Madison-Gallatin Fisheries Annual Monitoring Report 2001 By Patrick A. Byorth and Tim Weiss Montana Fish, Wildlife and Parks 1400 S. 19 th Street Bozeman, MT 59718 August 2002 Abstract The Madison and Gallatin watersheds provide ample fishing opportunities and an abundance of high quality aquatic resources. Managing fisheries these waters provide requires consistent monitoring and assessment of long-term trends. This document summarizes survey and inventory data collected during 2001 . Trend information and current status of fisheries inhabiting major waters are provided for each survey conducted. A number of challenges exist to wild trout fisheries in the area, such as whirling disease, increased angling pressure, and drought. Nonetheless, most fisheries in the area are heaithy and likely to persist with continued protection of habitat and water quality and quantity. Acknowledgements Field surveys are generally intensive activities that require hard work under sometimes-difficult conditions. The authors appreciate the assistance of the following individuals who participated in surveys: Wally McClure , Robin Gaustad, Dan Brewer, and Darin Watschke (USFS) conducted spawning surveys on the West Fork Hyalite Creek. Pat Clancey, Gary Senger, Jody Hupka, Justin Hawkaluk, Reed Simonson, and Scott Opitz (FWP) and Wally McClure (USFS) assisted in major rivers electrofishing. A number of FWP employees assisted in Hebgen Reservoir gill netting, including Wayne Black, Deanna Meredith, Bob McFarland, Harry Whitney, Dave Pac, and Justin Hawkaluk. Lynn Bacon (formerly of Wetlands West, Inc.) assisted in Nash Spring Creek surveys. Carol Endicott (Confluence Inc.) assisted in Catron Creek surveys. Dave and Laurie Schmidt of Wade Lake Resort assisted in surveys of Cliff and Wade Lake and provided moral support. Thanks to all of those who assisted us that we were unable to list. We also appreciate the support of anglers and sportsmen who fund the protection and enhancement of our natural treasures. Introduction The Madison and Gallatin watersheds provide a diversity of fishing opportunities and an abundance of high quality aquatic resources. Approximately 40% of the total angling pressure in Montana Fish, Wildlife, and Parks (FWP) administrative Region 3 is exerted in the Madison-Gallatin district (MacFarland and Meredith 1999, 2000). Ranging from world-renowned large river trout fisheries, to over 80 alpine lakes, three reservoirs, and numerous urban ponds, this area provides substantial recreational and economic value to the residents and visitors alike. Montana Fish, Wildlife, and Parks’ Fisheries Division is funded through hunting and fishing license sales and through Federal Aid in Sport Fish Restoration Act (16 U.S.C 777-777k). Broad objectives for the work of the Fisheries Division are established in a Six-Year Operations Plan (FWP 2000a). Objectives modified from the plan are: 1. Survey and Inventory : Survey and monitor the characteristics, status, and trends of fish populations, habitats, and angler use and harvest in selected streams and lakes, 2. Technical Guidance and Information : Review projects, public and private, that have the potential to affect fisheries resources and provide technical advice to sustain and enhance fisheries resources, 3. Fish Population Management : Implement fish stocking programs in habitats that can’t sustain fisheries naturally, to maintain fish populations and angler opportunities, and 4. Aquatic Education : Enhance the awareness, understanding, and support of aquatic resources by the general public to ensure that quality aquatic resources persist that encourage recruitment of young anglers and advocates. This report summarizes survey and monitoring activities within the Madison - Gallatin District, project F- 1 1 3 R 1 for the period from January 1 , 200 1 to December 31, 2001 . Data reported herein is continuation of historic monitoring and may have been recently reported by Byorth (2000a, 2000b) and Byorth and Weiss (2001). This report provides only basic trend information. Further analysis is necessary to draw conclusions beyond basic trends. Description of Study Areas Gallatin River The Gallatin River is the easternmost of three major Missouri River headwater drainages. The East and West Gallatin rivers drain approximately 1 800 miles 2 of the Bridger, Gallatin, and Madison mountains and the Horseshoe Hills (Figure 1) (Shields et al. 1999). The area is renowned for its wild trout fishing, providing an estimated 107, 315 angler-days in 1997 and 121,146 in 1999 (McFarland and Meredith 1999, 2000). 3 Figure 1. Map of the Gallatin Drainage, showing population monitoring study sections. 4 The West Gallatin River flows north through the Gallatin Canyon, which divides the Madison and Gallatin mountain ranges. The high elevation, narrow canyon maintains cool water temperatures throughout the summer with harsh conditions in the winter. The cool summer water temperatures and long winters result in slow growing trout. An average rainbow trout in the upper West Gallatin River will grow only to 12 inches after 4 to 5 years (MFWP Files). Severe winter conditions, including hazardous anchor ice, likely regulate trout abundance in the canyon. The lower 35 river miles of the West Gallatin River is more heavily influenced by irrigation diversions and channel instability. Urban and suburban development has increased attempts to stabilize the river by channelization and riprapping. In dry years, the lower West Gallatin River becomes severely dewatered by irrigation diversions (Vincent 1978). We monitor Fall trout populations in three survey sections in the upper West Gallatin River: the Porcupine Section (2.3 miles: from Porcupine Creek to the West Fork of the West Gallatin River), Jack Smith Section (2.2 miles: Jack Smith Bridge, Highway 191 North of Big Sky) and the Williams Bridge Section (2.84 miles: Williams Bridge to 1 mile South of Gallatin Gateway) (Figure 1). Each of these sections has been electrofished intermittently since the 1980’s. Detailed maps of each section are in Appendix A. The Shed’s Bridge Section had been electrofished historically, but has become impassable due to recent channel changes The East Gallatin River forms near Bozeman, Montana at the confluence of Sourdough Creek and Rocky Creek and within a few miles it joins Bridger Creek (Figure 1). The East Gallatin flows approximately 40 river miles through a heavily developed urban, suburban, and agricultural area before its confluence with the West Gallatin River. In the past, fish populations were heavily influenced by effluent from the Bozeman Municipal Sewage Treatment Plant. The primary treatment plant was replaced by a secondary treatment facility in 1971. (Vincent and Rehwinkle 1981). Improved water quality resulted in a substantial increase in wild trout abundance (Vincent 1978, Vincent 1979, Vincent and Rehwinkle 1981). Two adjacent fall population survey sections have been sampled historically to determine the influence of the Bozeman Municipal Sewage Treatment Plant and to monitor population trends in the East Gallatin River. The Upper Hoffman section extends 0.88 miles from Springhifl Road Bridge to approximately 100 yards above the sewage outfall. The Lower Hoffman Section begins at the sewage outfall and extends 1.05 miles downstream. The East and West Gallatin rivers join approximately 12 river miles upstream of the headwaters of the Missouri River. Combined influences of irrigation withdrawals, urban development, and sedimentation appear to restrict trout populations in the mainstem Gallatin River. The Logan Section is electrofished to monitor trout populations in the mainstem. The section is 4.3 miles long extending from Nixon Bridge to near the town of Logan, Montana (Figure 1). Madison River The Madison River is arguably one of the most popular trout streams in the United States (Sample 1998, Ross 1999). The Madison River forms in Yellowstone National Park at the confluence of the Firehole and Gibbon Rivers and flows into Montana just upstream of Hebgen Reservoir (Figure 2). The 5 Madison River flows from Hebgen Dam through Quake Lake and 1 10 miles to its confluence with the Gallatin and Jefferson rivers, at the headwaters of the Missouri River. The Madison’s legendary trout fishery arose out of a Long history , beginning in 1919 with the arrival of rainbow and brown trout introduced in Yellowstone Park (Vincent 1962). Fisheries management historically meant stocking catchable-sized trout in reaches of the Madison River until 1 969, when “wild trout management” was initiated (Vincent et al. 1990). All stocking was eliminated from the Madison River by 1973 based on research demonstrating that wild trout stocks were hindered by stocking trout (Vincent 1987). Five study sections characterize the Madison River trout populations (Figure 2). Detailed maps of each section are in Appendix A. The Pine Butte section lies approximately 12.0 miles below Quake Lake, extending from Pine Butte Creek to Lyons Bridge (3.0 miles). The Madison River through this reach has fairly uniform gradient, with a network of side channels that influence spawning and recruitment. The West Fork Madison River enters the Pine Butte Section approximately 0.6 miles above Lyons Bridge. Fishing regulations oil this reach have been catch-and-release only for trout since 1978 and no fishing from boats has been allowed since 1974. Since 1995, the fishing season has been from open the third Saturday in May through the end of February to protect spawning rainbow trout. Population estimates have been conducted on the Pine Butte Section since 1977. The Snoball Section lies between Squaw Creek and Windy Point. From 1975 to 1994, the section was 4.5 miles long. The section was shortened to 4.0 miles in 1994. The Madison River in this reach has few large tributaries and fewer side channels than the Pine Butte section. The Snoball section has been used to study the impacts of angling, regulations, and disease since 1977 when it was closed to all fishing. It was opened to catch-and-release fishing for trout and fishing from boats in March 1983 (M. Lere pers. comm, and MFWP Files). To further study the impacts of angling and whirling disease, it was closed to fishing again between March 1995 and February 1997. The Madison River changes character considerably in the Varney Section, approximately 40 miles downstream from Quake Lake. This section extends from Vamey Bridge to Eight Mile Ford Fishing Access Site, a length of 4.0 miles. Brown trout predominate in the complex and heterogeneous habitats that a braided channel provides. Habitat in the Vamey section is highly influenced by ice gorging (Vincent 1990). Annual fall population surveys have been conducted in the Vamey Section since 1967. Fishing regulations allow harvest of 5 brown trout, only one over 1 8 inches long, catch-and-release only for rainbow trout, in effect since 1992. Ennis Reservoir influences the Madison River significantly. After flowing 8 river miles through Beartrap Canyon, the gradient flattens and it takes on characters of a spring creek: broad and shallow with extensive weed beds and extensive fine sediment. Water temperature is the primary limiting factor in this reach. Ennis reservoir acts as a heat sink, increasing water temperatures in the Madison River to near lethal levels in mid-summer, causing fish kills in dry, and hot years (Vincent et al. 198 1). The Norris section characterizes trout populations in this reach, extending 4.0 miles from the mouth of Warm Springs Creek to the mouth of Cherry Creek. This reach is open to fishing year-round with a combined trout limit of 5 fish, 6 Hebgen Lake Hebgen Lake is storage impoundment on the Madison River, located four miles north of West Yellowstone, MT. Hebgen Dam is owned and operated by PPL Montana under FERC License 2188 to regulate flows to the hydroelectric plant at Madison Dam near Ennis . The Teservoir first filled in 1915 after construction of Hebgen Dam. At foil pool elevation of 6534 feet above mean sea level (amsl), the reservoir’s surface area is 12668 acres. The reservoir fishery is supported by wild, self-sustaining brown trout and rainbow trout. The primary management goal at Hebgen Lake is to establish a self-sustaining rainbow trout population. Currently, wild reproduction is supplemented with annual plants of 100,000 eagle lake rainbow trout fry, a wild strain. During 1980- 1988, McBride strain Yellowstone cutthroat trout were planted in Hebgen Lake. Their inability to naturally reproduce led to the cessation of the stocking program (Hetrick 1994). Mountain whitefish, native to foe Madison Drainage, also complement the fishery. Utah chubs occupy a large proportion of fish biomass in Hebgen Lake. They were likely introduced, probably by anglers as a baitfish, around 1935 (Leik 1978). Cliff and Wade Lakes Cliff Lake is located approximately 45 miles south of Ennis, MT. It is a 620 acre natural lake at an elevation of 63 1 3 amsl. Rainbow trout have historically dominated this fishery. Natural reproduction (Cliff Lake has at least three tributaries capable of supporting spawning) was occasionally supplemented with plants of hatchery stock. Until foe 1950’s, fishing was reportedly good for rainbow trout. Cliff Lake’s fishery has struggled in foe last 40 years. A 1961 graduate project found foe lake’s rainbow trout population to be heavily parasitized (Fox 1961). This, accompanied by disease and overpopulation, was suspected as a reason for the fishery’s decline. The last rainbow trout plant was in 1969. Surveys in the 1970’s and 1980’s indicated a rebound in the lake’s rainbow trout population. Bonneville cutthroat trout were stocked experimentally in 1990 to see if the Bonneville strain would utilize the abundant forage base in Cliff Lake consisting of lake chub and white sucker. Subsequent sampling in foe 1990’s suggested foe plant failed to produce a viable reproducing population. During foe mid 1990’s, Rainbow trout numbers began a downward trend and their physical condition deteriorated. Wade Lake is located one mile north of Cliff Lake. It is a 240 acre natural lake at an elevation of 62 17 amsl. The present state record brown trout was caught in Wade Lake, which still produces trophy- sized specimens. Rainbow trout were stocked on a regular basis, as the single small spring flowing into the lake supported little spawning. In 1991, FWP, the U.S. Forest Service, and Interfluve Inc. (a Bozeman, MT- based natural resource reclamation firm) constructed a 600 ft. spawning channel at the head of Wade Lake (Brooks 1992). Stocking ceased in 1991 and foe spawning channel now provides adequate spawning habitat to sustain rainbow and brown trout populations. White suckers are also present. Wade Lake is sampled periodically to ensure trout populations are stable. 8 Hyalite Reservoir Hyalite Reservoir is an irrigation storage impoundment on Hyalite (Middle) Creek, filled in 1951 with the completion of the Hyalite (Middle) Creek Dam. In 1993, dam reconstruction raised full pool elevation 8.2 vertical feet to 6715 amsl with surface area of approximately 260 acres. Summer and fall irrigation in the Gallatin Valley and municipal diversions cause extreme fluctuations in pool elevation. Westslope cutthroat trout (Oncorhyncus clarki lewisi) were the native trout species in the drainage, but are currently restricted to a tributary of Middle Creek below the dam (FWP 2000b). Eastern brook trout (Salvelinus fontinalis) and rainbow trout (Q. mykiss) were introduced in the Hyalite basin, as well as Yellowstone cutthroat trout (O. clarki clarki) (YCT). Wells (1976) reported rainbow-cutthroat trout hybrids in the reservoir. Brook trout still inhabit the reservoir, with YCT, which likely “genetically swamped” rainbow trout from above the dam. Montana Department of Fish and Game began planting YCT in 1953. Approximately 30,000 YCT fry are planted annually. Whereas Wells (1976) documented YCT spawning in the tributaries of the reservoir, he did not detect recruitment of cutthroat fry. Zubick (1983) documented successful spawning and recruitment of YCT and recommended cessation of stocking. Arctic grayling (Thymallus arcticus) are native to the Hyalite basin, although they were probably planted during the same time period as cutthroat trout. No records of grayling plants in the drainage exist in MFWP stocking databases. However, Emerald Lake, at the headwaters of the East Fork of Hyalite Creek, supports an Arctic grayling population. While no records exist, Emerald Lake was certainly stocked and is the probable original source of grayling to the reservoir. The current sport fishery is comprised mainly of YCT, Arctic grayling, and brook trout. A former state record Arctic grayling was caught in Hyalite Reservoir. The dam reconstruction and increased pool elevation flooded 80 to 90% of historical grayling spawning grounds in the West Fork of Hyalite Creek. The Montana Department of Natural Resources and Conservation (DNRC) constructed a new side channel to attempt to mitigate effects of lost spawning habitat. Recent management efforts focused on maintaining satisfactory angler catch rates of YCT by supplementing the naturally reproducing population with McBride strain hatchery YCT. In addition, we are monitoring success of mitigation at protecting the grayling population in conjunction with the Gallatin National Forest. Byorth and Weiss ( 2001 ) summarized fisheries surveys and impacts of raising reservoir pool elevation. Miscellaneous Surveys In addition to routine surveys and censuses, certain water bodies are sampled occasionally to address management questions. During 2001, Nash Spring Creek and East Catron Creek were eiectrofished to determine the impacts of stream relocation on trout populations. Both streams were historically channelized to drain wetlands or to maximize tillable acres for agricultural production. Over the last three years, these lands have been developed for commercial and residential properties. Developers applied for appropriate permits and were allowed to relocate the streams with specific requirements to improve fish habitat. Nash Spring Creek is a tributary of Sourdough (a.k.a. Bozeman) Creek. 9 Approximately, 1,650 feet of Nash Spring Creek was realigned in Summer of 2000, to accommodate home construction and route the stream through a city park. To assess impacts on fish densities, we electrofished two 500 ft. long sections. One section was in the relocated reach, beginning just below Goldenstein Lane, and the other was in an undisturbed reach extending 500 feet upstream from a fence crossing along the Sourdough Spur trail. East Catron Creek is a tributary of the East Gallatin River that has been realigned a number of times. Approximately 1,200 feet was realigned to accommodate the building of a motel in the early 1990’s. Another reach was realigned in 1999 to accommodate additional commercial construction, with additional projects currently in the permitting process to realign anolheT 2,500 in separate reaches. The goal of permitting is to improve fish habitat markedly as the area is developed. We electrofished four 500 feet reaches, in various states before and after relocation. Camp Creek is a tributary of the Gallatin River heavily impacted historically by agriculture and road and railroad alignment. Much of the Camp Creek basin is comprised of deep soils, an abundant source of fine sediment. State Highway 84 crosses Camp Creek approximately 14 miles west of Bozeman, MT. Much of Highway 84 is scheduled for major reconstruction, including the culvert through which Camp Creek passes. We backpack electrofished a 500 foot section above the culvert to calculate a two- pass population estimate. We electrofished below the culvert for 20 min to assess whether the culvert may be a fish passage barrier and characterize the population. Mountain lake surveys were conducted on Bear lakes in the Bear Creek drainage (T3SR7E Sec. 28) east of Bozeman, MT and Big Bear Lake, in the Big Bear Creek drainage west of Bozeman (T4SR5Esec 15). Lakes were visited and sampled with hook and line and/or gill nets. Potential spawning areas were assessed for evidence of natural reproduction. No fish were caught in gillnets, nor observed in Big Bear Lake. Hie inlet was heavily silted and filled with woody debris. Yellowstone cutthroat trout will be stocked in Big Bear Lake in 2002. Lower Bear Lake was covered with aquatic vegetation, and is unlikely to support fish through the winter. Upper Bear Lake supports a self-sustaining population of rainbow-cutthroat hybrids. Rainbow trout were present and self-sustaining by 1958 (FWP Files). We caught 5 fish 7.0 to 13.5 inches long by hook and line. We also observed a number of fish 7-14 inches in approximate length. Both inlet and outlet are likely to support spawning, and 2 apparent redds were seen in the inlet. The lake should be managed to remain self-sustaining. However, both lakes were used extensively for fire fighting during 2001 and the population may have suffered from dewatering. Methods Electrofishing is used to conduct Mark-Recapture experiments to estimate trout populations. A drift boat-mounted, mobile positive electrode system is used to capture trout on large rivers such as the Madison, Gallatin, and East Gallatin rivers. The drift boat system is equipped with 4,500 Watt generator and Coffelt Mark XXII-M rectifying Unit. During electrofishing runs, trout are netted, held in a live well. 10 anesthetized in an MS-222 bath, measured to 0.1 inches in total length, weighed to 0.01 lbs, marked with a fin clip, and released after recovering. Multiple marking runs are followed by recapture runs after 10 to 14 days. The number of electrofishing passes is determined by the sample sizes required to construct statistically valid population estimates (generally more than 10% of the population). The ratio of marked to unmarked fish in the recovery sample is used to estimate abundance according to FWP’s computerized Mark Recapture Log-likelihood model. On smaller streams, we use a backpack mounted electroshocker to capture trout and generally use similar fish handling methods and calculate depletion estimates. Scale samples are collected for age determination and to determine age class abundance. Detailed maps of study sections are in Appendix A. We use gill nets to sample Hebgen Lake and Cliff and Wade lakes. We set experimental gill nets 125 feet long by 6 feet deep with a bar mesh range from 1 to 3 inches. At Hebgen Reservoir, annual sampling occurs during the last week of May or the first week of June. A combination of 24 to 27 bottom and surface nets were set over a three night period. Nets are set at consistent locations each year, although low reservoir levels dictated the omission of certain sets in some years (Appendix A). Gill nets are set intermittently at Wade and Cliff lakes, generally during October. Four surface nets and one bottom net were set in Cliff Lake. Three surface nets and one bottom net were set in Wade Lake (Appendix A). On each lake or reservoir, gill nets are set during late afternoon and retrieved the following morning. Fish found alive are processed and released. All fish caught in nets are identified to species, measured to nearest 0.1”, weighed to nearest 0.01 lb., and examined for marks, hook scars, and sexual condition. Scale samples are taken from trout for age analysis. On Hebgen Reservoir, rainbow trout were examined for external hatchery characteristics and we extracted vertebrae from deceased specimens to examine for tetracycline marks. A microscope and a blacklight were used to examine vertebrae for tetracycline marks. Hyalite Reservoir satmonids are monitored annually through spawning surveys. Yellowstone cutthroat trout and Arctic grayling both spawn in the West and East Forks of Hyalite Creek. Spawner counts are conducted May - July annually, from reservoir pool elevation to Window Rock Bridge in the West Fork. Surveyors walk upstream, counting adult fish of both species, generally 2 days per week for the duration of spawning (generally mid-May to mid-July). Results West Gallatin River Trout populations are stable in reaches of the West Gallatin where monitoring is conducted. In the Gallatin Canyon (Porcupine and Jack Smith sections) rainbow trout predominate. Brown trout are found in very low numbers. For example: brown trout abundance in the Porcupine Section was estimated to be 66 per mile in 1998 and 1 1 8 per mile in 2000. All brown trout were age 3 and older. Apparently, brown trout recruitment is virtually non-existent in the canyon. Brown trout in these reaches are likely migrants. n Rainbow trout populations in the canyon were at or near the upper end of the recorded range of abundances. Long-terni trends in both Porcupine and Jack Smith sections are stable at relatively high levels after an apparent decline in the mid 1990’s in both sections. In the Porcupine Section, numbers of rainbow trout 8 inches and longer decreased slightly from 1998 to 2000 (Table 1), but all mature size classes remained near recorded highs. Strength of rainbow trout populations is likely due to consistent survival through a series of mild winters. For example, the 1995 year class (age 1 in 1996, Table 2) decreased from 510 as age 1, to 418 as age 3, to 357 as age 5. This moderate mortality rate reflects the tendency of rainbow trout recruitment in the upper Gallatin River to fluctuate based on spring runoff and winter mortality, especially of juveniles. The stock of mature fish (age 3+) available for spawning has remained stable in the Porcupine Section, an indication that angling mortality is unlikely to be a limiting factor (Table 2). Table 3 demonstrates the slow growth rates of rainbow trout in the Gallatin Canyon, reaching only an average of 9.0 inches as age 3, the likely age of sexual maturity. Table 1 . Rainbow trout population summary for trout longer than 8,0 inches (generally Age 3 and older) in the Porcupine Section of the West Gallatin River, Fall 1984 - 2000. Values are number per river mile by length category. Year Number > 8 inches Number > 10 inches Number > 13 inches 1984 915 329 29 1987 1250 412 25 1995 819 386 100 1996 558 333 87 1998 1355 702 162 2000 1221 629 143 Table 2. Rainbow trout population estimates by age class in the Porcupine section of the West Gallatin River, fall 1 996, 1998, and 2000. Values are number per river mile. Standard deviations (SD) are provided for total population estimates. Estimated Number By Age Class (number per mile) Year Age 1 1 Age 3 Age 4 Age 5 Total (SD) 1996 510 362 264 111 207 1454 (47) 1998 384 383 418 406 566 2157(245) 2000 278 447 515 303 357 1900 (210) Rainbow trout populations in the Jack Smith section are similar to the Porcupine section, displaying a peak in density in the late 1980’s with a decline in the mid 1990’s and a more recent increase. However, more recent surveys have not detected a return of rainbow trout densities equivalent to recorded levels, except for the 2000 surveys (Table 4). Population estimates derived in 2000 show a significant 12 increase, doubling previous recorded highs. This is likely an artifact of drought conditions and cold weather when electrofishing occurred. Typical winter habitat (e.g. deeper pools) in the Jack Smith section may have attracted artificially high numbers of rainbow trout to the Jack Smith Section during Fall 2000. However, the rainbow trout estimates by age class (Table 5) indicate age 3 and older populations are near long term averages. Poor recruitment of the 1993 age class (age 2 in 1995, Table 5) is reflected in the low estimate of age 5 rainbow trout in 1998. Recent estimates of age 2 rainbow trout indicate relatively strong age classes in 1996 and 1998, although these estimates are not based on actual scale readings, but on long- term length-at-age ratios. Table 3. Mean length-at-age of rainbow trout in the Porcupine Section of the West Gallatin River, Fall 1996, 1998, and 2000. Mean Length by Age Class (inches) Year Age 1 Age 2 Age 3 Age 4 Age 5 1996 4.8 69 i 8.8 10.5 12.5 1998 5.4 mm 8.9 10.1 11.5 2000 5.2 7.0 9.2 10.5 12.7 3 year Mean 5.1 7.1 9.0 10.4 12.2 Table 4. Estimated population of rainbow trout in the Jack Smith section of the Gallatin River obtained during the late summer or early fall of 1981-1984, 1989, 1995-1996, 1998, and 2000. Estimates are presented as number per river m ile. Year Number > 8 inches Number > 10 inches Number > 13 inches 1981 2819 1169 167 1982 2308 910 99 1983 2596 1217 108 1984 2490 1149 123 1989 3449 1413 131 1995 1460 896 181 1996 1505 936 237 1998 1464 749 167 2000 4946 2381 402 In the Williams Bridge Section, estimated rainbow and brown trout populations are at or near recorded highs in each size group (Table 6). Estimated populations by age class reflect a healthy age distribution pf rainbow trout in the Williams Bridge section, characteristic of a stable population with good recruitment (Table 7). The age composition of the brown trout population indicates inconsistent recruitment with an abundance of older, larger fish. Trout grow at slightly faster rates than in upstream reaches, but they still reflect some growth limitation likely due to cool water temperatures. 13 Table 5. Estimated rainbow trout abundance in the Jack Smith Section of the West Gallatin River by age class, fall 1981 -2000. Abundance estimates are in number per river mile. The estimates for 1996 -2000 are based on previously documented length-at-age ratios and should be considered preliminary. The others are based on actual scale samples and standard deviations (SD) are provided for total population estimates. Year Age 2 Age 3 Age 4 Age 5 Total (SD) 1981 2034 973 353 182 3542 (574) 1982 1951 1017 279 80 3327(211) 1983 1784 1300 431 123 3640(217) 1984 936 1324 614 387 3262(198) 1989 2231 1453 763 270 4718(321) 1995 437 380 350 855 2022 (229) 1996 1226 457 502 237 2422 1998 1037 506 360 184 2087 2000 3255 2100 1125 402 6882 Table 6 . Summary of Fall population estimates on rainbow and brown trout in the Williams Bridge Section of the West Gallatin River, 1977, 1990, 1997, 1999, and 2001. Estimates are in number per river mile. Rainbow Trout Brown Trout Year afahilif IIEEKiHH >10.0” 1977 673 443 146 604 483 338 1990 1316 638 131 484 435 330 1997 1125 585 218 609 510 261 1999 1224 568 198 562 505 360 2001 1424 696 212 795 671 468 Table 7. Mean length-at-age and estimated population (number per mile) of rainbow and brown trout in the Williams Bridge Section of the West Gallatin River, Fall 2001. Mean Length by Age Class (inches) Species Age 1 Age 2 Age 3 Age 4 Age 5+ Rainbow trout D 7.4 9.2 10.8 13.4 Brown trout 6.5 D 9.3 10.5 14.5 Population Estimate (number per mile (SD)) Rainbow trout 724(131) 566 (123) 394 (103) 440 (80) 229 (74) Brown trout 138(56) 79 (48) 142 (52) 18(48) 366 (172) 14 East Gallatin River The East Gallatin River is warmer and more productive than the West Gallatin River as reflected in trout growth rates (Table 8). However, rainbow trout growth rates may be somewhat limited by then- abundance (Table 9). For a stream of its size (less than 50 feet average width) the East Gallatin River supports a substantial trout fishery, numerically dominated by rainbow trout. Population estimates of age 1 and older rainbow and brown trout indicate a peak in density during 1998 - 2000 (Table 9). However, the impacts of the ongoing drought are reflected in a decreased abundance across both Hoffman sections and both species in 2001 . Persistent drought may be affecting the population through poorer habitat quality, less available habitat volume, increased susceptibility to predation and angling, and higher winter mortality. However, populations of both rainbow and brown trout in the Hoffman sections are within long term ranges of variability and can be expected to recover as drought conditions improve. Table 8. Length-at-age (inches) estimates for rainbow and brown trout in the Hoffman sections of the East Gallatin River based on scale samples 1985 - 1987. Species j Age 1 Age 2 Age 3 Age 4 Age 5 Age 6 Rainbow Trout 1 7.3 9.3 10.7 11.9 13.2 13.7 Brown Trout 8.1 10.5 12.6 14.0 15.0 — 16.0 Gallatin River The Gallatin River below the confluence of its forks suffers a variety of cumulative impacts including sedimentation, warm water temperatures, dewatering, and presence of M. cerebralis, the causative agent of whirling disease. Thus, trout populations are much lower than other area rivers. In 1999, we revived the Logan section for long-term monitoring, but the short span of data makes interpretation of trends difficult. Estimated rainbow trout populations were higher in 2001 than in previous surveys, while brown trout populations decreased somewhat (Table 10). Note very few juvenile rainbow or brown trout (less than 10 inches long) are present, indicating recruitment limitation. 15 Table 9. Rainbow and brown trout population summary (age 1+) for the upper and lower Hoffman sections of the East Gallatin River, 1994 - 2000. Population estimates are listed as number per mile by length group. | Upper Hoffman Section (1.2 miles) 1 Year (Fall) rainbow trout per mile Brown trout per mile >6.0 inches Pjjjj|gg| >13.0 inches 2 6.0 inches >10.0 inches 2 13.0 inches 1994 2550 600 110 847 645 271 1995 2157 450 141 1103 669 453 1996 2397 628 68 384 310 229 1997 1701 697 125 290 155 99 1998 3108 668 152 522 266 137 1999 4877 1712 213 663 427 208 2000 3408 1083 188 1053 724 358 2001 1649 648 80 748 458 262 Lower Hof] man Section (0.88 miles) Year (Fall) >6.0 inches 210.0 inches 2 13.0 inches 2 6.0 inches 210.0 inches 2 13.0 inches 1994 748 219 556 397 226 1995 3498 1108 320 501 363 225 1996 2557 1234 mm 646 550 464 1997 1915 982 405 359 316 149 1998 3376 1237 329 647 - - - 355 283 1999 mi 2288 757 539 198 2000 4633 3164 £ | 765 408 205 2001 2326 1700 739 526 319 138 16 Table 10. Rainbow and brown trout population estimates (number per mile) in the Logan Section (4.3 miles below Nixon Bridge) of the Gallatin, Montana, Spring 1999-2001. Brown Trout Rainbow Trout Year m 1 ■m >13.0 inches >6.0 inches >10.0 inches >13.0 inches 1999 473 390 208 353 270 107 2000 350 307 128 321 L 281 103 2001 304 274 184 487 454 344 Madison River Trout populations in the Madison River above Ennis Reservoir have been affected by a variety of influences over the years. Byorth (2000a) summarized the influence of regulations and whirling disease on populations through 1998. Whirling disease has been the primary factor limiting rainbow trout populations in the upper Madison since 1 991 (Vincent 1 996). In each monitoring section above Ennis Reservoir, trout populations increased in 1999 and 2000 and decreased slightly into 2001 at healthy levels. In the Pine Butte section, rainbow trout populations experienced an increase in numbers of age 1 fish. The 1998 year class of rainbow trout survived well into larger size classes. Similarly, the 1999 year class was substantial, but survival to maturity was less than the previous cohort. As these age classes matured, angling improved markedly according to anecdotal reports. Age 1+ rainbow trout populations were near long-term averages in 1999 and 2000, but decreased in 2001. Drought conditions may have impacted reproduction and survival by increasing susceptibility to whirling disease as well as lower stream flows diminishing winter habitat quality. Potential flow related limiting factors are further evident in brown trout population estimates (Table 1 1), After reaching long-term record abundance in 1999, Age 1+ populations remained strong until 2001 . Lower flows throughout 2001 may have impacted brown trout populations, but estimated brown trout abundance was near long-term averages in 2001 . Trout populations in the Snoball section exhibited a pattern similar to that of the Pine Butte section, but did not decline in 200 1 . Good recruitment was evident for the 1 998 cohort in the 1 999 fall rainbow trout population estimates (Table 12). While populations never regained abundances documented before whirling disease, rainbow trout numbers markedly increased over 1994 - 1997 levels (Byorth 2000a). Unlike the Pine Butte rainbow trout population, a slight increase in abundance was evident in Fall 2001 in the Snoball section, although estimates are preliminary. Estimated brown trout abundances in the 1999 and 2001 fall surveys were the second and third highest estimates on record, respectively (Table 12). 17 Table 1 1 . Rainbow and brown trout population estimates in (number per mile) the Pine Butte Section (3 .0 Miles above Lyons Bridge) of the Madison River, Montana, Fall 1994-2001 . Standard deviations (SD) are listed for finalized estimates. Rainbow Trout Year Age 1 Age 2 and older Total Age 1 and older Per Mile Per Mile Per Mile (SD) 1994 94 236 330 (20.5) 1995 510 175 685 (65.8) 1996 735 447 1182 (88.9) 1997 454 267 809 (73.3) 1998 847 305 1152 (85.9) 1999 2729 656 3385 (465.6) 2000* 2100 1659 3759 2001* 1794 702 2496 Brown Trout Year Age 1 Age 2 and older Total Age 1 and older Per Mile Per Mile Per Mile (SD) 1994 282 919 1201" (157.7) 1995 620 109 1129 (70.7) 1996 1158 446 1604 (84.2) 1997 831 929 1760 (154) 1998 1018 794 1812 (103.4) 1999 1419 1373 2792 (497.7) 2000 * 962 1171 2133 2001* 728 1024 1752 *2001 Preliminary, based on historic age data, subject to change with actual scale data. Table 12. Rainbow and brown trout population estimates (number per mile) in the Snoball Section (below Squaw Creek to Windy Point, 4.0 miles) of the Madison River, Montana, Fall 1994-2001. Standard deviations (SD) are listed for finalized estimates. Rainbow Trout Year Age 1 Age 2 and older Total Age 1 and older Per Mile Per Mile Per Mile (SD) 1994 232 289 521 (68.0) 1995 384 208 592 (45.7) 1996 348 406 754 (78.3) 1997 227 ' 190 417 (70.2) 1999 1050 374 1424 (88.8) 2001* — — — — — — - - — - 1353 510 1863 Brown Trout Year Age 1 Age 2 and older Total Age 1 and older Per Mile Per Mile Per Mile (SD) 1994 360 559 919 (51.8) 1995 5 66 " 6(2 wamamm i 1996 855 1182 2037 (233.2) 1997 633 604 1237 (141.3) 1999 874 954 1828 (70.5) 2001* 779 1018 1797 *2001 Preliminary, based on historic age data, subject to change with actual scale data. 18 Brown trout are predominant in the Vamey section. Estimated fall populations of age 1 and older brown trout peaked in 1998, remained strong through 2000, and declined into 2001 (Table 13). In 2001, abundance of brown trout decreased across age groups, in spite of apparently good recruitment of the 1999 year class. Decreased survival of all age classes likely reflects flow limitations during the summer of 2001. However, combined age 1 and older estimated brown trout abundance was near long-term average levels. Rainbow trout significantly decreased in abundance in the Vamey section in the mid-1990’s (Byorth 2000a). As in upstream reaches, estimated fall rainbow trout abundance increased with good recruitment from the 1998 and 1999 year classes. A downward trend in rainbow trout abundance is apparent in 2001 , but 2000 was apparently a moderately successful spawning year and should maintain near average numbers into 2002. Table 13. Rainbow and brown trout population estimates (number per mile) in the Vamey Section (Vamey Bridge to Eight-mile Ford, 4.0 miles) of the Madison River, Montana, Fall 1994-2001. Standard deviations (SD) are listed for finalized estimates. Rainbow Trout Year Age 1 Age 2 and older Total Age 1 and older Per Mile Per Mile Per Mile (SD) 1994 33 166 199 (27.6) 1995 351 132 483 (70.4) 1996 145 304 449 (54.9) 1997 106 113 282 (28.3) 1998 192 139 331 (36.2) 1999 740 236 976 (190.4) 2000* 1366 409 "1775 2001* 714 281 r 995 Brown Trout Year Age 1 Age 2 and older Total Age I and older Per Mile Per Mile Per Mile (SD) 1994 1278 631 1909 (75.1) 1995 770 704 1474 (76.3) 1996 1558 515 2073 (84.4) "1997 1122 949 2071 (123.5) 1998 2180 106! 3241 (132.8) 1999 1674 1244 2918(194.0) 2000* 1706 1076 2782 2001* 1133 r 850 1983 *2000-01 Preliminary, based on historic age data, subject to change with actual scale data. The trout fishery of the Madison River changes substantially below Ennis Reservoir. Rainbow and brown trout tend to be nearly equivalent in abundance. Impacts of whirling disease are apparently suppressed by thermal limitations, but warm mid-summer water temperatures can approach lethal levels. Rainbow trout abundance improved in the Norris Section continuing a recovery from low levels in the mid- 1990’$ to above average abundance in 2001 (Table 14). Brown trout have also fared well in the Norris 19 section from 1998 to 2001 reaching long-term average levels. However, persistent drought conditions are likely to affect survival of older age classes in the near future. Table 14. Rainbow and brown trout population estimates (number per mile) in the Norris Section (Warm Springs Creek to Cherry Creek, 4.0 miles) of the Madison River, Montana, Spring 1994-2001. Standard deviations (SD) are listed for finalized estimates. Rainbow Trout Year Age 2 Age 3 and older Total Age 2 and older Per Mile Per Mile Per Mile 1995 273 531 804 (55.7) 1996 184 535 719 (62.5) 1997 552 220 772 (38.7) 1998 555 736 1291 (104.5) 1999 820 772 1592 (266.9) 2000 330 937 1267 (76.6) 2001* 643 1422 2065 Brown Trout Year Age 2 Age 3 and older Total Age 2 and older Per Mile Per Mile Per Mile (SD) 1995 435 706 1141 (254.2) 1996 696 510 1206 (64.0) 1997 294 613 882 (63.0) 1998 601 507 1108 (66.1) 1999 980 1017 1997 (356.0) 2000 968 686 1654 (93.1) 2001 * 1085 1154 2239 *2001 Preliminary, based on historic age data, subject to change with actual scale data. Hebeen Reservoir Annual spring gill net series are used to gather trend information as an index of relative abundance of game and non-game species. While wild reproduction predominates for all species, rainbow trout are also stocked annually. Rainbow trout catches in floating nets (the best indicator for rainbow trout abundance) declined in catch-per-net from 1995, the highest catch rate on record for spring floating nets (Table 15). Long term average catch per net between 1973 and 2001 was 5.4 (SD 3.43) rainbow trout per net in spring floating nets. Prior to 1986, the onset of stocking wild strains of rainbow trout, net catches averaged 2.42 (SD 1 .02) rainbow per floating net. Since 1986, spring catch rates of rainbow trout have averaged 6.76 (SD 3.28). Catch-per-net of rainbow trout rose to above average levels in 1998 and 1999, but fell to post-1986 record lows in 2001 . Potential limiting factors may include poor natural reproduction due to drought conditions, poor planting success in 2000 (extensive mortality was reported by hatchery personnel), or simply sampling error. However, a creel census conducted June 2000 to May 200 1 indicated catch rates of rainbow trout ranging from 0. 19 to 0.62 per hour (FWP Files). The contribution of stocked rainbow trout to the Hebgen Reservoir fishery is under investigation. Recently collected information based on observed dorsal fin erosion versus tetracycline marks (tetmarks) as indicators of hatchery origin is summarized in Table 16. Not all fish exposed to tetracycline display a 20 vertebral mark (Jack Boyce, FWP Pers. Comm.), nor do all hatchery-reared fish exhibit fin erosion. We detected tetmarks on 0 to 6 % of rainbow trout caught in gill nets (Table 16). In comparison, we detected dorsal fish erosion on 3.9 to 22.5% of rainbow trout caught in gill nets during the same years. Thus, a conservative estimate of hatchery rainbow trout contribution to the fishery is less than 25%. We will continue researching hatchery contribution to the Hebgen rainbow trout population. Brown trout catches in sinking nets (the best index for brown trout abundance) averaged 10.94 (SD 3.44) since 1971. In recent years, spring brown trout catches in sinking nets have been near long-term average. However, spring catches were below average through much of the early 1990’s (Table 15). Mountain whitefish catch rates have been relatively stable since 1994 (Table 1 5). Utah chub catches have fluctuated widely since 1994, currently decreasing from high levels recorded in 1999. Table 1 5. Summary of rainbow trout (RB), brown trout (LL), mountain whitefish (MWF), and Utah chub (UC) catch-per-net in Spring gill net series on Hebgen Reservoir, 1995 to 2001. YEAR NO. OF NETS Floating Nets RB/NET LL/NET MWF/NET UC/NET 1995 12 15.3 8.4 1.1 18.9 1996 14 5.9 4.3 0.7 54.6 1997 14 5.6 3.9 0.1 89.2 1998 14 9.4 2.6 1.1 41.1 1999 13 7.2 13.3 1.5 143.2 2000 14 6.0 3.7 0.2 96.0 2001 14 2.5 2.4 0.29 62.5 YEAR NO. OF NETS Sinking Nets RB/NET LL/NET MWF/NET UC/NET 1995 12 0.8 7.1 18.5 13.4 1996 13 0.9 7.5 16.8 55.5 1997 11 0.8 8.5 16.3 24.5 1998 10 1.1 6.5 12.0 60.2 1999 11 0.8 11.7 19.4 26.6 2000 11 0.7 9.5 11.7 33.3 2001 11 0.5 11.1 18.1 69.2 Table 1 6. Summary of contribution of wild and hatchery-reared rainbow trout to gill net catches in Hebgen Reservoir, 1996-2001. Asterisks indicate incomplete data. % Catch Rainbow Trout % of Sample Tet- Year with Dorsal Fin Erosion Mark Positive 1996 5.2% * 2.9% 1997 13.8% 2.7% 1998 22.4% no data 1999 3.9% * 2.9% 2000 16.0% 6.3% 2001 22.5% 0.0% 21 Cliff and Wade Lakes Over the years, monitoring of fish populations in Cliff and Wade lakes has been limited to gill netting or night electrofishing. Gill netting has been a marginal index of population trends, limited by net selectivity. On Cliff Lake, parasite loads have limited growth and potentially limited trout abundance. Gill netting catches have varied considerably on Cliff Lake, reaching a low point in 1994 (Table 17). Since then, rainbow trout catches have been relatively consistent, with a high catch in 2000. Average length of rainbow trout in gill nets indicates selectivity of nets against trout less than 6.0 inches long. Maximum size of rainbow trout in gill net catches has ranged from approximately 17 to 18 inches in 1991 and 1993, to a low of 1 1.7 inches in 1998. Since 1998, maximum length of rainbow trout caught in gill nets ranged from 14.6 to 15.2 inches. The impact of parasite loads has not been adequately analyzed, but is likely the prime factor limiting growth and survival. Bonneville cutthroat trout, introduced in 1 990, have not been captured in gill nets, although anecdotal reports from anglers may indicate their continued presence. Similarly, brown trout were documented to be illegally introduced into Cliff Lake around 1992 (FWP Files), but none has been captured since. Since the completion of the Wade Lake spawning channel in 1 99 1 , no trout have been stocked (Brooks 1992, FWP Files). However, rainbow and brown trout gill net catches have been very consistent since then (Table 18). Rainbow trout gill net catches have ranged from 3.0 to 6.0 between 1993 and 2001. Only one sinking net is traditionally set on Wade Lake, so brown trout catches are consistently low. However, several nets partially sank in 2001, which may have resulted in increased catch of brown trout. Because of additional sinking nets, white sucker catches increased dramatically in 2001. In general, trout populations in Wade Lake appear to be stable, with little variation in average size. Table 17. Summary of catch rates and average length of rainbow trout caught in gill nets in Cliff Lake, 1991-2001. YEAR Number Number per net Mean length 1991 46 7.7 12.4 1993 21 4.2 15,5 - 1994 9 1.8 12.3 1998 31 6.2 8.9" 1999 26 5.2 10.9 2000 49 9.8 9.4 2001 25 6.3 10.2 22 Table 1 B. Summary of gill net catches on Wade Lake, 1993 - 200 1 . Year rainbow trout per net Average length of rainbow trout (inches) Brown trout per net White sucker per net 1993 6.0 16.5 0.2 5.0 1994 3.8 12.4 0.6 11.4 1998 4.2 14.9 0.4 16.0 1999 5.0 16.6 0.2 6.4 2001 3.0 14.5 0.8 302 Hyalite Reservoir Spawner counts in the West Fork Hyalite Creek indicate Yellowstone cutthroat trout and Arctic grayling may be recovering from the loss of spawning habitat due to raising reservoir levels (Byorth and Weiss 2001). In 2001, a total of 2643 Yellowstone cutthroat trout were observed in the West Fork, a record high (Table 19). Arctic grayling spawner surveys have been conducted over a longer period than Yellowstone cutthroat trout, but a similar trend is apparent. After raising the reservoir level inundated critical spawning habitat, the number of adult Arctic grayling spawners diminished (Byorth and Weiss 2001). Since 1998, the numbers of adult Arctic grayling observed has stabilized near 20 per survey (Table 20). While considerably lower than the average between 1986 and 1994 (70 per survey), it is a more sustainable level than lows after dam-raising. Table 19. Numbers of Yellowstone cutthroat trout (YCT) observed during spawner counts in the West Fork Hyalite Creek, 1995 - 2001, * indicates years of incomplete surveys. Updated from Byorth and Weiss 2001. Year Number of Surveys Number YCT Observed Number YCT Per Survey Peak Spawning Date 1995 6 259 43.2* June 12 * 1996 4 13 4.3* ♦ 1997 8 364 45.5 June 23 1998 16 1891 118 May 28 1999 11 1704 155 June 1 1 2000 9 1640 ' 182 June 2 2001 8 2643 330.4 June 6 23 Table 20. Numbers of Arctic grayling observed during spawner counts in the West Fork Hyalite Creek, 1986, 1989 ~ 2001, * indicates years of incomplete surveys. Updated from Byorth and Weiss 2001. Year Number of Surveys Number Grayling Observed Number Grayling Per Survey Peak Spawning Date 1986 1 152 152 June 16 1989 * 85 * * 1990 3 180 60 June 26 1991 1 50 50 June 26 ' ; 1992 2 154 77 June 10 1993 16 555 34 June 21 1994 20 945 r 47 June 6 1995 7 45 6.4* June 29* 1996 4 0 0* * 1997 8 5 0.6 June 23 1998 16 453 28.5 June 22 1999 11 203 18.5 June 24 2000 9 130 14.4 June 13-19 2001 8 175 22 June 19 Camp Creek We electrofished a 500 ft section of Camp Creek above the highway 84 culvert. We captured a total of 75 brook trout ranging in length from 4.3 to 8.4 inches. The two-pass population estimate was 82 per 500 ft (±9.96 95% Cl). In the plunge pool below the culvert, we captured 19 brook trout ranging in length from 4.1 to 7.1 inches in 20 minutes of effort. Hie presence of brook trout in like numbers and size ranges, above and below the culvert, suggests that the culvert is not a barrier, or was not a barrier in recent times. The plunge pool below the culvert was approximately 36 inches deep, and the fall between culvert outlet and water surface was approximately 18 inches. 24 Nash Soring Creek We electrofished two 500 ft sections in Nash Spring Creek: the City Park section in the relocated (formerly channelized) reach, and the Sourdough Trail section 0.25 miles downstream in the unimpacted reach in March 2001 . While sections were less than 0.25 miles apart, numbers of trout captured varied considerably (Table 21). In the City Park Section rainbow trout predominated, followed by brook trout and brown trout, respectively. However, in the Sourdough Trail Section, the unimpacted reach, brown trout were 84% of estimated trout abundance. Only 10 rainbow trout and 3 brook trout were captured. Mottled sculpin were much more abundant in the unimpacted reach (53 captured) than in the unimpacted reach (1 7 captured). In the City Park Section, the largest rainbow trout captured was 1 3.3 inches long; however, over half the rainbow trout captured was under 3.0 inches long and only 4 were over 7 inches. In the Sourdough Trail section, rainbow trout ranged from 2.7 to 11. 7 inches long. Brown trout ranged as high as 13.9 inches long, with over half under 6,0 inches long. In the City Park section, browns were 2.0 to 9.8 inches long. Brook trout were larger and more abundant in the City Park Section ranging from 3.3 to 10.0 inches long and 58% over 6.0 inches long. In the Sourdough Trail reach, only 3 brook trout were captured, all from 3.1 to 3.6 inches long. Apparently, the newly relocated reach provided a greater diversity of habitat to support all three species in higher numbers. However, the unimpacted reach may represent a more stable “climax” fish community where brown trout may out-compete the other species. We will continue to monitor the response of trout populations to the stream relocation. Table 21. Estimated abundance of trout in Nash Springs Creek in two 500 ft sections. Low sample sizes are reported as number captured. Point estimates and 95% confidence bands are reported if sample sizes were adequate. Section _ Brown Trout Rainbow Trout Brook Trout City Park 25 (24 to 27) 50 (44 to 06) 39 (38 to 44) Sourdough trail 78 (75 to 84) 10 3 East Catron Creek East Catron Creek runs through farmland that has undergone a rapid conversion to retail development since 1 996. Approximately l mile of stream has either been relocated or will be relocated by the end of 2002 to accommodate development. Because the stream was channelized for agriculture in the 1950’s, development offers the opportunity to restore the stream to more natural condition and improve fish habitat. To track changes in fish community structure during and after relocation, we electrofished several reaches of East Catron Creek. 25 The Wingate Section was relocated circa 1996. We electrofished 500 feet of relocated channel between Catron Street and a pipeline crossing. In 1999, we captured 107 fish of 6 different species (Table 22). Mountain whitefish comprised over half of the total, ranging in size from 5.7 to 7.0 inches long. In April 2001, we did not capture any mountain whitefish. We captured 34 brown trout in 1999, but only five in 2001. Brown trout ranged from 4.9 to 13.7 inches long in 1999 and 3.7 to 10.4 inches long in 2001. Brook trout were captured in both Wingate and Catron sections in 1999, but were found only in the Golden Willow Section in 2001 . Rainbow trout up to 6.0 inches long were captured in 1 999, but ranged from 4,9 to 10.0 inches long in 2001. Numbers of all other species declined in the Wingate section, except for white sucker, which increased markedly. Similar results were found in the Catron Street section, relocated in 2000. Abundance of all trout species decreased after relocation. Brown trout up to 13.8 inches were captured in 1999, but ranged in length from 4.7 to 6.2 inches in 2001 . Longnose dace and white sucker increased in the Catron Section. The Valley Center and Golden Willow sections are scheduled for relocation Summer 2002. Neither reach supported significantly different numbers of fish than the others in 2001, but a fathead minnow was captured. The Golden Willow Section supported more brown trout than the others did in 2001, from 4.5 to 6.4 inches long. 1 Thus far, it is difficult to attribute changes in fish abundance solely to stream relocation. Severe drought has affected groundwater levels and consequent stream flows since 1 999. In addition, extensive development upstream of the relocated reach may have effected water quality and quantity. In general, numbers of fish did not allow us to calculate population estimates and catch-per-effort may be biased by electrofishing conditions. We will continue to monitor these sections to track the affects of stream relocations and intended habitat improvement. Conclusion Trout populations are subject to a wide variety of environmental factors that regulate their abundances from year to year (Platts and Nelson 1988). In the Madison and Gallatin drainages, flow regimes, drought, predation (human and otherwise), and habitat condition all regulate trout populations to some extent. In general, trout populations are stable in the Gallatin drainage, mostly at or near recorded high levels. However, persistent drought is likely to affect trout populations in the next several years. In the Madison River, brown trout populations are above long-term averages in most sections. Rainbow trout, however, are subject to the effects of whirling disease, and likely to decrease from current levels due to recruitment limitation. Catch-per-effort trends in lakes and reservoirs are varied, with very strong stable populations in Wade Lake, average levels in Hebgen Lake, improving levels in Hyalite reservoir, and average levels in Cliff Lake still hampered by parasite loads. Impacts of development on urban streams in the Gallatin Valley are under investigation. In the future, we hope to have more conclusive data on the response of trout populations to stream relocation and enhancement. 26 This document reports monitoring activities in the Madison and Gallatin drainages during 2001. Summary data are provided to illustrate trends in fish populations or to address specific management concerns. Conclusions beyond the scope of basic trends are speculative and they would require more in- depth analysis. Table 22. Summary of numbers of fish caught per electrofishing surveys in East Catron Creek April 1 999 and April 2001. Species Valley Center April 2001 Wingate (relocated 1996) April 1999 April 2001 Catron Street (relocated 2000) April! 999 April 2001 Golden Willow April 2001 Brown Trout 4 24 5 19 7 8 Brook Trout 0 3 » 4 0 2 Rainbow Trout 4 6 2 4 1 1 Mountain Whitefish 0 54 0 o 0 0 Longnose Dace 4 0 7 1 8 10 White Sucker 4 10 43 3 . 13 3 Longnose Sucker 0 0 4 o 0 1 Mottled Sculpin 3 10 4 10 8 6 Fathead Minnow 1 0 0 0 o 0 27 Literature Cited Brooks, T. 1992. Montana moves mountains for wild trout. Montana Outdoors 23(4):15-18. Byorth, P. A. 2000a. Madison River trout population surveys: July 1994 - June 1999, project 3302. Montana Fish, Wildlife, and Parks, Bozeman. Byorth, P. A. 2000b. Gallatin River drainage trout population surveys: July 1994 - June 1999, project 3302. Montana Fish, Wildlife, and Parks, Bozeman. Byorth, P. A. and T. Weiss. 2001. The fishery of Hyalite Reservoir and impacts of raising Hyalite Dam. Montana Fish, Wildlife, and Parks, Bozeman. Fox, A. C. 1961. Parasite incidence in relation to size and condition of trout from two Montana Lakes. M.S. Thesis, Montana State University, Bozeman. Hetrick, N. J. 1994. An update on the status of fish populations in Hebgen Lake. Montana Fish, Wildlife and Parks and U.S.D.A Forest Service, Hebgen Lake Ranger District, West Yellowstone, MT. Leik, T. M. 1978 Distribution of the Utah chub (Gila atraria) in the upper Missouri River System. Prepared for United States Dept, of the Interior, Bureau of Reclamation. Montana Fish and Game Dept. Bozeman. McFarland, R. C. and D. Meredith. 1999. Montana statewide angling pressure mail survey. Montana Department of Fish, Wildlife, and Parks, Fisheries Information Services, Bozeman. McFarland, R. C. and D. Meredith. 2000. Montana statewide angling pressure mail survey. Montana Department .of Fish, Wildlife, and Parks, Fisheries Information Services, Bozeman. Montana Fish, Wildlife and Parks. 2000a. Fisheries program six-year operations plan (200-2006). Montana Fish, Wildlife, and Parks, Helena. Montana Fish, Wildlife and Parks. 2000b. Westslope Cutthroat Trout Genetic Distribution Map, Gallatin Drainage. Montana Fish, Wildlife and Parks Information Services, Helena, MT. Platts, W. S. and R. L. Nelson. 1988. Fluctiations in trout populations and their implications for land-use evaluation. N. Am. Jour. Fish Mgt. 8:333-345. Ross, J. 1999. America’s 100 best trout streams. Falcon Press. Helena, MT. 351pp. Sample, M. 1998. Fishing Montana. Falcon Press. Helena, MT. 254 pp. Shields, R. R. and four co-authors. 1999.Water resources data, Montana, water year 1998. Water-Data Report MT-98-1. U.S. Department of Interior, U.S. Geological Survey, Helena. Vincent, E. R.. 1978. Southwest Montana fisheries study: inventory and survey of the waters of the Gallatin and Madison drainages. Project F-9-R-26, Job la. Montana Department of Fish, Wildlife, and Parks, Bozeman. Vincent, E. R.. 1979. Southwest Montana fisheries study: inventory and survey of the waters of the Gallatin and Madison drainages. Project F-9-R-27, Job la. Montana Department of Fish, Wildlife, and Parks, Bozeman. 28 Vincent, E. R. and B. Rehwinkle. 1981. Southwest Montana fisheries study: inventory and survey of the waters of the Gallatin and Madison drainages. Project F-9-R-28, Job la. Montana Department of Fish, Wildlife, and Parks, Bozeman. Vincent, E. R., with J. Dooley and J. Horn. 1981 . Madison River thermal simulation study. Montana Department of Fish, Wildlife and Parks, Bozeman. Vincent, E. R. 1987. Effects of stocking catchable-sized hatchery rainbow trout on two wild trout species in the Madison River and O’Dell Creek, Montana. N. Am. J. Fish. Mgt. 7:91-105. Vincent. E. R., B. Shepard, W. Fredenberg, and R. Oswald. 1990. Statewide fisheries investigations: survey and inventory of cold water streams, Southwest Montana major rivers fisheries investigations. Project F-46-r-3, Job I-f. Montana Fish, Wildlife, and Parks, Bozeman. Vincent, E. R. 1996. Whirling disease and wild trout: The Montana experience. Fisheries 21(6):32-33. Vincent, R. E. 1962. Biogeographical and ecological factors contributing to the decline of Arctic grayling, Thymallus arcticus Pallus, in Michigan and Montana. Ph.D. Thesis. University of Michigan, Ann Arbor. Wells, J. D. 1976. The fishery of Hyalite Reservoir during 1974 and 1975. M.S. Thesis, Montana State University, Bozeman. Zubick, R. J. 1983. The fishery of Hyalite Reservoir, Montana, with an evaluation of cutthroat trout reproduction in its tributaries. M.S. Thesis, Montana State University, Bozeman. 29 Appendix A. Maps of streams, lakes, and reservoirs displaying study sections. 30 Printed from TOPO! 2000 National Geographic Holdings (www.topo.com) TOPO! map printed on 02/22/02 from "Montana. tpo" and "Untitled, tpg" 111 0 19,000' W 111°17,000' W 111°15.000' W 111°13.000' W 111°11.000' W WGS04 111°O0.OOO' W Printed from TQPOI ©2000 National Geographic Holdings (www.topo.com) TOPO! map printed on 02/22/02 from "Montana. tpo" and "Untitled. tpg" 111°16,000' W 111° 14.000' W 111° 12. 000' W 1 11° 10.000' W lll°OB.OOO' W WGS04 lll°05^000'W N .000'9£oSfr N .OOO't’SoSfr N ,000'ZSoSt’ « i i ? ¥ - i „■ , ■ * • ■ ^ ^ N ,000'9£oSi7 N ,000>£oS-b N ,OOOZ£oSt’ P TOPOI map printed on 02/22/02 from "Montana, tpo’ 1 and "Untitled. tpg" 111°26.000' w 111°24.000' W 111°22.000' W lll o 20,000' W 111 O 10.OOO' W WGS84 11 1°15.000‘ W TOPOI map printed on 02/22/02 from "Montana. tpo" and "Untitled, tpg" 111°05.000' W 11 1°04.000* W ll^OS.OOO’ W WGS04 lll^.OOO’ W TOPO! map printed on 02/22/02 from "Montana. tpo" and "Untitled. tpg" m°09.000 l W 11 1°08,000' W 111°07.000' W WGS04 lll o 06.000' W N ,000'6t’oSP TOPOI map printed on 02/22/02 from "Montana, tpo" and "Untitled. tpg" lll°38.000 l W 111°36.000' W 111°34.000' W lll o 32.000' W 111°30,000‘ W WGSB4 1 1 1°27.000' W Printed from TOPOt ©2000 National Geographic Holdings (www.topo.com) TOPO! map printed on 02/22/02 from "Montana, tpo" and “Untitled. tpg" 111°41,000' W 111°39.000' W 111°37.000' W lll°35.000 l W 111*33.000' W WGS84 111°30.000' W Printed from TOPOl 02000 Ntiunil Geogriptuc Moling* (www.topo.cotn) TOPO! map printed on 02/22/02 from "Montana. tpo" and "Untitled. tpg" lll°4e.000’ W 111°46.000' W lll°44.000 l W 111°42.000'W 111°40.000' W WGS04 111°37.000' W