Habitats serve a variety of functions on the North West Shelf (NWS). They support the life history stages of a diverse suite of tropical species including commercially harvested ones. In addition to natural disturbance regimes, habitats are altered in response to the sectoral uses, which in turn affects the distribution and life histories of species. Habitats thus serve as the nexus linking species with uses and natural disturbance, and different habitats serve different purposes at various stages of the life history of a species. A detailed understanding of habitats, at least at the structural level, is thus a prerequisite for a more comprehensive understanding of ecological structure and functions on the North West Shelf. This component of the North West Shelf Joint Environmental Management Study (NWSJEMS) aimed to collate and integrate data on habitats for the region of the North West Shelf extending from North West Cape to Port Hedland and from the coast to the 200 m isobath. The three main activities of the study were: Development of an integrated collection of information on habitats of the North West Shelf, including expert information; Application of the CSIRO Habitat Classification Framework to the data to determine the spatial nesting and structuring of habitat units on the North West Shelf; and Provision of the habitat structure classification for input into other models developed within NWSJEMS. This record describes data of key benthic marine ecosystems and habitats. These maps and descriptions of their component attributes were designed to assist the process modelling of the ecosystem and impacts of uses, as well as directly supporting planning and management by Western Australian agencies and industries.

This metadata record supports the following paper (abstract below): Green, D.B., Bestley, S., McMahon, C.R., Lea, M.A., Harcourt, R.G., Guinet, C. and Hindell, M.A., 2025. Elephant seal dive behaviour responds consistently to changes in foraging success regardless of sex or ocean habitat. PeerJ, 13, p.e20378. https://doi.org/10.7717/peerj.20378 This metadata record links to a Figshare repository that includes the analysis dataset along with workflows (and a readme) for creating it, running the analyses within the paper, and reproducing the figures. A complete record of the seal tracking data supporting this study can be found on the IMOS AODN data portal, along with additional data on depth, temperature and salinity collecetd by the seal tags. This can be accessed through the following URL: https://portal.aodn.org.au/search, and selecting the side tabs: "Biological platforms" --> "land-sea mammals" Paper Abstract Understanding how air-breathing diving animals moderate their dive behaviour when foraging successfully is foundational in the study of their foraging ecology. Yet, this fundamental relationship remains unresolved with previous research pointing to inconsistent relationships, differing nominally according to sex, habitat type and scale. Empirically testing the relationships between dive effort responses and foraging success is further hampered because of challenges obtaining concurrent measures of behavioural responses and foraging success at sea. We compiled a multi-decadal dive dataset from 609 southern elephant seals, including their dive responses (transit rate, and relative dive and surface recovery duration) and buoyancy – changes in which provide an indirect measure of body condition change and foraging success. Using this dataset, we tested how seal dive behaviour alters when foraging remotely at sea. We found that as foraging success increased, seals increased transit (ascent, descent) rates and decreased relative dive durations for a given depth, with no response in surface recovery. Our results were consistent across sexes and foraging habitats, and account for the general effects of buoyancy on dive behaviour. The homogeneity of these findings suggests that there is a general functional response in which elephant seals perform, on average, shorter, steeper dives during periods of successful foraging. Importantly, we can align these results with predictions from the marginal value theorem (MVT), that a forager should remain in a patch only until gains drop below the neighbourhood mean. Our findings have broad-based implications for how ecologists interpret dive responses of wild marine animals, demonstrating the value of seeking independent in situ information on foraging success.

Gillnet fishing trials at a number of sites off the east coast of Tasmania have been undertaken to collect samples of the banded morwong, which are characterised based on size, age, maturity stage and sex structure. Otoliths are sectioned for age determination. The dataset comprises a major component of work carried out from the beginning of 2001 and available historic data (1995 to 2000) have also been uploaded into this database to provide a complete dataset. See attached reports for further information.

Understanding the patterns and characteristics of sedimentary deposits on the conjugate Australian-Antarctic margins is critical to reveal the Cretaceous-Cenozoic tectonic, oceanographic and climatic conditions in the basin. However, unravelling its evolution has remained difficult due to the different seismic stratigraphic interpretations on each margin and sparse drill sites. Here, for the first time, we collate all available seismic reflection profiles on both margins and use newly available offshore drilling data, to develop a consistent seismic stratigraphic framework across the Australian-Antarctic basins. We find sedimentation patterns similar in structure and thickness, prior to the onset of Antarctic glaciation, enabling the basin-wide correlation of four major sedimentary units and their depositional history. We interpret that during the warm and humid Late Cretaceous (~83-65 Ma), large onshore river systems on both Australia and Antarctica resulted in deltaic sediment deposition offshore. We interpret that the onset of clockwise bottom currents during the Early Paleogene (~58-48 Ma) formed prominent sediment drift deposits along both continental rises. We suggest that these currents strengthened and progressed farther east through the Eocene. Coevally, global cooling (<48 Ma) and progressive aridification led to a large-scale decrease in sediment input from both continents. Two major Eocene hiatuses recovered by the IODP site U1356A at the Antarctic continental slope likely formed during this pre-glacial phase of low sedimentation and strong bottom currents. Our results can be used to constrain future paleo-oceanographic modelling of this region and aid understanding of the oceanographic changes accompanying the transition from a greenhouse to icehouse world.