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Item Effects of road construction on water quality parameters and bull trout (Salvelinus confluentus) populations in three Montana water bodies(Montana State University - Bozeman, College of Agriculture, 2019) Thatcher, Hannah Alicen; Chairperson, Graduate Committee: Scott PowellRoad construction adjacent to rivers and ensuing clearing of timber and shrubs can lead to alterations in the dynamics and morphology of channel features and water chemistry that provide habitats for aquatic biota. We examined associations between bull trout (Salvelinus confluentus) populations and water quality parameters related to road construction in three western Montana rivers over a 15-year study period. Bull trout have specific habitat requirements that can influence their overall abundance and distribution within a watershed, making them an important indicator species of general ecosystem health. We used average annual bull trout population data from Montana Fish, Wildlife, and Parks and daily water quality observations from the United States Geological Survey between 2000 and 2014 to analyze the correlation between the data sets. We used a nonparametric statistical test to determine whether any significant change was observed between the medians of pre- and post-construction water quality parameters and bull trout population numbers. The association between the water quality parameters and bull trout numbers was visually examined with scatter plots created in R where the Y-axis was population numbers and the X was the water quality parameter. The plots were then fit with a linear regression line and from this a visual interpretation of the association and strength of said associated was determined. The analysis yielded unexpected results with only some of the water quality parameters exhibiting a negative relationship with road construction disturbance. Two water bodies (Flathead River and Warm Springs Creek) showed no significant changes in bull trout population numbers, and the control water body with no road construction (the Blackfoot River) displayed significant differences between the pre- and post-construction water quality parameter medians. The parameters that did display expected outcomes (cadmium concentration in the Flathead River; water temperature, pH, and instantaneous discharge in Warm Springs Creek; and instantaneous discharge, pH, and cadmium concentration in the Blackfoot River) were not all strongly correlated with decreased bull trout population numbers. The water quality parameters common to all the study rivers that presented a negative association with bull trout numbers was pH. High levels of recreation and management activities on the Blackfoot River (the control) could explain these unexpected findings. The results do, however, partially corroborate previous studies on the negative association between bull trout population numbers and road construction-related disturbance. A longer study period combined with finer-grained data would be beneficial for future studies.Item Assessment, evaluation, and development of fish passage guidelines(Montana State University - Bozeman, College of Engineering, 2021) Denham, Travis John; Chairperson, Graduate Committee: Kathryn Plymesser; This is a manuscript style paper that includes co-authored chapters.Instream barriers such as dams and diversions have been designed and constructed on America's rivers for centuries. In recent decades, the negative impacts from instream barriers on freshwater ecosystems have become more well-known and an industry established focusing on mitigating these negative impacts and restoring freshwater ecosystems. A primary focus of practitioners working to restore freshwater ecosystems has been to reconnect aquatic organisms to their original range through the design and implementation of fish ladders, also known as fishways. Fishways provide passage routes for fish past instream barriers, upstream and downstream. Fishway design in the Pacific Northwest United States focused primarily on anadromous salmonids, more commonly known as salmon (genus Oncorhynchus), due to cultural, economic, and recreational significance of salmon. Salmon are strong swimmers when compared to many other fish species; therefore, fishways designed and constructed specifically to allow passage of salmon may not provide safe, timely, and effective passage of other fishes. The purpose of this document is to present a fishway design resource aimed at providing necessary species-specific background and abilities of weaker swimming fishes and evaluate the applicability of existing fishway design criteria when designing fishways for Bull Trout (Salvelinus confluentus). The fishway resource focuses on Bull Trout and Pacific Lamprey (Entosphenus tridentatus) and will be provided to the United States Fish and Wildlife Service (USFWS) as a draft document for future publishing. An extensive literature review was completed identifying species abilities, background, and comparison to existing design criteria, fishway practitioners were briefed on the project and their opinions related to content and format were solicited, and findings were thoroughly reviewed and discussed by and with USFWS staff. As a result of this project a concise fishway resource has been developed as a draft and template for USFWS staff. Additionally, an evaluation of the applicability of using anadromous salmonid passage criteria when designing passage facilities for Bull Trout was conducted. Lastly, future research projects were suggested to address data gaps in Bull Trout swimming performance and fishway designs for them.Item Out-migration dynamics of juvenile adfluvial bull trout in tributaries to the lower Clark Fork River, Montana(Montana State University - Bozeman, College of Letters & Science, 2021) Lewis, Madeline Collier; Chairperson, Graduate Committee: Christopher S. Guy; Christopher S. Guy, Eric W. Oldenburg and Thomas E. McMahon were co-authors of the article, 'Demographic characteristics and distribution of juvenile adfluvial bull trout at the tributary scale' submitted to the journal 'Transactions of the American Fisheries Society' which is contained within this thesis.; Christopher S. Guy, Eric W. Oldenburg and Thomas E. McMahon were co-authors of the article, 'Seasonal capture efficiencies influences knowledge of underlying out-migration dynamics in bull trout populations with juvenile downstream trap-and-haul programs' submitted to the journal 'North American journal of fisheries management' which is contained within this thesis.; Christopher S. Guy, Eric W. Oldenburg and Thomas E. McMahon were co-authors of the article, 'Individual characteristics and abiotic factors influence outmigration dynamics of juvenile bull trout' submitted to the journal 'Canadian journal of fisheries and aquatic sciences' which is contained within this thesis.In the lower Clark Fork River, Montana, a two-way trap-and-haul program is implemented to conserve the adfluvial life-history strategy in Bull Trout Salvelinus confluentus populations in the presence of hydropower dams. We used the infrastructure in place for the program, including a permanent weir trap and multiple stationary PIT antennas, to evaluate the demographic characteristics and out-migration dynamics of juvenile bull trout, and assess the efficacy of the downstream trapping component of the trap-and-haul program. We PIT-tagged 821 juvenile Bull Trout in Graves Creek, and 144 Bull Trout in East Fork Bull River in the summer of 2019 and summer of 2020. Bull Trout in Graves Creek were primarily age 1 and age 2, with a small number of age-3 Bull Trout present (< 1%). In East Fork Bull River, age-3 Bull Trout represented 14% - 46% of the population, with a small number of age-4 and older Bull Trout present (4% - 6%). From July 2019 through December 2020, 308 tagged Bull Trout outmigrated from Graves Creek, and most out-migrants were age 2 (n = 221). In East Fork Bull River, 18 Bull Trout out-migrated, and most out-migrants were age 3 (n = 13). Capture efficiency of the permanent weir in Graves Creek varied from 83% to 100% in autumn 2019 and 2020 and was substantially lower in the spring (14%). The majority of Bull Trout out-migrated from Graves Creek during autumn 2019, spring 2020, or autumn 2020 trapping seasons (n = 276). In Graves Creek, the largest Bull Trout within the 2018 year-class were five times more likely to out-migrate at age 1 when compared to smaller fish within the cohort. The magnitude of age-1 out-migration was positively related to density. Relative changes in abiotic factors, including discharge, water temperature, and photoperiod, were cues to out-migration, and the direction of change varied by season. Understanding the demographic characteristics and outmigration dynamics of the Bull Trout in Graves Creek and East Fork Bull River enables more informed management of the trap-and-haul program and can be used to inform conservation efforts of other migratory Bull Trout populations.Item Combination of acoustic telemetry and side-scan sonar provides insight for lake trout Salvelinus namaycush suppression in a submontane lake(Montana State University - Bozeman, College of Letters & Science, 2021) Siemiantkowski, Michael James; Chairperson, Graduate Committee: Christopher S. GuyExpansion of an invasive Lake Trout Salvelinus namaycush population in Swan Lake, Montana threatens a core area population of Bull Trout Salvelinus confluentus in Montana. Given the increased efficacy of suppression using novel embryo suppression methods, there is renewed interest in Lake Trout suppression in Swan Lake. The specific questions of this study were: 1) where are Lake Trout spawning, 2) where are the most used spawning sites, 3) what is the amount of spawning habitat, 4) does the estimated spawning area differ between estimates from telemetry locations and side-scan sonar imagery of suitable spawning substrate, and 5) how much phosphorous and nitrogen would be added to Swan Lake if carcass-analog pellet treatments were implemented? Acoustic tags were implanted in 85 Lake Trout in July and August of 2018 and 2019. Nightly tracking efforts during September, October, and November of 2018 and 2019 resulted in 1,744 relocations for 49 individual Lake Trout. Kernel-density analysis was used to evaluate Lake Trout aggregation locations identifying 10 distinct spawning sites -- corroborating previous studies. Visual observation of Lake Trout embryos confirmed spawning at three sites with the remaining seven sites considered to be unconfirmed spawning sites. All confirmed spawning sites were located in the littoral zone along areas of steep bathymetric relief and were the most used across both spawning seasons. In 2019, side-scan sonar imaging was used to classify and quantify the total area of suitable spawning substrate, which comprised 12.8% of the total surface area estimated for confirmed sites and 11.4% for unconfirmed spawning sites. Simultaneous treatment of all confirmed and unconfirmed spawning sites would require 205,709 + or - 86 kg of carcass-analog pellet material, resulting in 370.4 + or - 0.2 kg of phosphorous and 7,487.9 + or - 3.1 kg of nitrogen inputs to Swan Lake. Thus, pellet treatment would increase the Carlson's trophic state index (TSI) values from 20.8 to 27.7 for total phosphorous, and from 22.1 to 26.2 for total nitrogen. Based on a TSI threshold value of < 40 for an oligotrophic lake, the use of carcass-analog pellets could be a feasible addition to renewed Lake Trout suppression efforts in Swan Lake.Item Subadult bull trout out-migration in the Thompson River drainage, Montana(Montana State University - Bozeman, College of Letters & Science, 2017) Glaid, Jeffrey Robert; Chairperson, Graduate Committee: Christopher S. GuyBull Trout populations in the Thompson River drainage have declined over the past century. Declines have been attributed to habitat fragmentation, habitat degradation, and non-native species. Out-migration characteristics (e.g., temporal and spatial origins, abiotic cues, and movement) of subadult Bull Trout (100 - 300 mm TL) were evaluated throughout the drainage to increase our understanding of local populations and better inform conservation efforts. In autumn 2014, 53 subadult Bull Trout were tagged with passive integrated transponder (PIT) tags; 29 were also surgically implanted with acoustic transmitters. Minimal Bull Trout out-migration (N = 7) was observed in 2014. In summer 2015, 566 subadult Bull Trout were PIT-tagged in the Fishtrap Creek and West Fork Thompson River drainages (Thompson River tributaries). Stream-width PIT antennas were used to monitor out-migration at the confluences of the Thompson River tributaries and at the mouth of the Thompson River. Out-migrating Bull Trout (N = 135) were sampled using directional weir traps at the tributary confluences, PIT-tagged, and implanted with acoustic- (N = 29) or radio-tags (N = 14) in autumn 2015. From July through December 2015, 10.1% of all PIT-tagged Bull Trout out-migrated from the Thompson River tributaries (11.4% of fish in the Fishtrap Creek drainage [N = 420] and 6.2% of fish in West Fork Thompson River [N = 146]), with peak out-migration occurring in late October. Highest predicted probabilities of Bull Trout out-migration occurred at lengths of 179 mm in Fishtrap Creek (30.4%) and 165 mm in West Fork Thompson River (29.3%). Only 13.5% of all Bull Trout that entered the Thompson River (N = 192) entered Thompson Falls Reservoir, with peak out-migration occurring in December. Median daily water temperature, minimum daily atmospheric pressure, and lunar illumination were weakly associated with an increase in the number of out-migrants. Radio-tagged out-migrants were randomly distributed throughout the Thompson River and exhibited long periods of site fidelity between intermittent downstream movements. Bull Trout demonstrated low out-migration rates in the Thompson River drainage and prolonged habitation of the mainstem Thompson River, which was contrary to the a priori hypothesis of clustered out-migration by subadult Bull Trout.Item Efficacy of suppressing non-native lake trout in an isolated backcountry lake in Glacier National Park(Montana State University - Bozeman, College of Letters & Science, 2014) Fredenberg, Carter Roger; Chairperson, Graduate Committee: Christopher S. GuyPrior to the recent invasion of non-native lake trout Salvelinus namaycush, Glacier National Park (GNP) supported approximately one-third of the remaining natural lake habitat supporting threatened bull trout Salvelinus confluentus. However, bull trout populations have recently declined and are at high risk of extirpation in several lakes in western GNP due to the establishment of lake trout. In 2009, the U.S. Geological Survey and the National Park Service began suppressing lake trout in Quartz Lake (352 ha) to reduce impacts to native bull trout. The objectives of this study were to: (1) describe the demography of the lake trout population during the suppression program (2009-2013); (2) identify the timing and location of lake trout spawning; (3) determine the most efficient combination of gill net mesh color and twine diameter to capture juvenile lake trout (age 2 to age 4); (4) assess the effects of suppression on the growth rate of the lake trout population and use this information to model harvest scenarios; and (5) determine whether suppression negatively impacted bull trout. Lake trout exhibited slower growth, lower condition, and lower fecundity relative to other populations. Spawning locations were identified on cobble and boulder substrates (depths 2-20 m) near the base of two avalanche chutes where adults began aggregating between 1 and 9 October prior to thermal destratification (11-12 C°). Catch rates of spawning (ripe) adults were highest 12-25 October when temperatures declined to below 10 C°. Gill nets with 0.1 mm twine thickness and green color increased catchability of juvenile lake trout. Although density dependent parameters were not included, population simulation models indicated the population was growing exponentially and would likely reach carrying capacity within ten years without suppression. Suppression resulted in declining population growth rates (lambda) from 1.23 prior to suppression to 0.61-0.79 during suppression. Bull trout redd abundances remained stable throughout the suppression period. My results indicate targeted suppression successfully reduced lake trout abundance and that continued suppression at or above observed exploitation levels is needed to ensure continued population declines and to avoid impacts to the bull trout population.Item Autumn and winter movement and habitat use of resident bull trout and westslope cutthroat trout in Montana(Montana State University - Bozeman, College of Letters & Science, 1995) Jakober, Michael JoelItem Evaluation of the potential for 'resident' bull trout to reestablish the migratory life-form(Montana State University - Bozeman, College of Letters & Science, 1999) Nelson, M. LeeItem Comparison of methods to estimate the ages of bull trout in the Saint Mary River drainage, and an estimate of growth rates from scales(Montana State University - Bozeman, College of Letters & Science, 2001) Gust, Jarvis JayItem Influence of abiotic and biotic factors on occurrence of resident bull trout in fragmented habitats, western Montana(Montana State University - Bozeman, College of Letters & Science, 1996) Rich, Cecil Frank