Ocean Acidification in a Rapidly Increasing CO2 World. Carbon dioxide not only acts as a greenhouse gas but is being dissolved at increasing rates into the surface waters of the world's oceans, causing ocean acidity. We will examine how the rapidly increasing trend towards acidity in the oceans surrounding Australia is effecting the ability of marine organisms to calcify and determine the rate at which the world's ocean sink for CO2 is being reduced. New constraints will be placed on the critica ....Ocean Acidification in a Rapidly Increasing CO2 World. Carbon dioxide not only acts as a greenhouse gas but is being dissolved at increasing rates into the surface waters of the world's oceans, causing ocean acidity. We will examine how the rapidly increasing trend towards acidity in the oceans surrounding Australia is effecting the ability of marine organisms to calcify and determine the rate at which the world's ocean sink for CO2 is being reduced. New constraints will be placed on the critical threshold limits of CO2 emissions for sustainable calcification in both shallow tropical and deep-water marine ecosystems of the Southern Oceans.Read moreRead less
Probing the response of Southern Ocean phytoplankton to changes in iron biogeochemistry, light and pH associated with climate change. 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 climate change and ocean acidification will have on the ability of Southern Ocean phytoplankton to flourish.
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
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
The Southern Ocean's role in determining atmospheric CO2 levels: new insights from novel biogenic silica records of seawater pH. About half the emissions from the burning of fossil fuel since the Industrial Revolution have been absorbed by the oceans. However, considerable uncertainty surrounds the consequences of and the extent to which the oceans will continue to sequester CO2 into the future. This research will improve existing limited knowledge of the key biological and related ocean process ....The Southern Ocean's role in determining atmospheric CO2 levels: new insights from novel biogenic silica records of seawater pH. About half the emissions from the burning of fossil fuel since the Industrial Revolution have been absorbed by the oceans. However, considerable uncertainty surrounds the consequences of and the extent to which the oceans will continue to sequester CO2 into the future. This research will improve existing limited knowledge of the key biological and related ocean processes that transfer CO2 between the surface and depth, and the poorly understood effects on marine ecosystems of increasing ocean acidity due to CO2 absorption. This knowledge will contribute to predicting the course of future climate change and gauging the impacts on marine life and production systems.Read moreRead less
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
Deciphering strategies polar phytoplankton employ to lessen iron limitation. The Southern Ocean is of global importance. It comprises one-third of the global ocean by area and disproportionately absorbs two-thirds of anthropogenic ocean heat and half of anthropogenic carbon dioxide (CO2) emissions even though phytoplankton in this region are chronically iron-limited. This project aims to understand why copper uptake by phytoplankton lessens the effects of iron limitation and how copper substitut ....Deciphering strategies polar phytoplankton employ to lessen iron limitation. The Southern Ocean is of global importance. It comprises one-third of the global ocean by area and disproportionately absorbs two-thirds of anthropogenic ocean heat and half of anthropogenic carbon dioxide (CO2) emissions even though phytoplankton in this region are chronically iron-limited. This project aims to understand why copper uptake by phytoplankton lessens the effects of iron limitation and how copper substitutes for iron. This knowledge is critical for evaluating the impacts and feedbacks between iron and copper in regulating Southern Ocean productivity and ultimately its ability to drawdown atmospheric CO2. The results from this project will facilitate the development of improved ecosystem models and conservation tools.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
How iron is cycled in Southern Ocean waters. This project aims to probe the Southern Ocean phytoplankton’s ability to take up and retain iron, using iron isotope tracer techniques. The Southern Ocean regulates Earth's climate, but the supply of iron to Southern Ocean surface waters is low, restricting the ability of phytoplankton to flourish and draw down carbon dioxide. The results are expected to reveal survival strategies of phytoplankton in this iron-poor environment and their potential abil ....How iron is cycled in Southern Ocean waters. This project aims to probe the Southern Ocean phytoplankton’s ability to take up and retain iron, using iron isotope tracer techniques. The Southern Ocean regulates Earth's climate, but the supply of iron to Southern Ocean surface waters is low, restricting the ability of phytoplankton to flourish and draw down carbon dioxide. The results are expected to reveal survival strategies of phytoplankton in this iron-poor environment and their potential ability to adapt to environmental change. This knowledge could be used to develop models to manage this climate-sensitive region.Read moreRead less
DEEP SEA CORALS AS HIGH RESOLUTION RECORDERS OF SOUTHERN OCEAN NUTRIENT CHEMISTRY AND CIRCULATION. There is compelling evidence that the Earth has been warming dramatically since the end of the 19th century as a consequence of increasing atmospheric CO2. This study aims to understand the long-term role of the Southern Ocean as a 'store-house' for CO2, and its significance in controlling changes in the Earth's climate. We will use coral skeletons from the deep oceans as archives of ocean circu ....DEEP SEA CORALS AS HIGH RESOLUTION RECORDERS OF SOUTHERN OCEAN NUTRIENT CHEMISTRY AND CIRCULATION. There is compelling evidence that the Earth has been warming dramatically since the end of the 19th century as a consequence of increasing atmospheric CO2. This study aims to understand the long-term role of the Southern Ocean as a 'store-house' for CO2, and its significance in controlling changes in the Earth's climate. We will use coral skeletons from the deep oceans as archives of ocean circulation and nutrient levels. This information will help unravel how biological activity in the Southern Ocean has responded during previous episodes of climate change, and how this has controlled the levels of CO2 in the Earth's atmosphere. This will provide a better understanding of greenhouse warming and its effect on our future climate.Read moreRead less