Iron sources and cycling in the Tasman Sea. Determining factors that influence the health and vitality of coastal and open-ocean regions is crucial to maintaining marine biodiversity and the Earth's climatic balance. This research project will determine the role iron plays in influencing phytoplankton growth, which ultimately regulates the drawdown of carbon dioxide by the oceans.
Bubble, Bubble CO2 is the trouble: A Natural Ocean Acidification Experiment in a coral reef setting. Carbon dioxide seep sites expose shallow coral reefs in Papua New Guinea to volcanic carbon dioxide resulting in gradients of seawater ranging from pH 8.0 (normal) to a more acidic pH of 7.5. Some areas of these reefs experience carbon dioxide exposure equivalent to IPCC predictions for 2050 and 2100. This project will reconstruct seawater pH using radiocarbon as a novel tracer of carbon dioxide ....Bubble, Bubble CO2 is the trouble: A Natural Ocean Acidification Experiment in a coral reef setting. Carbon dioxide seep sites expose shallow coral reefs in Papua New Guinea to volcanic carbon dioxide resulting in gradients of seawater ranging from pH 8.0 (normal) to a more acidic pH of 7.5. Some areas of these reefs experience carbon dioxide exposure equivalent to IPCC predictions for 2050 and 2100. This project will reconstruct seawater pH using radiocarbon as a novel tracer of carbon dioxide input at a coral reef site that has been exposed to high carbon dioxide due to volcanic seeps (seep carbon dioxide has no carbon-14) for an unknown period of time (at least many decades, but possibly centuries). These results will help to understand the time it takes to change calcifying organisms into “winners” or “losers” as an analog for Ocean Acidification due to increased atmospheric carbon dioxide input.Read moreRead less
Deep-sea carbonate cycles and their role in glacial-interglacial atmospheric CO2 changes. The causes for past atmospheric carbon dioxide (CO2) changes and their mechanistic links to the histories of climate and ocean carbonate chemistry remain elusive, but may hold future-relevant information. This project aims to use novel methods to quantify deep ocean carbonate ion concentrations, a critical but poorly constrained parameter of the global carbon cycle, at 10 key locations spanning the global o ....Deep-sea carbonate cycles and their role in glacial-interglacial atmospheric CO2 changes. The causes for past atmospheric carbon dioxide (CO2) changes and their mechanistic links to the histories of climate and ocean carbonate chemistry remain elusive, but may hold future-relevant information. This project aims to use novel methods to quantify deep ocean carbonate ion concentrations, a critical but poorly constrained parameter of the global carbon cycle, at 10 key locations spanning the global ocean during the last 350 000 years. By feeding new data into a model, this project aims to gain critical insights into mechanisms controlling past deep-sea carbonate cycles and atmospheric CO2 changes, thereby leading to improved understandings of the climate system.Read moreRead less
Impact of increased sediment and nutrient discharges on the long-term sustainability of the Great Barrier Reef. The Great Barrier Reef, one of Australia's greatest natural assets, is under increasing threat from extreme climatic events caused by global warming and from land-based pollution. This research will identify the main sources of sediment and nutrient pollution caused by river runoff and by how much this has increased above 'natural levels'. We will discover how the very sensitive offsho ....Impact of increased sediment and nutrient discharges on the long-term sustainability of the Great Barrier Reef. The Great Barrier Reef, one of Australia's greatest natural assets, is under increasing threat from extreme climatic events caused by global warming and from land-based pollution. This research will identify the main sources of sediment and nutrient pollution caused by river runoff and by how much this has increased above 'natural levels'. We will discover how the very sensitive offshore coral reefs have responded to increased pollution and whether this is the cause of the very devastating crown-of-thorn-starfish infestations. Understanding the long-term effects of land-based pollution on the ecology of coral reefs in the GBR will thus provide a scientific basis to help ensure that it has a sustainable future.Read moreRead less
Holding coral reefs together with soluble cement. This project aims to characterise and understand cement formation in coral reefs. Coral reefs are constructed by cementing together aragonite building blocks made by corals. The main cementing agent is high-magnesium calcite, the most soluble carbonate mineral and susceptible to ocean acidification. High-magnesium calcite cements are best developed on the high energy margins of coral reefs. This project will quantify how crustose coralline algae ....Holding coral reefs together with soluble cement. This project aims to characterise and understand cement formation in coral reefs. Coral reefs are constructed by cementing together aragonite building blocks made by corals. The main cementing agent is high-magnesium calcite, the most soluble carbonate mineral and susceptible to ocean acidification. High-magnesium calcite cements are best developed on the high energy margins of coral reefs. This project will quantify how crustose coralline algae produces high-magnesium calcite and controls the dissolution and reprecipitation of high-magnesium cements. This project intends to quantify rates of reef cementation, susceptibility to ocean acidification and warming, and possible mitigating effects of alkalinity addition.Read moreRead less
Hot iron: Are submarine volcanoes important for Southern Ocean iron supply? The scarcity of iron limits biological productivity and carbon uptake in the nutrient rich waters of the Southern Ocean. This project will explore for the first time the role of undersea "hot spot" volcanoes in supplying iron to surface waters, thus linking the solid earth and the biosphere. The project will measure iron abundance, reactivity and nutritional value in buoyant plumes emanating from vents near Heard/McDonal ....Hot iron: Are submarine volcanoes important for Southern Ocean iron supply? The scarcity of iron limits biological productivity and carbon uptake in the nutrient rich waters of the Southern Ocean. This project will explore for the first time the role of undersea "hot spot" volcanoes in supplying iron to surface waters, thus linking the solid earth and the biosphere. The project will measure iron abundance, reactivity and nutritional value in buoyant plumes emanating from vents near Heard/McDonald Islands, Australia's only active volcanoes. The project aims to estimate the hydrothermal contribution to regional biological productivity and extrapolate to the whole Southern Ocean. Successful outcomes will benefit Australia by identifying iron sources that govern productivity and carbon uptake of an economically important ecosystem.Read moreRead less
Calcification and shell chemistry response of Southern Ocean planktic foraminifers to ocean acidification and changing climates. Plankton that form tiny calcium carbonate shells will be cultured to determine how they will respond to acidification of the Southern Ocean caused by rising CO2 in the atmosphere. The same experiments will be used to gauge from their fossil shells how the Southern Ocean has caused and responded to changing atmosphere CO2 over the last glacial climate cycle
A changing climate for calcification on the Great Barrier Reef: past, present and future. The Great Barrier Reef (GBR) is a national and international icon, recognised through its inscription as a World Heritage Area and economic and social value to Australians. Maintenance of the GBR as we know it is now compromised by a rapidly changing climate. Ocean acidification, warming water temperatures and increased freshwater will progressively be detrimental to the fundamental reef-building process ....A changing climate for calcification on the Great Barrier Reef: past, present and future. The Great Barrier Reef (GBR) is a national and international icon, recognised through its inscription as a World Heritage Area and economic and social value to Australians. Maintenance of the GBR as we know it is now compromised by a rapidly changing climate. Ocean acidification, warming water temperatures and increased freshwater will progressively be detrimental to the fundamental reef-building process of calcification. Informed policy and management strategies in a rapidly changing physical environment require determination, for short and long time frames, of the regional consequences and impacts of changing reef-building capacity.Read moreRead less