- Title
- Investigating environmental stressors to mitigate chytridiomycosis in the environment of threatened amphibians
- Creator
- Clulow, Simon
- Relation
- University of Newcastle Research Higher Degree Thesis
- Resource Type
- thesis
- Date
- 2017
- Description
- Research Doctorate - Doctor of Philosophy (PhD)
- Description
- Translocations and reintroductions are an increasingly important tool in conservation. The focus is often on the breeding and reintroduction, and less consideration is given to the environment into which animals are released. Many such programs achieve less favourable outcomes, or fail completely, because the impacts of the environmental conditions in the reintroduction landscape are not adequately taken into account or mitigated. There is a need for studies in real-world scenarios to test the paradigm that environmental manipulation could improve fitness and survival in populations, and increase the probability of establishment of viable, self-sustaining populations. Reintroductions of amphibians impacted by chytridiomycosis into environments where the disease is present provide a scenario where this paradigm can be tested. This thesis explores that paradigm, investigating ways in which real-world environments might be able to manipulated to adversely impact the disease organism responsible for chytridiomycosis, while remaining favourable to the amphibian host. It begins by exploring the state of translocation programs around the world, before moving on to study the relationship between environment and disease/host relating specifically to amphibians and the chytrid fungus, Batrachochytrium dendrobatidis (Bd). Using a model species that is both susceptible to Bd and subjected to many conservation translocation programs, many of which have failed in the past, I explored whether it might be possible to increase translocation success of wild populations by manipulating certain environmental stressors. Along the way, I developed and optimised an assay for studying ecoimmunology for amphibians (necessary for the current studies), investigated the outcomes of translocating my study species in the presence of the disease without intervention by environmental manipulation, the role of ontogeny in the susceptibility to the disease, and looked at the effect of temperature and seasonality on wild populations. Finally, I directly tested the core paradigm of mitigating the impact of emerging disease by environmental manipulation, and demonstrated that it is feasible, leading to potentially significant conservation outcomes. I conclude that studies leading to the understanding of mechanisms of disease transmission and dynamics as they play out in realistic environmental scenarios is a conservation strategy worth pursuing, since such investigations may identify management strategies that increase resilience of susceptible species at the landscape level.
- Subject
- Litoria aurea; green and golden bell frog; PHA; phenotypic carry-over; stress; chytrid; chytridiomycosis; development; anura; season; spatial heterogeneity; temperature; reintroduction; translocation; amphibian chytrid fungus; Batrachochytrium dendrobatidis; disease; global environment change; immunoecology
- Identifier
- http://hdl.handle.net/1959.13/1388389
- Identifier
- uon:32750
- Rights
- Copyright 2017 Simon Clulow
- Language
- eng
- Full Text
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| Thumbnail | File | Description | Size | Format | |||
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| View Details Download | ATTACHMENT01 | Thesis | 6 MB | Adobe Acrobat PDF | View Details Download | ||
| View Details Download | ATTACHMENT02 | Abstract | 637 KB | Adobe Acrobat PDF | View Details Download |