Graphic Design and illustrations:Brett Littleton, ILS Design Unit, DPIPWE Main cover and page header photos: Kaylene AllanCover boat illustration: Courtesy of Boating Industry Association of VictoriaBack inside cover photo: Hydro Tasmania Acknowledgements:This project was funded by NRM South, Hydro Tasmania, NRM North and Cradle Coast NRM. Sincere thanks to the many people who reviewed the draft manual and provided photos, including staff from DPIPWE,
Abstract. While the fungal disease mucormycosis has infected Tasmanian platypuses for nearly three decades, its impacts remain largely unknown. This study documents the spatial and temporal distribution of mucormycosis in Tasmanian platypuses as a baseline for assessing its impacts. Over 1800 platypus capture and observation records were collated and mapped, and indicate that between 1982 and 2007 mucormycosis-infected platypuses were present in at least 11, and potentially 22, of Tasmania's 48 river catchments. During 2008-09, live-trapping surveys were undertaken to determine the spread, prevalence and persistence of the disease. Surveys of 75 rivers and creeks across 18 catchments captured 167 individuals, and an additional 12 platypuses were obtained from the public.
Chytridiomycosis in amphibians, and mucormycosis in the platypus Ornitho rhynchus anatinus and amphibians, are serious fungal diseases affecting these aquatic taxa. In Tasmania, Australia, the fungi that cause these diseases overlap in range along with Phytophthora cinnamomi (Pc), an invasive fungal plant pathogen. To identify disinfectants that may be useful to reduce anthropogenic spread of these fungi to uninfected wilderness areas, for example by bush walkers and forestry or fire-fighting operations, we tested 3 disinfectants and a fire-fighting foam against Mucor amphibiorum (Ma) and tested 1 disinfectant and the foam against Batracho chytrium dendrobatidis (Bd). Combining the present study with previous work we found Bd was more susceptible to all 4 chemicals than Ma. Phytoclean, a disinfectant used at 2 to 10% for 30 s to control Pc, killed cultures of Bd at 0.075% and Ma at 5%, when also applied for 30 s. The disinfectant F10sc was not effective against Ma at standard exposures, but previous work shows Bd is killed at 0.03% with a 1 min exposure. Path-X is effective against Bd at 0.001% with a 30 s exposure and killed Ma at 1% with a 5 min exposure. Forexpan S, a foam added to water at 0.1 to 1% to control forest fires, killed Bd but not Ma when used at 1% for 2 min. Therefore, Phytoclean and Path-X have broader efficacy, although Path-X has not been trialled against Pc. Interestingly a positive mating strain of Ma (from a platypus) was more resistant to disinfectants than a negative strain (from a frog). Current protocols against Pc that involve high concentrations (10%) of Phytoclean are likely to reduce spread of pathogenic wildlife fungi, which is important for protecting biodiversity.KEY WORDS: Chytridiomycosis · Mucormycosis · Pathogenic fungi · Platypus · Amphibian · Phytophthora cinnamomi Resale or republication not permitted without written consent of the publisherDis Aquat Org 99: [119][120][121][122][123][124][125] 2012 the risk of further spread is an important control measure.Mucormycosis, caused by the zygomycete Mucor amphibiorum (Ma), is the most significant disease affecting platypus in Tasmania, although it has not been detected in mainland platypuses (Connolly et al. 1998). In the platypus, infection causes an ulcerative dermatitis, and the fungus may disseminate to internal organs (Obendorf et al. 1993). Infected platypuses can develop impaired thermoregulation and mobility and may die. Mucormycosis also occurs in mainland Australian amphibians but has not been detected in Tasmanian frogs (Connolly et al. 1998). It can cause a fatal, systemic infection in captive and wild frogs and cane toads Bufo marinus , Creeper et al. 1998. A platypus strain of the fungus was able to experimentally infect amphibians (Stewart & Munday 2005). Ma is heterophallic; positive strains produce resistant zygospores if mated with a negative strain, but only positive strains have been found in Tasmania (Schipper 1978, Connolly 2009. Ma also reproduces asexually via infective sporangiospores (Ste...
Conservation of frogs is of global concern, owing to declines resulting from habitat destruction, global climate change, and disease. Knowledge of genetic variation in frog species is therefore desirable for the identification of management units. Here we surveyed mitochondrial DNA sequence variation in the Tasmanian endemic hylid frog Litoria burrowsae, which is infected by chytrid fungus, Batrachochytrium dendrobatidis, and may be declining. Neither phylogeographic structure nor deep phylogenetic divergence was detected in the species, although its populations were highly differentiated with respect to haplotype frequencies. The low-haplotype diversity in L. burrowsae suggests a recent bottleneck in the species, and population genetic structuring may reflect isolation by distance as well as founder effects associated with range expansion. Three putative management units were identified that require verification based on nuclear DNA variation and adaptation to local environments.
Context The global reduction of amphibian biodiversity as a result of the disease chytridiomycosis (caused by the fungus Batrachochytrium dendrobatidis; Bd) has highlighted the need to accurately detect local population declines in association with Bd presence. Although Bd has spread globally, some remote regions such as the Tasmanian Wilderness World Heritage Area (1.40 million ha; TWWHA) in Australia, remain largely, but not entirely, disease free. The Tasmanian tree frog (Litoria burrowsae) resides primarily within TWWHA boundaries, and is believed to be susceptible to chytridiomycosis. Aims In the absence of historical abundance data, we used a single-season multi-state site-occupancy model to investigate the impact of Bd on L. burrowsae populations, on factors affecting species detection and to inform ongoing surveillance and conservation. Methods We recorded frog detection and ranked call intensity (estimation of population size) from repeated independent surveys within a season to estimate the role of covariates, such as presence of Bd and environmental variables, on species occupancy and detection probability. Key results Modelling revealed large frog populations are more likely to be present at naturally formed than human-formed ponds, strong winds negatively affect detection of populations, and time after sunset affects detection of large populations. Large frog populations were more likely to be Bd-negative; however, models including Bd presence were not well supported, in part a result of the small number of Bd-positive sites recorded. Conclusions and Implications The utility of site-occupancy modelling in understanding the impact of disease on populations is little known, but has the potential to improve the accuracy and efficiency of many conservation programs.
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