Theses and Dissertations at Montana State University (MSU)

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The effects of RGGI on mortality outcomes
(Montana State University - Bozeman, College of Agriculture, 2024) Power, Nicholas Markert; Chairperson, Graduate Committee: Justin Gallagher
Most debates around market-based solutions to reduce greenhouse gas emissions often focus on greenhouse gas emissions reductions and cost-effectiveness. The Regional Greenhouse Gas Initiative (RGGI) is a cap-and-trade program designed to curb greenhouse gas emissions, and was implemented in 2009 across nine states in the greater New England area. The World Health Organization (WHO) states that over 6.5 million people die from air pollution annually. Particulate Matter of 2.5 microns or less in diameter is a major component in greenhouse gas emissions and has a myriad of deleterious effects to human health. This paper explores whether the RGGI policy had an impact on mortality rates, using a difference-in-differences approach, and estimates reduction in Cardiovascular related mortalities for the age cohort 15-64. I estimate that there are approximately 12 fewer deaths per county effected by the RGGI policy from 2009- 2019.Combined with the 45 counties affected by the policy, there are an estimated 553 fewer cardiovascular related mortalities for the 15-64 age group from 2009-2019 as compared to the counties unaffected by the policy. Robustness checks are run to verify the reliability of this finding.
Medical technology and mortality transition: the diphtheria antitoxin and childhood mortality in the United States, 1880-1910
(Montana State University - Bozeman, College of Agriculture, 2023) Salimi Rad, Sadiq; Chairperson, Graduate Committee: D. Mark Anderson
Diphtheria was a deadly infectious disease in the late 19th and early 20th centuries, particularly among children. In 1895, an antitoxin was developed that could effectively treat the disease. This was the first and only infectious disease in the United States at the time with a scientifically-based treatment. To gauge the impact of access to the antitoxin on child mortality, I leverage large and stable differences in physicians per capita rates across 38 U.S. cities. Physicians were the primary distributors of the antitoxin at the time. For every percentage point increase in the rate of physicians per capita prior to the antitoxin's availability, there is a corresponding one percent reduction in child mortality. These findings suggest that the introduction of the antitoxin played an important role in saving children's lives and had a significant impact on the course of medical technology and child health in the United States.
Vital rates, annual abundance, and movement of white sharks in the northeastern Pacific
(Montana State University - Bozeman, College of Letters & Science, 2020) Kanive, Paul Edward; Chairperson, Graduate Committee: Jay J. Rotella; Jay J. Rotella, Salvador J. Jorgensen, Taylor K. Chapple, James E. Hines, Scot D. Anderson, Barbara A. Block were co-authors of the article, 'Size-specific apparent survival rate estimates of white sharks using mark-recapture models' in the journal 'Canadian journal of fisheries and aquatic sciences' which is contained within this dissertation.; Jay J. Rotella, Taylor K. Chapple, Scot D. Anderson, Timothy White, Barbara A. Block and Salvador J. Jorgensen were co-authors of the article, 'Estimation of regional annual abundance and evidence for increasing numbers of white sharks off California' which is contained within this dissertation.; Jay J. Rotella, Taylor K. Chapple, Scot D. Anderson, Mauricio Hoyos-Padilla, Barbara A. Block, Salvador J. Jorgensen were co-authors of the article, 'Connectivity between the central California and Guadalupe Island white shark populations' which is contained within this dissertation.
Reliable estimates of populations' vital rates and abundance are fundamental requirements for making assessments and informed management decisions regarding any species. For large marine fish species whose movements are extensive throughout ocean basins, data for individuals are difficult to acquire. Without empirical data, large assumptions must be made about a species' vital rates (i.e. survival and fecundity) to make population assessments, which can potentially lead to erroneous results. Using mark-recapture and acoustic-telemetry data, I conducted analyses estimating vital rates, annual abundance, and coastal movement for white sharks (Carcharodon carcharias) off California, US. First, I used a novel approach to estimate size-specific annual apparent survival rates and to test for differences in survival between sexes after accounting for imperfect sex assignment. Our results provide little evidence for differences in sex-specific survival rates. However, I estimated the first size-specific annual apparent survival rates for sub-adult and adult white sharks. Second, I estimated annual abundance for four white shark demographic groups off the coast of California over an eight-year study period. The estimated total annual population of sub-adult and adult white sharks increased from 180 to 266 individuals during the study. Additionally, group-specific population growth rate point estimates were all > 1.00, which indicates that all groups had positive annual positive growth during the study period, although, uncertainty around those estimates were greater for sub-adults than adults and does not rule out other possibilities for population trajectories. Finally, through collaboration between Mexico and the US, I was able to analyze a comprehensive acoustic telemetry dataset that explored connectivity between two main aggregation sites that form the northeastern Pacific population of white sharks. I found that movement between the two regions was rare and more probable to be sub-adult sharks. These analyses underscore the value of collecting and analyzing empirical data to develop reliable estimates of vital rates for a top marine predator. The work also illustrates the ongoing need to cultivate international research collaboration to include data from both the US and Mexico to make accurate population inferences for the northeastern Pacific population of white sharks.
Distribution, phenology, growth, and overwinter mortality of age-0 smallmouth bass in the Yellowstone River, with implications for upstream range expansion
(Montana State University - Bozeman, College of Letters & Science, 2020) Voss, Nicholas Sheridan; Chairperson, Graduate Committee: Alexander V. Zale; Robert Al-Chokhachy, Adam J. Sepulveda, Christine E. Verhille, Michael P. Ruggles and Alexander V. Zale were co-authors of the article, 'Distribution, phenology, growth, and overwinter mortality of age-0 smallmouth bass in the Yellowstone River, with implications for upstream range expansion' submitted to the journal 'Transactions of the American Fisheries Society' which is contained within this thesis.
Non-native fish introductions are a leading threat to freshwater biodiversity, and accurate assessments of future impact are often hindered by the challenge of anticipating future range expansion. Successful introductions of non-native Smallmouth Bass Micropterus dolomieu have occurred globally and often exhibit secondary spread to upstream habitat. This has occurred in the Yellowstone River, Montana (USA). Observations of adults in socio-economically valuable trout habitat have highlighted a need to better understand the controls on the upstream distribution of Smallmouth Bass in this system, particularly the influence of cold upstream climates on first-year growth and size-selective overwinter mortality (a potential life history bottleneck at northern latitudes). We documented the phenology, growth, and survival of age-0 Smallmouth Bass in relation to water temperature between the uppermost distribution of adults, and downstream regions where they are abundant. Successful reproduction (i.e., age-0 presence) was rare or absent throughout the uppermost 150 km of the upstream distribution of adults, suggesting that something currently prevents or discourages successful reproduction farther upstream. Surprisingly, the mean late-autumn body size of age-0 Smallmouth Bass did not differ significantly among the uppermost 200 km of their distribution, despite upstream declines in ambient water temperature. Although water temperature was a key attribute affecting age-0 growth, upstream shifts towards earlier hatching mediated the expected negative effect of colder upstream climates. Furthermore, surveys of overwinter survivors and simulations of age-0 starvation mortality indicated that age-0 individuals at the upstream extent of their distribution successfully recruited to the age-1 year-class in four consecutive years. Taken together, our results suggest that Smallmouth Bass have not yet reached the thermal limit of their upstream distribution, and that first-year growth, survival, and consequent spread by this non-native predator are probably driven by the complex interactions of spawn timing and ambient thermal and hydrologic regimes in the Yellowstone River.
Variation of life-history strategies in pinnipeds with an emphasis on survival rates and spatial distribution of male Weddell seals in Erebus Bay, Antartica
(Montana State University - Bozeman, College of Letters & Science, 2020) Brusa, Jamie Louise; Chairperson, Graduate Committee: Jay J. Rotella; Jay J. Rotella, Robert A. Garrott, J. Terrill Paterson and William A. Link were co-authors of the article, 'Variation of annual apparent survival and detection rates with age, year, and individual identitiy in male Weddell seal (Leptonychotes weddellii) from long-term mark-recapture data' in the journal 'Population ecology' which is contained within this dissertation.; Jay J. Rotella, Katharine M. Banner and Patrick R. Hutchins were co-authors of the article, 'A comparative study evaluating how stage-specific survival rates vary with life-history traits in male pinnipeds' submitted to the journal 'Journal of evolutionary biology' which is contained within this dissertation.; Jay J. Rotella was a co-author of the article, 'Influence of age and individual identity in the use of breeding colony habitat by male Weddell seals (Leptonychotes weddellii) in Erebus Bay, Antarctica' submitted to the journal 'Journal of mammalogy' which is contained within this dissertation.
This dissertation explores various components of male life-history theory using a species-specific approach focusing on Weddell seals (chapters 2 and 4) and a comparative approach focusing on pinniped (seal and sea lion) species (chapter 3). To better understand how marine mammal populations can function and to gain insight about the evolution of male Weddell seal fitness, my coauthors and I estimated the age-specific survival rates of male Weddell seals living in Erebus Bay, Antarctica. Actuarial senescence (decreasing age-specific survival with increasing age) has been documented for several wildlife species. However, contrary to females, little information exists regarding age-specific patterns of survival, including actuarial senescence, for males. We used 35 years of mark-recapture data to estimate age-specific survival rates in male Weddell seals using a hierarchical model approach in a Bayesian framework. We found that male survival estimates were moderate for pups and yearlings, highest for 2-yearolds, and gradually declined with age thereafter such that the oldest animals observed had the lowest survival rates of any age, illustrating that male Weddell seals in this population exhibit actuarial senescence. We further investigated male Weddell seal ecology by describing the spatial patterns of male Weddell seals in Erebus Bay using regression modeling and kernel density methods. The intermediately aged males tended to have the most reproductive-age female neighbors, but individual heterogeneity played a stronger role than age. We found that younger males tended to settle in more offshore and less crowded areas of the habitat relative to older males. From a comparative approach, we assessed the patterns of tradeoffs among various fitness traits in male pinnipeds by examining the relationships between stage-specific survival rates and body size, baculum size, mating strategies, and delayed social maturity. Comparative studies similar to ours have tended to focus on females of avian and some terrestrial species and have mostly addressed reproductive traits. However, we lack information about males and connections between survival rates and other life-history traits. We found evidence for a relationship between precopulatory, rather than postcopulatory, traits and survival rates. We highlight the need for more empirical survival rate data and robust comparative methods.
Post-sepsis syndrome: improving morbidity & mortality following hospitalization
(Montana State University - Bozeman, College of Nursing, 2020) Woods-Tatarka, April Ann; Mauws, Amanda Frances; Chairperson, Graduate Committee: Angela Jukkala
Sepsis is the life-threatening organ dysfunction caused by a dysregulated host response to infection. Globally, statistics are grim with 19 million cases diagnosed annually. Each year in the United States (US) there are over 1.6 million people diagnosed with sepsis; over 250,000 of these will not survive. Currently, it is a leading cause of morbidity, mortality, and hospital readmissions in the US. The population of focus was those residing within the north-central Montana region. The purpose of this project was to explore the topic of post-sepsis syndrome (PSS) and its occurrence following a primary diagnosis of sepsis. The goal of this project was the development of a quality improvement initiative focused on establishing a care-management program for patients diagnosed with sepsis. Ultimately, maximizing patient health and healthcare organization outcomes. An interprofessional team was convened to develop an evidence-based quality-improvement plan to decrease the human and financial costs of sepsis and PSS. The purposed evaluation of the quality-improvement project includes monthly PDSA cycles with project goals reviewed bi-annually.
Impacts of weather, habitat, and reproduction on the survival and productivity of wild turkeys in the northern Black Hills, South Dakota
(Montana State University - Bozeman, College of Letters & Science, 2019) Yarnall, Michael James; Chairperson, Graduate Committee: Andrea Litt; Andrea R. Litt, Chad P. Lehman and Jay J. Rotella were co-authors of the article, 'Precipitation and reproductive effort combine to alter survival of wild turkey hens in the northern Black Hills, SD' submitted to the journal 'Journal of wildlife management' which is contained within this thesis.; Andrea R. Litt, Chad P. Lehman and Jay J. Rotella were co-authors of the article, 'Impacts of weather on reproductive productivity of wild turkeys in the northern Black Hills, SD' submitted to the journal 'Journal of wildlife management' which is contained within this thesis.
The study of population ecology is motivated by a desire to understand variation in the factors that drive wildlife population dynamics. Robust vital rate estimates are crucial for effective wildlife conservation and management, particularly for at-risk or harvested species. In avian populations, the survival of females, nests, and young are important drivers of population growth, although the relative importance of each rate can differ among species. Annual and regional variation in vital rates within species is common; further, local climatic and habitat conditions may influence population dynamics. During 2016 - 2018, we used radio telemetry to study the impacts of weather and habitat conditions on the survival and productivity of Merriam's wild turkeys (Meleagris gallopavo merriami) in the northern Black Hills of South Dakota. Specifically, we quantified the impacts of 1) precipitation and reproductive effort on hen survival, 2) precipitation and habitat conditions on nest survival, and 3) precipitation and temperature on early poult survival. Precipitation reduced the survival of hens and nests, although the magnitude depended on the hen's incubation status or the vegetation characteristics at the nest site. Based on precipitation data from 2017, the estimated annual survival rate for a hen that did not incubate was 0.535 (SE = 0.038), whereas that and for a hen that incubated for 26 days was 0.436 (SE = 0.054). The probability that a nest would survive from initiation to hatching for a nest initiated by an adult hen on the median date of nest incubation in 2017 was estimated to be 0.432 (SE = 0.084). The estimated probability that a poult would survive from hatching to 4 weeks of age was 0.387 (SE = 0.061). Our results clearly demonstrate a negative cost of reproduction, as predicted by life-history theory, and show that hens and nests in this ecosystem are more vulnerable to predation during or immediately following rainfall, as predicted by the moisture-facilitated nest-predation hypothesis. Survival and productivity of turkeys was lower in our study area than in other portions of the Black Hills; we recommend that managers take steps to limit human-induced hen mortality of this important game species.
Spatiotemporal covariates, individual characteristics, and mountain lion harvest as potential sources of variation in elk calf survival
(Montana State University - Bozeman, College of Letters & Science, 2019) Forzley, Michael James; Chairperson, Graduate Committee: Jay J. Rotella
To understand the efficacy of increasing the harvest of large carnivores for increasing elk calf survival, we compared calf survival data collected from two elk herds before, during, and after a mountain lion harvest treatment which consisted of increases in prescribed mountain lion harvest quotas. We collected survival data from 534 radio-tagged elk calves in both the East Fork and West Fork herds of the upper Bitterroot Valley of west-central Montana. We used these data and time-to-event analyses to estimate the annual rates of survival and cause-specific mortality for elk calves in the study, as well as estimate the relationships between elk calf survival and several factors previously related to variation in annual elk calf survival. Average annual rates of survival for female calves before the mountain lion harvest treatment (pre-treatment era) were 0.38 (95% CI = 0.00-0.54) in the West Fork herd, and 0.37 (95% CI = 0.09-0.65) in the East Fork herd. Annual rates of survival for female calves during the harvest treatment (during-treatment era) were 0.65 (95% CI = 0.47-0.83) in the West Fork herd and 0.65 (95% CI = 0.46-0.87) in the East Fork herd. Annual rates of survival for female calves 4-5 years post-harvest treatment (post-treatment era) were 0.46 (95% CI = 0.31-0.61) in the West Fork herd and 0.47 (95% CI = 0.32-0.62) in the East Fork herd. Survival of male calves followed a similar pattern. Rates of mountain lion predation were highest in the pre-treatment era, moderate in the during-treatment era, and lowest in the post-treatment era. However, decreased rates of mountain lion predation following mountain lion harvest treatment coincided with increased probability of non-predation related mortality, and short-term changes in annual elk calf survival. Our results suggest that mountain lion harvest management prescriptions designed to achieve moderate, short-term reductions in mountain lion population abundance may be effective in allowing for short-term increases in elk calf recruitment and may be an effective management tool to increase calf recruitment.
Evaluation of embryo suppression methods for nonnative lake trout in Yellowstone Lake, Yellowstone National Park, Wyoming, USA
(Montana State University - Bozeman, College of Letters & Science, 2019) Poole, Alex Stephen; Chairperson, Graduate Committee: Alexander V. Zale
Introduced Lake Trout Salvelinus namaycush threaten native Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri in Yellowstone Lake, Yellowstone National Park. Gill nets have been used to suppress subadult and adult Lake Trout since 1995. Because survival of embryonic and larval life history stages can have profound effects on population dynamics of Lake Trout, suppression at those stages, especially if used in concert with intensive gill netting of older fish, could enhance suppression efforts. Therefore, I conducted controlled laboratory and field experiments to systematically evaluate the effects of a variety of candidate chemical (sodium chloride, calcium carbonate, gelatin, and liquid and powdered rotenone), biological (carcass and carcass analog), and physical (sediment) suppression methods on different developmental stages of Lake Trout embryos and larvae. Liquid and powdered rotenone applications, fish carcass and carcass analog exposures, and sediment deposition significantly increased embryo mortality in laboratory experiments. Sodium chloride, calcium carbonate, and gelatin applications were not effective. In-situ exposure to ground carcass material in Yellowstone Lake resulted in 100% embryo mortality in 14 and 28 kg/m 2 biomass treatments; sediment deposition caused 97% embryo mortality among overwintering incubators. Embryo mortality was probably caused by hypoxic conditions within substrates. Embryo suppression methods differed in their effectiveness, rate at which mortality was achieved, and ease of application. These differences, as well as Lake Trout spawning site characteristics such as depth, contour, fetch, substrate size, interstitial depth, isolation, and presence of non-target organisms ultimately determine which embryo suppression method will be most applicable in a given situation. Nevertheless, implementation of successful embryo suppression techniques evaluated in this study could be used to increase mortality of Lake Trout in Yellowstone Lake. Incorporating effective embryo suppression in an Integrated Pest Management approach has the potential to provide more effective Lake Trout suppression in the long term.
Quantifying the spatial structure of invasive lake trout in Yellowstone Lake to improve suppression efficacy
(Montana State University - Bozeman, College of Letters & Science, 2019) Williams, Jacob Robert; Chairperson, Graduate Committee: Christopher S. Guy
Conserving Yellowstone Cutthroat Trout by suppressing invasive Lake Trout in Yellowstone Lake is a high priority for Yellowstone National Park natural-resource managers. Insight into the spatial structure of Lake Trout throughout the lake will help increase the efficacy of the Lake Trout suppression program. Lake Trout (N = 578) were surgically implanted with dual acoustic and radio transmitters from 2015 through 2017. Mobile acoustic (boat) and radio (fixed-wing aircraft) telemetry surveys were performed to identify aggregations of Lake Trout. Telemetry surveys occurred during the spawning period (autumn) in 2016 and during the summer and spawning period in 2017. Lake Trout exhibited distinct aggregations during the summer and spawning period. Lake Trout aggregated at nine locations during the summer 2017 and were most frequently located in the West Thumb. Lake Trout aggregated at 22 locations during the spawning period including 12 previously undocumented putative spawning locations. Two aggregations in the West Thumb, Carrington Island and Anglers Bluff, had the highest relative densities of Lake Trout. Aggregations during the summer were generally farther from shore, greater in depth, and more dispersed than aggregations during the spawning period. Targeting locations of Lake Trout, as identified through telemetry, with gill nets was an effective strategy for increasing catch-per-unit-effort. The Lake Trout suppression program is probably altering the behavior of Lake Trout in Yellowstone Lake, which explains the high number of spawning locations and low spawning site fidelity relative to other research studies on Lake Trout spawning behavior. This study provided valuable insight into the spatial structure of Lake Trout in Yellowstone Lake. The areas Lake Trout aggregated will continue to be targeted by gillnetting and novel embryo suppression methods.

Theses and Dissertations at Montana State University (MSU)

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