- UNSW
- ...
- Centre for Ecosystem Science
- Our research
- Rivers and wetlands
- Micro-invertebrate community dynamics and flooding in the Macquarie marshes
- Home
- About us
-
Our research
- Atmospheric
-
Conservation practice
- Water Information System for the Environment (WISE)
- Red list of ecosystems
- Shrub encroachment as a legacy of native mammal decline
- Foraging and habitat ecology of the yellow-tailed black-cockatoo
- Tackling prey naïveté in Australia’s threatened mammals
- Biodiversity sampling in Strzelecki Regional Reserve
- The reintroduction of locally extinct mammals: The landscape ecosystem approach
- The persistence of common wombats in road impacted environments
- Temperate highland peat swamps on sandstone
- Cumberland plain woodland restoration
- Strategic adaptive management
- Limit to climate change adaption in floodplain wetlands - Macquarie Marshes
- Managing for ecosystem change in the greater blue mountains world heritage area
- Adaptive management of Ramsar Wetlands
- Managing for biodiversity in boom and bust cycle environments
- Submission on Biodiversity Act Review
- Marine ecosystems
-
Remote sensing and GIS
- Mangrove response to climatic variability
- Using radar satellite imagery to detect and monitor flooding in arid Australian wetlands
- Supporting continental retrieval of vegetation biophysical attributes
- The Injune Landscape Collaborative Project
- Tree species shifts in response to environmental change
- Regrowth mapping
- Regional biodiversity responses to climate change
- Will climate change affect the ecology of temporary lakes in Australia?
-
Rivers and wetlands
- Changes to the Darling River and Menindee Lakes – past, present and future
- Lowbidgee wetlands of the Murray-Darling Basin - The Nimmie-Caira
- A stitch in time – synergistic impacts to platypus metapopulation extinction risk
- Tube fishway project
- National waterbird survey
- Eastern Australian waterbird survey
- Feather map of Australia
- Life history and dynamics of a platypus (Ornithorhynchus anatinus) population: four decades of mark-recapture surveys
- Adequacy of environmental assessment of the proposed Macquarie River pipeline to the city of Orange
- Increasing production from inland aquaculture in Papua New Guinea for food and income security
- Aquaculture and environmental planning group
- Understanding soil-related constraints on aquaculture production in the highlands of Papua New Guinea
- Improving technologies for inland aquaculture in Papua New Guinea (ACIAR Project FIS2014062)
- Drying of ancient Thirlmere Lakes caused by human activities
- Application of GIS and remote sensing to assess sustainable mariculture and protect conservation zones
- Improving the sustainability of rice-shrimp farming systems in the Mekong Delta, Vietnam
- A SWOT analysis of Papua New Guinea’s inland fisheries and aquaculture sectors
- Carbon and floodplain biota in the Macquarie marshes
- Micro-invertebrate community dynamics and flooding in the Macquarie marshes
- Just add water? The effectiveness of environmental flows during wetland vegetation restoration
- Application of motion sensing cameras as a tool for monitoring riparian fauna
- Captive or wild?
- Brolga and Sarus crane diet comparison
- Lake Brewster pelican banding
- Aquatic invertebrate strategies for coping with drought
- Submission on Draft Lake Eyre Basin Strategic Plan
- The Menindee Lakes Water Savings Project – an example of poor decision-making
- Flow-MER
-
Terrestrial ecosystems
- Post-fire recovery of threatened ecological communities
- Environment Recovery Project: Australian bushfires
- Community stability of upland swamp vegetation
- An innovative approach to maximising catchment water yield in a changing climate
- Post-fire seed production in Hakea Gibbosa
- Managing fire regimes with thresholds to save threatened flora and fauna
- Stopping the toad
- Trophic cascades in NSW North Coast forests
- Individual hunting behavior in feral cats
- Mallee Ecosystem Dynamics
- Investigating artificial waterhole utilisation and management in north-eastern Botswana
- Investigating the spatial ecology, habitat use, behaviour, and ecosystem engineering of hippopotamus (Hippopotamus amphibius), a keystone species in the Okavango Delta and Chobe River, northern Botswana
- Does overgrazing reduce ecosystem functions
-
Study with us
- Courses
-
Postgraduate research projects
- Platypus breeding
- Maximising establishment success in reintroduced populations
- PhD scholarship saving our species - patch value, viability and resilience
- PhD scholarship – mechanics of species irruptions
- Conservation ecology of Greater bilby: survival, reproductive success and movement ecology in a breeding sanctuary in NSW
- Scientia PhD scholarship - Identifying healthy burning practices for Australia’s threatened plant species
- Scientia PhD scholarship - Ecosystem restoration through rewilding
- Platypus population health and dynamics
- Tackling prey naiveté in Australia’s endangered mammals
- Testate amoebae: a new biomarker of climate change and human impact in peatlands
- Surface water dynamics as a function of climate and river flow data
- Multisensor integration for environmental flows
- Response of northern Australian mangroves to climatic variability
- Comparative effects of extreme heat on threatened desert mammals
- Alumni - Where are they now?
- FAQ
- Workshops
- Our Impact
- News
- Wild Deserts
- Home
- About us
-
Our research
Conservation practice
- Water Information System for the Environment (WISE)
- Red list of ecosystems
- Shrub encroachment as a legacy of native mammal decline
- Foraging and habitat ecology of the yellow-tailed black-cockatoo
- Tackling prey naïveté in Australia’s threatened mammals
- Biodiversity sampling in Strzelecki Regional Reserve
- The reintroduction of locally extinct mammals: The landscape ecosystem approach
- The persistence of common wombats in road impacted environments
- Temperate highland peat swamps on sandstone
- Cumberland plain woodland restoration
- Strategic adaptive management
- Limit to climate change adaption in floodplain wetlands - Macquarie Marshes
- Managing for ecosystem change in the greater blue mountains world heritage area
- Adaptive management of Ramsar Wetlands
- Managing for biodiversity in boom and bust cycle environments
- Submission on Biodiversity Act Review
Remote sensing and GIS
- Mangrove response to climatic variability
- Using radar satellite imagery to detect and monitor flooding in arid Australian wetlands
- Supporting continental retrieval of vegetation biophysical attributes
- The Injune Landscape Collaborative Project
- Tree species shifts in response to environmental change
- Regrowth mapping
- Regional biodiversity responses to climate change
- Will climate change affect the ecology of temporary lakes in Australia?
Rivers and wetlands
- Changes to the Darling River and Menindee Lakes – past, present and future
- Lowbidgee wetlands of the Murray-Darling Basin - The Nimmie-Caira
- A stitch in time – synergistic impacts to platypus metapopulation extinction risk
- Tube fishway project
- National waterbird survey
- Eastern Australian waterbird survey
- Feather map of Australia
- Life history and dynamics of a platypus (Ornithorhynchus anatinus) population: four decades of mark-recapture surveys
- Adequacy of environmental assessment of the proposed Macquarie River pipeline to the city of Orange
- Increasing production from inland aquaculture in Papua New Guinea for food and income security
- Aquaculture and environmental planning group
- Understanding soil-related constraints on aquaculture production in the highlands of Papua New Guinea
- Improving technologies for inland aquaculture in Papua New Guinea (ACIAR Project FIS2014062)
- Drying of ancient Thirlmere Lakes caused by human activities
- Application of GIS and remote sensing to assess sustainable mariculture and protect conservation zones
- Improving the sustainability of rice-shrimp farming systems in the Mekong Delta, Vietnam
- A SWOT analysis of Papua New Guinea’s inland fisheries and aquaculture sectors
- Carbon and floodplain biota in the Macquarie marshes
- Micro-invertebrate community dynamics and flooding in the Macquarie marshes
- Just add water? The effectiveness of environmental flows during wetland vegetation restoration
- Application of motion sensing cameras as a tool for monitoring riparian fauna
- Captive or wild?
- Brolga and Sarus crane diet comparison
- Lake Brewster pelican banding
- Aquatic invertebrate strategies for coping with drought
- Submission on Draft Lake Eyre Basin Strategic Plan
- The Menindee Lakes Water Savings Project – an example of poor decision-making
- Flow-MER
Terrestrial ecosystems
- Post-fire recovery of threatened ecological communities
- Environment Recovery Project: Australian bushfires
- Community stability of upland swamp vegetation
- An innovative approach to maximising catchment water yield in a changing climate
- Post-fire seed production in Hakea Gibbosa
- Managing fire regimes with thresholds to save threatened flora and fauna
- Stopping the toad
- Trophic cascades in NSW North Coast forests
- Individual hunting behavior in feral cats
- Mallee Ecosystem Dynamics
- Investigating artificial waterhole utilisation and management in north-eastern Botswana
- Investigating the spatial ecology, habitat use, behaviour, and ecosystem engineering of hippopotamus (Hippopotamus amphibius), a keystone species in the Okavango Delta and Chobe River, northern Botswana
- Does overgrazing reduce ecosystem functions
-
Study with us
Postgraduate research projects
- Platypus breeding
- Maximising establishment success in reintroduced populations
- PhD scholarship saving our species - patch value, viability and resilience
- PhD scholarship – mechanics of species irruptions
- Conservation ecology of Greater bilby: survival, reproductive success and movement ecology in a breeding sanctuary in NSW
- Scientia PhD scholarship - Identifying healthy burning practices for Australia’s threatened plant species
- Scientia PhD scholarship - Ecosystem restoration through rewilding
- Platypus population health and dynamics
- Tackling prey naiveté in Australia’s endangered mammals
- Testate amoebae: a new biomarker of climate change and human impact in peatlands
- Surface water dynamics as a function of climate and river flow data
- Multisensor integration for environmental flows
- Response of northern Australian mangroves to climatic variability
- Comparative effects of extreme heat on threatened desert mammals
- Our Impact
- News
- Wild Deserts

Food-web dynamics and flooding regimes
A decade ago, researchers showed that waterbird densities, diversity and breeding declined in the Macquarie Marshes as river regulation and water abstractions increased and flooding reduced. It was also known that loss of flooding and extended drying on the Darling River floodplain reduced the density and diversity of microinvertebrates when sediments were inundated in the laboratory. We wanted to know whether microinvertebrates in the Macquarie Marshes were impacted by loss of flooding and if components of their food web were also impacted. Microinvertebrates are smaller than 250mm and include rotifers and microscopic crustaceans such as cladocerans (water fleas), ostracods, copepods.
Microinvertebrates play a key role in floodplain river food webs as prey to a wide range of fauna including native fish, waterbirds and macro-invertebrates, as well as being important consumers of algae, bacteria and biofilms. They form an important link between primary producers and higher trophic levels. Microinvertebrates contribute to biodiversity and their reproduction, growth, and recruitment is heavily influenced by flow regimes. This makes them good indicators for assessing the success or failure of flow restoration. They are also important in the life cycles of fish and both fish diversity and recruitment are strongly influenced by the availability of suitable food resources. Limited food supply of microinvertebrates is a key factor causing failed recruitment and high initial mortality of larval fish. Blooms of microinvertebrates are associated with better condition in some fish species particularly those utilising wetlands where densities of microinvertebrates are higher than in nearby river channel. Microinvertebrates pulse after floods and this higher food availability is associated with improved body condition of fish after floods compared to periods of low flow.
We compared floodplain sediments dry for 11, 4 and 1 year. We found that densities of microinvertebrates were extremely high, but that this food resource declined with loss of flooding. Further down the food web, loss of flooding also depleted organic matter and caused an earlier shift to oxygen production via photosynthesis of algae and a reduction in respiration (the breakdown of organic matter). Levels of organic carbon, phosphorous and nitrogen in the sediments and the water declined as the time without flooding extended. Microbial community composition involved in the breakdown of organic matter and the dominant algae both changed with loss of flooding. These observed changes indicate that after long periods without flooding, the lower food web will be less productive and diverse when flooding eventually occurs. There will be less food to support waterbirds and fish. As we finalise analysis of this study, we're developing thresholds of concern to trigger management action when densities and diversities of microinvertebrates or concentrations of nutrients fall to these critical levels.
Temporary versus constant flows: a flat-lined pulse
We compared floodplain sediments dry for 11, 4 and 1 year. We found that densities of microinvertebrates were extremely high, but that this food resource declined with loss of flooding. Further down the food web, loss of flooding also depleted organic matter and caused an earlier shift to oxygen production via photosynthesis of algae and a reduction in respiration (the breakdown of organic matter). Levels of organic carbon, phosphorous and nitrogen in the sediments and the water declined as the time without flooding extended. Microbial community composition involved in the breakdown of organic matter and the dominant algae both changed with loss of flooding. These observed changes indicate that after long periods without flooding, the lower food web will be less productive and diverse when flooding eventually occurs. There will be less food to support waterbirds and fish. As we finalise analysis of this study we are developing thresholds of concern to trigger management action when densities and diversities of microinvertebrates or concentrations of nutrients fall to these critical levels.
Floodplain inundation: a wetland springs to life
In the Macquarie Marshes, floods are associated with massive waterbird breeding events and a proliferation of wetland plants. When we looked beneath the surface, we also found remarkable productivity in the food webs that underpin waterbird communities. Densities of microinvertebrates were world renowned (10-20,000/litre) after an environmental allocation inundated floodplain along Gum Cowal and Bora Creeks in 2005. Nutrient levels pulsed and microbial activity was higher than we had previously observed in the constant creeks. Macroinvertebrate diversity was greater in floodplain habitats and along temporary creeks than observed in constant creeks. Our findings show that multiple levels of the food web thrive after floods to support waterbird breeding events. Our ongoing research is exploring the food web links between invertebrates, waterbirds, fish and plants after flooding.







