Southern Ocean Ecosystems: Environmental Change and Conservation

Research aims to understand the impact of global change on Southern Ocean ecosystems. Photo: AAD

Like marine ecosystems world-wide, the Southern Ocean faces many threats and conservation issues as a result of physical, chemical and biological changes. These changes are already occurring and will continue to occur because of fishing, climate change and ocean acidification. Changes to Southern Ocean ecosystems have consequences for the global carbon cycle, the conservation of threatened and depleted marine species and for the sustainable exploitation of fisheries.

Scientific research under this theme is helping scientists understand the impact of global change on Southern Ocean ecosystems, the effective conservation of Antarctic and Southern Ocean wildlife and the sustainable, ecosystem-based management of Southern Ocean fisheries.

The research is divided into four streams:

• Marine ecosystem change
• Wildlife conservation
• Southern Ocean fisheries
• Protecting marine biodiversity

The health and conservation of Southern Ocean ecosystems is important to a number of international treaty bodies and inter-governmental initiatives, including the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR), the International Whaling Commission (IWC), Agreement on the Conservation of Albatrosses and Petrels (ACAP), the Australian Fisheries Management Authority (AFMA) and the Intergovernmental Panel on Climate Change (IPCC). This theme will address strategic needs identified by these peak bodies, as well as national priorities.

This pteropod, Clio pyramidata antarctica, is one species that may be affected by ocean acidification. Photo: Keith Martin-Smith

The research will:

• Improve understanding of the impacts of ocean acidification on selected biota and ecosystems of the Southern Ocean, including assessment of their resilience to predicted change scenarios.
• Identify sensitive marine indicator species or systems for tracking and understanding the impacts of environmental change.
• Assess the risks of global change impacts on Southern Ocean ecosystems and species of high conservation or fisheries value. This includes evaluating the probability of different food web structures arising under predicted changes in the ocean and sea ice systems.
• Improve knowledge about the status and trends of important Antarctic wildlife populations (whales, seals and seabirds), leading to improved conservation planning and management measures.
• Improve scientific information for fisheries managers (including strategies to reduce bycatch) and integration of fisheries data into ecosystem models to assist in management decisions.
• Design a comprehensive, adequate and representative network of spatial management areas. These include marine protected areas in the Southern Ocean (and within the CCAMLR Area), particularly focusing on the marine biodiversity in the waters off East Antarctica.

Monitoring of key ecosystem components is a fundamental part of this research theme. For the past 20 years the Australian Antarctic Division’s Southern Ocean ecosystems research has supported a number of strategic monitoring initiatives for individual species, communities and whole ecosystems. These include plankton surveys, underway sampling from research vessels, land-based monitoring of Adelie penguin populations, and fish and baleen whale population surveys. Data from this work will provide the foundations for analyses for the first few years of the science strategic plan. The results of these analyses will guide future monitoring programs.

Theme leaders:  Dr Andrew Constable and Dr Bill de la Mare