Resource patchiness, dispersal and species co-occurrence: an experimental and levels-of-evidence approach in some lowland streams. Millions of dollars are being spent on rehabilitating river ecosystems that have often been highly simplified by human activities. It is important that such rehabilitation be well-grounded in sound ecological knowledge. We will test how the availability of essential resources of food and living space affect the identity and density of species present. We expect to p ....Resource patchiness, dispersal and species co-occurrence: an experimental and levels-of-evidence approach in some lowland streams. Millions of dollars are being spent on rehabilitating river ecosystems that have often been highly simplified by human activities. It is important that such rehabilitation be well-grounded in sound ecological knowledge. We will test how the availability of essential resources of food and living space affect the identity and density of species present. We expect to provide practical advice allowing managers to enhance biodiversity in streams surrounded by, and serving, agricultural areas. Likewise, we will be able to advise on the consequences of excessive water extraction on the likely success of such rehabilitation in rivers with highly variable flows.Read moreRead less
Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of ....Diadromous stream fishes: a model system for investigating sources of variation in recruitment. Our aim is to examine the relationship between adult abundance and recruitment in local populations of a diadromous stream fish to identify the source(s) of variation in recruitment. We will accomplish this by measuring larval production and recruitment among streams that vary in adult abundance, strength of settlement cues, and potential for larval dispersal. We will also use environmental markers of larval origin to quantify the degree of self-recruitment and dispersal within/among populations. The results will broaden our understanding of the influence of local (production, habitat) versus regional (dispersal) processes to local population dynamics, information needed for effective stream management.Read moreRead less
Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also ....Open or closed? Dispersal and recruitment in populations of aquatic invertebrates with spatially distributed resources. The general aim of this research is to examine the contribution of fertilised eggs and recently hatched juveniles to the local population dynamics of some stream invertebrates. It seems likely that these stages act as population 'bottlenecks' , and our research will quantify the relations between these two stages and between neonates and mature larvae. Our research will also indicate whether these populations are likely to be closed (i.e., groups of individuals are relatively isolated) along channels or not. We believe our results will show much stream research focuses on the wrong life-stages; practices of river management may need re-assessment.Read moreRead less
Impacts of changing detrital source biodiversity on estuarine ecosystems. Coastal development, invasive pests, and climate change are impacting abundances of estuarine aquatic plants. This in turn is affecting the composition and magnitude of detrital enrichment, threatening biodiversity, fisheries production and endangered birds. Our pioneering research will forecast the impacts of changing detrital-source biodiversity on soft-sediment communities and the food webs they support in Australia and ....Impacts of changing detrital source biodiversity on estuarine ecosystems. Coastal development, invasive pests, and climate change are impacting abundances of estuarine aquatic plants. This in turn is affecting the composition and magnitude of detrital enrichment, threatening biodiversity, fisheries production and endangered birds. Our pioneering research will forecast the impacts of changing detrital-source biodiversity on soft-sediment communities and the food webs they support in Australia and the USA. Ecological generalities obtained can be used to support policy development that ensures sustainable management of estuaries. This work will also facilitate training of early career researchers and focus research efforts of leading US researchers towards issues crucial for Australian estuarine management.Read moreRead less
A novel approach to tracking estuarine food chains: combined use of fatty acid and stable isotope biomarkers. Fatty acid biomarkers provide promising novel tracers for studying estuarine food chains. Stable isotopes, commonly employed in food chain studies, lack specificity to allow easy determination of feeding relationships. Different primary producers are characterised by unique fatty acid sequences. This study will thoroughly evaluate the applicability of fatty acid biomarkers in tracking ....A novel approach to tracking estuarine food chains: combined use of fatty acid and stable isotope biomarkers. Fatty acid biomarkers provide promising novel tracers for studying estuarine food chains. Stable isotopes, commonly employed in food chain studies, lack specificity to allow easy determination of feeding relationships. Different primary producers are characterised by unique fatty acid sequences. This study will thoroughly evaluate the applicability of fatty acid biomarkers in tracking both natural and human-impacted estuarine food chains. By developing a new approach of combining the advantages of fatty acid bioamrkers and stable isotopes in studying estuarine trophodynamics, this study will provide essential information for the management of estuarine biotic resources.Read moreRead less
Dynamic networks in a patchy landscape: will species interactions adjust to increased climatic extremes? This project addresses pressing questions on how increased climatic extremes will affect species diversity in arid Australia, building on the longest ecological dataset available for the continent's vast but fragile inland landscapes. Our tests of key ideas about strong interactions among species, their role in building resilient communities and conserving biodiversity, will generate consider ....Dynamic networks in a patchy landscape: will species interactions adjust to increased climatic extremes? This project addresses pressing questions on how increased climatic extremes will affect species diversity in arid Australia, building on the longest ecological dataset available for the continent's vast but fragile inland landscapes. Our tests of key ideas about strong interactions among species, their role in building resilient communities and conserving biodiversity, will generate considerable international interest, while our focus on interactions of species at water sources will address knowledge gaps to inform best practice in managing converted pastoral lands. The results will contribute to retaining healthy functioning ecosystems, and the vital production systems they support, as the global climate changes.Read moreRead less
Bottom-up effects of nutrients on estuarine fish related ecosystems. Over 84% of Australians live within 50 km of the coast, and have large impacts on coastal ecosystems, such as increasing nutrients in estuaries. Nutrients have strong bottom-up effects on fish ecosystems, especially during critical juvenile life history stages. Elevated nutrients can alter fish productivity and sustainability, having ecosystem and social implications. This project will combine experimental evidence with novel a ....Bottom-up effects of nutrients on estuarine fish related ecosystems. Over 84% of Australians live within 50 km of the coast, and have large impacts on coastal ecosystems, such as increasing nutrients in estuaries. Nutrients have strong bottom-up effects on fish ecosystems, especially during critical juvenile life history stages. Elevated nutrients can alter fish productivity and sustainability, having ecosystem and social implications. This project will combine experimental evidence with novel approaches of fatty acid tracers in food-webs and fish otolith (earbone) chemistry, to determine how nutrients affect fish ecosystems, recruitment, and survivorship. This project will provide information needed to create sustainable fisheries, to safeguard Australia's fisheries resources for future generations.Read moreRead less
Next-generation models to predict cyanobacteria harmful algal blooms. This project aims to address the need for improved predictions of cyanobacteria (blue-green algae) harmful algal blooms. Accurate predictions of blooms with computer models are important to support management strategies to prevent their occurrence. This project is expected to generate new knowledge of strain-level variation in cyanobacteria that leads to toxic blooms. This project will lead to new knowledge of the significance ....Next-generation models to predict cyanobacteria harmful algal blooms. This project aims to address the need for improved predictions of cyanobacteria (blue-green algae) harmful algal blooms. Accurate predictions of blooms with computer models are important to support management strategies to prevent their occurrence. This project is expected to generate new knowledge of strain-level variation in cyanobacteria that leads to toxic blooms. This project will lead to new knowledge of the significance of strain-level variation in cyanobacteria harmful algal blooms, how strains influence toxin production and models for prediction of bloom and toxins. The project will generate significant benefits for water security for the purposes human consumption and recreation, and ecosystem health.Read moreRead less
Desert island biogeography: vertebrate dynamics after fire-induced fragmentation of habitat in central Australia. Recent wildfires in the Simpson Desert have burnt over three million hectares of hummock grassland, creating an archipelago of unburnt spinifex islands amid extensive areas of bare sand. Small mammals and reptiles are now confined to these refugia. This project seeks to characterise the patchy distributional pattern of terrestrial vertebrates among spinifex islands, and to experiment ....Desert island biogeography: vertebrate dynamics after fire-induced fragmentation of habitat in central Australia. Recent wildfires in the Simpson Desert have burnt over three million hectares of hummock grassland, creating an archipelago of unburnt spinifex islands amid extensive areas of bare sand. Small mammals and reptiles are now confined to these refugia. This project seeks to characterise the patchy distributional pattern of terrestrial vertebrates among spinifex islands, and to experimentally evaluate factors (grazing, predators, food) influencing community recovery. Using an extensive prefire database, the project provides an unique and novel opportunity to chart and model responses of terrestrial vertebrates to wildfire, and to provide guidance for sustainable use of biodiversity in central Australia.Read moreRead less
Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest ....Conservation biology of the largest Australian freshwater tortoise, the broad-shelled tortoise, Chelodina expansa - rare and endangered or cryptic and secure? The Murray is a highly managed river, with flows controlled by catchments and diversions. The combined impacts of water resource development, habitat modification and introduced species are astonishingly diverse, and include extinctions of some fish and invertebrates and depression of populations of many other species. Australia's largest chelid turtle, the broad-shelled turtle, is a high-level consumer thought to be particularly sensitive to these changes. We will use an innovative combination of non-destructive technologies to investigate the conservation biology of this species in the Lower Murray, where it is regarded as rare and where its biology is virtually unknown to inform conservation management and restoration initiativesRead moreRead less