fisheries Study. Main River and Tributaries, Volume II. Final Report FY 1983 - 1987. Confederated Salish and Kootenai Tribes, Pablo, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-AI79- 83BP39830. Echo, J.B. 1954. Some ecological relationships between yellow perch and cutthroat trout ' in Thompson Lakes, Montana. Trans. Am. Fish. Soc. 84: 239-248. Enk, M. 1985. Modelling the effects of forest sediment on bull trout, in D.D. McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. Enk, M. 1992. Personal communication. Flathead National Forest, Bigfork, Montana. Fraley, J.J and B.B. Shepard. 1989. Life history, ecology, and population status of migratory bull trout r s«1ve1inus confluentus') in the Flathead Lake and River system, Montana. Northwest Science. 63: 133-143. 60 Gould, W.R. 1987. Features in the early development of bull trout Salvelinus confluentus. Northwest Science. 61: 264-268. 61 Hanzel, D.A. 1985. Past and present status of bull trout in Flathead Lake, in D.D. McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. Oregon State Game Commission. 1968. Annual Report, Fishery Division, citjari in: Willamette National Forest. 1989. Biology of the bull trout (Salvelinus confluentus") : a literature review. Eugene, Oregon. Hanzel, D.A. 1976. The seasonal, area, and depth distribution of cutthroat trout and Dolly Varden in Flathead Lake. Job Perf. Rept. Proj. No. F-33-F10, Job I-a. Montana Department of Fish, Wildlife and Parks, Kalispell, Montana. 3p. Hanzel, D.A. 1985. Past and present status of bull trout in Flathead Lake, in D.D. McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. Heimer, J.T. 1965. A supplemental Dolly Varden spawning area. Master's Thesis, University of Idaho, Moscow, Idaho, cited in: Willamette National Forest. 1989. Biology of the bull trnutr Salvelinus confluentus^ : a literature review. Eugene, Oregon. Huston, J.E. 1974. Hungry Horse Reservoir study. Job Progress Report, Project F-34-R- 7, Job Ila. Montana Department of Fish, Wildlife and Parks, Kalispell, Montana. Jeppson, P.W. and W. S. Platts. 1959. Ecology and control of the Columbia River squawfish in northern Idaho lakes. Trans. Am. Fish. Soc. 88: 197-203. Leary, R.F. 1985. Electrophoretic variation within and between populations of bull trout in the upper Columbia River drainage, in D.D. McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. Leary, R.F. 1992. Personal communication. University of Montana, Missoula, Montana. Leary, R.F., F. W. Allendorf, and S. H. Forbes. 1991. Conservation genetics of buU trout in the Columbia and Klamath River drainages, submitted for publication to Conservation Biology. Leary, R.F., F.W. Allendorf, and K.L. Knudsen. 1983. Consistently high meristic counts in natural hybrids between brook trout and bull trout. Systematic Zoology. 32: 369-376. 62 Leathe, S.A., S. Bartelt, and L.M. Morris. 1985a. Cumulative effects of micro-hydro development on the fisheries of the Swan River drainage, Montana. 11. Technical information. Montana Department of Fish, Wildlife and Parks, KalispeU, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-A179-82BP36717 Project 82-19. Leathe, S.A., S. Bartelt, and L.M. Morris. 1985b. Cumulative effects of micro-hydro development on the fisheries of the Swan River drainage, Montana. III. Fish and habitat inventory. Montana Department of Fish, Wildlife and Parks, KalispeU, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-A179-82BP36717 Project 82-19. Leathe, S.A. and M.D. Enk. 1985. Cumulative effects of micro-hydro development on the fisheries of the Swan River drainage, Montana. I. Summary Report. Montana Department of Fish, Wildlife and Parks, KalispeU, Montana, and the Flathead National Forest, Bigfork, Montana. Prepared for the Bonneville Power Administration, Contract Nos. DE-A179-82BP36717 and DE-A179-83BP39802, Portland, Oregon. Leathe, S.A. and P.J. Graham. 1982. Flathead Lake fish food habits study - Final Report. Montana Department of Fish, Wildlife and Parks, KalispeU, Montana. 114 p. Markle, D.F. 1992. Evidence of buU trout X brook trout hybrids in Oregon, in Howell, P.J. and D.V. Buchanan, eds. Proceedings of the Gearhart Mountain buU trout workshop. Oregon Chapter of the American Fisheries Society, CorvaUis, Oregon. 67 p. MameU, L.F. 1985. Bull trout investigations in Glacier National Park, in D.D. McDonald, ed. Proceedings of the Flathead Basin buU trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. MameU, L.F. 1992. Personal communication. Glacier National Park, West Glacier, Montana. Marotz, B. 1992. Personal communication. Montana Department of Fish, Wildlife and Parks, KalispeU. May, B., J.E. Huston, and S. McMullin. 1979. Lake Koocanusa post-impoundment fisheries study. Completion Report. Montana Department of Fish, Wildlife and Parks, KalispeU, Montana. 63 May, B. and T. Weaver. 1987. Quantification of Hungry Horse Reservoir water levels needed to maintain or enhance reservoir fisheries. Annual Report 1986. Montana Department of Fish, Wildlife and Parks, Kalispell, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-AI79- 84BP12659. Project No. 83-465. May B. and 7 other authors. 1988. Quantification of Hungry Horse Reservoir water level needed to maintain or enhance reservoir fisheries. Methods and data summary 1983-1987. Montana Department of Fish, Wildlife and Parks, Kalispell, Montana. Prepared for Bonneville Power Administration, Portland, Oregon. Contract No. DE-AI79-84BP12659. Project No. 83-465. McCart, P. 1985. Parallels between life histories of bull trout and far northern species, in D.D. McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. McPhail, J.D. and C.B. Murray. 1979. The early life history and ecology of Dolly Varden r Salvelinus malma^ in the upper Arrow Lakes. Department of Zoology and Institute of Animal Resources, University of British Columbia, Vancouver, Bntish Columbia. 113 p. Montana Department of Fish, Wildlife and Parks. 1992. Status of bull trout in the Flathead drainage - Draft. Kalispell, Montana. Moomaw, Cannon, and Hoyt. 1952. An Archeological Survey of the Missoula Valley. Moyle, P.B. 1976. Inland Fishes of California. University of California Press. Nelson, J.S. 1965. Effects of fish introductions and hydroelectric development on fishes in the Kamamskis River system. Alberta. J. Fish. Res. Bd. Can. 22: 721-753. Oliver G. 1979. A final report on the present fisheries use of the Wigwam River with an 'emphasis on the migratory life history and spawning behavior of Dolly Varden char, Salvelinus malma (Walbaum). Fisheries investigations m tributaries of the Canadian portion of Libby Reservoir. British Columbia Fish and Wildlife Branch, Victoria, British Columbia, cited in: Willamette National Forest. 1989. Biology of the bull trout r Salvelinus confluentusV a literature review. Eugene, Oregon. Onishuk, M. 1959. Poor man's salmon. Montana Sports Outdoors. 1: 9 - 13. Perkinson, D. 1992. Personal communication. U.S.D.A. Forest Service, Libby, Montana. 64 Peters, D. 1992. Personal communication. Montana Department of Fish, Wildlife and Parks, Missoula, Montana, Pratt K.L 1984. Habitat selection and species interactions of juvenile westslope ' cutthroat trout and bull trout in the upper Flathead River basin. Master s thesis, University of Idaho, Moscow, Idaho. Pratt K 1985. Habitat preferences of juvenile bull trout in the Flathead River basin, in ' D D McDonald, ed. Proceedings of the Flathead Basin bull trout biology and population dynamics modeling exchange. Fisheries Branch, British Columbia Ministry of Environment, Cranbrook, British Columbia. Pratt K.L. 1992. A review of bull trout life history, in: Howell, P.J. and D.V. Buchanan, ' eds. Proceedings of the Gearhart Mountain bull trout workshop. Oregon Chapter of the American Fisheries Society, Corvallis, Oregon. 67 p. Ratliff, D, 1987. Bull trout spawning report, Metolius River tributaries, 1987. Portland General Electric, Portland, OR. cited in: Willamette National Forest. 1989. Biology of the bull trout ( B A 6 FLATHEAD R, S FK SOLDIER CR LOWER TWIN CR 03601.00 V 1 > B A 6 FLATHEAD R, S FK LOWER TWIN CR TWIN CR 03700.00 V 9 B A 6 FLATHEAD R, S FK TWIN CR TIN CR 03800.00 V P B A 6 FLATHEAD R, S FK TIN CR SPOTTED BEAR R 03801.00 V P B A 6 FLATHEAD R, S FK SPOTTED BEAR R ADDITION CR 03900.00 V P B A 6 FLATHEAD R, S FK ADDITION CR JUNGLE CR 04300.00 V ? B A 6 FLATHEAD R, S FK JUNGLE CR HARRISON CR 04500.00 V ? B A 6 FLATHEAD R, S FK HARRISON CR LOST JACK CR 04600.00 V ? 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CR QUINTONKON CR BALL CR BRANCH CR CONNER CR SLIDE CR HEADWATERS HEADWATERS HEADWATERS TRAPPER CR WHITE R, S FK NEEDLE FALLS SOURCE WILDCAT CR HEADWATERS HAHN CR BABCOCK CR MARSHALL CR 08900.00 05300.00 05400.00 20201.00 20202.00 06900.00 12600.00 12601.00 MOUT 19801.00 19801.00 03100.00 14700.00 11800.00 11800.13 11801.00 11802.00 12000.00 12100.00 03000.00 03200.00 03201.00 03202.00 03400.00 03401.00 14800.00 12500.00 02700.00 11400.00 11401.00 11401.00 01600.00 01700.00 09200.00 09300.00 09700.00 U R R R R V U U U U D V V V V V V V V V V V V V V V V V V V V V R C c B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B B N N N D D A D D N N B B A A A A A A A A A A B A B B B B C C A B N N N 10 10 6 9 9 6 7 6 6 6 6 6 6 6 6 6 6 7 6 7 7 7 7 8 8 6 7 Lake Name Lower Boundary Upper Boundary Lakes RRN Abundance Use Genetics Habitat Risk Rating Rating BIG SALMON L MOUTH HUNGRY HORSE RES MOUTH NOH_TRANSPORT REACH 07500.00 D A B A 5 NON TRANSPORT REACH 00300.00 DA B A 5 stream Name Lower Boundary STATUS OF BULL TROUT IN HONTAMA Stillwater Drainage #17010210 Streams Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating ANT ICE CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR LOGAN CR STILLUATER R STILLWATER R STILLUATER R STILLWATER R STILLWATER R STILLWATER R STILLUATER R STILLWATER R STILLUATER R STILLUATER R STILLUATER R STILLUATER R STILLUATER R STILLUATER R STILLUATER R STILLUATER R STILLWATER R STILLWATER R SUNDAY CR SUNDAY CR SUNDAY CR SUNDAY CR SUNDAY CR SUNDAY CR SUNDAY CR SWIFT CR SUIFT CR SWIFT CR SUIFT CR, E FK SWIFT CR, U FK SUIFT CR, W FK UHITEFISH R MOUTH MOUTH GOOD CR EVERS CR TALLY L JOHNSON CR SMOKE CR EAST SANKO CR SANKO CR REID CR GRIFFIN CR OETTIKER CR TAYLOR CR BILL CR MOUTH SPRING CR UHITEFISH R BEAVER CR TOBIE CR UNNAMED LOGAN CR L STILLUATER L MARTIN CR LE BEAU CR U STILLUATER L SPRING CR SUNDAY CR HUY 93 BRIDGE HELLROARING CR FITZSIMMONS CR CHEPAT CR RUSKY CR MOUTH LOUIS CR HARVEY CR PAUL CR BLESSED CR TOM CR ADVENT CR UHITEFISH L ANT ICE CR SWEDE CR mUTH MOUTH UNNAMED MOUTH HEADWATERS 01100.00 C L B N GOOD CR 02400.00 E C E N EVERS CR 03200.00 E C E N TALLY L 03201.00 E C E N JOHNSON CR 03600.00 U J E N SMOKE CR 03601.00 U J E N EAST SANKO CR 03602.00 u J E N SANKO CR 03603.00 u J E N REID CR 03604.00 u J E N GRIFFIN CR 03605.00 u J E N OETTIKER CR 04200.00 u J E N TAYLOR CR 04201.00 u J E N BILL CR 04202.00 u J E N CYCLONE CR 04203.00 u J E N SPRING CR 00100.00 R C E D 12 UHITEFISH R 00101.00 R C E D 12 BEAVER CR 01400.00 R C E D 12 TOBIE CR 01401.00 R C E D 12 UNNAMED 01402.00 R c E D 12 LOGAN CR 01403.00 R c E D 12 L STILLUATER LK 01500.00 R c E D 12 MARTIN CR 01501.00 U c E D 11 LE BEAU CR 01600.00 U c E D 11 U STILLUATER L 01601.00 U c E D 11 SPRING CR 01601.13 U c E D 11 SUNDAY CR 01602.00 U c E D 11 HUY 93 BRIDGE 01/00.00 U c E N HELLROARING CR 01700.00 U c E N FITZSIMMONS CR 01701.00 V J E C 10 CHEPAT CR 01900.00 V J E C 10 RUSKY CR 01901.00 V J E C 10 HEADUATERS 01902.00 V J E C 10 LOUIS CR 02000.00 E z E N HARVEY CR 02001 .00 E z E N PAUL CR 02002.00 E z E N BLESSED CR 02003.00 E z E N TOM CR 02004.00 E z E N ADVENT CR 02005.00 E z E N HEADWATERS 02100.00 E z E N ANT ICE CR 00600.00 V J D A 7 SWEDE CR 04300.00 V J A 7 SUIFT CR, E FK 04301 .00 V J D A 7 HEADUATERS 00700.00 c L B N UNNAMED 00800.00 c L B N HEADUATERS 00900.00 c L B N ROSE XING BRIDGE 00200.00 R C E N » STATUS OF BULL TROUT IN MONTANA Sti I Iwater Drainage #17010210 Streams Stream Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Rating Habitat Risk Rating UHITEFISH R UHITEFISH R UHITEFISH R UHITEFISH R UHITEFISH R ROSE XING BRIDGE HODGSON ROAD BRIDGE UALKER CR HASKILL CR COU CR HODGSON ROAD BRIDGE UALKER CR HASKILL CR COU CR UHITEFISH L 00200.00 00200.00 00202.00 00203.00 00204.00 R R R R R C C C C C E E E E E N N N N N Lakes f Lake Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Rating Habitat Risk Rating CYCLONE L FROZEN L MOUTH NON_TRANSPORT REACH U U A A B B A 6 A 6 LOUER STILLUATER L TALLY L TALLY L MOUTH MOUTH NON TRANSPORT REACH NON TRANSPORT REACH 03400.00 03500.00 U U U A A A E E E B 9 B 9 B 9 UPPER UHITEFISH L UHITEFISH L UHITEFISH L UHITEFISH L MOUTH MOUTH MOUTH MOUTH NON_TRANSPORT REACH NON TRANSPORT REACH NON TRANSPORT REACH NON_TRANSPORT REACH 00400.00 00500.00 04400.00 U V V V A A A A E E E E B 9 B 9 B 9 B 9 STATUS OF BULL TROUT IN MONTANA Swan Drainage #17010211 Streams i stream Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating BEAVER CR BETHEL CR BUCK CR CEDAR CR COLD CR COLD CR COLD CR COLD CR COLD CR, N FK COLD CR, S FK COLD CR, S FK COONEY CR COONEY CR DOG CR DOG CR DOG CR ELK CR ELK CR ELK CR ELK CR, N FK ELK CR, N FK ELK CR, S FK GLACIER CR GLACIER CR GOAT CR GOAT CR GOAT CR HOLLAND CR JIM CR JIM CR LION CR LION CR LOST CR LOST CR, N FK LOST CR, N FK LOST CR, S FK PIPER CR PIPER CR S WOODWARD CR SOUP CR SOUP CR SQUEEZER CR SQUEEZER CR SWAN R SWAN R SWAN R MOUTH UNNAMED 04400.00 R J E N MOUTH HEADWATERS 10400.00 A Z B N MOUTH UNNAMED 08100.00 U Z E N MOUTH UNNAMED 07000.00 U J E N MOUTH COID CR, S FK 01500.00 V J D B 8 COLD CR, S FK UNNAMED 01600.00 V J D B 8 UNNAMED COLD CR, N FK 01601.00 V R D A 7 COLD CR. N FK HEADWATERS 01800.00 V R D A 7 MOUTH HEADWATERS 01700.00 C J B N MOUTH 2.1 MILES ABOVE MOUT 01900.00 U Z E N 2.1 MI ABOVE MOUTH HEADWATERS 01900.00 U Z E N MOUTH 2.7 MILES ABOVE MOUT 08700.00 R J B N 2.7 MI ABOVE MOUTH HEADWATERS 08700.00 R J B N MOUTH CAT CR 09600.00 R J E N MOUTH RD 3.3 MI ABOVE MOUT 09601 .00 R J E N RD 3.3 MI ABOVE MOUT HEADWATERS 09601.00 R J E N MOUTH 5.4 MI ABOVE MOUTH 02100.00 V J I A 7 5.4 MI ABOVE MOUTH HEADWATERS 02100.00 V J I A 7 UNNAMED ELK CR, N FK 02101 .00 V J I A 7 MOUTH .9 MILES ABOVE MOUTN 02200.00 V J B B 7 MOUTH .9 MILES ABOVE MOUTH 02200.00 V J B B 7 .9 MI ABOVE MOUTH ELK L 02300.00 U J B N KRAFT CR CRAZY HORSE CR 03100.00 A J E N CRAZY HORSE CR GLACIER L 03101 .00 C J E N MOUTH SQUEEZER CR 05000.00 V J 1 A 7 SQUEEZER CR SCOUT CR 05200.00 V J I A 7 SCOUT CR BETHEL CR 05201.00 V J I B 8 HOLLAND L HEADWATERS 04900.00 V J B B 7 MOUTH JIM CR, W FK 01300.00 U J E N JIM CR, U FK HEADWATERS 01301.00 U J E N MOUTH 6 MILES ABOVE MOUTH 10200.00 V J B B 7 6 MILES ABOVE MOUTH HEADWATERS 10200.00 V J B B 7 MOUTH LOST CR, N FK 05500.00 U J E H MOUTH UNNAMED 05700.00 V J D A 7 UNNAMED HEADWATERS 05701.00 R L B B 8 MOUTH HEADWATERS 05600.00 V J D B 8 MOUTH 1.2 MILES ABOVE MOUT 07100.00 U J E N 1.2 MI ABOVE MOUTH HEADWATERS 07100.00 U J E N MOUTH UNNAMED 01101.00 R >) E N MOUTH 0.4 MILES ABOVE CAMP 05400.00 R Z E N 0.4 MI ABOVE CAMP HEADWATERS 05400.00 R z E N MOUTH BRIDGE AT RM 4.0 05100.00 V J I A 7 BRIDGE AT RM 4.0 HEADWATERS 05100.00 V J I A 7 FLATHEAD L MUD LAKE OUTLET 00100.00 U C E N MUD LAKE OUTLET WOLF CR 00200.00 U C E N WOLF CR BEAR CR 00201.00 u c E N f * STATUS OF BULL TROUT IN MONTANA Swan Drainage #17010211 Streams t Stream Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating SWAN R BEAR CR SWAN L 00202.00 U c E N SWAN R SWAN L YEW CR 00700.00 V c D SWAN R YEW CR LIME CR 00701.00 V c D SWAN R LIME CR GILDART CR 00702.00 V c D SWAN R GILDART CR LOST CR 00900.00 V c D SWAN R LOST CR CILLY CR 00901.00 V c D SWAN R CILLY CR SOUP CR 00902.00 V c D SWAN R SOUP CR WHITETAIL CR 00903.00 V c D SWAN R WHITETAIL CR SQUAW CREEK 01000.00 V c D SWAN R SOUAW CREEK WOODWARD CR 01001.00 V c D SWAN R GOAT CR CEDAR CR 01200.00 V c D SWAN R CEDAR CR LION CR 01201.00 V c D SWAN R LION CR PIPER CR 01202.00 V c D SWAN R PIPER CR JIM CR 01203.00 V c D SWAN R JIM CR ALDER CR 01400.00 V c D SWAN R ALDER CR PONY CR 01400.13 V c D SWAN R PONY CR CONDON CR 01401.00 V c D SWAN R CONDON CR COLD CR 0140?. 00 V c D SWAN R COLO CR ELK CR 02000.00 V c D SWAN R ELK CR GLACIER CR 02400.00 V c D SWAN R GLACIER CR COONEY CR 03200.00 V c D SWAN R COONEY CR RUMBLE CR 03201.00 V c D SWAN R RUMBLE CR BUCK CR 03202.00 V c SWAN R BUCK CR BARBER CR 03203.00 V c D SWAN R BARBER CR HOLLAND CR 03204.00 V c D SWAN R HOLLAND CR BEAVER CR 03300.00 V c D SWAN R BEAVER CR LINDBERGH L 03400.00 V c D SWAN R WOODWARD CR GOAT CR 06200.00 V c D WOODWARD CR MOUTH S WOODWARD CR 01100.00 R J E N Lake Name Lower Boundary Upper Boundary Lakes RRN Abundance Use Genetics Habitat Risk Rating Rating HOLLAND L MOUTH HOLLAND L MOUTH LINDBERGH L MOUTH LINDBERGH L MOUTH SWAN L MOUTH SWAN L MOUTH SWAN L MOUTH NON TRANSPORT REACH 04700.00 D A NON TRANSPORT REACH 04800.00 D A NON TRANSPORT REACH 03600.00 D A NON TRANSPORT REACH 03700.00 D A NON TRANSPORT REACH 00400.00 D A NON TRANSPORT REACH 00500.00 D A NON TRANSPORT REACH 00600.00 D A A A A A A A A 7 7 7 7 6 6 6 STATUS OF BULL TROUT IN MONTANA Lower Flathead #17010212 Streams « stream Name Lower Boundary Upper Boundary RRN i ^bundance Use Genetics Habitat Risk Rating Rating FLATHEAD R MOUTH SEEPAY CR 00100.00 R D D 1 FLATHEAD R SEEPAY CR CAMAS CR 00300.00 R D D 1 FLATHEAD R CAMAS CR RACEHORSE GULCH 00400.00 R D D ' FLATHEAD R RACEHORSE GULCH MAGPIE CR 00500.00 R D D 1 FLATHEAD R MAGPIE CR REVAIS CR 00700.00 R D D 1 FLATHEAD R REVAIS CR JOCKO R 00900.00 R D D FLATHEAD R JOCKO R MISSION CR 02500.00 R D D FLATHEAD R MISSION CR CROW CR 04000.00 R D D FLATHEAD R CROW CR LITTLE BITTERROOT R 05000.00 R FLATHEAD R LITTLE BITTERROOT R WHITE EARTH CR 05400.00 R D D FLATHEAD R WHITE EARTH CR FLATHEAD L 05700.00 R D D JOCKO R FINLEY CR PISTOL CR 01600.00 R E N JOCKO R JOCKO R, M FK JOCKO R, S FK 01700.00 R E N JOCKO R PISTOL CR JOCKO R, M FK 02000.00 R E N MISSION :r DRY CR HEADWATERS 03000.00 R E N POST CR UNNAMED HEADWATERS 03200.00 R E N Lakes f Lake Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating MCDONALD L MISSION RES ST MARY'S RES V R R A A A B B 7 E N E N stream Name Lower Boundary STATUS OF BULL TROUT IN MONTANA Lower Clark Fork #17010213 Streams Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating f • BULL R MOUTH BULL R, E FK 10300.00 R R A B 7 BULL R BULL R. E FK BULL R, S FK 10500.00 R R A B 7 BULL R, H FK MOUTH BULL R, N FK 10700.00 R R A B 7 BULL R, M FK BULL R, N FK HEADWATERS 10800.00 R R A B 7 BULL R, N FK MOUTH HEADWATERS 10900.00 R R A B 7 BULL R, S FK MOUTH HEADWATERS 10600.00 R R A B 7 CLARK FK R DRY CR ELK CR 00201.00 R E D 12 CLARK FK R ELK CR BIG EDDY CR 00400.00 R E D 12 CLARK FK R BIG EDDY CR BULL R 00401.00 R E D 12 CLARK FK R BULL R PILGRIM CR 00500.00 R E D 12 CLARK FK R PILGRIM CR ROCK CR 00700.00 R E D 12 CLARK FK R ROCK CR NOXON RES 00701.00 R E D 12 CLARK FK R NOXON RES BEAVER CR 02900.00 R E 12 CLARK FK R BEAVER CR DEEP CR 03500.00 R E D 12 CLARK FK R DEEP CR MOSQUITO CR 03501.00 R E D 12 CLARK FK R MOSQUITO CR GRAVES CR 03502.00 R E D 12 CLARK FK R GRAVES CR SQUAW CR 03600.00 R E D 12 CLARK FK R SQUAW CR PROSPECT CR 03700.00 R E D 12 CLARK FK R PROSPECT CR CHERRY CR 04500.00 R E D 12 CLARK FK R CHERRY CR THOMPSON R 04700.00 R E B 10 CLARK FK R THOMPSON R EDDY CR 04800.00 V D B 8 CLARK FK R EDDY CR SWAMP CR 05000.00 V D B 8 CLARK FK R SWAMP CR BUFFALO BILL CR 05400.00 V D B 8 CLARK FK R BUFFALO BILL CR LYNCH CR 05500.00 V D B 8 CLARK FK R LYNCH CR COMBEST CR 05600.00 V D B 8 CLARK FK R COMBEST CR MCLAUGHLIN CR 06000.00 V D B 8 CLARK FK R MCLAUGHLIN CR FLATHEAD R 06100.00 V D B 8 COOPER GULCH MOUTH HEADWATERS 16900.00 C B B 6 CROW CR MOUTH CROW CR, E FK 17000.00 U E N CROW CR, E FK MOUTH HEADWATERS 17200.00 U E N ELK CR MOUTH ELK CR, W FK 00300.00 U E N FISHTRAP CR MOUTH JUNGLE CR 09300.00 U E N FISHTRAP CR JUNGLE CR BASIN CR 09301.00 U E N FISHTRAP CR BASIN CR BEATRICE CR 09302.00 U E N FISHTRAP CR BEATRICE CR FISHTRAP CR, W FK 09303.00 U E N FISHTRAP CR FISHTRAP CR, W FK BEARTRAP FK 09400.00 U E N GRAVES CR MOUTH THORNE CR 09800.00 R B N GRAVES CR THORNE CR HEADWATERS 09801.00 R B N LITTLE THOMPSON R MOUTH LITTLE ROCK CR 07400.00 R E N LITTLE THOMPSON R LITTLE ROCK CR MUDD CR 07401.00 R E N LITTLE THOMPSON R MUDD CR LITTLE THOMPSON R, N 07600.00 R E N LITTLE THOMPSON R LITTLE THOMPSON R, N MCGINNIS CR 07600.13 R E N LITTLE THOMPSON R MCGINNIS CR ALDER CR 07601.00 R E N LITTLE THOMPSON R ALDER CR HEADWATERS 07602.00 R E N PILGRIM CR MOUTH HEADWATERS 00600.00 U E N PROSPECT CR MOUTH DRY CR 03800.00 V R B 8 PROSPECT CR DRY CR CLEAR CR 03900.00 V R D B 8 PROSPECT CR CLEAR CR WILKES CR 04100.00 V R D B 8 PROSPECT CR PROSPECT CR PROSPECT CR PROSPECT CR ROCK CR ROCK CR ROCK CR, W FK SWAMP CR THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R THOMPSON R, U FK THOMPSON R, W FK THOMPSON R, W FK THOMPSON R, W FK THOMPSON R, U FK VERMILION R VERMILION R VERMILION R VERMILION R WILKES CR BRUSH GULCH DAISY CR THERRIAULT GULCH MOUTH ROCK CR, U FK MOUTH NOXON RES MOUTH THOMPSON R, W FK BAY STATE CR BIG HOLE CR DEERHORN CR FISHTRAP CR LITTLE THOMPSON R BEAR CR CHIPPY CR BIG PRAIRIE CR SEMEM CR MEADOW CR BIG ROCK CR LAZIER CR MOUTH HONEYMOON CR BIG SPRUCE CR FOUR LAKES CR ANNE CR NOXON RES CANYON CR CATARACT CR LYONS GULCH BRUSH GULCH DAISY CR THERRIAULT GULCH CROW CR ROCK CR, W FK HEADWATERS HEADWATERS GALENA CR THOMPSON R, W FK BAY STATE CR BIG HOLE CR DEERHORN CR FISHTRAP CR LITTLE THOMPSON R BEAR CR CHIPPY CR BIG PRAIRIE CR SEMEN CR MEADOW CR BIG ROCK CR LAZIER CR INDIAN CR HONEYMOON CR BIG SPRUCE CR FOUR LAKES CR ANNE CR HEADWATERS CANYON CR CATARACT CR LYONS GULCH GROUSE CR 04200.00 04200.13 04201.00 04201.13 16300.00 16301.00 17800.00 10200.00 06500.00 06600.00 06800.00 07000.00 07200.00 07300.00 07700.00 07900.00 08100.00 08101.00 08102.00 08103.00 08300.00 08301.00 09600.00 09601.00 09601.13 09602.00 09603.00 10000.00 10000.13 10001.00 10002.00 V V V V R R R R V V V V V V V V V V V V V V V V V V V V V V V c c c c c c c c c c c D D D E E E B D D D D D D D D D D D D D D D D D D D D D D D B B B B C C c N B B B B B B B B B B B B B B B B B B B B B B B 8 8 8 8 11 11 11 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 8 « Lake Name Lower Boundary Upper Boundary Lakes RRN Abundance Use Genetics Habitat Risk Rating Rating NOXON RES MOUTH NON TRANSPORT REACH 00900.00 12 t 4 STATUS OF BULL TROUT IN MOMTAMA St. Mary Drainage #10010002 Streams Stream Name Lower Boundary Upper Boundary RRN Abundance Use Genetics Habitat Risk Rating Rating BOULDER CR MOUTH HEADWATERS 02100.00 Z E N DIVIDE CR MOUTH HEADWATERS 04200.00 Z E N KENNEDY CR MOUTH OTATSO CR 01100.00 z E H KENNEDY CR OTATSO CR HEADWATERS 01300.00 z E N LEE CR MOUTH HEADWATERS 00200.00 z E N OTATSO CR MOUTH HEADWATERS 01200.00 z E N ST MARY R BOUNDARY CR UNNAMED 00900.00 z E N ST MARY R UNNAMED KENNEDY CR 01000.00 z E N ST MARY R KENNEDY CR SWIFT CURRENT CR ouoo.oo z E H ST MARY R SWIFT CURRENT CR LOWER ST MARY L 02200.00 z E N ST MARY R LOWER ST MARY L DIVIDE CR 02600.00 z A E N ST MARY R DIVIDE CR ST MARY L 02700.00 z A E N ST MARY R ST MARY L HEADWATERS 03900.00 z A E N ST MARY R MOUTH BOUNDARY CR 04700.00 z A E N • Lake Name Lower Boundary Upper Boundary Lakes RRN Abundance Use Genetics Habitat Risk Rating Rating CRACKER L LOWER ST MARY L ST MARY L NON_TRANSPORT REACH NON TRANSPORT REACH NON_TRANSPORT REACH 02400.00 NON TRANSPORT REACH 02900.00 A Z Z A A A B N N