Wedge-tailed shearwaters (Ardenna pacifica) are widely distributed across tropical and subtropical oceans, with their breeding range recently extending south. For populations at their southernmost extent, habitat use, segregation, and trophic niche remain poorly understood. In this study we investigated the habitat use, segregation, and trophic niche in two disjunct populations of wedge-tailed shearwaters in eastern Australia, located at temperate and subtropical latitudes, between 2015 and 2019. Both populations exhibited consistent spatial segregation across all years of the study. Individuals from the temperate population consistently used waters off southeastern Australia, with a pre-staging detour towards the subtropical frontal zone before their winter migration to the western Pacific Ocean, in the Philippine Sea. At the same time, subtropical conspecifics exploited waters further east and north, with a proportion undertaking a pre-staging detour only in the first year. Stable isotope analysis (δ15N and δ13C) of chick feathers further revealed trophic and habitat segregation between colonies, with the subtropical population consistently occupying a smaller trophic niche area and exhibiting lower interannual variation across all years. Both populations exhibited a high degree of interannual variability in foraging strategies and trophic niches, indicating a capacity for behavioural adaptivity in response to prey availability and oceanic conditions. This adaptability may facilitate future range shifts into temperate habitats, which is important given projected climate-driven changes to ocean dynamics in southeastern Australia.

This resource is a map of Aboriginal, Torres Strait Islander body (RATSIB) is a body recognised by the Commonwealth under s 203AD of the NTA to represent native title holders and persons who may hold native title and to consult with Aboriginal and Torres Strait Islander persons within a specified area. The statutory functions of RATSIBs are detailed in Part 11 Division 3 of the NTA and include: a) facilitation and assistance to prepare and progress native title applications and negotiation of future act processes; b) certification of native title applications and applications for registration of an ILUA; c) resolution of disputes between constituents; d) notification to persons who hold or may hold native title in the area of notices that relate to land and water in the RATSIB area; and e) agreement making to be a party to ILUAs as appropriate in its specified area. Provides a spatial representation of native title matters, related to custodial statutory functions associated with Registers in support of the Native Title Act 1993.

Mapping of benthic habitat and seafloor bathymetry of Swanbourne, WA derived from satellite imagery captured on 03 June 2017 at a spatial resolution of 2 m. Mapping extent covered as much of the Defence gazetted waters as possible, to a depth of approximately 18 m based on water clarity. Recently dead or senesced (e.g. winter dieback of leaves) and mobile seagrass have the same satellite signature as live seagrass at spectral resolutions of the sensor (WorldView-2). This ensured areas of winter dieback and/or senescence were captured as areas of seagrass for the purposes of impact assessment.

The datasets contain summaries of Queensland aquaculture locations in state marine and estuarine waters. The data has been recorded and submitted to Queensland DPI.

δ18Oara profile for shelled pteropod calcification depth estimate based on seawater salinity and temperature measured by Argo floats. The oxygen isotopic composition of pteropod shells (δ18Optero) was compared to the δ18Oara at different depths. The calcification depth is defined as the depth where the values of δ18Optero and δ18Oara were equal within their respective uncertainties. Shelled pteropods are at risk from ocean acidification, with known effects on their shell durability and calcification. Pteropods typically form their aragonitic shells over specific depth ranges known as the ‘calcification depth’, which varies depending on species and habitats. Some Southern Ocean waters are already undersaturated with respect to aragonite and this could negatively affect shelled pteropods. However, the calcification depths of the pteropods have not been determined nor used to infer consequences of changing seawater carbonate chemistry in the Southern Ocean. In this study, we analysed the stable oxygen isotopic composition of Limacina rangii shells, collected by sediment traps in the subantarctic zone, to estimate their calcification depth. Shallow calcification depths (13-126 m) were detected in summer-autumn, while L. rangii calcified their shells deeper in the water column during winter-spring, with an average maximum calcification depth of 525 m. Recent shoaling of the aragonite saturation horizon is likely to negatively affect pteropods that calcify their shells in deep water. Such shoaling is likely to reduce shell formation and threaten population viability.

This resource is a map of Surface pH and comes from from a simulation that uses the multi-model mean forcings from RCP8.5 projection to drive an ocean eddy-resolving model (OFAM3). Insights for Warming and Acidification Increased frequency and duration of marine heatwaves increase the likelihood of more frequent and severe coral bleaching events. Tasman Sea approaches a permanent marine heatwave state by GWL3. Great Barrier Reef and Ningaloo Reef will experience annual conditions for extreme bleaching by GWL3. Acidity at GWL3: Southern Ocean surface waters south of 60S will drop below an annual mean aragonite saturation state of 1. Values above 1.0 are required to produce calcareous shells or skeletons optimally. Values below 1 are considered corrosive, and skeletons and shells may be subject to dissolution. The ocean environment will become more stressful for marine organisms and ecosystems. The references for the simulations are: Feng, M., Zhang, X., Oke, P., Monselesan, D., Chamberlain, M. A., Matear, R. J., & Schiller, A. (2016). Invigorating ocean boundary current systems around Australia during 19792014: As simulated in a near-global eddy-resolving ocean model. Journal Of Geophysical Research-Oceans. Hayashida, H., Matear, R. J., & Strutton, P. G. (2020). Background nutrient concentration determines phytoplankton bloom response to marine heatwaves. Global Change Biology, 26(9), 48004811. https://doi.org/10.1111/gcb.15255 Hayashida, H., Matear, R. J., Strutton, P. G., & Zhang, X. (2020). Insights into projected changes in marine heatwaves from a high-resolution ocean circulation model. Nature Communications, 11(1), 19. https://doi.org/10.1038/s41467-020-18241-x Matear, R. J., Chamberlain, M. A., Sun, C., & Feng, M. (2015). Climate change projection for the western tropical Pacific Ocean using a high-resolution ocean model: Implications for tuna fisheries. Deep Sea Research Part II: Topical Studies in Oceanography, 113(0), 2246. Matear, R. J., Chamberlain, M. A., Sun, C., & Feng, M. (2013). Climate change projection of the Tasman Sea from an Eddy-resolving Ocean Model. Journal Of Geophysical Research-Oceans, 118(6), 29612976. Zhang, X., Oke, P. R., Feng, M., Chamberlain, M. A., Church, J. A., Monselesan, D., et al. (2016). A near-global eddy-resolving OGCM for climate studies. Geoscientific Model Development Discussions. Diagnostics The key ocean diagnostics are displayed according to Global Warming Levels (GWLs) using the 20 year period that define a given GWL. The key ocean diagnostics are: 1. Sea Surface Temperature monthly climatology 2. Surface Aragonite Saturation State monthly climatology 3. Surface pH monthly climatology 4. Intensity of Marine Heat Wave 5. Duration of Marine Heat Wave 6. NPP monthly climatology (N mol/m^2/s) 7. Degree Heating Weeks (average of the annual maximum value dhw_amax, maximum (dhw_max) and minimum (dhw_max) annual value over GWL period 8. Bottom Temperature 9. Full ocean depth temperature (note simulation used restoring to T and S below 2000m)10. Magnitude of Bottom Stress (bmf) 10. Bottom aragonite saturation state Data/confidence Confidence: high confidence in the direction of change, medium confidence in the magnitude of change and low confidence in the ecological consequence of the changes. (consistent with IPCC AR6) Limitation: ocean simulations that are not well suited for representing the high-resolution dynamics and features of the Australian coastal areas. https://github.com/AusClimateService/hazard_ocean/blob/main/README.md

This resource is a map of Custodial geospatial data held by the National Native Title Tribunal (NNTT) consists of those datasets necessary to contribute to the statutory functions associated with Registers and other information, in support of the Native Title Act 1993 (Cth). Provides a spatial representation of native title matters, related to custodial statutory functions associated with Registers in support of the Native Title Act 1993.