MONTANA STATE This "cover" page added by the Internet Archive for formatting purposes s 597.55 M26TLP 1989 3 0864 0014 4490 3 TIMING. LOCATION AND POPULATION CHARACTERISTICS O"^ SPAWNING MONTANA ARCTIC GRAYLING (THYMALLUS ARCTICUS MONTANUS [MILNER] ) IN THE BIG HOLE RIVER DRAINAGE, 1988 March 29, 1989 by Bradley B. Shepard and Richard A. Oswald Montana Department of Fish, Wildlife and Parks 1400 South 19th Street Bozeman , Montana 59715 Funding Provided by: Montana Department of Fish, Wildlife and Parks Montana Natural Heritage Program - Nature Conservancy . Forest _Serv i.ce ....^QcAlaeisrw^efl ion STATE DOCUMENTS COLLECTION MAR 1 2 1990 MONTANA STATE LIBRARY 1515 E. 6th AVE. HELENA. MONTANA 59620 GRAYLING SPAWNING REPORT EXECUTIVE SUMMARY Spawning Montana Arctic grayling (Thvmallu5 arcticus montanus [Mxlner]) within the upper Big Hole River drainage were sampled using electrof ishing fro.-n April through June 1988. Sample sites included the main stem Big Hole River from Wise River up to Jackson and the lower portions of 11 tributaries to the river. Distribution of spawning grayling, habitat utili;:ed for spawning, and characteristics of the spawning population were described . Four hundred grayling were captured. The first ripe male and female were captured on April 20 and April 27, respectively, in the Big Hole River near the town of Wisdom. The number^ of captured ripe females peaked during the period between April 29 and May 11 with the first spent female captured on May 4. Spawning appeared to be triggered by a combination of declining river flows after the initial spring sub-peak flow caused by low elevation run-off and maximum daily water temperatures increasing to 50 F. The sex ratio of all captured fish identified a^ mature, ripe, or spent was 2.0 males: 1.0 female. A large portion of age II fish were sexually mature. The average lengths and weights of ripe males (n = 158) and ripe females (n = 34) were 10.9 inches and 0.42 pounds and 11.3 inches and 0.51 pounds, respectively. Grayling spawned primarily within the main stem Big Hole River from the mouth of the North Fork Big Hole River upstream to 3 miles above Wisdom, in a few scattered side channels below the North Fork, and in the lower portions of Swamp, Big Lake, and Rock creeks. Spawning sites were characterized as riffles with clean surface gravel which appeared "bright" near pool or run habitats, generally within actively degrading or aggrading side channels or alluvial gravel fans at the mouth's of tributaries. Mos-. spawning grayling were captured in areas of hydrologic in- stability. The age composition of the sampled population suggested that the 1987 and 1985 year classes (age I and III fish, respectively) were poor year classes. Conversely, the 1986 year class (age II fish) was a good year class. These relative year class strengths may be controlled by water flows during the first year of life. Of sight fish tagged during the 1988 spawning run and recaptured later during the summer of 1983, two stayed in the upper river near spawning areas and five moved down river oS far as Divide Dam. One fish which was tagged in Deep Creek^on October 29, 1987 was recaptured near Wisdom on May 4, 1988 Page - ii GRAYLING SPAWNING REPORT (where it moved to presumeably spawn), and then moved back to Deep Creek where it was captured on August 4, 1988. Of ten fish tagged during 1937 sampling and recaptured durirg the 1988 spawning season, half were tagged in the river nsar Fishtrap Creek either during the previous May or November, four were tagged in the Wisdom area during the previous May, and the other was the Deep Creek fish mentioned above. This tag return information lends support to observations by the authors that the Big Hole River supports a population of grayling which appear to use the entire river above Divide on a seasonal basis. A portion of this grayling population normally moves to the upper river (near Wisdom) during the spring and remains in this area of the river during the summer before emigrating down river to winter habitats. Page - iii GRAYLING SPAWNING REPORT TABLE GF CONTENTS Page EXECUTIVE SUMMARY ii TABLE OF CONTENTS iv LIST OF TABLES vi LIST OF FIGURES vii ACKNOWLEDGEt^ENTS viii INTRODUCTION 1 STUDY SITE DESCRIPTION 5 METHODS 8 FISH COLLECTION 8 SPAWNING SITE CHARACTERIZATION 12 RESULTS 13 TIMING OF SPAWNING , 13 CHARACTERISTICS OF THE SPAWNING RUN 13 DISTRIBUTION OF SPAWNING WITHIN THE DRAINAGE 13 MOVEMENT ASSESSED USING TAG RETURNS IS CHARACTERISTICS OF SPAWNING SITES 13 Visual Characteristics 18 Streambed Composition 22 DISCUSSION 24 TIMING OF SPAWNING , 24 CHARACTERISTICS OF THE SPAWNING RUN ..... 25 DISTRIBUTION OF SPAWNING WITHIN THE DRAINAGE 26 Page - iv GRAYLING SPAWNING REPORT TABLE OF CONTENTS (continued ) Page DISCUSSION (continued) MOVEMENT ..... 27 SPAWNING SITE CHARACTERISTICS 29 STATUS OF POPULATION AND ENHANCEMENT FEASIBILITY ... 29 LITERATURE CITED 33 Page — v GRAYLING SPAWNING REPORT * ■ LIST OF TABLES Page Summary of angling regulations tor Arctic grayling in the Big Hole River from 1970 through 1990 ....... 4 Electrof ishing samplxng dates, locations, and approxi- mate length of sample sections for electrof ishing sampling of the 1988 spawning Arctic grayling popu- lation in the Big Hole River. "NOSN" indicates no other fish species netted during that saiipling 9 Mean length, length range, and sex ratio information by age for the portion of the Big Hole River Arctic grayling spawning run sampled during 19GB 15 Summary of tag return information for recaptured Arctic grayling captured during the spring of 1988 19 Page - vi GRAYLING SPAWNING REPORT LIST OF FIGURES Page 1. Map of the Big Hole River drainage 6 2. Daily discharge (cfs) and mean, minimum, and maximum water temperatures in the Big Hole River near Wisdom, Montana from April through June 1988. Preliminary data collected by the USGS. The time of grayling spawning IS shown in the cross-hatched block above the X-axis. . 7 3. Catch of grayling 8.0 inches and longer in the Big Hole River and its tributaries by date during 1938. Grayling were segregated into ripe male, ripe female, spent f=male, and other classes 14 4. Length frequency of Arctic grayling captured during the 1988 spawning run by half inch length group. Grayling were segregated into ripe male, ripe female, and other classes. Ripe fish included all fish identified as either mature, ripe, or spent . 16 5. Growth of grayling in the Big Hole River drainage estimated from mean lengths at age 17 6. Grayling movement assessed from tag return data for grayling tagged during 1987 and recaptured during the spring of 1988 (A) and tagged during the spring of 1988 and recaptured later in 1988 (B). The origin of arrows is the tagging location and the arrow's heads indicate recapture locations 21 7. Composition of a typical riffle streambed site where grayling were found spawning in the main stem Big Hole River and in a similar site where no grayling spawning was documented in the North Fork Big Hole River. All streambed compositions were determined from ten hollow core (McNeil and Ahnell 1964) samples 23 Page — vii GRAYLING SPAWNING REPORT ACKNOWLEDGEMENTS The U.S. ForE?5t Service, Montana Natural Heritage Program of the Nature Conservancy, and Montana Department of Fish, Wildlife and Parks provided funding for this project. The authors would especially like to thank Dave Center of the Montana Natural Heritage Program; Don Bartschi of the U.S. Forest Service, Regional Office; Ron Prichard, the Beaverhead National Forest's Supervisor; Joe Spehar and the entire Staff of the Wisdom Ranger District; and Larry Peterman and Jerry Weils of the Montana Department of Fish, Wildlife and Parks for their support and encouragement. A special thanks to Fisheries Biologist Harold Stevensen for his field work and experience and to Ken DeCock, Greg Gibbons, and Tim Mosolf for their untiring and cheerful help in the field. Dave Center, Don Skaar, and George Liknes reviewed early drafts of this report and their comments were invaluable and, in most cases, incorporated into this report. Any reference to product names are intended to document the type of equipment used and do not represent a product endorse- ment. Page - viii GRAYLING SPAWNING REPORT INTRODUCTION The last riverine (fluvial) native population cf Montana Arctic grayling (Thymallus arcticus montanus QMilner]) in the contiguous 48 United States exists in the upper Big Hole River of southv'jestern Montana (Liknes and Gould 1987). The historic range of the fluvial grayling in the lower 48 states included most of the upper Missouri River basin above Great Falls and northern Michigan. The Michigan populations were extirpated around 1936 (Hoi ton 1971; Scott and Grossman 1973). The distribution of fluvial grayling in Montana has progressively been reduced (Henshall 1906; Vincent 1962) until now the Big Hole River supports the only true fluvial population in the state. A population inhabiting a canal system (Sunnyslope Canal within the Sun River drainage) and a remnant population in the Madison River above Ennis Lake exist, however, the status of these populations are likely dependent upon reservoirs within their systems (Bill Hill, MDFWP, Choteau and Dick Vincent, MDFWP, Bozeman, personal communication). This dramatic reduction in range has led to the designation of the fluvial grayling as a "species of special concern" by the Endangered Species Committee of the American Fisheries Society (Johnson 1987), the Natural Heritage Program, and the (Montana Department of Fish, Wildlife and Parks ( t-IDFWF ) , as a "sensitive species" by the U.S. Forest Service, Northern Region (files, USDA Forest Service, Northern Region, Missoula, Montana), and a Category 2 species under consideration for ESA listing by the Fish and Wildlife Service (Federal Register). Electrophoretic analyses conducted on seven Montana grayling populations (Grebe Lake, Lake Agnes, Rodqers Lake, Elizabeth Lake, Fuse Lake, Sunnyslope Canal, and the Big Hole River) and one Alaska population (Chena River) found that the lake popula- tions were not greatly divergent from each other (Everett and Allendorf 1985). These authors found the Big Hole River, Chena River and Sunnyslope Canal populations were more different from the lake populations than from each other. Both the Big Hole and Chena populations are fluvial populations. The origin of the Sunnyslope Canal population is unknown, however, the most reasonable theory about their genetic make-up is that these fish undergo intense selective pressures because they live in a canal where ail movement must be down stream and the canal is dewatered every fall. The above authors implied that the Big Hole River population has maintained its native fluvial genotypes even though adfluvial (]a!:e) stocks may have been planted :;.n the iiig Hole River during the rriid-1900' s. The MDFWP has attempted to fr.onitor the abundance of the Big Hole River grayling population since the mid-1970's. Resulting data indicated a relative decline in abundance which prompted Page - 1 GRAYLING SPAWNING REPORT prDgrsssively restrxctxng sport angling harvest from a 10 fish limit to a catch and release limit between 1975 and 1983 (Table 1). In addition to reducing limits, MDFWP initiated a graduate study on the population in conjunction with the Montana Coopera- tive Fisheries Research Unit (Montana State University, Bozeman, Montana) which was the first in-depth attempt to document grayling population abundance and distribution (Liknes 1981). A literature review of grayling spawning requirements and timing found that grayling are annual spawners (Craig and Poulin 1975), likely home (Warner 1955; Craig and Poulin 1975; Tack 1980), migrate long distances to reach spawning grounds (Henshall 1907; Brown 1938; Nelson 1954; Reed 1964; Bishop 1971; Craig and Poulin 1975; Kratt and Smith 1977), initiate spawning migrations immediately prior to or during ice breakup of main stem rivers when water temperatures are 32 to 39 F (Brown 1938; Nelson 1954; Wojcik 1955; Warner 1955; Reed 1964; Schallock 1966; Williams 1968; Tack 1971; Bishop 1971; Tripp and McCart 1974; Craig and Poulin 1975; Krueger 1981; Falk et al . 1982), spawn at .^ixter temperatures between 36 to 50 F (Tryon 1947; Wojcik 1954; Rawson 1950; Warner 1957; Kruse 1959; Reed 1964; Williams 1968; Bishiop 1971; Netsch 1975; Wells 1976; Falk et al . 1982), spawn over a 2 to 24 day period (Kratt and Smith 1977), and spawn in current velocities ranging fron 1.1 to 4.8 ft/s (krueger 1981). Selection of substrate --^or spawning varies widely. Spawning usually occurs over gravel substrates (Henshall 1907; Rawson 1950; Nelson 1954; Bishop 1971), but may occur over mud-bottomed pools With vegetation (Scott and Grossman 1973). Liknes (1981) surveyed the Big Hole River grayling popula- tion during 1978 and 1979 by elec trof ishing and drift net sampling. He found grayling in three sections of the main stem Big Hole River and the lower reaches of 11 tributary streams and believed that the population was confined to the main stsm Big Hole River and tlie lower portions of its tributaries above the mouth of the North Fork Big Hole River. Shepard (1987 and files, Beaverhead National Forest, Dillon, MT) found three additional streams, Fishtrap, O'Dell and Wyman creeks, and Wise River also contained grayling. The grayling in O'Dell and Wyman creeks and Wise River probably originated from grayling drifting out of mountain lakes within the upper Wyman creek drainage. Shepard ' s findings supported the contention of Liknes that grayling were confined mainly to the upper Big Hole River valley tottom, however, Shepard (1986, 19S7 and files, Beaverhe^.d National Forest, Dillon, MT ) and Oswald (files, MDFWP, Dillon, MT) h-ave documented grayling in most of the Big Hole River from Jackson downstream to its mouth. Page GRAYLING SPAWNING REPORT Grayling in the Big Hole River ?.ppear to be concentrated between Divide and I'Jisdom and use this portion of the river seasonally by moving up into the Wisdom area during the spring with a significant portion of the population normally re,Tiair>ing in this area through the summer before migrating down river to winter habitats. Shepard (19S7) radio tagged adult grayling during the fail of 1986 and found most radioed grayling moved down river out of the Wisdom area, during October. Some years adult grayling do not remain in the Wisdom area during the sumnier, but move^ down river immediately after spawning. It is unclear what cues this early movement but preliminary observa- tions indicate that it is related to severe reductions in flow. Lil.nes i,i9Sl) sampled age O grayling within the Big Hole drainage and concluded that grayling spawned sometime during late April or early May. Shepard (1987) attempted to trap spawning graylirig from April 7 through June 25, 1986, as they moved into several tributaries and a channel of the Big Hole River with little success. In 1987 a committee was organized by the MDFWP that included representatives of MDFWP; Population Genetics Laboratory, University of flontana; Montana Cooperative Fisheries Research Unit, Montana State University; Montana Natural Heritage Program — Nature Conservancy; U.S. Forest Service; U.S. Fish and Wildlife Service; r.!ational Park Service; and American Fisheries Society. This Committee recommended and organized a study to collect more detailed information to describe the locations, distribution, and site characteristics of grayling spawning sites within the Big Hole River drainage, and the timing and population characteristics of the spawning run. This report summarizes data collected during the first year of that effort. Page GRAYLING SPAWNING REPORT Tabla 1. Summary of angling regulations for Arctic grayling in the Big Hols River from 1970 through 1790. Regulation years Grayling regulation 1970/71 - 1977/7B Ten pounds and one fish or 10 fish in combination with brown, cutthroat, and rainbow trout. 1978/79 - 1980/81 Five fish with only one fish exceeding 18 inches in combination with brown, cutthroat, and rainbow trout. 1981/82 - 1982/83 Five fish with only one fish axceeding 13 inches in combination with brown, cutthroat, and rainbow trout except from Divide Dam to Melrose Bridge where it was three fish, under 13 inches and one fish over 22 inches in combination with brown, cutthroat, iind rainbow trout. 1983/34 One grayling either under 13 or over 22 inches. 1984/85 - 1987/38 One grayling over 13 inches. 1988/39 - 19G9/90 Catch and release for grayling. Page GRAYLING SPAWNING REPORT STUDY SITE DESCRIPTION The study area included the upper Big Hole River drainage above Divide, Montana (Figure 1). Sampling was concentrated within tha main stem Big Hole River between the towns of Wise River and Jackson and m the lower portions of its tributaries including the North Fork Big Hole River, Big Lake Creek, Deep Creek, Fishtrap Creek, Governor Creek, F:Qck Creek, Sandhollow Creek, Seymour Creek, Steel Creek, Swamp Creek, and Warm Springs Creek. During sampling. Big Hole River flows and water tempera- tures rangec fro.n 618 to 3320 cfs and 33 to 75 F, respectively, using preliminary data supplied by the USGS from a gauge located at the Highway 43 bridge near Wisdom (Figure 2). Page - 5 'pcTy DISCHARGE (CFS) AND WATER TEMP (C) BIG HOLE RIVER. WISDOM D I 8 O h a r g e (cfs) 4000 3000 2000 1000- iiiiiiiiiiimliiiiiiiimiiiiiiiiimiiiiiiliiiiiiiiiiiiiiliimiiiiiiiiiiiiiim Apr 1 Apr 18 May 1 May 16 May 31 Jun 15 U8Q8 provisional data iiiiiiliiiiiiii Jun 30 Figure 2, Daily discharge (cfs) and mean, minimum, and maximum water temperatures in the Big Hole River near Wisdom, Montana from April through June 19S3. Preliminary data collected by the USGS. The time of grayling spawning is shown in the cross- hatched black above the X— axis. Pa, GRAYLING SPAWNING REPORT riETHODS FISH COLLECTION Grayling were captured using either boat mounted electro- fishing gear (either a Buffalo Drift boat or Coleman Crawd£-.d outfitted with a 240 watt gas powered generator connected to a Harvey Leach constructed variable voltage pulsator with mobile anodes) or a backpack elec trof isher (Coeffelt BP-iC) electro- fished in a downstream direction. Sampling began on April 6, in an Br&A of the Big Hols River free of ice, and continued through June 29 (Table 2). Two crews operated during the peak of the spawning run. A total of approximately 54 miles of river and 20 miles of tributaries were surveyed during the spawning season. Stunned grayling, rainbow trout, and brook trout were captured, except as noted on Table 2. For all captured fish, length was measured to the nearest O.i inch and weights were recorded to the nearest 0.01 pound. Sex and state of maturity (immature; mature, but not ripe; ripe; or spent) was recorded for all grayling. Sex >J3termination was based on extrusion of gametes, the ability to feel eggs V'githin the bodv cavity, and the shape of the dorsal fins as documented by Rawson (1950). Ripeness of female grayling was difficult to determine until immediately prior to and during spawning. It was difficult to determine if males were spent because sperm could still be extruded from spent fish. S.Tsaller grayling (fish less than 10.0 inches) v^erEf not checked for sex and state of maturity during the early part of the sampling (prior to April 27). Scale samples were removed from grayling and scale impres- sions were made m acetate. Scale samples were later read for age determination. Age interpretation from scale samples up to age IV was believed relatively accurate, while estimation beyond age IV was suspect. Growth interpreted from scales should be reliable because scale samples were obtained in the spring during annulus formation. All grayling and rainbow trout longer than 8.0 inches were tagged with a "spaghetti-type" numbered anchor tag. Recaptures of previously tagged fish were noted. Points of capture for grayling were visually noted and recorded m the field. RecoriJed infor-mation included the general hiabitat type and streambed condition where fish were captured and the location by river landmark. These capture locations were later converted to rivermile locations using USGS maps (scale: 1;24,000) and a Rivermile index. Page - 8 GRAYLING SPAWNING REPORT Table 2. Electrof ishing sampling datas, locations, and approx- imate length of sample sections for eit-ctrof ishing sampling of the 1998 spawning Arctic grayling population in the Big Hole River. "NOSN" indicates no other fish species netted curing that sampl ing = Date Location Section length (mi Comments 4-06-83 Big Hole R. - rial ion's scales to Stanchf ield ' s 1.8 No grayling NOSN 4-12-88 Big Hole R. - Seymcur Ck to Dickie Bridge 5.8 No grayling Massive ice flows NOSN 4-12-88 Big Hole R. - Pool at Sportman's Park Gne grayling Massive ice flows NOSN 4-13-88 Fishtrap Ck . - Above Highway 43 1.0 No grayling Lots of ice 4-14-88 N Fk Big Hole R. - below 0.1 Else ' s Ranch No grayling 4-20-88 Big Hole R. - above 5.0 Highway 43 bridge by Wisdom o« grayling 4-21-88 Big Hole R. - Squaw Ck to Fishtrap access S.l 3 grayling NOSN 4-21-88 Sandhollow Ck - below N Fk Big Hole Rd O. No grayling 4-21-88 Big Hole R. - 40 Bar Ranch to Fred Hirschy's 4.3 No grayling 1 rainbow 4-22-88 Swamp Ck . - N Fk Big Hole Rd to mouth 4-22-88 Big Hole R. - Swamp Ck to Sandhollow Ck 4— 2d— 88 Seymour Ck . — above and below Highway 43 bridge 2.0 5 grayling 1 grayling No grayling 4-26-88 Fishtrap Ck . - side channel at Access site 0. 1 No grayling 19 rainbow Page - 9 GRAYLING SPAWNING REPORT Table 2. (continued) Date 4-26-38 4-27-SS 4-27-88 4-27-88 4-28-88 4-29-88 5-02-88 5-03-38 5-03-08 5-03-88 5-04-88 5-05-B8 5-06-SS -09-88 Location Sac tion length (mi ) Sand hoi low Ck . - above N Fk Big Hole Rd Big Hole R. - Steel Ck mouth to above cemetery Steel Ck. - Steel Ck Rd to Bxg Hole R Sig Hole R. - Sandhollow Ck to Doolittle Ck 0 . 5 2.0 1.2 9.6 N Fk Big Hole R. - upper 6.0 to lower N Fk roads Big Hol= R. - above 5.0 Highway 43 bridge at Wisdom Big Hole R. - below 5.4 Highway 43 bridge at Wisdom Rock Ck . - lower end 0.8 above mouth at Big LaKe Ck Big Lake Ck , Rock Ck below 0.1 Sandhollow Ck . - N Fk Big Hole Rd 5-04-88 Big Hole R. - above Highway 43 bridge at Wisd 5.0 om Big Hole R. - below 5.4 Highway 43 bridge at Wisdom Big Hole R. - 40 Bar 4.3 Ranch to Fred Hirschy's Big Hole R. - Doolittle 6.6 Ck to Squaw Ck Swamp Ck. - N Fk Big 2.0 Rd to mouth Comments No grayling 13 grayling 6 grayling 40 grayling NOSN Sampled about 3.0 mi. No grayling 45 grayling 52 grayling 15 grayling 4 grayling Creek dry 35 grayling 39 grayling NOSN No grayling 6 rainbow 11 gi^aylinq NCSN 23 grayling Page - 10 Table 2. (continued). GRAYLING SPAWNING REPORT Date Location Section lengtn (mi ) Comments 5-09-88 5-09-38 5-10-88 5-10-88 5-11-88 5-11-88 5-11-88 5-11-88 5-16-88 5-17-88 6-13-88 6-15-88 6-21-88 6-29-88 Big HoLe R. — Swamp Ck to Sandhollow Ck Big Hole R. — Squaw Ck to Fishtrap access Big Hole R. - North Fork Big Hole to Doolittle Ck 0.2 8, i.O N Fk Big Hole R. N Fk Rd to nouth lower Governor Ck . - T. Clemow 0.5 Rd to Warm Springs Ck Warm Springs Ck - Governor Ck to mouth 0.5 Big Hole R. - Warm 2.5 Springs Ck to Twin Lks Rd Big Hole R. — Sandhollow 5.5 Ck to Doolittle Ck Deep Ck . — Ski Rd bridge 2.0 to mouth at Big Hole R. Big Hole R. - above 5.0 Highway 43 bridge at Wisdom Big Hole R. - Fishtrap 3.0 access to Sportsman's Park Big Hole R. - Wisdom 9.8 Cemetery to Doolittle Ck Big Hole R. - Dickie bridge to Jerry Ck 8.4 3 grayling 14 grayling NOSN 3 grayling 1 grayling near mouth 1 grayling No grayling No grayling 2 rainbow 19 grayling NOSN 2 grayling 43 rainbow 7 grayling 12 grayling 15 grayling 1 grayling Page - 11 GRAYLING SPAWNING REPORT SPAWNING SITE CHARACTERIZATION Sites where ripe grayling were captured were visually characterxzed including habitat type (rxffle, pool, etc.), substrate type (size category ranked into one or more of the following size classes: silt, sand, qrs.vei , cobble, or boulder), and channel type (main channel, side channel, braided channel). In addition, ten strearr.bed samples were taken from one known grayling spawning site in the Big Hole River and a similar habitat type unused by spawning grayling in the North Fork of the Big Hole River with a hollow-core sampler (modified from McNeil and Ahnell 1964). These core samples were oven dried and sieved through 2.0, 1.0, 0.5, 0.37, 0.25, 0.09, 0.03, and 0.003 inch mesh sieves and the material retained on each sieve was weighed to the nearest 0.01 pound. Material left suspended in the water during sampling was estimated according co methods presented in Shepard et al. (1984). The percentage of each size class of material was calculated for each core and averaged by site. Page - 12 GRAYLING SPAWNING REPORT RESULTS TIMING OF SPAWNING The first ripe male grayling was captured on April 20 in the Big Hole River above the Highway 43 bridge near Wisdom (Figures 1 and 3). The first female grayling identified as ripe was captured in the Big Hole River on April 27 near the Wisdom Cemetery an the east channel. The nurrbers of ripe females peaked during the period between April 29 and May 11. The numbers of ripe males peaked during the period between April 22 to May 17. The first spent female was captured on May 4. CHARACTERISTICS OF THE SPAWNING RUN The sex ratio of ail fish identified as mature, ripe, or spent was 2.0 malesil.O female (Table 3). Length and age frequency information for mature fish illustrated that a large portion of the age II fish were sexually mature (Table 3 and Figure 4). The fact that the sex ratios change betv-^een age classes suggests that not ail female grayling were maturing at age II and that female grayling may be suffering higher mortality than males after age iV (Table 3). The average length and weight of ripe males i. n = 158) was 10.9 inches and 0.42 pounds, respectively. The average length and weight of ripe females (n = 34) was 11.3 inches and 0.51 pounds, respectively. The majority of growth in length was attained at by age III with the fastest growth occurring during the first and second years of life (Figure 5) . DISTRIBUTION OF SPAWNING igiTHIN THE DRAINAGE The majority of grayling spawning during 1988 occurred within the main stem Big Hole River between the North Fork of the Big Hole River upstream to approximately 3.0 miles above the Highway 43 bridge near the town of Wisdom and in the lower portions (generally from their mouth upstream one to two miles) of Swamp, Big Lake, and Rock creeks (Figure 1). Isolated spawning areas were observed in side channels within the main stem Big Hole River above the Highway 43 bridge near Squaw Crnek and between Sawlog and Fishtrap creeks. Page - 13 Z zoc ^ < 5 LU Oz u. o Ocd O^ Z^ = LL Z -3 Z -3 CM h Z32mtijQ: oii- u. — coi 01 Qi •^ ■H c 0 III H -H L nj oj -1 e 4J m 01 OJ a Qj c ■•-' H Ul •H tu L in L -^ ID >^ Q U Qi JD -P C C 0 H i-i in QJ I- OJ QJ •o C - _ n3 OS -tJ n Ul m j:: 111 en fc u L cn III C -tJ 111 -H ■-I in (13 e O ul OJ • -t-i lU ■+- OQ -H 01 c -0 ■H C f-i n] > nJ I— I r. '- L. >. lU 01 11 nJ r-M IT) -i-l c OJ CTi a C Ul > L 4- ^H CD 0 CC U OJ CO Qj ■M r-i cc a. 113 0 O ■-* U X --I L 0) L 3 Oi •H IL Paqe If GRAYLING SPAWNING REPORT Table 3. Mean ienqth, length range, and se;< ratio information by age for the portion of the 3ig Hole Rxver Arctic grayling spawning run sampled during 1983. Age Number Mean length Length range Percent Sex ratio class sampled (inches) (inches J mature ( male : female ) 1 67 5.7 4.4 - - 7.2 None 2 169 9.8 8.1 - - 11.2 66 3.7:1.0 3 25 11.7 10.2 - - 12.8 92 J. . 9 : 1 . 0 4 61 12.7 11.6 - - 14.9 97 1.0:1.0 5 + 24 13.4 12.6 - - 14.6 iOO 2 . 4 : 1 . 0 Total 346 2.0:1.0 Page - 15 Zx lulu p T LU ZCL LU S 5^ < 111 I CM iSilii- itiiiiipwa- ■ilflSBi- i- 1 1 - o o CO CO < o I o 2 LJJ o q o o n r ai -P ni L en i-H 01 a 3 c 4J nj a.<-> rtJ u x: U H C L C 0 ■H *- -i-J -H I— ( C >^ m -H Ti r L -a en oj u en ■H c 01 u L en Xt 0 3 01 a ■H en C OJ H L C n3 S t) a cj> >^ in U H C CO -I QJ CO >- D c^ m cr -H nj L 0) M- j:: -p r on . -M c a C L Q m n !^ _J T3 en ■H m *- L 3 01 +J a m ■H 6 L • r 01 -4 «1 0) m ■D — < m u D 01 n x: uj 0 >*- •H •O 4J C C 03 OJ T3 '■ -H 01 01 H 01 c a -^ 01 H --I a L iTi ui O CM 01 L 3 cn H Ll Z^^CQLUCr Paoie- - IC? BIG HOLE GRAYLING Mean Length (TL) by Age 16-1 LENGTH (In.) Figurs 5. Growth of grayling in the Big Hole River drainage estimated from mean lengths at age. Pa-^e. - if GRAYLING SPAWNING REPORT MOVEMENT ASSESSED USING TAG RETURNS A total of 30 grayling were recaptured during this sampling. Twenty of these recaptures were tagged within the same year (1988) and ten were tagged in previous years (Table 4). Of the ten grayling tagged during 1987 and recaptured during our sampling, five were tagged m the river between Fishtrap Creek and Sportsmen's Park either during the previous Hay or November, four were tagged in the Wisdom area during the previous May, and one was tagged in Deep Creek the previous October (Figure 6 — A). All fish tagged during the winter (November) and recaptured during our spring sampling had moved up river. Subsequent returns of seven fish tagged during our spring elec trof ishing by anglers found that over half the fish tagged and recaptured (four of seven) moved down river as far as the Divide Dam and the longest recorded down river movement was 51 miles (Figure 6 - B). The other three were captured in the Wisdom area from May to early July. To summarize this tag return data, during 1938 the majority of mature-sized grayling (fish 8.0 inches and longer) moved upstream in the early spring to spawning areas (primarily from the North Fork up to Wisdom) from wintering areas within the lower river (from as far downstream as Divide Dam), spawned, and then moved dov^n river or into tributaries after spawning (Table 4 and Figure 6). During past years mature-sized grayling spent the entire summer within the upper portion ot the drainage in the Wisdom Area. as documented by summer and fall electrof ishing (Liknes 1978; Oswald 1984; Oswald 1986). CHARACTERISTICS OF SPAWNING SITES Visual Characteristics Grayling usually were found spawning in riffle areas over gravel which appeared "bright" due to the absence of periphyton and/or siit and sand sized material on the surface of the streambed. These riffle areas of "bright" gravel were often associated with recently created side channels, below beaver dams and irrigation diversion structures, and/or near mouths' cf tributaries where alluvial gravel fans had formed. Mature grayling were collected near each riffle of clean gravel below every beaver dam in a recently formed side channel belovvj Wisdom which contained numerous beaver dams. 3y the (Tiiddls of the spawning season elec trof ishers became relatively efficient at identifying areas inhere ripe grayling were likely to be captured. These areas could be characterized as being m areas of hydro- logic instability, often in recently cut side c^■annels where a riffle with "bright" gravel was situated near a pool or run. 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CD Ll Ll — I CD _) CD > Pa^e- - ZO GRAYLING TAG RECAPTURES TAG DURING 1987 AND RECAP 1988 130 120 - 110 - 100 00 - so - 70 80 -\ 60 BHR - Rlvermlle — I — Aug 1887 Apr I D«0 Apr 1888 TAG DURING SPAWN AND RECAP AFTER BHR - Rlvermlle ISOt 120 110- 100- •0- 80- 70- 60- B iiiiiiuiiiiMiiiiiiiiiiMiiiiiiiniiiiiiiiiiliMiniiMiiiiliriMiiiiiiniliiiiiiiMiMriliiMiiMiniiilMiiiiiiiiiiiiliiiiniiiiM Apr 20 May 6 May 20 Jun 4 Jun 10 Jul 4 Jul 18 Aug 3 Aug 18 1988 Figure 6. Brayiing movement assessed from tag return data for grayling tagged during 1987 and recaptured during the spring of 198B (A) and tagged during the spring of 1983 and recaptured later in 1938 (B). The origifi of arrows is the tagging iocarion and the Arro'.'t heaas indicate recapture locations. Z\ GRAYLING SPAWNING REPORT Streambed Composition The streambed within a known grayling spawning rifflp in the Big Hole River contained 30/1 large gravel (particles between 6.0 and 0.5 inches), 507. fine gravel (particles between 0.5 and 0.09 inches), and 207. sand and silts (particles less than 0.09 inches), while a similar site not used by grayling in the North Fork Big Hole River contained 30%, 407., and 307. of the same size classes, respectively (Figure 7). There were lower percentages of fine material (smaller than 0.25 inches in diameter) in the Big Hole spawning site (307.) versus the North Fork site not used for spawning (437.). There were statistically significant differences between the two sites for the cummulative percentages of material less than 0.374 inche'3 (p < O.02), less than 0.25 inch (p < 0.002), less than 0.09 inches (p < 0.004) based on Mann-Whitney tests (Daniels 1973) computed using a STAtGRAPHICS computer package version 2.6 ( STSC 1986). There were no significant differences between cummulative percentages for the other size classes analyzed. During the e;- li nj i;i r-( m t -p L n-j -1 4J Ul CO m i. 2 cn a LU ri c e e O'LC h • c id > M- c c i- ^ in Q HO) 2 flj H- ■■MB ^ rt nj > '-s LU C N 0 a H tf 0 13 X u^ cc n -a CO ■H L mo +-' cn rp rn OJ C -r-t r< M C '-1 H m Q -• 0 e -1 0 'il '— 1 _l_ L '-I CL i- e > mm e m m ifl cn -p c 0 -c 4J L -H m i: u 2 Ul IJICQ -0 y 13. This suggests that grayling initiatec spawning in response to the combined cues of daily maximum water temperatures rising above 50 F in conjunction with the falling limb of the initial spring sub-peak flow event that is characteristic of the upper Big Hole River nydrograph. Spawning then occurred during a relatively stable flow period between the initial spring sub- peak flow and the mam higher spring peak flow that occurred during late-May and early-June- Mean daily water temperatures during the peak of spawning activity (April 27 to day 10) averaged 47 F, but during the last five days of April (when spawning was initiated) mean daily water temperatures av^r^ged 48 F. A review of previous studies found t j me of spawning w^5 variable. Environmental factors that cued spawning activity were suggested to be water temperature and flow changes. Brown (1938) stated that 'The actual period of spawning for the Montana grayling has been found to vary greatly between different years and between different localities in the same year." Previous studies of grayling in Montana found that spawning occurred from mid-March through July. Specifically spawning occurred, mid- March to April 24 in Odell Creek, a Madison River tributary, peaking around April 16 (Brown 1938); from mid-May to early June in Narrows Creek, a tributary to Elk Lake in the Centennial Valley of southwest Montana (Lund 1974); from early May through May in an inlet of Rogers Lake in the northwest portion of the state (Tryon 1947); through early July with the time of initial spawning unknown in three high mcuntain lake inlets within the Wise River drainage, a tributary to the Big Hole River (Erik sen 1975) ; f rcTi mid-May to l^.te June in tributaries to G(-ate Lake in Yellowstone National Park ( Kruse 1959); from May 19 to June 6 in Red Rock Creek and from May 23 to June 1 in Antelope Creek, both tributaries to Upper Red Rock Lake in the Centennial Valley of Page - 24 GRAYLING SPAWNING REPORT southwest Montana (Nelson 1954); fran early Jane through late? June in an inlet stream to Lake Agnes in southwest Montana (Peterman 1972); and fron iriid-JLily thrDugh late July in an inlet to Hyalite Reservoir, near Eoz^man, Montana (Wells 1976). A revie'Aj of grayling studies conducted in Alaska found the majority of those grayling populations spawried from mid-May to mid-June, however, some populations were found to spawn as early as lata April and others as late as early July (Armstrong 1986). A review of studies conducted in Canada found that spawning generally occurred from April through June ( Rawson 1950; Bishop 1971; McCart et al . 1972; de Sruyn and McCart 1974; Tripp and McCart 1974; Kratt and Smith 1977? Talk et al. 1982). In past studies of grayling m Montana spawning was found to commence when water temperatures reaKzt-\^d the 40—50 F range and the upper end of this range was the suggested temperature where most spawning activity was observed by the majority of the authors (Brown 1938; Tryon 1947; Nelson 1954; Kruse 1959; Hoi ton 1971; Peterman 1972; Lund 1974; Wells 1976). Lund (1974) also documented that grayling began their spawning runs on declining stream flows in inlets to Elk Lake, Montana when daily stream and lake temperatures averaged approximately 45 F. Water temperature and spring flooding were believed to be factors that stimulated spawning in Armstrong's (1986) review of the Alaska studies on grayl.mg. Specifically, Tack (1973) believed that a water temperature of around 39 F triggered grayling spawning in interior streams of Alaska which was also the temperature Alt (1976) suggested grayling spawned in wastern Alaska. Warner (1955) also found grayling spawning at around 39 F in some inlets to Fielding Lake, Alaska. Bishop (1971) noted that grayling moved onto spawning grounds at water temperatures of 46 to 50 F and that spawning took place ^t 50 F. Canadian studies have reported water temperatures between 39 to 50 F to be an important cue for the initiaTiion of grayling spawning (Rawson 1950; Fripp and McCart 1974; Stuart and Chislett 1979). CHARACTERISTICS OF THE SPAWNING RUN The sex ratio for the Big Hole grayling spawning population was 2.0 males: 1.0 female. Kruse (1959) documented sex ratios of spawning runs into Grebe Lake, Yellowstone Park, spawning grounds to be 2.0:1.0 in 1953 and 0.9:1.0 in 1954. Lund (1974) found that females outnumbered mal'-;s in spawning populations of grayling entering Narrows Creek fr^m Elk Lake, Montana at a rar.io of 2.1:1.0 and 1 . 7 : 1 . (/ m J 972 end 1973, respectively. Bishop (1971) found a sex ratio or spawning crayling entering Providence Creek, a tributary to Great Slave Lake in Canada to be 1.3 males: i.O female. Ward (1951) found the sex ratio changed during Page - 25 GRAYLING SPAWNING REPORT the course of the spawning run in an Alberta tributary from 3.0 males: 1.0 female early in the run to 5.0 malesii.O female late in the run . The grayling in the Big Hole River system became sexually mature at age II. Hubert et al.'s (1985) reviev-^ of riverine grayling studies found that age at sexually maturity varied, dependent upon latitude and population density. In general, the above authors reported that grayling populations with low to moderate densities at lower latitudes attained sexual maturity at ago II to III, while in northern latitudes or high population densities fish matured at age IV and older, not reaching sexual maturity until age VI in many Alaskan waters. Tack (1974) concluded that angler harvest may have been responsible for grayling r.iaturing at a smaller size (earlier age) in the Chena River than in ijther waters of Alaska. The growth curve for grayling in the Big Hole system illustrates that the majority of growth is put on during their first two years (Figure 5). The presence of some juveniles in tributaries to the river and the interpretation of early growth from a few scales suggests that a small segment of the juvenile population may rear for up to two years in river tributaries. In Hubert et al.'s review (1935) of riveririe populations they reported that grayling m Hon tana and Wyoming reach 7.2 to 9.8 inches in 2 years and -from 11.2 to 14.7 in 4 years. Growth for the Big Hole grayling population appears to be toward the upp^r end of this range through age II (9.6 inches), while the average length of age IV grayling (12.7 inches) lies in the middle of the range reported by Hubert et ai. (1965). DISTRIBUTION OF SPAWNING WITHIN THE DRAINAGE The distribution of spawning grayling within the Big Hole drainage shows that areas above the North Fork of the Big Hole River were more intensively used for spawning. Precise reasons for this distribution of spawning Are unknown at this time, however, the following speculation may encourage further investigation. One possible explanation for the spawning distribution could be the high fine sediment load contributed to the Big Hole from the North Fork watershed. This drainage is underlain by highly erosive granitic batholithic material and lias recently experienced more intensive land-use. Previous streambed sampling by the senior author in 19S7 found that a riffle a.reA within the ri^er near Wisdom contained only 16X fine material (material less than 0.25 inch), whiile a riffle located aiova the Highway 43 bridge near Squaw Creek (An Ar^a below the North Fork) contained 297. fine material, and a riffle near Sportsmen's Park Page - 26 GRAYLING SPAWNING REPORT contained 21"'. fine mate'-ial (files, oeavarhead fwational Forest Dillon, iiT) . Another- potential explanauian for this spawnirg distribution is that the portion of the rx\'sr £bove the North Fork may bs inherently lest stable resulv.ing if! more areas o* "hydrolcgic mstabi 1 1 ty " V'ihxch creates preferred spawning habitat. MOVEMENT The movement patterns observed through recaptures of tagged fish and by the authors during their work on the Big Hole suggests that a segment of tfie ri\erine Eiig Hole grayling population spend the winter in deep pooifb in the portion of the river below the l^iisdom areai as far as the Divide Dam and perhaps in the lower portions of some tributaries which have deep pools cr areas of groundwater recharge. During th.e spring, the fiiajority of the mature grayling move up river ^nd spawn in the portion of the river from the mouth of thie North Fork up to immediately above Wisdom, and in the lower portions of Swamp, Bteel , 3ig Lai-.e, Rock, and Sand Hollow creeks. During years of average and above average river flows rnost of those grayling that moved up river during the spring ^emain in the upper portion of the river throughout the suminer to feed before ir.ovirg back down river in the fall (usually sometime during October) to return to winter habitat areas. The e;.act mechanism which triggers this down river movement is not known, but is suspected tc be a combination of rising river flows (resulting from either fall rains, increased return flows from irrigation, or a combination of the two) and declining water temperatures. During years of extreme low flow we have observed that a large portion of the grayling which moved up river during the spring migrate back down river immediately after spawning. This movement pattern was observed m 1985, 1987, and 1983, all years of low flow. What triggers this immediate down river migration is unclear, but may be related to drastic reductions in river flow during the late spring/early summer period. At the present time, we Are unsure if juvenile grayling follow this same migration pattern in the Big Hole system. We have not captured many juvenile grayling in the lower portions of the Big Hole, but have frequently captured juveniles in the Wisdom a,r^A. It may be that juvenile grayling m the Big f-lole either r"ear up through age 11 in rhs upper portion of the drainage, cr follow similar movement patterns as adults. During electrof ishing sampling in the fRll of 1986, juvenile (age O) grayling disappeared from the Wisdom area between the mark and recapture sampling. This would support the latter of the above two theories. Page - 27 GRAYLING SPAWNING REPORT Other authors have noted thxs type of annual rnxgraticn pattern in other riverine grayling populations. The following discussion of grayling movements in Alaska systems is taken from Armstrong (1986). He summarized the reasons for these "complex migrations to overwintering, spavNining, and feeding sites" to be "adaptions to different systems or differemc parts of the same system" which "enables the young [which "emerge early and develop rapidly"] to leave systems before they become frozen and uninhabitable in winter." He further states that "entire populations of grayling migrate downstream and out of certain tributaries and enter" main stem rivers for the winter. These populations leave streams which dry up or freeze solid, but also leave spring— fed streams. In conversations with Steve Tack (Fairbanks, Alaska) Armstrong and Tack speculated that the reason grayling leave these spring-fed streams is that these streams often have extensive frazil ice in winter. Armstrong also states that in larger unsilted rivers in Alaska (the iSig Hole would most closely resemble these systems) most grayling inhabit the upper reaches during the summer and migrate down stream to overwinter in the deeper water of the main stem. The majority of these Alaska populations begin this down stream movement in September, similar to the time Big Hole grayling population moved down river from the upper basin in previous normal flow years. Grayling in Alaska were found to migrate from a tew miles up to iOO miles to reach overwintering habitat. In these unsilted Alaska rivers grayling use different portions of the system during the summer depending upon their age and maturity. Young— of —the— year tended to remain near areas where they emerged, usually m the upper reaches of the system. Juveniles (ages I, II, and III) used the lower portions oT the rivers and their tributaries. Adults either moved upstream to feed in the upper reaches of the rivers, or if they spawned in the upper reaches, remained there throughout the summer. The grayling in Alaska were found to return annually to feeding areas and it was suggested that they probably show similar fidelity to spawning sites. Hubert et al.'s (1985) review documented the same types of migration patterns and clarified the following. Downstream migration to wintering areas was found to occur when water temperatures approached 32 F (Yoshihara 1972). All ages of grayling moved downstream to overwintering areas in large streams and rivers during late summer and fall (Yoshihara 1972; Kratt and Smith 1977; Tack 1980). Wintering areas included pools of intermittent and flowing streams, as well as spring-fed tog streams (Craig and Poulin 1975) which did not freeze to the bottom during winter months ( Krueger 1981). Page - 28 GRAYLING SPAWNING REPORT SPAWNING SITE CHARACTERISTICS We found Big Hole grayling spawning over gravel that was very clean on its surface. Spawning occurred in riffle areas in close proximity to pool or deep run habitats. Most previous investigators have found that grayling spanned in riffles or in transition zones between riffles and pools (hlershall 1907; Rawson 1950; Nelson 1954; Bishop 1971). Eggs and spawning have generally been found on gravel and not on mud, silt, sand, or clay substrates (Henshail 1907; Rawson 1950; Nelson 1954; Warner 1955; Bishop 1971; Tack 1971; Tack 1973; Kratt and Smith 1977), however, Bi^ovMn (1938) found the Agnes Lake, Montana spawners spawning over silt and sand at a ratio of 3:1 in the inlet, Curtis (1977) found grayling from Wyoming lakes in inlet and outlet streams spawning over a sand/ fine gravel substrate, Bendock (1979) found a lake population of grayling spawning over a wide variety of material from large rubble to vegetated silt within the lake. Reed (1964) found grayling spawning over mud in a side slough, and Tack (1980) found grayling spawning on sedges m a stagnant pond. To summarize, it appears that lake popula- tions of grayling may have adapted to spawning over fine material, while river and stream populations generally spawn over gravel in riffle areas. There has been little work done to evaluate spawning success in different substrate conditions. This question should be addressed in future research. STATUS OF POPULATION AND ENHANCEMENT FEASIBILITY We will give a brief assessment of our opinion on the present status of the riverine grayling population in the Big Hole River system and briefly explain recent attempts directed at enhancement of this population. We will also briefly discuss the problems which will likely be associated with attempting to re- establish riverine populations of grayling into other waters m the state. The following is speculation based on observation and a review of the literature. The riverine population which exists in the upper Big Hole River system above Divide, Montana appears to be a single population and at least a portion of this population uses the entire upper river system on a seasonal basis. This population is presently at a low level and the recent trend (from 1983 to the present) has been a declina (Oswald m prep.). Year class strengths and weaknesses appear to be linked to river flows with below average flows producing weak year classes and normal a^-^d slightly above average flows producing strong year classes. Ironically, it appears that flows which B.re way above average may also produce weak year classes. Grayling £ire notoriously Page - 29 GRAYLING SPAWNING REPORT vulnerable to angling (Fal.k and Gillman 1974; Tack 1974; Graback" 1981) and recent regulation restrictions have attempted to remove that component of mortality from the riverine Big Hole population (Table 1). The other three potential avenues for preservmc and/or enhancing this population B.rs: 1) habitat enhancemant, either through the enhancement of river flows or direct habitat enhancement by creating more preferred habitats; 2) population enhancement through releases of riverine stock grayling fry into the system; and 3) control of competitors and predators, if further research finds these tv-jo types of interactions contribute significantly to overall mortality. We will discuss each of these options in detail. One of the most likely candidates for preserving and /or enhancing populations is to provide more stable river flows and reduce potential loss of grayling in irrigarion ditches. By providing more stable flows, particularly during the relative short spawning and incubation period, survival from eggs through the first summer of life should be enhanced. More work is needed to confirm our observations from 1988 and further refine the relationship between the timing of spawning and river flows and water temperatures. If we can accurately predict when spawning will occur, we can work with local irrigators to provide for more stable river flows from the initiation of spawning through the time fry emerge (a two to three week time period). The senior author has already approached irrigators in the upper Big Hole vallev near Wisdom and received a very positive response to this concept. There appears to be a very real possibility of initiating this type of management. Another potential source of mortal itv is the loss of grayling, particularly fry and juveniles, into irrigation ditches. One way to limit this loss would be to attempt to return any grayling fry or juveniles back to the river from irrigation ditches before these ditches Brs shut down for haying or at the end of the season. Work done in the Gallatin River system found that an incremental shut-down of ditches o^er a two to three day period triggered trout to move up the ditch and return to the river (Clothier 1953 1954; Kraft 1972). Orienta- tion of irrigation diversions relative to the river channel can also reduce loss of fish into ditches (Spindler 1955). Again, the senior author approached the irrigators of the upper Big Hole drainage and these irrigators agreed to begin implementing the incremental shut-down of ditches immediately, and were wiUmq •-- discuss orientation and operation of diversion structures to minimize fish loss. The loss of grayling migrating down river during the fall to seek overwjnter habitat into irrigation ditches does not appear to be a concern in the upper Big Hol° drainage (from Jackson down to Squaw Creek). The irrigators m Page - 30 GRAYLING SPAWNING REPORT this portion of the draxnage indicated that their irrigation diversions were 'shut off either in July prior to haying (and not turned back on again) or around Labor Day in S3ptsfr;ber, prior to the initiation of down river movement by grayliiig. Direct habitat enhancement would depend upon better defining habitat requirements of this population and determining if physical habitat was limiting populations. If this was the case, a habitat improvement program could be initiated. This optiion would rely on the collection of more information. Direct enhancement of riverine grayling populations in the Big Hole River could be accomplished by supplementing ths existing population with other riverine stock or with frv hatched from eggs taken from Big Hole grayling. There is a risk in the first option in that it could potentially introduce undesirable genetic material into the present population and alter the genetic makeup of the existing native population. The second option is the more preferable, however, one problem with this option 15 that the availability of eggs to supplement the population is presently limited due to the low numbers of mature females in the population and the difficulty in obtaining eggs during the extremely short spawning period. During tiie 1983 spawning season approximately 5 , OOO fertilized eggs were ootaired from the Big Hole grayling population for fry behavior research conducted by Dr. C. Kaya (Montana State University, Bozeman ) . After Dr, Kaya hatd completed his experiments and these fry had suffered some mortality due to disease, approximately 3,000 fry remainea. These fry were released into a lake which was previously barren of fish. This lake has an inlet which should provide suitable spawning habitat for these grayling. This release should provide additional fry for the Big Hole system. Our plan is to return to the lake vjhen these fry mature (m two to three years) to obtain fertilized eggs by trapping the inl3t stream. It is hoped that during the course of maturing these released fry do not lose too much of the genetic component that makes them riverine Big Hole River stock due to adaption to the lake environment. The objectives of this release were two-fold. One was to provide a source of fry to stock back into the Big Hole system so that we could enhance thie Big Hole population while we were investigating how to enhance survival within the Big Hole system. The other objective was to preserve some genetic material from the Big Hole grayling population in an isolated location so that if the Big Hole population suffered a catastrophic decline to extinction we would have a source -or re- introducing grayling back into the Big hole. Since the 3 , 0'. O fry which were stocked into the lake m 1983 were the progeny of only SIX feiviales, we plan to spawn some additional females during 1939 to increase the genetic variabilLt/ within this lake population. Page - GRAYLING SPAWNING REPORT We do not plan r.a allow these fish more than two generations, and preferably only one, of lake residence prior to our returning for eggs to supplement the Big Hole population. The exception to that would be if the Big Hole grayling population went extinct due to a catastrophic event. The issue of competition and predation will have to be addressed by conducting the research to determine if these two factors contribute to significant mortality within the Big Hole River grayling population. It would be premature at the present time to suggest acting on this possibility without further evidence. The possibility of re-establishing riverine populations of grayling into waters in Montana which do not presently support them should be addressed. At the present time it appears that re-establishing grayling populations will be difficult, at best. The experience that U.S. Fish and Wildlife Service biologiats had in Yellowstone ^^atiDnal Park trying to re-establish a grayling population into Canyon Creek, a tributary to the Firehole River, suggests that rivt^rine populations require relatively large drainage? systems that sltb accessible. It the Canyon Creek experiment, a falls on lower Canyon Creek was enhanced to provide a total barrier to upstream migration so thax exotic species of fish could not ascend Canyon Creek and coa^;pet3 or prey on the grayling population re-introduced into Canyon Creek. An attempt was made to renove all fish within Canyon Creek prior to the introduction of grayling v-jhich were obtained from the Big Hole River. However, it appears that these introduced grayling moved out of Canyon Creek, probably seeking winter habitat, and could not return. This suggests that it will not be possible to re-establish populations of riverine grayling into small isolated tributaries, but will require medium to large river drainages which can provide spawning, summer feeding, and overwintering habitats. The effort to accomplish this type of re-introduction would be immense and may mean that existing fish species could not be removed prior to grayling re— introduction . The potential for re-establishing riverine grayling in Montana where they do not presently exist will require more research and a strong commitment to that type of effort. Page GRAYLING SPAWNING REPORT LITERATURE CITED Alt, K T. 1976. Inventory and cataloging of sport fish waters of western Alaska. Alaska Department of Fish and Game. Federal Aid m Fish Restoration, Annual Performance Report, 1975-1976. Project F-9-a , 17(G-I-P): 156, Juneau, Alaska. Armstrong, R. H. 1986. A review of Arctic grayling studies in Alaska, 1952-19B2- Biological Papers of the University of Alaska, Number 23, Institute of Arctic Biology, Unive'-si t-)' of Alaska, Fairbanks, Alaska. Bendock, T. N. 1979. Inventory and cataloging of arctic area waters. Alaska Department of Fish and Game, Federal Aid in Fish Restoration, Annual Performance Report, 1973-1979. Project F-^-11, 20(G-I-I;, Juneau, Alaska. Bishop, F. G. 1971. Observations on spawning habits and fecundity of the Arctic grayling. Progressive Fish- Cuiturist 33:12-19. Brown, C. J. D. 1938. Observations on the life-history and breeding habits of the Montana grayling. Copiea 3:132- 136. Clothier, l-i. D. 1953. Fish loss and movement in irrigation diversions form the West Gallatin River, Montana. Journal of Wildlife Management 17:144-153. Clothier, W. D. 1954. Effect of water reductions on fish movement m irrigation diversions. Journal of Wildlife Management 13:150-160. Craig, P. C, and V. A. Poulin. 1975. Movements and growth of Arctic grayling (Thymailus arcticus) and juvenile Arctic char (Salvelinus alpinus) in a small arctic stream, Alaska. Journal of the Fisheries Research Board of Canada 32:689- 698. Curtis, M. 1977. The age, growth and management of the Arctic grayling (Thymailus arcticus) in Wyoming. M.S. Thesis, University of Wyoming, Laramie, Wyoming. Daniel, W. W- 19^8. Applied nonparametric statistics. Hougntcn Mifflin Company, Boston, Massachusetts. Page GRAYLING SPAWNING REPORT deBruyn, M., ana P. McCart. 1974. Life iiistory of the grayling ( ihymal lus arcticus) m Beaufort Sea cJrairtages in the Yukon Territory. Pages 92-130 in_ Arctic Gas Biological Report Series, Volume 20, Aquatic Environments Limited, Calgary, Alberta. Eriksen, C. H. 1975. Physiological ecology and management of the r&rs "southern" grayling Thymallus arcticus tricolor Cope. Verh. Internat. Verein . Limnol . 19:2448-2455. Everett, R. J., and F. W. Allendorf. 1935. Population genetics of Arctic grayiing:Grebe Lake, Yellowstone National Park. Population Genetics Laboratory Report 85/1. University of Montana, Missoula, Montana. Falk, M. R. and D. V. Gillman. 1974. Impact of a sport fishery on Arctic grayimq in tne Brabant Island atss. Northwest Territories. Canada I>epartment of the Environment, Fisheries and Marine Service, Fisheries Operations D- irectcrate, Data Reporc Number CEN/T-74-7, Toronto, Canada. Falk, M. R., M. M. Roberge, D. V. Gillman, and G. Low. 1932. 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Johnson, J. E. 1987. Protected fishes of the Unite.- Stales and Canada. American Fisheries Society, Bethesda, Maryland. Page - 34 ^ GRAYLING SPAWNING REPORT Kraft, M. E. 1972. Effects of control led flow reduction on a trout stream. Journal of ths Fisherxes Research Board of Canada 29:1405-1411. Kratt, L. F., and R. J, F. Bmith. 1977. A post-hiatching sub- gravel stage in the life history of the Arctic grayling, Thymallus arc ticus. Transactions of the American Fisheries Society 106:241-243. Krueger, S. W. 1981. Freshwater habitat relationships, Arctic grayling, Ihymallus arc ticus. Unpubl ;.she>J Report, Alaska Department of Fisn and Game, Habitat Division, Juneau, Alaska . Kruse, T. E. L9r>9. Grayling of Grebe Lake, Yellowstone National Park, Wyoming. Fishery Bulletin 149, Volume 59, U.S. Fish and Wildlife Service, Washington, D.C. Liknes, G. A. 1981. The fluvial Arctic grayling ( Thymal lus arc ticus ) of the upper Big Hole River Drainage, Montana. M.S. Thesis, Montana State University, Bozeman , MonTiana. Liknes, G. A., and W. R. Gould. 1987. The distribution, habitat and population characteristics of fluvial Arctic grayling (Thymallus arcticus) in Montana. Northwest Science 61:122- 129. Lund, J. A. 1974. The reproduction of salmonids in tlie inlets of Elk Lake, Montana. M.S. Thesis, Montana Stats Univer- sity, Bozeman, Montana. McNeil, W. J., and IJ. H. Ahnei 1 . 1964. Success of pink salmon spa'wning relative to the size of spawning bed matarials. U.S. Fish and Wildlife Service Special Scientific Report — Fisheries 469. Nelson, P. H. 1954. Life history and management of the American grayling (Thymallus arcticus tricolor) in Montana. Journal of Wildlife Management 18:324-342. Netsch, N. F. 1975. Fishery resources of waters along the route of the trans-Alaska pipeline between Yukon River adn Atigun Pass in north central Alaska. U.S. Fish and Wildlife Service Resource Publication 124:1-45. Cswaid, R. A. 1984. Inventt-ry and survey of the waters of the Big Hole and Ruby River drainages. Job Progress Report, Federal Aid in Fish and -/Ji Id life Restoration Acts, Project Number F-9-P-31 and 32, Job Numoer i-b, Bozeman, Montana. Page - 35 ^ GRAYLING SPAWNING REPORT Oswald, R. A. 1936. Inventory and surv-y of the waters of the Big Hole, Beaverhead and Ruby Rxver drainages. Job Progress Report, Federal Aid in Fish and Wildlife Restoration Aci-s Project Number r--9-R-34, Job Number 1-b, Bozeman, Montana! Peterman, L. G. 1972. The biology and population characteristics of the Arctic grayling m Lake Agnes, Montana. M.S. Thesis, Montana State University, Bozeman Montana. ' Rawson, D. S. 1950. The grayling (Tymallus sicnifer) in northern Saskatchewan. Canadian Fish Cuiturist 6:3-10. Reed, R. J. 1964. Life history and migration patterns of Arctic grayling, Thymalius arcticus (Pallas), in the Tanana River drainage af Alaska. Alaska Department of Fish and Game Research Report Number 2, Juneau, Alaska. 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Enk . 1984 Monitoring levels of fine sediment within tributaries to Flathead Lake and impacts of fine sediment on bull trout recruitment. Pages 146-156 in. F. Richardson and R. H. Hamre, editors. Proceedings of the Wild Trout III Sy.T.posium neld September, i984 in Yellowstone National Park, Wyoming. Spindler, J. C. 1955. Loss of game fish m relations to physical characteristics of irrigation canal intakes. uournal of Wildlife Management 19:375-382. Page - 36 % GRAYLING SPAWNING REPORT STSC Inc. 1986. Statgraphics : Statistical graphics system. Statistical Graphics Corporation, Rockville, flaryland. Stuart K. M, and G. R. Chislett. 1979. Aspects of the life history cf Arctic grayling in the Sukunka drainage. Final Report, British Columbia Fish and Wildlife Branch, Prince George, British Columbia. Tack, S. L. 1971. Distribution, abundance, and natural history of the Arctic grayling in the Tanana River drainage. Alaska Department of Fish and Game, Federal Aid in Fish Restor- ation, Annual Report of Progress, 1970-1971. Project F-9-3, 12(R-I), Juneau, Alaska. Tack, S. L. 1973. Distribution, abupdance, and natural history of the Arctic grayling in the Tanana River drainage. Alaska Department of Fish and Game, Federal Aid in Fish Restor- ation, Annual Report of Progress, 1972-1973. Project F-9-5, 14(R-I), Juneau, Alaska. Tack, S. L. 1974. Distribution, abundance, and natural history of the Arctic grayling in the Tanana River drainage. Alaska Department or F.\sh and Game, Federal Aid in Fish Restor — ation, Annual Performance Reporc, 1973-1974. Project F-9-6, 15(R-I), Jun»^au, Alaska. Tack, S. L. 1930. Migrations and distribution of Arctic grayling, Thymallus arcticus (Pallas), in interior and arctic Alaska. Alaska Department of Fish and Game, Federal Aid in Fish Restoration, Annual Performance Report, 1979- 1980. Project F-9-12, 21(R-I), Juneau, Alaska. Tripp, D. B., and P. J. McCart. 1974. Life histories of grayling (Tnymallus arcticus) and longnose suckers (Cat- ostomus catostomus) in the Donnelly River System, Northwest Territories. Pages 1-91 iji Arctic Gas Biological Report Series, Volume 20, Aquatic Environments Limited, Calgary, Alberta. Tryon , C. A. Jr. 1947. The Montana grayling. Progressive Fish- Culturist 9:136-142. Vincent, R. E. 1962. Eiogeographical and ecological factors contributing to the decline of Arctic grayling, Thymal li'.s arcticus (Pallas), in Michigan and Montana. Ph.D. Dis- sertation, University of Michigan, Ann Arbor, Michigan. Page ^ GRAYLING SPAWNING REPORT Ward, J. C. 1951. The biology of the Arctic grayling in the southern Athabasca draxnage. M.A. Thesis, University of Alberta, Edmonton, Alberta, Canada. Warner, G. W. 1955. Spawning habits of grayling in interior Alaska. U.S. Fish and Wildlife Service and Al^iska Eame Commission, Federal Aid in Fish Restoration, Quarterly Progress Report. Project F-l-R-5, Work Plan E, Job Number 1, 5(2), Juneau, Alaska. Warner, G. W. 1957. Movements and migrations of grayling in interior Alaska. U.S. Fish and Wildlife Service and Alaska Game Commission, Federal Aid in Fish Restoration, Quarterly Progress Repor t. Project F-l-R-6, Work Plan C, Job Number 3, 6(4), Juneau, Alaska. Wells, J. D. 1976. The fishery of Hyalite Reservoir during 1974 and 1975. M.S. Thesis, Montana State University, Bozeman , Montana . Williams, F. T. 1968. Grayling investigations on Tolsona and Moose LaKes. Alaska Department of Fish and Game, Federal Aid m Fish Restoration, Annual Report of Progress, 1967- 1963. Project F-5-R-9, 9(14-B) : 257-264 , Juneau, Alaska. Wojcik, F. J. 1954. Spawning hiabits of grayling in interior Alaska. U.S. Fish and Wildlife Service and Alaska Game Commission, Federal Aid in Fish Restoration, Quarterly Progress Report. Project F-l-R-3, Work Plan 1, 3(3), Juneau, Alaska. Wojcik, F. J. 1955. Life history and management of the grayling in interior Alaska. M.S. Thesis, University of Alaska, Fairbanks, Alaska. Yoshihara, H. 1972. Monitoring and evaluation of Arctic waters with emphasis on the North Slope drainages. Alaska Department of Fish and Game. Federal Aid in Fish Restor — ation. Annual Report of Progress, 1971-1972. Project F-9-4, 13(G-111-A), Juneau, Alaska. Page - 38 MONTANA STATE This ''cover" page added by the Internet Archive for formatting purposes