Theses and Dissertations at Montana State University (MSU)
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Item Relations among arctic grayling, nonnative salmonids, and abiotic conditions in the Big Hole River, Montana(Montana State University - Bozeman, College of Letters & Science, 2017) McCullough, Austin Robert; Chairperson, Graduate Committee: Christopher S. GuyArctic Grayling Thymallus arcticus in Montana have experienced declines in abundance and distribution over the last century, which contributed to the species being designated as a Species of Concern and petitioned for protection under the Endangered Species Act. Conservation of Arctic Grayling in the Big Hole River watershed was based on presumed environmental influences. Interactions with nonnative species, increasing stream water temperatures, drought, and habitat alterations are suggested to influence Arctic Grayling abundances, although sparse quantitative information exists to support these hypotheses. My objective was to evaluate the influence of these biotic and abiotic factors on Arctic Grayling abundances using data collected in the Big Hole River drainage from 1983 through 2015. Arctic Grayling and nonnative salmonids were sampled at 32 sites, stream temperature data were collected at 33 sites, stream discharge data were collected at 21 sites, and habitat data were collected at 441 sites. Ordinary least squares and quantile (Tau = 0.90) regression analyses were used to evaluate the relationships among Arctic Grayling catch per unit effort (CPUE), nonnative salmonids CPUE, stream temperature, stream discharge, and habitat condition. The strongest univariate relationship was a positive correlation between the CPUE of Arctic Grayling > or = age 1 and Brook Trout Salvelinus fontinalis CPUE (r = 0.55, N = 77), which was contrary to the a priori predicted relationship. Multivariate analyses suggested that high water temperatures and low discharges during drought conditions have the greatest limiting influences on the CPUE of Arctic Grayling > or = age 1; Brown Trout CPUE, low water temperatures, and high maximum discharges were suggested as having the greatest limiting influences on age-0 Arctic Grayling CPUE. My findings support current management to increase discharge during drought conditions and further explore relationships between Arctic Grayling CPUE, habitat conditions, and Brown Trout CPUE.Item Effects of stream temperature and climate change on fluvial arctic grayling and non-native salmonids in the upper Big Hole River, Montana(Montana State University - Bozeman, College of Letters & Science, 2015) Vatland, Shane Jeffrey; Chairperson, Graduate Committee: Alexander V. Zale; Robert E. Gresswell and Geoffrey C. Poole were co-authors of the article, 'Quantifying stream thermal regimes at management-pertinent scales: combining thermal infrared and stationary stream temperature data in a novel modeling framework' in the journal 'Water resources research' which is contained within this thesis.; Robert E. Gresswell, Steve Hostetler and Alexander V. Zale were co-authors of the article, 'Effects of climate change on the thermal habitats of arctic grayling and non-native stream salmonids' submitted to the journal 'Global change biology' which is contained within this thesis.The upper Big Hole River basin in southwestern Montana supports one of the last naturally-reproducing populations of fluvial Arctic grayling Thymallus arcticus in the coterminous United States. Warm summer water temperatures and negative interactions with non-native fish (brook trout Salvelinus fontinalis, rainbow trout Oncorhynchus mykiss, and brown trout Salmo trutta) have been identified as critical factors constraining this grayling population. Arctic grayling and these non-native fishes are all cold-water species with similar temperature requirements. Understanding when, where, and to what extent water temperatures are suitable for these fishes provides a physical basis for conservation planning. In chapter 2, I used a combination of thermal infrared (TIR) imagery and stationary temperature recorders to estimate water temperatures at a relatively fine spatial (every ~ 100 m of stream length) and temporal (continuous) resolution over a large extent of the Big Hole River (~ 100 km) during the warmest part of the summer in 2008. This modeling revealed considerable spatial and temporal heterogeneity in water temperature and highlighted the value of assessing thermal regimes at relatively fine spatial and temporal scales. In chapter 3, I assessed the potential effects of climate change on thermal suitability of summer water temperatures for these salmonids. Water temperature simulations projected significant warming from the 1980s through the 2060s. Despite this warming, water temperatures in some sections of stream remained below thermal tolerance thresholds through the 2060s. These stream temperature data provide a critical foundation for understanding the dynamic, multiscale habitat needs of these mobile stream fish and can aid in developing conservation strategies for fluvial Arctic grayling.Item System analysis of the spread of introgressive hybridization in salmonid population through an agent-based simulation model(Montana State University - Bozeman, College of Agriculture, 2015) Della Croce, Patrick Lorenzo Davide; Chairperson, Graduate Committee: Geoffrey Poole; Geoffrey C. Poole, Robert A. Payn and Clemente Izurieta were co-authors of the article, 'Simulating the effects of stream network topology on the spread of introgressive hybridization across fish populations' in the journal 'Ecological modelling' which is contained within this thesis.; Geoffrey C. Poole and Gordon Luikart were co-authors of the article, 'Detecting and quantifying introgression in hybridized populations: simplifying assumptions yield overconfidence and uncertainty' submitted to the journal 'Molecular ecology resources' which is contained within this thesis.; Geoffrey C. Poole, Robert A. Payn and Robert E. Gresswell were co-authors of the article, 'Early detection of non-native alleles in fish populations: when sample size actually matters' submitted to the journal 'Fisheries' which is contained within this thesis.Using the specific example of introgressive hybridization between native cutthroat trout (Oncorhynchus clarkii sp., CTT) and introduced rainbow trout (O. mykiss, RBT), I have designed and developed an individual-based model that mimics the spread of introgressive hybridization in a river network inhabited by salmonids accounting for realistic population demographics, genetics, and stochasticity. As a tool capable of providing mechanistic explanations for observed patterns of introgression, the model is used in Chapter 2 to show that network bifurcations act as semi-permeable barriers to the spread of introgression across river network by decreasing (a) the rate of spread of non-native alleles and (b) the predictability of such spread. As a tool to test the effects of realistic population demographics and realistic mechanisms for the passage of alleles from one generation to the next the model is used in Chapters 3 and 4 to show that commonly used sampling and analysis methods greatly overestimate the power to detect and the precision to quantify introgression in populations.Item Connectivity in a montane river basin : salmonid use of a major tributary in the Smith River system(Montana State University - Bozeman, College of Letters & Science, 2015) Ritter, Thomas David; Chairperson, Graduate Committee: Alexander ZaleThe Smith River is a popular recreational sportfishery in western Montana, but salmonid abundances there are relatively low and limited by high summer water temperatures and low discharges. Smith River tributaries may serve as thermal refuges and also as important spawning and nursery areas. Tributaries unaltered by anthropogenic disturbances may be especially important. If so, maintaining connectivity between the main-stem river and its tributaries would be essential. Moreover, an understanding of salmonid habitat use and management in a stressed system could help identify potential climate change adaptation strategies and tactics. My goal was to determine the roles of a major undisturbed tributary in the life histories and movements of salmonids in a montane river basin. My focus was on Tenderfoot Creek, a remote, unaltered major tributary to the Smith River. A PIT-tag detection network monitored the seasonal movements of rainbow x cutthroat hybrid trout, Mountain Whitefish, Brown Trout, and Brook Trout. Abundances were estimated by electrofishing and snorkeling. Despite thermally stressful conditions in the Smith River, no tagged fish were directly observed using Tenderfoot Creek as a thermal refuge, although such use probably occurred at the confluence within the Smith River. Interchange between Tenderfoot Creek and the Smith River was common for Brown Trout, Mountain Whitefish, and rainbow x cutthroat hybrid trout and consisted mostly of spawning migrations. Some large, presumably dominant Brown Trout appeared to establish permanent territories within Tenderfoot Creek. Spawning effort by Mountain Whitefish and rainbow x cutthroat hybrid trout was high; about 7,568 Mountain Whitefish were observed in spawning aggregations in autumn and estimated abundance of rainbow x cutthroat hybrid trout juveniles (N = 25,127) was much higher than that of other taxa. Brown Trout also spawned in Tenderfoot Creek (159 redds counted in 2011 and 2012), and Brook Trout spawned in side channels and tributaries. Tenderfoot Creek is heavily used by Smith River fishes for spawning; maintaining its connectivity and habitat quality is therefore beneficial to recruitment to the Smith River fishery.Item Environmental and molecular aspects of salmonid whirling disease(Montana State University - Bozeman, College of Agriculture, 1998) Clark, Stacie MarieItem Interactions among oligochaetes and a myxozoan parasite, Myxobolus cerebralis(Montana State University - Bozeman, College of Letters & Science, 2003) Steinbach, Leah Candace; Chairperson, Graduate Committee: Billie KeransItem The reproduction of salmonids in the inlets of Elk Lake, Montana(Montana State University - Bozeman, College of Letters & Science, 1974) Lund, John AndrewItem Influence of environmental features on Tubifex tubifex and Myxobolus cerebralis infected Tubifex tubifex in Yellowstone National Park : implications for whirling disease risk(Montana State University - Bozeman, College of Letters & Science, 2010) Alexander, Julie Diane; Chairperson, Graduate Committee: Billie L. KeransWhirling disease (WD) is an emerging parasitic disease of salmonids that is increasing in severity and geographic range. Whirling disease is caused by the myxosporean parasite, Myxobolus cerebralis, and can effect significant mortality in wild and cultured salmonid populations. Myxobolus cerebralis was recently detected in Yellowstone National Park (YNP) where it may be causing native Yellowstone cutthroat trout (YCT) to decline. Myxobolus cerebralis exploits the aquatic oligochaete, Tubifex tubifex, as its primary host and spores released by T. tubifex are infective to salmonid fish. The aim of this study was to assess WD risk for YCT populations in YNP by focusing on the disease source, T. tubifex, which had not previously been characterized. My objectives were to characterize T. tubifex populations and dynamics of M. cerebralis infections in T. tubifex and to establish factors associated with M. cerebralis infections in T. tubifex. In addition, I examined relationships between infection dynamics in T. tubifex and transmission to fish hosts (WD risk). In Pelican Creek, T. tubifex and M. cerebralis infected T. tubifex were widely distributed and abundant. Infected T. tubifex were most abundant in reaches characterized by intermediate geothermal influence. However, WD risk was high in all reach types, which indicated that low parasite success in the oligochaete host in reaches with high or no geothermal influence did not translate into reduced WD risk in these reaches. In tributaries throughout YNP, susceptible T. tubifex were widely distributed but experimental and field data suggest M. cerebralis-infected T. tubifex may be unable to survive in all tributaries where uninfected T. tubifex were found. In particular, environmental factors influenced by confinement, including proportions of coarse and fine substrates, may preclude establishment of M. cerebralis in tributaries in YNP. Thus, environmental features, rather than oligochaete host factors, may be most influential for M. cerebralis dynamics in T. tubifex and WD risk to fish in YNP. While further research is needed to identify specific mechanisms, these results suggest environmental features related to confinement may be useful for assessing WD risk at broad scales when the oligochaete host is characterized by low genetic variability.Item An assessment of culverts of fish passage barriers in a Montana drainage using a multi-tiered approach(Montana State University - Bozeman, College of Letters & Science, 2005) Burford, Duncan Drake, Jr.; Chairperson, Graduate Committee: Tom McMahonRestriction or blockage of fish movement due to culverts may have important consequences to fish populations. Problems include the direct loss of critical upstream habitats, and the loss of connectivity with neighboring populations; however, culvert barriers may also serve to protect native species from nonnative species encroachment. Culverts can impede fish movement due to high water velocities, inadequate water depths, and excessive outfall heights among other factors. Most previous studies have focused on fish passage at only a few culverts and thus the extent to which culverts impede fish passage across large drainage basins is largely unknown. In this study, a multi-tiered approach was used to assess fish passage through culverts throughout the upper Clearwater River drainage, Montana. The FishXing software program was used to assess juvenile and adult fish passage at 46 culverts across a wide range of stream discharge. At a subset of 20 culverts, population sampling upstream and downstream of each culvert at low flow was used to determine the degree to which culverts are influencing relative abundance, size structure, and species presence. At a further subset of 10 sites, passage was measured directly at low flow by monitoring the movement of marked fish through culverts with differing physical characteristics. FishXing results indicated that 76-85% of the culverts were barriers, depending on the streamflow and lifestage assessed. The population sampling results indicated that there were a only few differences in relative abundance or size structure at the culverts sampled at low flow, and there was little evidence to suggest that species presence was different below versus above the culverts. The direct passage study results showed that some passage occurred at 90% of the culverts studied at low flow. However, 7 of the 10 culverts showed some degree of passage impedance. There was a moderately significant positive relationship between passage impedance and outlet height (r2 = 0.41, P = 0.047). In summary, the culverts were restricting passage to upstream habitats that may be important for spawning, growth, and survival, but they were generally not isolating populations nor serving as barriers to protect native species from non-native species encroachment.Item Salmonid response to superfund remediation in Silver Bow Creek, Montana(Montana State University - Bozeman, College of Letters & Science, 2013) Naughton, Joseph Patrick; Chairperson, Graduate Committee: Thomas E. McMahon; Robert E. Gresswell (co-chair)Uncontrolled disposal of hard rock mining wastes in the Butte hill mining district of Montana, led to the extirpation of fish from Silver Bow Creek throughout the 20th century. Superfund remediation has been ongoing since 1998 and metal concentrations are reduced. However, water quality remains poor due to inadequate treatment of municipal sewage. To assess the effectiveness of Superfund remediation in reestablishing salmonid populations, we evaluated seasonal salmonid abundance and movement in the Silver Bow Creek watershed over a 3-year period. Spatially-continuous abundance surveys were conducted in 34 main stem stream km and each sampled westslope cutthroat trout Oncorhynchus clarkii lewisi (n = 787) and brook trout Salvelinus fontinalis (n = 1,846) was PIT-tagged. Movements of PIT-tagged individuals were monitored at seven stationary antenna sites and during six seasonal portable antenna surveys. Monthly synoptic water quality samples were collected. In the main stem, water quality was poor below the wastewater effluent and was characterized by acutely toxic copper concentrations, elevated ammonia levels (e.g., NH 3-N = 2.8 mg/L), and hypoxia during summer nights (e.g., DO = 1.4 mg/L). Longitudinal abundance of salmonids closely resembled the longitudinal trend in DO. Regression analysis revealed strong associations between salmonid occurrence and abundance with DO (positive) and copper (negative) concentrations during the summer. However, westslope cutthroat trout relative abundance increased between summer and winter in remediated segments that had been hypoxic during the summer. Few brook trout recolonized the remediated main stem during the study period and the wastewater effluent may have deterred brook trout movement. Westslope cutthroat trout moved into remediated segments during the late summer and early fall as hypoxia subsided. The majority of westslope cutthroat trout sampled in the main stem were large-bodied adults (> or = 200 mm TL) contrasting with the predominantly small-bodied counterparts in the tributaries. Despite hypoxia and copper toxicity, recolonization of indigenous westslope cutthroat trout apparently was driven by the reexpression of a fluvial-adfluvial migratory behavior, a pattern that was not possible during the 100-150 years of main stem contamination.