Assessment of post-wildfire erosion risk and effects on water quality in south-western Australia

Investigations of wildfire impact on water resources have escalated globally over the last decade owing to an awareness of climate-related vulnerabilities. Within Australia, research into post-wildfire erosion has focused on water supply catchments in the south-eastern region. Here, we examine post-wildfire erosion risk and its potential for water quality impacts in a catchment in south-western Australia. The catchment of the Harvey River, which drains from forested escarpments onto an agricultural coastal plain and into valuable coastal wetlands, was burnt by wildfire in 2016. The aims of this study were to determine erosion risk across contrasting landforms and variable fire severity, using the Revised Universal Soil Loss Equation (RUSLE), and to determine whether post-fire water quality impacts could be detected at permanent river monitoring stations located on the coastal plain. RUSLE outputs showed erosion hot-spots at intersections of steep terrain and high fire severity and that these areas were confined to forested headwaters and coastal dunes. Monthly water quality data showed conspicuous seasonal patterns, but that sampling frequency was temporally too coarse to pick up predicted event-related effects, particularly given that the pre-existing monitoring sites were distal to the predicted zone of contamination. © IAWF 2020 Open Access

Intestinal Microbiome Richness of Coral Reef Damselfishes (Actinopterygii: Pomacentridae)

Fish gastro-intestinal system harbors diverse microbiomes that affect the host's digestion, nutrition, and immunity. Despite the great taxonomic diversity of fish, little is understood about fish microbiome and the factors that determine its structure and composition. Damselfish are important coral reef species that play pivotal roles in determining algae and coral population structures of reefs. Broadly, damselfish belong to either of two trophic guilds based on whether they are planktivorous or algae-farming. In this study, we used 16S rRNA gene sequencing to investigate the intestinal microbiome of 5 planktivorous and 5 algae-farming damselfish species (Pomacentridae) from the Great Barrier Reef. We detected Gammaproteobacteria ASVs belonging to the genus Actinobacillus in 80% of sampled individuals across the 2 trophic guilds, thus, bacteria in this genus can be considered possible core members of pomacentrid microbiomes. Algae-farming damselfish had greater bacterial alpha-diversity, a more diverse core microbiome and shared 35 ± 22 ASVs, whereas planktivorous species shared 7 ± 3 ASVs. Our data also highlight differences in microbiomes associated with both trophic guilds. For instance, algae-farming damselfish were enriched in Pasteurellaceae, whilst planktivorous damselfish in Vibrionaceae. Finally, we show shifts in bacterial community composition along the intestines. ASVs associated with the classes Bacteroidia, Clostridia, and Mollicutes bacteria were predominant in the anterior intestinal regions while Gammaproteobacteria abundance was higher in the stomach. Our results suggest that the richness of the intestinal bacterial communities of damselfish reflects host species diet and trophic guild

Community composition of carrion-breeding blowflies (Diptera: Calliphoridae) along an urban gradient in south-eastern Australia

Urbanisation is a process that results in rapid modification of the natural environment, dramatically altering community structure. Blowflies (Diptera: Calliphoridae) are common inhabitants of the urban ecosystem, although little is understood about their distributions or habitat preferences within the urban environment. Blowflies require carrion for development, and as carrion is an ephemeral resource, the effect of urbanisation on these flies may be expected to differ from insects that utilise more uniformly distributed resources. In this study, blowflies were captured at various locations along an urban gradient in the region of Sydney, Australia, during summer and winter. Four habitat categories were sampled: bush, farm, suburban and urban. Using analysis of similarities (ANOSIM), calliphorid assemblages differed between all habitats, except urban and suburban. Species associations with environmental variables were also analysed using canonical correspondence analysis (CCA). Calliphorid abundances were lower in the winter trapping period, compared with the summer trapping period. Chrysomya was the most abundant genus during summer, whilst Calliphora was the most abundant genus during the winter. Some species also displayed temporal changes in their habitat preferences and synanthropic behaviour. Other species were only present in the urban habitats during winter, suggesting that they rely on urban refuges at this time of year. The ecological effects of urbanisation were clearly observed in the present study, since three distinct calliphorid assemblages were found at three different levels of urbanisation within the urban gradient. This study provides information on blowfly responses to urbanisation of use to forensic and ecological entomologists

Microbiomes of Western Australian marine environments

27 pages, 5 figures, 1 appendixMicrobes are fundamentally important to the maintenance of all habitats, including those in the ocean: they govern biogeochemical cycles, contribute to resistance from disease and nutritional requirements of macroorganisms and provide enormous biological and genetic diversity. The oceanic environment of the west coast of Australia is dominated by the Leeuwin Current, a poleward flowing boundary current that brings warm water down the coastline from the north. Due to the influence of the current, tropical species exist further south than they would otherwise, and stretches of the coastline host unique assortments of tropical and temperate species. Seawater itself, as well as the benthic macroorganisms that inhabit ocean environments, form habitats such as extensive areas of seagrass beds, macroalgal forests, coral reefs, sponge gardens, benthic mats including stromatolites, continental slopes and canyons and abyssal plain enviroments. These environments, and the macroorganisms that inhabit them, are all intrinsically linked with highly abundant and diverse consortiums of microorganisms. To date, there has been little research aimed at understanding these critical organisms within Western Australia. Here we review the current literature from the dominant coastal types (seagrass, coral, temperate macroalgae, vertebrates and stromatolites) in Western Australia. The most well researched are pelagic habitats and those with stromatolites, whereas data on all the other environments are slowly beginning to emerge. We urge future research efforts to be directed toward understanding the diversity, function, resilience and connectivity of coastal microorganisms in Western AustraliaPeer Reviewe

Australian vegetated coastal ecosystems as global hotspots for climate change mitigation

Este artículo contiene 10 páginas, 3 tablas, 2 figuras.Policies aiming to preserve vegetated coastal ecosystems (VCE; tidal marshes, mangroves and seagrasses) to mitigate greenhouse gas emissions require national assessments of blue carbon resources. Here, we present organic carbon (C) storage in VCE across Australian climate regions and estimate potential annual CO2 emission benefits of VCE conservation and restoration. Australia contributes 5–11% of the C stored in VCE globally (70–185 Tg C in aboveground biomass, and 1,055–1,540 Tg C in the upper 1m of soils). Potential CO2 emissions from current VCE losses are estimated at 2.1–3.1 Tg CO2-e yr-1, increasing annual CO2 emissions from land use change in Australia by 12–21%. This assessment, the most comprehensive for any nation to-date, demonstrates the potential of conservation and restoration of VCE to underpin national policy development for reducing greenhouse gas emissions.This project was supported by the CSIRO Marine and Coastal Carbon Biogeochemical Cluster, CSIRO Oceans and Atmosphere, the ECU Faculty Research Grant Scheme and Early Career Research Grant Schemes, UTS Plant Functional Biology and Climate Change Cluster, NSW Southeast Local Land Services, Department of Environment, Land, Water and Planning (DELWP), Parks Victoria, Victorian Coastal Catchment Management Authorities (GHCMA, CCMA, PPWCMA, WGCMA, EGCMA), University of Queensland Centennial Scholarship, Hodgkin Trust Scholarship, Australian Institute of Nuclear Science and Engineering, Northern Territory Government Innovation Grant, Australian Research Council (DE130101084, DE140101733, DE150100581, DE160100443, DE170101524, DP150103286, DP150102092, DP160100248, DP160100248, DP180101285, LE140100083, LE170100219, LP150100519, LP160100242 and LP110200975), the Generalitat de Catalunya (MERS 2014 SGR-1356), the ICTA ‘Unit of Excellence’ (MinECo, MDM2015-0552), Obra Social “LaCaixa”, SUMILEN, CTM 2013-47728-R, Ministry of Economy and Competitiveness and UKM-DIP-2017- 005.Peer reviewe