Browsing by Subject "wildlife disease"

Now showing 1 - 4 of 4
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    Data and code in support of: Release of live baitfish by recreational anglers drives fish pathogen introduction risk
    (2022-06-06) McEachran, Margaret C.; Phelps, Nicholas B. D.; Drake, D. Andrew R.; Mladonicky, Janice M.; Picasso, Catalina; phelp083@umn.edu; Phelps, Nicholas B. D.; University of Minnesota Department of Fisheries, Wildlife and Conservation Biology; University of Minnesota Department of Veterinary Population Medicine; University of Minnesota Gabbert Raptor Center; Fisheries and Oceans Canada Great Lakes Research Laboratory
    This repository contains supplementary information, simulation data, and R computer code to accompany the manuscript titled "Release of live baitfish by recreaional anglers drives fish pathogen introduction risk." The purpose of this project was to quantify the risk of fish pathogen introduction, conceptualized as the number of fish infected with a priority pathogen released in a given year of fishing, under a range of conditions.
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    Developing an ecosystem health approach for reducing risk of fish pathogen introduction in a coupled social-ecological system
    (2022-05) McEachran , Margaret
    Today’s interconnected society provides ample opportunity for the inadvertent spread of dangerous diseases. Human activities are also capable of spreading wildlife diseases that can have devastating impacts on populations and threaten biodiversity. In inland fisheries, the use and release of live baitfish by recreational anglers has been identified as a particularly important pathway for the spread of pathogens. Despite regulations prohibiting it, baitfish release is widespread and common among anglers, providing substantial opportunity for pathogen spread via this pathway. To address key knowledge gaps and understand the social and ecological dimensions of risk of pathogen spread, I developed an ecosystem health approach to identify, quantify, and mitigate the risk of fish pathogen introduction via the release of live baitfish in Minnesota, USA. I first created a hazard prioritization method to identify the pathogens most likely to harm important Minnesota fishes via release of live baitfish. To quantify the risk of one of these pathogens being released into Minnesota waters, I implemented a survey of adult anglers and used this data to parameterize a stochastic risk assessment model. I modelled pathogen introduction risk across a variety of scenarios representing baseline, outbreak, and source-control scenarios. I found that the average number of angling trips resulting in pathogen release was high across all modeled scenarios, ranging from fewer than 10,000 in a small, localized outbreak, to 1.2 million in a statewide outbreak in multiple live baitfish species. Additionally, I found reducing the rate of illegal release could offer meaningful risk reduction in some scenarios with high pathogen prevalence and/or broad pathogen distribution, but this effect was less pronounced in scenarios where the outbreak was geospatially or otherwise limited. Finally, I used the Theory of Planned Behavior to identify the social and psychological determinants of baitfish release behavior and found that knowledge of the existing regulatory framework and subjective norms around live baitfish disposal play an important role in deterring illegal release. In these four chapters, I demonstrate the implementation of an integrated social-ecological approach to a complex ecosystem health issue and provide a roadmap for managing the risk of fish pathogen introduction via live baitfish release in Minnesota.
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    Effects of environmental factors on pathogen exposure and transmission in wild rodent populations
    (2023-08) Mistrick, Janine
    Anthropogenic land-use change is altering ecosystems across the globe and has been implicated as a major factor increasing the spillover of zoonotic diseases from wildlife into human populations. Wild rodents are of particular importance for spillover as they host the largest diversity of zoonotic pathogens of any mammalian order. Moreover, rodent hosts of zoonotic pathogens have been found to increase in abundance in anthropogenic landscapes. In my dissertation, I investigate the effects of environmental factors related to anthropogenic land-use change on pathogen prevalence and transmission in wild rodent populations. Using an observational field study across landscape and habitat types, I broadly investigate the effects of anthropogenic development on the prevalence of zoonotic bacterial pathogens in wild Peromyscus mice (Chapter 1). I then turn to finer spatial scales to consider how spatial overlap can be used to approximate transmission in wildlife populations (Chapter 2). Using wild bank voles (Clethrionomys glareolus) as a model system, I leverage a replicated, experimental field study to quantify the effects of food supplementation and helminth macroparasite removal on vole space use and spatial overlap to approximate transmission opportunities (Chapter 3). Finally, I test how spatial overlap predicts infection of an endemic viral pathogen and examine whether the relationship between spatial overlap and infection is influenced by food abundance and macroparasite infection (Chapter 4). My research indicates that agricultural development may increase the prevalence of zoonotic bacterial pathogens in wild rodents. Further, I show that environmental factors alter the space use of wild rodents and that both environmental conditions and host traits are important to predict how spatial overlap affects transmission of an endemic pathogen. As such, my dissertation research has contributed empirical evidence that shows how environmental conditions alter zoonotic pathogen prevalence and transmission in wild rodent populations. This represents an important step forward in our ability to quantify the effects of anthropogenic land-use change on disease dynamics in wildlife, advancing our ability to understand and predict transmission dynamics and control spillover potential from wildlife into human populations.
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    Supplementary files for an expert-based risk ranking framework for assessing potential pathogens in the live baitfish trade
    (2022-05-06) McEachran, Margaret C.; Travis, Dominic A.; Phelps, Nicholas B. D.; Sampedro, Fernando; thom4412@umn.edu; McEachran, Margaret C.; Minnesota Aquatic Invasive Species Research Center
    The purpose of this study was to develop a “hazard identification” and ranking tool to identify the pathogens that pose the highest risk to wild fish from the release of live baitfish by recreational anglers in freshwater systems. We developed a screening protocol and semi-quantitative stochastic risk ranking framework by combining published data with expert elicitation (n=25) and applied the framework to identify high-priority pathogens for the bait supply in Minnesota, USA. Normalized scores were developed for seven risk criteria (likelihood of transfer, prevalence in bait supply, likelihood of colonization, current distribution, economic impact if established, ecological impact if established, and host species) to characterize a pathogen’s ability to persist in the bait supply and cause impacts to wild fish species of concern. Of an initial list of 33, 15 potential pathogens met the criteria for inclusion and were evaluated using the semi-quantitative framework. The generalist macroparasite Schizocotyle acheilognathi was identified as presenting highest overall threat to wild Minnesota fish, followed by the microsporidian Ovipleistophora ovariae, and viral hemorrhagic septicemia virus. Our findings contribute to the development of risk-based prevention and surveillance methods in support of front-line managers charged with maintaining both the aquatic sporting industry and sustainable, healthy natural resources in Minnesota. In addition, the ranking framework provides a standardized conceptual framework for prioritizing management as novel disease needs emerge.