Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams ... more Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams and are the major primary producers that sit at the base of food webs. Given their ecological importance, the aim of the present study was to investigate the spatial patterns of freshwater biofilm biomass and diatom assemblage composition in response to differences in physical and chemical variables in the Bremer, Logan and Albert catchments in south-east Queensland. Patterns in benthic diatom assemblage structure were examined during base flow conditions and the focus was on relating the spatial hierarchical interrelationships among ultimate (i.e. catchments and geology) and proximate (i.e. flow, nutrients, light, conductivity, pH and turbidity) environmental drivers. The spatial difference observed in the benthic diatom assemblages was predominantly driven by proximate environmental drivers, which, in turn, were affected by ultimate drivers. Flow played a critical role in controlling b...
The Healthy Country project is a Queensland Government funded ‘proof of concept’ initiative to de... more The Healthy Country project is a Queensland Government funded ‘proof of concept’ initiative to demonstrate that bringing together the best science, planning and on ground implementation can significantly reduce non-urban diffuse source pollutants entering the waterways. It started in January 2008 with an $8 million investment to address erosion in the south-east Queensland region by targeting and trialing restoration activities in three priority subcatchments within the Bremer and Logan Rivers and Lockyer Creek catchments. The three focal subcatchments are in the upper Lockyer Creek, in the upper Bremer River and Knapp Creek in the Logan-Albert River. Project partners include the SEQ Healthy Waterways Partnership (SEQ HWP), SEQ Catchments Ltd, Queensland Primary Industries and Fisheries (QPIF), Department of Employment, Economic Development and Innovation and the SEQ Traditional Owners Alliance (SEQTOA). As part of the project, three focal catchments have been selected to develop appropriate rehabilitation tools and techniques for the region. Key outputs include: (i) the development of methods to determine the primary sediment and nutrient sources, (ii) the design of tools that can be used to specify what works should occur where, (iii) the trial of different rehabilitation methods and (iv) the development of methods to monitor, evaluate and adapt land and waterways management actions.
Dryland rivers are renowned for their periods of ‘boom’ related to the episodic floods that exten... more Dryland rivers are renowned for their periods of ‘boom’ related to the episodic floods that extend over vast floodplains and fuel incredible production, and periods of ‘bust’ where the extensive channel network is restricted to the permanent refugial waterholes. Many of these river systems are unregulated by dams but are under increasing pressure, especially from water abstraction and overland flow interception for agriculture and mining. Although some aquatic organisms with desiccation-resistant life stages can utilise ephemeral floodplain habitats, the larger river waterholes represent the only permanent aquatic habitat during extended periods of low or no flow. These waterholes act as aquatic refugia in an otherwise terrestrial landscape. Variable patterns of connection and disconnection in space and time are a fundamental driver of diversity and function in these dryland river systems, and are vital for dispersal and the maintenance of diverse populations, generate the spatial a...
Debate exists about the effects of hydrological variation on food web dynamics and the relative i... more Debate exists about the effects of hydrological variation on food web dynamics and the relative importance of different sources of organic carbon fuelling food webs in floodplain rivers. Stable carbon isotope analyses and ecological stoichiometry were used to determine the basal sources in dry season macroinvertebrate food webs in two floodplain river systems of Australia’s wet–dry tropics that have contrasting flow regimes. Algae, associated with phytoplankton and biofilm, were the primary food source, potentially contributing >55% organic carbon to the biomass of a wide range of primary and secondary consumers. However, many consumers assimilated other sources in addition to algae, e.g. detritus from local C3 riparian vegetation. Food webs were characterised by substantial flexibility in the number and types of sources identified as important, which was indicative of generalist feeding strategies. These findings suggest ‘dynamic stability’ in the food webs, which imparts resili...
Many aquatic ecosystems have been severely degraded by water-resource development affecting flow ... more Many aquatic ecosystems have been severely degraded by water-resource development affecting flow regimes and biological connectivity. Freshwater fish have been particularly affected by these changes and climate change will place further stress on them. The Murray–Darling Basin (MDB), Australia, represents a highly affected aquatic system with dramatically modified flow regimes. This has impaired the health of its rivers, and potentially limited the adaptive capacity of its biota to respond to a changing climate. Here, we present our predictions of the potential impacts of climate change on 18 native fish species across their distributional ranges against the back-drop of past and continuing water-resource development (WRD). Because most of these species are found across a wide range of geographical and hydrological settings, we classified the MDB into 10 regions to account for likely variation in climate-change effects, on the basis of latitude, elevation and WRD. Cold water-toleran...
Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams ... more Diatoms (Division Bacillariophyta) commonly dominate benthic algal communities in upland streams and are the major primary producers that sit at the base of food webs. Given their ecological importance, the aim of the present study was to investigate the spatial patterns of freshwater biofilm biomass and diatom assemblage composition in response to differences in physical and chemical variables in the Bremer, Logan and Albert catchments in south-east Queensland. Patterns in benthic diatom assemblage structure were examined during base flow conditions and the focus was on relating the spatial hierarchical interrelationships among ultimate (i.e. catchments and geology) and proximate (i.e. flow, nutrients, light, conductivity, pH and turbidity) environmental drivers. The spatial difference observed in the benthic diatom assemblages was predominantly driven by proximate environmental drivers, which, in turn, were affected by ultimate drivers. Flow played a critical role in controlling b...
The Healthy Country project is a Queensland Government funded ‘proof of concept’ initiative to de... more The Healthy Country project is a Queensland Government funded ‘proof of concept’ initiative to demonstrate that bringing together the best science, planning and on ground implementation can significantly reduce non-urban diffuse source pollutants entering the waterways. It started in January 2008 with an $8 million investment to address erosion in the south-east Queensland region by targeting and trialing restoration activities in three priority subcatchments within the Bremer and Logan Rivers and Lockyer Creek catchments. The three focal subcatchments are in the upper Lockyer Creek, in the upper Bremer River and Knapp Creek in the Logan-Albert River. Project partners include the SEQ Healthy Waterways Partnership (SEQ HWP), SEQ Catchments Ltd, Queensland Primary Industries and Fisheries (QPIF), Department of Employment, Economic Development and Innovation and the SEQ Traditional Owners Alliance (SEQTOA). As part of the project, three focal catchments have been selected to develop appropriate rehabilitation tools and techniques for the region. Key outputs include: (i) the development of methods to determine the primary sediment and nutrient sources, (ii) the design of tools that can be used to specify what works should occur where, (iii) the trial of different rehabilitation methods and (iv) the development of methods to monitor, evaluate and adapt land and waterways management actions.
Dryland rivers are renowned for their periods of ‘boom’ related to the episodic floods that exten... more Dryland rivers are renowned for their periods of ‘boom’ related to the episodic floods that extend over vast floodplains and fuel incredible production, and periods of ‘bust’ where the extensive channel network is restricted to the permanent refugial waterholes. Many of these river systems are unregulated by dams but are under increasing pressure, especially from water abstraction and overland flow interception for agriculture and mining. Although some aquatic organisms with desiccation-resistant life stages can utilise ephemeral floodplain habitats, the larger river waterholes represent the only permanent aquatic habitat during extended periods of low or no flow. These waterholes act as aquatic refugia in an otherwise terrestrial landscape. Variable patterns of connection and disconnection in space and time are a fundamental driver of diversity and function in these dryland river systems, and are vital for dispersal and the maintenance of diverse populations, generate the spatial a...
Debate exists about the effects of hydrological variation on food web dynamics and the relative i... more Debate exists about the effects of hydrological variation on food web dynamics and the relative importance of different sources of organic carbon fuelling food webs in floodplain rivers. Stable carbon isotope analyses and ecological stoichiometry were used to determine the basal sources in dry season macroinvertebrate food webs in two floodplain river systems of Australia’s wet–dry tropics that have contrasting flow regimes. Algae, associated with phytoplankton and biofilm, were the primary food source, potentially contributing >55% organic carbon to the biomass of a wide range of primary and secondary consumers. However, many consumers assimilated other sources in addition to algae, e.g. detritus from local C3 riparian vegetation. Food webs were characterised by substantial flexibility in the number and types of sources identified as important, which was indicative of generalist feeding strategies. These findings suggest ‘dynamic stability’ in the food webs, which imparts resili...
Many aquatic ecosystems have been severely degraded by water-resource development affecting flow ... more Many aquatic ecosystems have been severely degraded by water-resource development affecting flow regimes and biological connectivity. Freshwater fish have been particularly affected by these changes and climate change will place further stress on them. The Murray–Darling Basin (MDB), Australia, represents a highly affected aquatic system with dramatically modified flow regimes. This has impaired the health of its rivers, and potentially limited the adaptive capacity of its biota to respond to a changing climate. Here, we present our predictions of the potential impacts of climate change on 18 native fish species across their distributional ranges against the back-drop of past and continuing water-resource development (WRD). Because most of these species are found across a wide range of geographical and hydrological settings, we classified the MDB into 10 regions to account for likely variation in climate-change effects, on the basis of latitude, elevation and WRD. Cold water-toleran...
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Papers by F. Sheldon