The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

The Australian Submarine Canyons service identifies the location of 753 submarine canyons surrounding mainland Australia and its external territories, with associated metrics.

This data represents the average time between events when the Shields parameter (Shields, 1936) exceeds 0.25 based on a Peaks-Over-Thresholds (POT) analysis. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. The unit for the dataset is day. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f'ur Wasserbau und Schiffbau 26: 5-24

This data represents a dimensionless ecological disturbance index, as the ratio of ecological succession and disturbance recurrence interval times the fraction of the area disturbed in any event. Small values of the ecological disturbance index represent decreasing proportions of time when disturbed/recovering habitats are present.

<div>Australia’s vast marine estate offers high-quality offshore wind resources that have the potential to help produce the renewable energy that Australia will need to achieve its net zero emissions targets. Mature offshore renewable industries in Europe have demonstrated that marine geoscience is critical for supporting the sustainable development, installation, operation and decommissioning of offshore wind farms. Geoscience information is used to design targeted seabed surveys and identify areas suitable for offshore infrastructure, thereby reducing uncertainty and investment risk. These data also provide important regional context for environmental impact assessments and informs evidence-based decisions consistent with government policies and regulations. Effective geomorphic characterisation of the seabed requires a standardised, multi-scalar and collaborative approach to produce definitive geomorphology maps that can support these applications. These maps synthesise interpretations of bathymetry, shallow geology, sedimentology and ecology data, to illustrate the distribution and diversity of seabed features, compositions and processes, including sediment dynamics and seabed stability. We present mapped examples demonstrating the utility of a nationally consistent seabed geomorphology mapping scheme (developed in collaboration with European agencies), for application to a broad range of geographic settings and policy-needs, including the sustainable development of offshore renewable energy in Australia. Presented at the 2024 AMSA-NZMSS Conference Hobart Tas

Australia’s marine jurisdiction covers over 10 million square kilometres, and we estimate that only 25% of its seafloor has been mapped to the adequate resolution required to support the sustainable development and management of our marine estate. Considering that seabed mapping underpins most aspects of ocean sciences and engineering, and contributes strongly to Australia’s economic, environmental and social values, it is critical that we address this fundamental knowledge gap. AusSeabed was founded three years ago—a cross sector collaborative national program aimed at coordinating ocean mapping efforts to maximise benefits to stakeholders. AusSeabed is working to address many challenges surrounding efficient data acquisition, quality assurance, processing and delivery to various end-users with an aim to eliminate duplication of effort and improve data quality and consistency across sectors. A fundamental component of the AusSeabed program is the design and development of a federated, cloud-based, open-source platform to address the whole supply chain from data acquisition to delivery. Importantly, this work is enabling seamless collation of seabed mapping datasets and their integration with other marine data types from a variety of previously isolated and inaccessible holdings. Strong community commitment and a powerful resonance with stakeholders have driven rapid program growth and are a testament to the value of deliberate and effective collaboration for national benefit. This presentation will give an overview of AusSeabed’s current progress, highlights and forward plan.

Dense water formed in the Mertz Polynya supplies the lower limb of the global overturning circulation and ventilates the abyssal Indian and Pacific Oceans. In February 2010, an 80 km section of the Mertz Glacier Tongue calved, altering the regional distribution of ice, and the polynya activity. After calving, the absolute salinity and density of dense shelf water decreased abruptly, and surface waters freshened by up to 1 g kg-1. Break-out and melt of thick multi-year sea ice, likely rich in iron, provided a favourable light and nutrient setting for a bloom of large diatoms, doubling carbon uptake relative to pre-calving conditions. These observations highlight the sensitivity of bottom water formation, biogeochemical cycles and biological productivity to changes in the Antarctic icescape.

This data represents the integrated Shields (Shields, 1936) parameter exceeding 0.25 divided by the integrated total Shields parameter. The Shields parameter (non-dimensional bed shear stress) value of 0.25 is assumed to be the threshold for creating disturbed patches. This value is several times larger than that required to initiate traction bedload transport (~0.05) and falls in the middle of the ripple and dune bedform stability field. It represents conditions when the seabed is highly mobile and where patches of disturbed habitat are likely to be created. Shields, A. 1936. Application of similarity principles and turbulence research to bed-load movement. Mitteilunger der Preussischen Versuchsanstalt f¨ur Wasserbau und Schiffbau 26: 5-24

<div>The development of Australia’s offshore renewable energy (ORE) industry can learn and benefit from decades of international experience and research. However, local knowledge of our unique receiving environment and the organisms that depend on it is critical for ensuring development minimises impacts on marine ecosystems. Long-term monitoring and adaptive management strategies that consistently evaluate and address environmental impacts of offshore wind farms will be necessary throughout the operational lifespan of ORE. This collaborative National Environmental Science Program project established an inventory of environmental and cultural data and best practice monitoring standards to support regulatory decision-making for ORE development for current proposed and declared areas: Hunter, Gippsland and Bass Strait, Illawarra, Southern Ocean and south-west Western Australia. We provide detail on 1) potential impacts of installation, operation, and decommissioning; 2) best practice standards for monitoring; 3) cultural and environmental values of Indigenous communities with links to development areas; 4) seabed geomorphology and habitat characterisation; potential interactions with oceanography and 5) the seasonality and distribution of interacting species. The inventory, which is available to the Government, proponents, and researchers, will improve the effectiveness of future research for the sustainable development of ORE in Australia. Presented at the 2024 AMSA-NZMSS Conference Hobart Tas