A refuge for amphibian reintroduction - manipulating salinity in created habitat for a chytrid-susceptible model species, Litoria aurea (green and golden bell frog)

This thesis investigated the potential of water salinity to limit the pathogenicity of Bd (the amphibian chytrid fungus) in a created habitat mosaic. Results demonstrate that determining the outcomes of varying aquatic habitat treatments in a constructed, constrained system is a complex problem, with many interactions. Nevertheless, there was no evidence that any of the habitat components (treatments) incorporated into the experimental design negatively impacted the fitness, or reduced the survival of the model amphibian species, Litoria aurea. The results of this thesis in fact suggest that the most appropriate strategy for optimising the probability of persistence of L. aurea in a landscape in which they have been shown to persist, is to offer a landscape mosaic of waterbodies of varying hydroperiod and salinity. Such a mosaic offers choice for optimal breeding and dispersal throughout the seasonal climatic cycle, while exposing individuals, even intermittently, to elevated salinities that may confer survival across the whole habitat. Taken together, these environmental variables in a complex mosaic may tip the balance of population dynamics from decline and extinction towards persistence. The implications of this approach extend beyond L. aurea to the management of other amphibian species that persist with Bd in complex environments.