ORCID Profile
0000-0003-0188-3290
Current Organisations
James Cook University
,
University of New England
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Research Topics
In Research Link Australia (RLA), "Research Topics" refer to ANZSRC FOR and SEO codes. These topics are either sourced from ANZSRC FOR and SEO codes listed in researchers' related grants or generated by a large language model (LLM) based on their publications.
Top 5 Research Topics
ANZSRC Field of Research (FoR)
Conservation and Biodiversity | Population Ecology | Environmental Rehabilitation (excl. Bioremediation) | Environmental Science and Management | Ecosystem Function | Ecological Applications |
ANZSRC Socio-Economic Objective (SEO)
Fresh, Ground and Surface Water Flora, Fauna and Biodiversity | Control of Pests, Diseases and Exotic Species at Regional or Larger Scales | Expanding Knowledge in the Environmental Sciences | Ecosystem Assessment and Management of Fresh, Ground and Surface Water Environments | Flora, Fauna and Biodiversity at Regional or Larger Scales
Related Links
Publications
White blood cell profiles in amphibians help to explain disease susceptibility following temperature shifts
Publisher: Elsevier BV
Date: 12-2017
DOI: 10.1016/J.DCI.2017.08.018
Abstract: Temperature variability, and in particular temperature decreases, can increase susceptibility of hibians to infections by the fungus Batrachochytrium dendrobatidis (Bd). However, the effects of temperature shifts on the immune systems of Bd-infected hibians are unresolved. We acclimated frogs to 16 °C and 26 °C (baseline), simultaneously transferred them to an intermediate temperature (21 °C) and inoculated them with Bd (treatment), and tracked their infection levels and white blood cell profiles over six weeks. Average weekly infection loads were consistently higher in 26°C-history frogs, a group that experienced a 5 °C temperature decrease, than in 16°C-history frogs, a group that experienced a 5 °C temperature increase, but this pattern only approached statistical significance. The 16°C-acclimated frogs had high neutrophil:lymphocyte (N:L) ratios (suggestive of a hematopoietic stress response) at baseline, which were conserved post-treatment. In contrast, the 26°C-acclimated frogs had low N:L ratios at baseline which reversed to high N:L ratios post-treatment (suggestive of immune system activation). Our results suggest that infections were less physiologically taxing for the 16°C-history frogs than the 26°C-history frogs because they had already adjusted immune parameters in response to challenging conditions (cold). Our findings provide a possible mechanistic explanation for observations that hibians are more susceptible to Bd infection following temperature decreases compared to increases and underscore the consensus that increased temperature variability associated with climate change may increase the impact of infectious diseases.
A male-specific sex marker for the endangered western sawshelled turtle (Myuchelys bellii) using in silico whole-genome subtraction
Publisher: Springer Science and Business Media LLC
Date: 06-04-2022
DOI: 10.1007/S12686-022-01266-3
Abstract: Artificial incubation of eggs for the mass release of hatchlings is a common conservation intervention for imperilled turtle species. Programs designed to reinforce wild populations need to ensure that they are releasing appropriate male to female ratios into the wild. In many turtle species, the sex of juveniles cannot be identified using external morphology until they approach sexual maturity. For the endangered western sawshelled turtle, Myuchelys bellii , sexual dimorphism does not occur until at least 6 years of age. We aimed to develop a molecular test to identify the sex of M. bellii during the life stages where they cannot be sexed morphologically—embryos, hatchlings and small juveniles. We used in silico whole-genome subtraction of a female M. bellii (XX) from a male (XY) to identify a Y chromosome-specific sequence which we characterized and developed into a PCR sex test. Our research is the first to use a whole-genome subtraction method in-silico to successfully establish sex chromosome markers in a freshwater turtle species. Developing this technology provides an opportunity for conservation programs to ensure that populations are supplemented with a proportionate number of male and female hatchlings. Further, it allows large scale measurement of naturally occurring sex ratios in hatchlings and small juveniles, which in turn enables estimates of sex ratios within wild populations free from age-at-maturity bias. The application of sex-specific marker technology also provides an opportunity to quantify the influence of sex on behaviour, movement and survival in the segment of populations that cannot be morphologically sexed.
Diet of a threatened pond frog differs over a small spatial scale
Publisher: Inter-Research Science Center
Date: 28-01-2014
DOI: 10.3354/ESR00559
Spinal arthritis in invasive cane toads is linked to rate of dispersal as well as to latitude
Publisher: Springer Science and Business Media LLC
Date: 27-09-2019
DOI: 10.1038/S41598-019-50314-W
Abstract: Initial research on the spread of cane toads ( Rhinella marina ) through tropical Australia reported a high incidence of spinal arthritis (spondylosis) in toads at the invasion front (where toads disperse rapidly), but not in areas colonized earlier (where toads are more sedentary). The idea that spondylosis was a cost of rapid dispersal was challenged by wider spatial s ling which linked rates of spondylosis to hot (tropical) climates rather than to dispersal rates. Here, the authors of these competing interpretations collaborate to reinterpret the data. Our reanalysis supports both previous hypotheses rates of spondylosis are higher in populations established by fast-dispersing toads, and are higher in tropical than in temperate environments they are also higher in larger toads. The functional reason for climatic effects is unclear, but might involve effects on the soil-living bacteria involved in the induction of spondylosis and/or may reflect higher movement (as opposed to dispersal) or more pronounced dry-season aggregation rates of toads in tropical conditions.
A review of the role of parasites in the ecology of reptiles and amphibians
Publisher: Wiley
Date: 20-12-2018
DOI: 10.1111/AEC.12695
Winter microhabitat selection of a threatened pond amphibian in constructed urban wetlands
Publisher: Wiley
Date: 14-04-2015
DOI: 10.1111/AEC.12256
Island provides a pathogen refuge within climatically suitable area
Publisher: Springer Science and Business Media LLC
Date: 26-06-2015
The return of the frogs: The importance of habitat refugia in maintaining diversity during a disease outbreak
Publisher: Wiley
Date: 06-2019
DOI: 10.1111/MEC.15108
Abstract: Recent decades have seen the emergence and spread of numerous infectious diseases, often with severe negative consequences for wildlife populations. Nevertheless, many populations survive the initial outbreaks, and even undergo recoveries. Unfortunately, the long-term effects of these outbreaks on host population genetics are poorly understood to increase this understanding, we examined the population genetics of two species of rainforest frogs (Litoria nannotis and Litoria serrata) that have largely recovered from a chytridiomycosis outbreak at two national parks in the Wet Tropics of northern Australia. At the wetter, northern park there was little evidence of decreased genetic ersity in either species, and all of the s led sites had high minor allele frequencies (mean MAF = 0.230-0.235), high heterozygosity (0.318-0.325), and few monomorphic markers (1.4%-4.0%) however, some recovered L. nannotis populations had low N
Melanesia holds the world’s most diverse and intact insular amphibian fauna
Publisher: Springer Science and Business Media LLC
Date: 04-11-2022
DOI: 10.1038/S42003-022-04105-1
Abstract: Identifying hotspots of biological ersity is a key step in conservation prioritisation. Melanesia—centred on the vast island of New Guinea—is increasingly recognised for its exceptionally species-rich and endemic biota. Here we show that Melanesia has the world’s most erse insular hibian fauna, with over 7% of recognised global frog species in less than 0.7% of the world’s land area, and over 97% of species endemic. We further estimate that nearly 200 additional candidate species have been discovered but remain unnamed, pointing to a total fauna in excess of 700 species. Nearly 60% of the Melanesian frog fauna is in a lineage of direct-developing microhylids characterised by smaller distributions than co-occurring frog families, suggesting lineage-specific high beta ersity is a key driver of Melanesian anuran mega ersity. A comprehensive conservation status assessment further highlights geographic concentrations of recently described range-restricted threatened taxa that warrant urgent conservation actions. Nonetheless, by world standards, the Melanesian frog fauna is relatively intact, with 6% of assessed species listed as threatened and no documented extinctions and thus it provides an unparalleled opportunity to understand and conserve a mega erse and relatively intact insular biota.
Infection increases vulnerability to climate change via effects on host thermal tolerance
Publisher: Springer Science and Business Media LLC
Date: 24-08-2017
DOI: 10.1038/S41598-017-09950-3
Abstract: Unprecedented global climate change and increasing rates of infectious disease emergence are occurring simultaneously. Infection with emerging pathogens may alter the thermal thresholds of hosts. However, the effects of fungal infection on host thermal limits have not been examined. Moreover, the influence of infections on the heat tolerance of hosts has rarely been investigated within the context of realistic thermal acclimation regimes and potential anthropogenic climate change. We tested for effects of fungal infection on host thermal tolerance in a model system: frogs infected with the chytrid Batrachochytrium dendrobatidis . Infection reduced the critical thermal maxima (CT max ) of hosts by up to ~4 °C. Acclimation to realistic daily heat pulses enhanced thermal tolerance among infected in iduals, but the magnitude of the parasitism effect usually exceeded the magnitude of the acclimation effect. In ectotherms, behaviors that elevate body temperature may decrease parasite performance or increase immune function, thereby reducing infection risk or the intensity of existing infections. However, increased heat sensitivity from infections may discourage these protective behaviors, even at temperatures below critical maxima, tipping the balance in favor of the parasite. We conclude that infectious disease could lead to increased uncertainty in estimates of species’ vulnerability to climate change.
The effect of inundation on frog communities and chorusing behaviour
Publisher: Elsevier BV
Date: 12-2022
Structural mapping of PEAK pseudokinase interactions identifies 14-3-3 as a molecular switch for PEAK3 signaling
Publisher: Springer Science and Business Media LLC
Date: 19-06-2023
DOI: 10.1038/S41467-023-38869-9
Abstract: PEAK pseudokinases regulate cell migration, invasion and proliferation by recruiting key signaling proteins to the cytoskeleton. Despite lacking catalytic activity, alteration in their expression level is associated with several aggressive cancers. Here, we elucidate the molecular details of key PEAK signaling interactions with the adapter proteins CrkII and Grb2 and the scaffold protein 14-3-3. Our findings rationalize why the dimerization of PEAK proteins has a crucial function in signal transduction and provide biophysical and structural data to unravel binding specificity within the PEAK interactome. We identify a conserved high affinity 14-3-3 motif on PEAK3 and demonstrate its role as a molecular switch to regulate CrkII binding and signaling via Grb2. Together, our studies provide a detailed structural snapshot of PEAK interaction networks and further elucidate how PEAK proteins, especially PEAK3, act as dynamic scaffolds that exploit adapter proteins to control signal transduction in cell growth/motility and cancer.
Evaluating monitoring methods to guide adaptive management of a threatened amphibian (Litoria aurea)
Publisher: Wiley
Date: 19-03-2014
DOI: 10.1002/ECE3.980
On-Campus Students Moving Online During COVID-19 University Closures: Barriers and Enablers
Publisher: Queensland University of Technology
Date: 08-09-2021
DOI: 10.5204/SSJ.1780
Abstract: This practice report shares the experiences of on-c us students enrolled in their second or third year of undergraduate business studies at Charles Sturt University, Australia as they moved to online study during the COVID-19 shutdowns. It details both the barriers and enablers to successful study the students identified. Barriers included loss of support networks, online fatigue, and technology connectivity. Enablers for success included empathic and understanding staff clear directions and, engaging, interactive delivery of the online learning activity. The report concludes with recommendations for future practice in assisting on-c us learners with the transition from a physical to a virtual learning environment. In particular, a strong teacher presence is recommended to foster the development of an engaged learning community where student-to-student interactions are facilitated and students feel supported and connected.
Chelodina expansa Gray 1857 – Broad-Shelled Turtle, Giant Snake-Necked Turtle
Publisher: Chelonian Research Foundation
Date: 06-01-2014
Methods for normalizing microbiome data: An ecological perspective
Publisher: Wiley
Date: 22-11-2019
Salinity tolerances and use of saline environments by freshwater turtles: implications of sea level rise
Publisher: Wiley
Date: 25-03-2018
DOI: 10.1111/BRV.12410
Abstract: The projected rise in global mean sea levels places many freshwater turtle species at risk of saltwater intrusion into freshwater habitats. Freshwater turtles are disproportionately more threatened than other taxa thus, understanding the role of salinity in determining their contemporary distribution and evolution should be a research priority. Freshwater turtles are a slowly evolving lineage however, they can adapt physiologically or behaviourally to various levels of salinity and, therefore, temporarily occur in marine or brackish environments. Here, we provide the first comprehensive global review on freshwater turtle use and tolerance of brackish water ecosystems. We link together current knowledge of geographic occurrence, salinity tolerance, phylogenetic relationships, and physiological and behavioural mechanisms to generate a baseline understanding of the response of freshwater turtles to changing saline environments. We also review the potential origins of salinity tolerance in freshwater turtles. Finally, we integrate 2100 sea level rise (SLR) projections, species distribution maps, literature gathered on brackish water use, and a phylogeny to predict the exposure of freshwater turtles to projected SLR globally. From our synthesis of published literature and available data, we build a framework for spatial and phylogenetic conservation prioritization of coastal freshwater turtles. Based on our literature review, 70 species (∼30% of coastal freshwater turtle species) from 10 of the 11 freshwater turtle families have been reported in brackish water ecosystems. Most anecdotal records, observations, and descriptions do not imply long-term salinity tolerance among freshwater turtles. Rather, experiments show that some species exhibit potential for adaptation and plasticity in physiological, behavioural, and life-history traits that enable them to endure varying periods (e.g. days or months) and levels of saltwater exposure. Species that specialize on brackish water habitats are likely to be vulnerable to SLR because of their exclusive coastal distributions and adaptations to a narrow range of salinities. Most species, however, have not been documented in brackish water habitats but may also be highly vulnerable to projected SLR. Our analysis suggests that approximately 90% of coastal freshwater turtle species assessed in our study will be affected by a 1-m increase in global mean SLR by 2100. Most at risk are freshwater turtles found in New Guinea, Southeast Asia, Australia, and North and South America that may lose more than 10% of their present geographic range. In addition, turtle species in the families Chelidae, Emydidae, and Trionychidae may experience the greatest exposure to projected SLR in their present geographic ranges. Better understanding of survival, growth, reproductive and population-level responses to SLR will improve region-specific population viability predictions of freshwater turtles that are increasingly exposed to SLR. Integrating phylogenetic, physiological, and spatial frameworks to assess the effects of projected SLR may improve identification of vulnerable species, guilds, and geographic regions in need of conservation prioritization. We conclude that the use of brackish and marine environments by freshwater turtles provides clues about the evolutionary processes that have prolonged their existence, shaped their unique coastal distributions, and may prove useful in predicting their response to a changing world.
Removal of an exotic fish influences amphibian breeding site selection
Publisher: Wiley
Date: 09-04-2017
DOI: 10.1002/JWMG.21232
Infection dynamics, dispersal, and adaptation: understanding the lack of recovery in a remnant frog population following a disease outbreak
Publisher: Springer Science and Business Media LLC
Date: 06-2020
Life stage specific variation in the occupancy of ponds by Litoria aurea, a threatened amphibian
Publisher: Wiley
Date: 18-10-2013
Predator presence and vegetation density affect capture rates and detectability of litoria aurea tadpoles: Wide-ranging implications for a common survey technique
Publisher: Public Library of Science (PLoS)
Date: 25-11-2015
Strategic conservation action for frogs
Publisher: Wiley
Date: 04-2018
DOI: 10.1111/ACV.12410
A trade-off in conservation: Weed management decreases the abundance of common reptile and frog species while restoring an invaded floodplain
Publisher: Elsevier BV
Date: 11-2014
Amphibians on the brink
Publisher: American Association for the Advancement of Science (AAAS)
Date: 04-08-2017
Abstract: Preemptive policies can protect hibians from devastating fungal diseases
Spinal arthritis in cane toads across the Australian landscape
Publisher: Springer Science and Business Media LLC
Date: 20-08-2018
DOI: 10.1038/S41598-018-30099-0
Abstract: Loss of fitness can be a consequence of selection for rapid dispersal ability in invasive species. Increased prevalence of spinal arthritis may occur in cane toad populations at the invasion front as a cost of increased invasiveness, but our knowledge of the ecological drivers of this condition is lacking. We aimed to determine the factors explaining the prevalence of spinal arthritis in populations across the Australian landscape. We studied populations across a gradient of invasion histories. We collected 2415 toads over five years and determined the presence and size of spondylosis for each in idual. We examined the effect of host size, leg length and invasion history on the prevalence of spondylosis. Host size was a significant predictor of spondylosis across populations. Contrary to our expectation, the overall prevalence of spondylosis was not positively related to invasion history and did not correlate with toad relative leg length. Rather than invasion age, the latitude at which populations were s led provided an alternate explanation for the prevalence of spondylosis in cane toad populations and suggested that the incidence of this condition did not increase as a physiological cost of invasion, but is instead related to physical variables, such as climate.
Optimising the hatching success of artificially incubated eggs for use in a conservation program for the western saw-shelled turtle (
Publisher: CSIRO Publishing
Date: 09-12-2022
DOI: 10.1071/ZO22014
Abstract: Artificial incubation of eggs and the release of hatchlings into the wild is a common conservation intervention designed to augment threatened turtle populations. We investigate a range of incubation temperatures to establish an optimal temperature for maximum hatching success of western saw-shelled turtle (Myuchelys bellii) eggs. We report on the influence of incubation temperature on incubation duration and hatching success and describe two experimental incubation methods which, for the same incubation temperature (27°C), resulted in 77% and 97% hatching success, respectively. Eggs were incubated at constant temperatures (27°C, 28°C and 29°C) to determine the influence of temperature on incubation period, hatchling morphology and external residual yolk. Incubation duration was negatively correlated with incubation temperature. We report on the morphology of eggs and hatchlings and show that their dimensions are positively correlated with maternal adult size and mass. A constant incubation temperature of 27°C produced the highest hatching success and smallest external residual yolk on hatching and is therefore recommended for incubation of eggs for population reinforcement programs. Our study is the first to optimise artificial incubation procedures for M. bellii and will be a valuable resource for M. bellii and other threatened freshwater turtle conservation initiatives.
Disease surveillance of the amphibian chytrid fungus Batrachochytrium dendrobatidis in Papua New Guinea
Publisher: Wiley
Date: 17-08-2020
DOI: 10.1111/CSP2.256
Sex, light, and sound: location and combination of multiple attractants affect probability of cane toad (Rhinella marina) capture
Publisher: Springer Science and Business Media LLC
Date: 24-01-2014
Effects of emerging infectious diseases on host population genetics: a review
Publisher: Springer Science and Business Media LLC
Date: 18-04-2017
Six-year demographic study reveals threat of stochastic extinction for remnant populations of a threatened amphibian
Publisher: Wiley
Date: 24-07-2014
DOI: 10.1111/AEC.12080
Employing citizen science to understand amphibian and reptile diversity and distribution in the Himalayan Kingdom of Bhutan
Publisher: Elsevier BV
Date: 09-2022
Realistic heat pulses protect frogs from disease under simulated rainforest frog thermal regimes
Publisher: Wiley
Date: 14-08-2017
Effectiveness of acoustic indices as indicators of vertebrate biodiversity
Publisher: Elsevier BV
Date: 03-2023
Combining ex situ and in situ methods to improve water quality testing for the conservation of aquatic species
Publisher: Wiley
Date: 23-09-2017
DOI: 10.1002/AQC.2700
Fighting an uphill battle: the recovery of frogs in Australia's Wet Tropics
Publisher: Wiley
Date: 15-11-2017
DOI: 10.1002/ECY.2019
Island of opportunity: can New Guinea protect amphibians from a globally emerging pathogen?
Publisher: Wiley
Date: 03-06-2019
DOI: 10.1002/FEE.2057
Salinity of incubation media influences embryonic development of a freshwater turtle
Publisher: Springer Science and Business Media LLC
Date: 02-08-2013
DOI: 10.1007/S00360-012-0695-2
Abstract: Variations in water potential have marked effects on aspects of embryological development in reptiles. Therefore variation in the salinity of the incubation environment is likely to have significant consequences on the early life stage. The combination of an extended incubation period, coupled with the real threat of soil salinisation within their range makes Chelodina expansa an ideal model to assess the influence of salinity on turtle embryology. We quantified the influence of salt on the development of C. expansa hatchlings in four substrate treatments varying in salinity. Embryos incubated in higher salinities had 39 % less survival than those incubated in substrates with freshwater. Hatchlings that emerged from eggs in saline treatments were smaller with higher concentrations of plasma sodium, chloride, urea, and potassium. The physiological effects of salinity mirror those of turtles incubated in drier media with low water potential. Salinisation of river banks has the potential to reduce hatching success and fitness of nesting reptiles.
Opportunities for research and conservation of freshwater turtles in Australia
Publisher: Wiley
Date: 13-08-2023
DOI: 10.1111/AEC.13403
Abstract: Australia's freshwater turtles have high endemicity and many are threatened by extinction. Following a symposium held at the 2022 conference of the Australian Society of Herpetologists, we summarized the current status of research and conservation for Australian freshwater turtles and identified opportunities for future research. Eight species (32%) of Australia's 25 native freshwater turtles are listed as threatened by Australia's Federal Government. Symposium discussions on the primary gaps in research identified the lack of baseline data to inform population modelling as a key deficiency. Knowledge of the most effective conservation actions, the effectiveness of attempts to aid population recovery, and whether these actions are required at all, remains lacking for many species. A heavy bias exists between some well‐studied species compared with others for which little or no information is published. Community science, engagement with First Nations people, advances in technology, and recognition of the importance of turtles are contributing to better knowledge.
The role of non-declining amphibian species as alternative hosts for Batrachochytrium dendrobatidis in an amphibian community
Publisher: CSIRO Publishing
Date: 2016
DOI: 10.1071/WR15223
Abstract: Context Pathogens with reservoir hosts have been responsible for most disease-induced wildlife extinctions because the decline of susceptible hosts does not cause the decline of the pathogen. The existence of reservoirs for Batrachochytrium dendrobatidis limits population recovery and conservation actions for threatened hibians. As such, the effect of reservoirs on disease risk within host community assemblages needs to be considered, but rarely is. Aims In this study we aimed to determine if hibian species co-occurring with the green and golden bell frog Litoria aurea, a declining species susceptible to B. dendrobatidis, act as alternate hosts. Methods We quantified B. dendrobatidis infection levels, sub-lethal effects on body condition and terminal signs of disease in hibian communities on Kooragang Island and Sydney Olympic Park in New South Wales, Australia, where two of the largest remaining L. aurea populations persist. Key results We found L. aurea carried infections at a similar prevalence (6–38%) to alternate species. Infection loads ranged widely (0.01–11 107.3 zoospore equivalents) and L. aurea differed from only one alternate host species (higher median load in Litoria fallax) at one site. There were no terminal or sub-lethal signs of disease in any species co-occurring with L. aurea. Conclusion Our results suggest that co-occurring species are acting as alternate hosts to L. aurea and whether their presence dilutes or lifies B. dendrobatidis in the community is a priority for future research. Implications For L. aurea and many other susceptible species, confirming the existence of reservoir hosts and understanding their role in community disease dynamics will be important for optimising the outcomes of threat mitigation and habitat creation initiatives for their long-term conservation.
Movement and habitat use of Australia’s largest snake-necked turtle: Implications for water management
Publisher: Wiley
Date: 24-01-2012
Susceptibility to disease varies with ontogeny and immunocompetence in a threatened amphibian
Publisher: Springer Science and Business Media LLC
Date: 29-03-2016
DOI: 10.1007/S00442-016-3607-4
Abstract: Ontogenetic changes in disease susceptibility have been demonstrated in many vertebrate taxa, as immature immune systems and limited prior exposure to pathogens can place less developed juveniles at a greater disease risk. By causing the disease chytridiomycosis, Batrachochytrium dendrobatidis (Bd) infection has led to the decline of many hibian species. Despite increasing knowledge on how Bd varies in its effects among species, little is known on the interaction between susceptibility and development within host species. We compared the ontogenetic susceptibility of post-metamorphic green and golden bell frogs Litoria aurea to chytridiomycosis by simultaneously measuring three host-pathogen responses as indicators of the development of the fungus-infection load, survival rate, and host immunocompetence-following Bd exposure in three life stages (recently metamorphosed juveniles, subadults, adults) over 95 days. Frogs exposed to Bd as recently metamorphosed juveniles acquired higher infection loads and experienced lower immune function and lower survivorship than subadults and adults, indicating an ontogenetic decline in chytridiomycosis susceptibility. By corresponding with an intrinsic developmental maturation in immunocompetence seen in uninfected frogs, we suggest these developmental changes in host susceptibility in L. aurea may be immune mediated. Consequently, the physiological relationship between ontogeny and immunity may affect host population structure and demography through variation in life stage survival, and understanding this can shape management targets for effective hibian conservation.
The conservation impacts of ecological disturbance: time‐bound estimates of population loss and recovery for fauna affected by the 2019–2020 Australian megafires
Publisher: Wiley
Date: 03-2022
DOI: 10.1111/GEB.13473
Abstract: After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019–2020 Australian megafires, we estimated population losses and recovery in fire‐affected fauna, to inform conservation status assessments and management. Temperate and subtropical Australia. 2019–2030 and beyond. Australian terrestrial and freshwater vertebrates one invertebrate group. From 1,050 fire‐affected taxa, we selected 173 whose distributions substantially overlapped the fire extent. We estimated the proportion of each taxon’s distribution affected by fires, using fire severity and aquatic impact mapping, and new distribution mapping. Using expert elicitation informed by evidence of responses to previous wildfires, we estimated local population responses to fires of varying severity. We combined the spatial and elicitation data to estimate overall population loss and recovery trajectories, and thus indicate potential eligibility for listing as threatened, or uplisting, under Australian legislation. We estimate that the 2019–2020 Australian megafires caused, or contributed to, population declines that make 70–82 taxa eligible for listing as threatened and another 21–27 taxa eligible for uplisting. If so‐listed, this represents a 22–26% increase in Australian statutory lists of threatened terrestrial and freshwater vertebrates and spiny crayfish, and uplisting for 8–10% of threatened taxa. Such changes would cause an abrupt worsening of underlying trajectories in vertebrates, as measured by Red List Indices. We predict that 54–88% of 173 assessed taxa will not recover to pre‐fire population size within 10 years/three generations. We suggest the 2019–2020 Australian megafires have worsened the conservation prospects for many species. Of the 91 taxa recommended for listing/uplisting consideration, 84 are now under formal review through national processes. Improving predictions about taxon vulnerability with empirical data on population responses, reducing the likelihood of future catastrophic events and mitigating their impacts on bio ersity, are critical.
Remote sensing to characterize inundation and vegetation dynamics of upland lagoons
Publisher: Wiley
Date: 2022
DOI: 10.1002/ECS2.3906
Abstract: Understanding broad trends in the distribution and composition of wetlands is essential for making evidence‐based management decisions. Determining temporal change in the extent of inundation in wetlands using remote sensing remains challenging and requires on‐ground verification to determine accuracy and precision. Therefore, optimization and validation of remote sensing methods in threatened wetlands is a high priority for their conservation. Despite their ecological importance in the landscape, we have little knowledge of the variation in the spatial extent of inundation in upland lagoons, a threatened ecological community in New South Wales, Australia. Our project developed locally trained algorithms to predict the extent of water and emergent vegetation using imagery from the Landsat‐5, ‐7, and ‐8 satellites. The best model for upland lagoons used shortwave infrared reflectance (performing better than normalized difference spectral indices), with model accuracy against validation transects greater than 95%. We applied the model to images from 1988 to 2020 across 58 lagoons to generate a dataset that demonstrates the variable water regime and vegetation change in response to local rainfall over 32 years such as in the lagoons. Our results reduce threats to a dynamic threatened ecological community by filling an important knowledge gap and demonstrate a valuable method to understand historical and current changes in the hydrology of dynamic wetland systems more broadly.
Assessing the value of acoustic indices to distinguish species and quantify activity: A case study using frogs
Publisher: Wiley
Date: 16-12-2020
DOI: 10.1111/FWB.13222
Red hot frogs: identifying the Australian frogs most at risk of extinction
Publisher: CSIRO Publishing
Date: 20-08-2021
DOI: 10.1071/PC21019
Abstract: More than a third of the world’s hibian species are listed as Threatened or Extinct, with a recent assessment identifying 45 Australian frogs (18.4% of the currently recognised species) as ‘Threatened’ based on IUCN criteria. We applied structured expert elicitation to 26 frogs assessed as Critically Endangered and Endangered to estimate their probability of extinction by 2040. We also investigated whether participant experience (measured as a self-assigned categorical score, i.e. ‘expert’ or ‘non-expert’) influenced the estimates. Collation and analysis of participant opinion indicated that eight species are at high risk ( % chance) of becoming extinct by 2040, with the disease chytridiomycosis identified as the primary threat. A further five species are at moderate–high risk (30–50% chance), primarily due to climate change. Fourteen of the 26 frog species are endemic to Queensland, with many species restricted to small geographic ranges that are susceptible to stochastic events (e.g. a severe heatwave or a large bushfire). Experts were more likely to rate extinction probability higher for poorly known species (those with experts), while non-experts were more likely to rate extinction probability higher for better-known species. However, scores converged following discussion, indicating that there was greater consensus in the estimates of extinction probability. Increased resourcing and management intervention are urgently needed to avert future extinctions of Australia’s frogs. Key priorities include developing and supporting captive management and establishing or extending in-situ population refuges to alleviate the impacts of disease and climate change.
Reptilian Mycophagy: A global review of mutually beneficial associations between reptiles and macrofungi
Publisher: Mushroom Research Foundation
Date: 2019
Constant-temperature predictions underestimate growth of a fungal amphibian pathogen under individual host thermal profiles
Publisher: Elsevier BV
Date: 2023
Low disease-causing threshold in a frog species susceptible to chytridiomycosis
Publisher: Oxford University Press (OUP)
Date: 25-04-2016
Abstract: A simple diagnosis of the presence or absence of an infection is an uninformative metric when in iduals differ considerably in their tolerance to different infection loads or resistance to rates of disease progression. Models that incorporate the relationship between the progression of the infection with the potential alternate outcomes provide a far more powerful predictive tool than diagnosis alone. The global decline of hibians has been lified by Batrachochytrium dendrobatidis, a pathogen that can cause the fatal disease chytridiomycosis. We measured the infection load and observed signs of disease in Litoria aurea Receiver operating characteristic curves were used to quantify the dissimilarity between the infection loads of L. aurea that showed signs associated with chytridiomycosis and those that did not. Litoria aurea had a 78% probability of developing chytridiomycosis past a threshold of 68 zoospore equivalents (ZE) per swab and chytridiomycosis occurred within a variable range of 0.5-490 ZE. Studies should incorporate a species-specific threshold as a predictor of chytridiomycosis, rather than a binary diagnosis. Measures of susceptibility to chytridiomycosis must account not only for the ability of B. dendrobatidis to increase its abundance on the skin of hibians but also to determine how each species tolerates these infection loads.
Condition thresholds in Australia’s threatened ecological community listings hinder conservation of dynamic ecosystems
Publisher: CSIRO Publishing
Date: 2021
DOI: 10.1071/PC20040
Abstract: Environmental degradation is threatening bio ersity and ecosystem function globally. Mandating ecosystem-level protection in policy and legislative frameworks is essential to prevent bio ersity loss. Australia’s Environment Protection and Bio ersity Conservation Act 1999 is the key legislative mechanism for supporting bio ersity at the national level, but has so far been ineffective at protecting habitat and ecological communities. Here we identify a major flaw in the current approach to listing threatened ecological communities (TECs): restrictive condition thresholds that threaten ecosystem function in dynamic ecosystems. Using two wetland TECs as a case study (Upland Wetlands and Coolibah-Black Box Woodlands), we argue that Australia’s environmental legislation should adopt a landscape-scale approach to TEC protection that acknowledges ecosystem function, accounts for different states in temporally dynamic systems, and sustains landscape connectivity of TEC distribution. We present a state-and-transition model for each TEC to show how human activities affect the reference-state continuum of wet and dry phases. We also show that the current listed condition thresholds do not acknowledge alternative ecosystem states and exclude areas that may be important for restoration and conservation of the TEC at the landscape-scale. Description of alternative and transitional states for dynamic systems, including how, when and why ecological communities shift between different states, should be formally integrated into the TEC listing process to protect Australia’s vulnerable ecosystems from further degradation and loss.
Stable isotope analyses reveal predation on amphibians by a globally invasive fish (Gambusia holbrooki)
Publisher: Wiley
Date: 25-02-2016
DOI: 10.1002/AQC.2631
Using a Bayesian network to clarify areas requiring research in a host–pathogen system
Publisher: Wiley
Date: 10-08-2017
DOI: 10.1111/COBI.12950
Abstract: Bayesian network analyses can be used to interactively change the strength of effect of variables in a model to explore complex relationships in new ways. In doing so, they allow one to identify influential nodes that are not well studied empirically so that future research can be prioritized. We identified relationships in host and pathogen biology to examine disease-driven declines of hibians associated with hibian chytrid fungus (Batrachochytrium dendrobatidis). We constructed a Bayesian network consisting of behavioral, genetic, physiological, and environmental variables that influence disease and used them to predict host population trends. We varied the impacts of specific variables in the model to reveal factors with the most influence on host population trend. The behavior of the nodes (the way in which the variables probabilistically responded to changes in states of the parents, which are the nodes or variables that directly influenced them in the graphical model) was consistent with published results. The frog population had a 49% probability of decline when all states were set at their original values, and this probability increased when body temperatures were cold, the immune system was not suppressing infection, and the ambient environment was conducive to growth of B. dendrobatidis. These findings suggest the construction of our model reflected the complex relationships characteristic of host-pathogen interactions. Changes to climatic variables alone did not strongly influence the probability of population decline, which suggests that climate interacts with other factors such as the capacity of the frog immune system to suppress disease. Changes to the adaptive immune system and disease reservoirs had a large effect on the population trend, but there was little empirical information available for model construction. Our model inputs can be used as a base to examine other systems, and our results show that such analyses are useful tools for reviewing existing literature, identifying links poorly supported by evidence, and understanding complexities in emerging infectious-disease systems.
Achieving no net loss in habitat offset of a threatened frog required high offset ratio and intensive monitoring
Publisher: Elsevier BV
Date: 2013
The interplay of fungal and bacterial microbiomes on rainforest frogs following a disease outbreak
Publisher: Wiley
Date: 07-2022
DOI: 10.1002/ECS2.4037
Abstract: Emerging infectious diseases are a serious threat to wildlife populations, and there is growing evidence that host microbiomes play important roles in infection dynamics, possibly even mitigating diseases. Nevertheless, most research on this topic has focused only on bacterial microbiomes, while fungal microbiomes have been largely neglected. To help fill this gap in our knowledge, we examined both the bacterial and fungal microbiomes of four sympatric Australian frog species, which had different population‐level responses to the emergence of chytridiomycosis, a widespread disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd) . We sequenced 16,884 fungal licon sequence variants (ASVs) and 41,774 bacterial ASVs. Bacterial communities had higher richness and were less variable within frog species than were fungal communities. Nevertheless, both communities were correlated for both ASV richness and beta ersity (i.e., frogs with similar bacterial richness and community composition tended to also have similar fungal richness and community composition). This suggests that either one microbial community was having a large impact on the other or that they were both being driven by similar environmental factors. For both microbial taxa, we found little evidence of associations between Bd (prevalence or intensity) and either in iduals' ASVs or beta ersity. However, there was mixed evidence of associations between richness (both bacterial and fungal) and Bd , with high richness potentially providing a protective effect. Surprisingly, the relative abundance of bacteria that have previously been shown to inhibit Bd was also positively associated with Bd infection intensity, suggesting that a high relative abundance of those bacteria provides poor protection against infection.
The ecology and morphology of Australia's desert turtle (Emydura macquarii emmotti)
Publisher: Wiley
Date: 25-09-2023
DOI: 10.1111/AEC.13434
Interaction between temperature and sublethal infection with the amphibian chytrid fungus impacts a susceptible frog species
Publisher: Springer Science and Business Media LLC
Date: 14-01-2019
DOI: 10.1038/S41598-018-35874-7
Abstract: The hibian chytrid fungus Batrachochytrium dendrobatidis is an emerging infectious pathogen present on every continent except Antarctica. It causes the disease chytridiomycosis in a subset of species but does not always result in disease or death for every host. Ambient temperature influences both hibian metabolism and chytrid pathogenicity, however the interactive effects on host physiology is not well understood. We investigated the sublethal effect of B . dendrobatidis infection on a susceptible host, Litoria aurea to test (1) whether the infection load, metabolic activity, body fat and gonad size differed in L . aurea at either 24 °C or 12 °C ambient temperatures and (2) whether previous Bd infection caused long-term changes to body fat and gonad size. Litoria aurea in 12 °C treatments had higher infection loads of B . dendrobatidis and lower survivorship. Metabolic rate was higher and fat mass was lower in infected in iduals and in animals in 24 °C treatments. Male L . aurea previously infected with B . dendrobatidis had smaller testes 5 months-post clearance of infection, an effect likely to translate to fitness costs in wild populations. These experiments demonstrate a physiological cost to sublethal B . dendrobatidis infection, which suggests a reduction in host fitness mediated by temperature in the host’s environment regardless of whether infection leads to mortality.
Salinity tolerances of two Australian freshwater turtles, Chelodina expansa and Emydura macquarii (Testudinata: Chelidae)
Publisher: Oxford University Press (OUP)
Date: 2016
microDecon: A highly accurate read‐subtraction tool for the post‐sequencing removal of contamination in metabarcoding studies
Publisher: Wiley
Date: 05-2019
DOI: 10.1002/EDN3.11
Ecological and physiological impacts of salinisation on freshwater turtles of the lower Murray River
Publisher: CSIRO Publishing
Date: 2013
DOI: 10.1071/WR11214
Abstract: Context The increasing intensity and extent of anthropogenically mediated salinisation in freshwater systems has the potential to affect freshwater species through physiological and ecological processes. Determining responses to salinisation is critical to predicting impacts on fauna. Aims We aimed to quantify the response of wild-caught turtles from freshwater lakes that had become saline in the lower Murray River catchment. Methods Plasma electrolytes of all three species of freshwater turtle from South Australia were compared among two freshwater sites (Horseshoe Lagoon and Swan Reach), a brackish lake (Lake Bonney) and a saline lake (Lake Alexandrina). Key results Chelodina longicollis, C. expansa and Emydura macquarii from a brackish lake had higher concentrations of plasma sodium and chloride than those from freshwater habitats. However, osmolytes known to increase under severe osmotic stress (urea and uric acid) were not elevated in brackish sites. Turtles from the highly saline lake were colonised by an invasive marine worm which encased the carapace and inhibited limb movement. Conclusions Freshwater turtles in brackish backwaters had little response to salinity, whereas the C. longicollis in a saline lake had a significant physiological response caused by salt and further impacts from colonisation of marine worms. Implications Short periods of high salinity are unlikely to adversely affect freshwater turtles. However, secondary ecological processes, such as immobilisation from a marine worm may cause unexpected impacts on freshwater fauna.
A review of the current global status of blast fishing: Causes, implications and solutions
Publisher: Elsevier BV
Date: 10-2021
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Related Funding Activities
Linkage Projects - Grant ID: LP200200884
Start Date: 05-2022
End Date: 05-2026
Amount: $601,024.00
Funder: Australian Research Council
View Funded ActivityDiscovery Early Career Researcher Award - Grant ID: DE200101424
Start Date: 06-2020
End Date: 06-2023
Amount: $425,469.00
Funder: Australian Research Council
View Funded Activity