Microscale insights into ocean-scale processes: microbial behaviour as a driver of ocean biogeochemistry. Microscopic plankton regulate the ocean's chemical cycles, which ultimately support life on earth. However, the ecological interactions driving these processes are poorly understood. This project will use novel approaches to decipher the behaviours of marine microbes, providing a more complete perception of how ocean ecosystems operate and influence climate.
Benthic Processes and Oceanic Internal Waves. Direct observations will be made of the turbulent motion and sediment re-suspension near the sea bed of the ocean in regions strongly influenced by tides and internal waves. Combined with numerical models, the study will provide new insights into processes that are of fundamental importance to understanding the global dissipation of tidal energy and the role of internal waves in these processes. With observations from the continental slope region of ....Benthic Processes and Oceanic Internal Waves. Direct observations will be made of the turbulent motion and sediment re-suspension near the sea bed of the ocean in regions strongly influenced by tides and internal waves. Combined with numerical models, the study will provide new insights into processes that are of fundamental importance to understanding the global dissipation of tidal energy and the role of internal waves in these processes. With observations from the continental slope region of the Australian North West Shelf, results will also benefit the offshore engineering industry through knowledge of sediment scour and loadings on offshore structures.Read moreRead less
Abrupt Southern Hemisphere Climate Change: The Role Of The Southern Ocean Thermohaline Circulation. Australia's climate is extreme, with harsh droughts, severe bushfire seasons, climate change, soil loss, and salinity all posing potentially enormous socio-economic challenges over the next ten-fifty years. Research into climate change and climate variability is thus highly significant for Australia, and will underpin efforts to protect our biodiversity and ensure the nation's environmental sustai ....Abrupt Southern Hemisphere Climate Change: The Role Of The Southern Ocean Thermohaline Circulation. Australia's climate is extreme, with harsh droughts, severe bushfire seasons, climate change, soil loss, and salinity all posing potentially enormous socio-economic challenges over the next ten-fifty years. Research into climate change and climate variability is thus highly significant for Australia, and will underpin efforts to protect our biodiversity and ensure the nation's environmental sustainability. We propose to launch a major new study of the stability of the Southern Ocean's thermohaline circulation and its role in global climate. This work could have significant long-term benefits for those sectors of society sensitive to shifts in climate; including agriculture, energy, freshwater supply, health, and tourism.Read moreRead less
Ocean-reef interactions as drivers of continental shelf productivity in a changing climate. Poor coastal management results in the irreparable destruction of reef systems' function and biodiversity, nationally and globally. To manage marine resources effectively we must implement sustainable practices, including forward planning in the context of climate change. A critical limitation in determining appropriate actions is a poor understanding of mechanisms driving productivity. Our project will p ....Ocean-reef interactions as drivers of continental shelf productivity in a changing climate. Poor coastal management results in the irreparable destruction of reef systems' function and biodiversity, nationally and globally. To manage marine resources effectively we must implement sustainable practices, including forward planning in the context of climate change. A critical limitation in determining appropriate actions is a poor understanding of mechanisms driving productivity. Our project will provide key information on the oceanographic mechanisms supporting Australia's coastal systems, linking nutrient supply, physical drivers and climate. By linking all these factors we will both assist in determining appropriate ecosystem management, and provide a knowledge base to support adaptation to future changes in Australia's climate.Read moreRead less
Development of a mechanistic model of marine biological activity. The development of predictive models of marine biological activity lags that in physical oceanography. While modellers of ocean circulation use primarily physical laws, biological processes have typically been modelled using empirical approximations. Many biological processes in the ocean, however, are constrained by quantifiable biophysical limits. This study aims to improve our ability to predict the dynamics of biological po ....Development of a mechanistic model of marine biological activity. The development of predictive models of marine biological activity lags that in physical oceanography. While modellers of ocean circulation use primarily physical laws, biological processes have typically been modelled using empirical approximations. Many biological processes in the ocean, however, are constrained by quantifiable biophysical limits. This study aims to improve our ability to predict the dynamics of biological populations in the marine environment by the development of a model based on mechanistic descriptions of organisms interacting with their environment. The model's performance will be assessed by its ability to predict in situ and remotely sensed data from Australian waters.Read moreRead less
Quantifying the role of salps in marine food webs and organic carbon export. Australia has recently committed significant resources to the observation and forecasting of ocean temperature and circulation that will vastly improve the understanding of environmental forcing of regional scale biological processes. This project will use ocean circulation hindcasts, ship-board measurements and laboratory studies to capture the dynamics of the zooplankton community, and in particular a fast-growing cla ....Quantifying the role of salps in marine food webs and organic carbon export. Australia has recently committed significant resources to the observation and forecasting of ocean temperature and circulation that will vastly improve the understanding of environmental forcing of regional scale biological processes. This project will use ocean circulation hindcasts, ship-board measurements and laboratory studies to capture the dynamics of the zooplankton community, and in particular a fast-growing class of gelatinous zooplankton, the salps, in the waters off southeast Australia. During bloom events, salps can alter the functioning of marine ecosystems. This project will quantify the impact of salp blooms on fish resources and ocean uptake of carbon in southeast Australian waters.Read moreRead less
Resolving uncertainty over the importance of N-fixation versus denitrification in coastal systems. Nutrient enrichment of coastal waters is a significant national and international problem requiring urgent action. Despite many studies and many millions of dollars in research funding we know virtually nothing about the relative importance of the major nitrogen cycling pathways, N-fixation and denitrification. Many hundred's of millions of dollars are likely to be spent over the next ten years on ....Resolving uncertainty over the importance of N-fixation versus denitrification in coastal systems. Nutrient enrichment of coastal waters is a significant national and international problem requiring urgent action. Despite many studies and many millions of dollars in research funding we know virtually nothing about the relative importance of the major nitrogen cycling pathways, N-fixation and denitrification. Many hundred's of millions of dollars are likely to be spent over the next ten years on the management of nitrogen enrichment of Australia's coastal waters. This study will use a new method for directly measuring N-fixation to resolve uncertainty over the importance of N-fixation versus denitrification in coastal systems; information which is critical for the efficient allocation of management resources.Read moreRead less
Mapping and Modelling the Ocean's Unseen Biodiversity. From the reef to the rainforest, Australia is famous for its unique biodiversity. Less well known is that Australia's coastline is predicted to be a global hotspot for biodiversity in marine microbes, the unseen life forces that maintain ocean health and productivity. This project aims to overcome historical technological and logistical hurdles by using cutting-edge sampling, genetic and modelling tools to provide the first models of microbi ....Mapping and Modelling the Ocean's Unseen Biodiversity. From the reef to the rainforest, Australia is famous for its unique biodiversity. Less well known is that Australia's coastline is predicted to be a global hotspot for biodiversity in marine microbes, the unseen life forces that maintain ocean health and productivity. This project aims to overcome historical technological and logistical hurdles by using cutting-edge sampling, genetic and modelling tools to provide the first models of microbial diversity patterns and organismal range in Australian marine systems. This is expected to be a crucial step for understanding the evolutionary and ecological processes that shape contemporary biodiversity.Read moreRead less
Mechanisms of Iron Acquisition by the Cyanobacterium Trichodesmium in Coastal Waters. The toxic cyanobacterium Trichodesmium is the most conspicuous phytoplankter in Great Barrier Reef waters which, as a nitrogen fixer, produces and biologically packages "new" nitrogen into forms potentially available to other marine organisms and, as such, is likely to be a key driver of food web dynamics on the GBR. In this study, we will clarify the mechanism by which the critical nutrient iron is acquired by ....Mechanisms of Iron Acquisition by the Cyanobacterium Trichodesmium in Coastal Waters. The toxic cyanobacterium Trichodesmium is the most conspicuous phytoplankter in Great Barrier Reef waters which, as a nitrogen fixer, produces and biologically packages "new" nitrogen into forms potentially available to other marine organisms and, as such, is likely to be a key driver of food web dynamics on the GBR. In this study, we will clarify the mechanism by which the critical nutrient iron is acquired by this organism and, in so doing, assess the role that terrestrial activities play in iron supply.Read moreRead less
Factors influencing the bioavailability of iron in marine waters. Strong evidence now exists that iron availability controls the productivity and species composition of planktonic organisms in open oceans and coastal and estuarine environments. The mechanisms by which iron is rendered available and induces growth remain unclear but appear to involve, in many instances, light and both generic and specific organic complexants of iron. In this study, we investigate the effect of selected naturally ....Factors influencing the bioavailability of iron in marine waters. Strong evidence now exists that iron availability controls the productivity and species composition of planktonic organisms in open oceans and coastal and estuarine environments. The mechanisms by which iron is rendered available and induces growth remain unclear but appear to involve, in many instances, light and both generic and specific organic complexants of iron. In this study, we investigate the effect of selected naturally occurring complexants on redox transformations of iron with particular emphasis given to the potential ability of organics and light to increase the bioavailability of iron.Read moreRead less