Southern Ocean oxygen variability since the last glacial maximum. Recently observed decreases in ocean oxygen concentration could decrease ocean biodiversity and accelerate climate change. This project will determine the links between climate change and ocean oxygenation since the last ice age, and provide a way to predict future oxygen concentrations.
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
Examining the vulnerability of ocean carbon biogeochemistry in a high CO2 world. Rising CO2 levels in the atmosphere from human activity is changing the biogeochemistry of the ocean, with large potential consequences on future atmospheric CO2. This work will explore these changes and will result in a more complete understanding of how the ocean will either accelerate or delay the increase in atmospheric CO2.
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
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
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.
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