How effective are environmental flows? Novel approaches for monitoring and assessing ecological responses to large-scale flow alteration. Australia has begun a multi-billion dollar program to return water to stressed rivers as environmental flows. However, during times of unprecedented water scarcity, such an investment in the environment can be controversial because the ecological benefits of released water are mostly poorly understood. This project will demonstrate the effectiveness of environ ....How effective are environmental flows? Novel approaches for monitoring and assessing ecological responses to large-scale flow alteration. Australia has begun a multi-billion dollar program to return water to stressed rivers as environmental flows. However, during times of unprecedented water scarcity, such an investment in the environment can be controversial because the ecological benefits of released water are mostly poorly understood. This project will demonstrate the effectiveness of environmental flows, and promote greater understanding of the links between flow patterns and river health. The project will build upon existing knowledge to create a sound framework for planning, monitoring, and evaluation of environmental watering decisions across regional Australia, greatly improving our ability to sustainably manage rivers into the future.Read moreRead less
The effect of dissolved organic matter on the toxicity and bioavailability of metals in tropical freshwater ecosystems. Mine waste materials in tropical Australia, including historical, current and future operations, represent one of the threats to the quality and biodiversity of tropical freshwater ecosystems. Dissolved organic carbon (DOC) is thought to influence metal toxicity. In order to adequately understand the risks of priority metals and metalloids from mining and other activities (eg. ....The effect of dissolved organic matter on the toxicity and bioavailability of metals in tropical freshwater ecosystems. Mine waste materials in tropical Australia, including historical, current and future operations, represent one of the threats to the quality and biodiversity of tropical freshwater ecosystems. Dissolved organic carbon (DOC) is thought to influence metal toxicity. In order to adequately understand the risks of priority metals and metalloids from mining and other activities (eg. urban development) to tropical freshwater ecosystems, it is essential that the role of DOC is quantified. The outcomes of this project will provide improved metal risk assessment methodologies; quantitative understanding of the relationship between DOC and the bioavailability and toxicity of key metals such arsenic, aluminium, cadmium, copper, uranium and zinc.Read moreRead less
New tools to detect ecological effects of contaminants in estuaries. Identifying risks to estuarine environments from pollutants is difficult for environmental managers, who must choose between laboratory toxicity testing that is precise, but hard to generalise to field situations, and more realistic field-based monitoring, which is expensive, with a high signal to noise ratio. New molecular techniques may provide more options. Metabolomics can provide insights into the health of animals, and ec ....New tools to detect ecological effects of contaminants in estuaries. Identifying risks to estuarine environments from pollutants is difficult for environmental managers, who must choose between laboratory toxicity testing that is precise, but hard to generalise to field situations, and more realistic field-based monitoring, which is expensive, with a high signal to noise ratio. New molecular techniques may provide more options. Metabolomics can provide insights into the health of animals, and ecogenomics offers a way to rapidly assess the composition of an ecological community. These techniques offer great promise, but they must be cross-validated against existing methods to derive the best ’toolbox’. Working with Melbourne Water and CSIRO the investigators aim to do this using demonstration estuaries in Victoria.Read moreRead less
How does flow regulation affect food web linkages between juvenile and larval fish and aquatic invertebrates in a coastal river? River regulation to supply water for human demands has altered flow regimes in many Australian rivers. These changes in flow impact on native invertebrate and fish community composition. Environmental flow allocations seek to alleviate these impacts but managers are hampered by lack of data on the effects of flow on food web linkages, particularly for juvenile and lar ....How does flow regulation affect food web linkages between juvenile and larval fish and aquatic invertebrates in a coastal river? River regulation to supply water for human demands has altered flow regimes in many Australian rivers. These changes in flow impact on native invertebrate and fish community composition. Environmental flow allocations seek to alleviate these impacts but managers are hampered by lack of data on the effects of flow on food web linkages, particularly for juvenile and larval fish (JLF). We aim to compare food webs of invertebrates and JLF in six tributaries of the Hunter River, three of which are regulated, to determine how flow regulation changes trophic linkages. A flow release in one tributary will let us test the hypothesis that river regulation restricts food availability to JLF, reducing their viability, growth rates, and abundance.Read moreRead less
Transformations of catchment nutrients in southeast Queensland. Human activity in catchments throughout southeast Queensland has increased nutrient loads in receiving waters. However, until recently there has been a lack of accurate quantification of these loads, and little understanding of their role in stimulating algal blooms. This proposal will examine the links between catchment nutrient inputs to waterways, their transformations and effects on stimulating algal growth in freshwater systems ....Transformations of catchment nutrients in southeast Queensland. Human activity in catchments throughout southeast Queensland has increased nutrient loads in receiving waters. However, until recently there has been a lack of accurate quantification of these loads, and little understanding of their role in stimulating algal blooms. This proposal will examine the links between catchment nutrient inputs to waterways, their transformations and effects on stimulating algal growth in freshwater systems. The outcomes from this research will be information on how catchment nutrients are affecting water quality, thus providing a vehicle for targeting management strategies designed to reduce nutrient loads.Read moreRead less
New approaches for protecting stream health in temperate Australia: Devising nutrient and salinity guidelines using diatoms. Salinity and nutrient enrichment are the most significant forms of water quality degradation in Australian lowland rivers. This project will identify the biological effect of the water quality pollution and develop new methods for its assessment. Most importantly, through the identification of water quality "thresholds" which result in reduced biodiversity, better guidelin ....New approaches for protecting stream health in temperate Australia: Devising nutrient and salinity guidelines using diatoms. Salinity and nutrient enrichment are the most significant forms of water quality degradation in Australian lowland rivers. This project will identify the biological effect of the water quality pollution and develop new methods for its assessment. Most importantly, through the identification of water quality "thresholds" which result in reduced biodiversity, better guidelines for maintaining stream health will be developed.Read moreRead less
Sediment and seed bank dynamics in river systems of southeastern Australia: Implications for vegetation-based river rehabilitation. Every year in Australia millions of dollars are spent revegetating degraded riparian corridors as part of best practice river rehabilitation. The planting and maintenance of riparian tubestock is an expensive but essential component of current on-the-ground river management across the country. What if the success rate of riparian rehabilitation could be enhanced by ....Sediment and seed bank dynamics in river systems of southeastern Australia: Implications for vegetation-based river rehabilitation. Every year in Australia millions of dollars are spent revegetating degraded riparian corridors as part of best practice river rehabilitation. The planting and maintenance of riparian tubestock is an expensive but essential component of current on-the-ground river management across the country. What if the success rate of riparian rehabilitation could be enhanced by combining geomorphic and ecological knowledge to maximise the germination of native seeds stored in riparian seed banks? As the conservation of biodiversity becomes integral to environmental management, understanding riparian seed bank dynamics and seedling establishment within a geomorphic framework is an essential tool in river rehabilitation practice.Read moreRead less
Sediment-derived scenarios of wetland status and change, the Lower River Murray, SA. River Murray wetlands changed early in European settlement so the pre-impact conditions are invisible to managers relying on anecdote or monitoring. Baseline conditions of wetlands can be derived from ecological archives preserved in sediments. Fossil diatom assemblages, reflective of past water quality, and other fossils, will be exhumed from sediment sequences to reconstruct wetland conditions. The integration ....Sediment-derived scenarios of wetland status and change, the Lower River Murray, SA. River Murray wetlands changed early in European settlement so the pre-impact conditions are invisible to managers relying on anecdote or monitoring. Baseline conditions of wetlands can be derived from ecological archives preserved in sediments. Fossil diatom assemblages, reflective of past water quality, and other fossils, will be exhumed from sediment sequences to reconstruct wetland conditions. The integration of multiple indicators of the past will generate graphic re-enactments of natural wetland dynamics. These will provide a vision for community and government on-ground managers enabling them to perceive appropriate targets for wetland state and so generate measures to work towards sustainable conditions.Read moreRead less
Retrospective ecological character assessment for a review of Ramsar status of The Coorong, SA. Integrated analyses of the chemical and biological remains contained in the sediments of the Coorong will provide for a reconstruction of ecological change and variability over the last several thousand years. Detailed analyses of the recent sediments will measure how the condition of the Coorong has departed from this natural background and so provide an audit of human impact on the last wetland in t ....Retrospective ecological character assessment for a review of Ramsar status of The Coorong, SA. Integrated analyses of the chemical and biological remains contained in the sediments of the Coorong will provide for a reconstruction of ecological change and variability over the last several thousand years. Detailed analyses of the recent sediments will measure how the condition of the Coorong has departed from this natural background and so provide an audit of human impact on the last wetland in the Murray darling Basin. This evidence will directly inform the determination of the ecological character of this Ramsar listed, national ecological asset and steer its management for a sustainable future. Read moreRead less
Spatial scale of influence of riparian and catchment land use on stream ecosystem health. Human activities at the landscape scale comprise one of the greatest threats to the ecological integrity of river ecosystems. Government and community groups across Australia are making significant efforts in riparian protection and rehabilitation in an attempt to improve the health of degraded waterways but are hampered in their goal to maximise the environmental gains for every dollar or unit effort inve ....Spatial scale of influence of riparian and catchment land use on stream ecosystem health. Human activities at the landscape scale comprise one of the greatest threats to the ecological integrity of river ecosystems. Government and community groups across Australia are making significant efforts in riparian protection and rehabilitation in an attempt to improve the health of degraded waterways but are hampered in their goal to maximise the environmental gains for every dollar or unit effort invested. The proposed research on understanding the spatial scale of influence of land use and the aggregative effects on stream ecosystems will provide a robust framework to assess various options and optimise benefits from management actions. Read moreRead less