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2019

43 record(s)
 
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  • The AUStralian Tidal Energy (AUSTEn) project was a three year project (2018 - 2020) funded by the Australian Renewable Energy National Agency (agreement number G00902) led by the Australian Maritime College (University of Tasmania), in partnership with CSIRO and University of Queensland. The project had a strong industry support (Atlantis Resources Limited, MAKO Tidal Turbines Ltd, Spiral Energy Corporation Ltd). The aim of the project was to assess the technical and economic feasibility of tidal energy in Australia, based on the best understanding of resource achievable. For further information and output of the project, please visit the AUSTEn project website www.austen.org.au.

  • IMAS/CSIRO undertook a multibeam mapping campaign in eastern and Southern Tasmania to map shelf waters of the Freycinet, Huon and Tasman Fracture Marine Parks and several reference areas for the Tasman Fracture Park, including waters around Pedra Brancha and South-west Cape. The dataset includes a post-processed transit along the mid-shelf i=of Western Tasmania. The dataset includes raw mutibeam outputs and post-processed data, including Caris Files, xyz data and geotiffs. A data report for this has been produced by CSIRO. The study was intended to increase knowledge of the distribution of habitats within the SE Australian Australian Marine Park network, and at nearby reference areas with similar habitat. This information is required to underpin subsequent biological monitoring of key habitats within the AMP network, and to contrast the observations within parks with nearby fished locations to determine the extent that changes in biological communities are driven by natural vs anthropogenic pressures.

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    Data accompanying Layton et al. 2019, Resilience and stability of kelp forests: the importance of patch dynamics and environment-engineer feedbacks. PLOS ONE. To explore how resilience and stability of kelp habitats is influenced by this habitat degradation, we created an array of patch reefs of various sizes and supporting adult Ecklonia radiata kelp transplanted at different densities. This enabled testing of how sub-canopy abiotic conditions change with reductions in patch size and adult kelp density, and how this influenced demographic processes of microscopic and macroscopic juvenile kelp.

  • Phytoplankton productivity in the polar Southern Ocean (SO) plays an important role in the transfer of carbon from the atmosphere to the ocean’s interior, a process called the biological carbon pump, which helps regulate global climate. SO productivity in turn is limited by low iron, light, and temperature, which restrict the ef- ficiency of the carbon pump. Iron and light can colimit productivity due to the high iron content of the photosynthetic photosystems and the need for increased photosystems for low-light acclimation in many phytoplankton. Here we show that SO phytoplankton have evolved critical adaptations to enhance photosynthetic rates under the joint constraints of low iron, light, and temperature. Under growth-limiting iron and light levels, three SO species had up to sixfold higher photosynthetic rates per photosystem II and similar or higher rates per mol of photosynthetic iron than tem- perate species, despite their lower growth temperature (3 vs. 18 °C) and light intensity (30 vs. 40 μmol quanta·m2·s−1), which should have decreased photosynthetic rates. These unexpectedly high rates in the SO species are partly explained by their unusually large photosynthetic antennae, which are among the largest ever recorded in marine phytoplankton. Large antennae are disadvan- tageous at low light intensities because they increase excitation energy loss as heat, but this loss may be mitigated by the low SO temperatures. Such adaptations point to higher SO production rates than environmental conditions should otherwise permit, with implications for regional ecology and biogeochemistry.

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    Between 2009-2012, Geoscience Australia conducted three surveys to Joseph Bonaparte Gulf and the Timor Sea on the R.V. Solander, in collaboration with the Australian Institute of Science and the Museum and Art Gallery of the Northern Territory. The study areas overlapped the Oceanic Shoals Commonwealth Marine Reserve and the carbonate banks and terraces within it. The surveys were conducted as part of the Australian Government's Energy Security Program (2007-2011) and the National Environment Research Program (2011-2015). On the surveys, a benthic sled was deployed to collect biological samples from the seafloor. Samples were sorted onboard according to phylum, photographed and then sent to taxonomists for species-level identifications. This dataset provides a list of all identified sponge species. The associated image catalogue of collected sponges can be accessed here: https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/1216e0f4-099c-49f6-96f7-ed3eadc0cd15

  • This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project A14 - "Identification of near-shore habitats of juvenile white sharks in Southwestern Australia". For specific data outputs from this project, please see child records associated with this metadata. -------------------- In early 2018, the CSIRO provided the first estimate of abundance for the southern-western adult white shark. Establishing an estimate of total abundance was not possible due to the lack of information of the juvenile life history stage in south-western Australia. The estimate of adult abundance also included trend (essentially zero or slightly negative), however, it was noted that to confirm the trend, a further decade of sampling would be required. This can be reduced if we identify near-shore habitats where juvenile white sharks from the southern-western population can be readily accessed. This pilot project will investigate credible anecdotal evidence of juvenile white sharks using near-shore habitat near the head of the Great Australia Bight, and inform future project development steps. The pilot project will include collaboration and the opportunity for capacity building with the Yatala Land Management group. The outcome of this pilot project will inform whether or not to proceed to future (on-water) activities. Planned Outputs • Spatial maps showing juvenile white-shark aggregation areas that include Australian marine park boundaries and zoning in jpeg format • Shapefile of juvenile white-shark aggregation areas provided to ERIN • High quality and project relevant images (still and video) suitable for communications purposes • Summary (and images) of opportunistic wildlife observations within the Great Australian Bight Marine Park (Commonwealth waters) • Final report

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    In support of future science missions, an engineering demonstration was conducted to show the ability of the nupiri muka AUV to be deployed and operated at an ice shelf. The AUV was deployed from Davis Station, Antarctica, to conduct underwater surveys in the vicinity of, and beneath, the Sørsdal ice shelf. The AUV conducted several surface transits from the station to the ice shelf, where dive missions at various depths were conducted. The primary mode of operation was the AUV tracking near the seafloor. In addition, a patch survey was conducted near the stations, where several sediment grabs were taken.

  • Cyclone data was used to develop a spatial model using the intensity and to determine whether Sea Surface Temperature or Tropical Cyclone Heat Potential contributes to the North Indian Ocean cyclone intensity and, if so, how?

  • Antarctic krill (Euphausia superba) are a keystone species in the Southern Ocean, but little is known about how they will respond to climate change. Ocean acidification, caused by sequestration of carbon dioxide into ocean surface waters (pCO2), is known to alter the lipid biochemistry of some organisms. This can have cascading effects up the food chain. In a year-long laboratory experiment adult krill were exposed to ambient seawater pCO2 levels (400 μatm), elevated pCO2 levels that mimicked near-future ocean acidification (1000, 1500 and 2000 μatm) and an extreme pCO2 level (4000 μatm). The laboratory light regime mimicked the seasonal Southern Ocean photoperiod and krill received a constant food supply. Total lipid mass (mg g -1 DM) of adult krill was unaffected by near-future levels of seawater pCO2. Fatty acid composition (%) and fatty acid ratios associated with immune responses and cell membrane fluidity were also unaffected by near-future pCO2, apart from an increase in 18:3n-3/18:2n-6 ratios in krill in 1500 μatm pCO2 in winter and spring. Extreme pCO2 had no effect on krill lipid biochemistry during summer. During winter and spring, krill in extreme pCO2 had elevated levels of omega-6 fatty acids (up to 1.2% increase in 18:2n-6, up to 0.8% increase in 20:4n-6 and lower 18:3n-3/18:2n-6 and 20:5n-3/20:4n-6 ratios), and showed evidence of increased membrane fluidity (up to three-fold increase in phospholipid/sterol ratios). These results indicate that the lipid biochemistry of adult krill is robust to near-future ocean acidification.

  • The fatty acid content and composition of the Antarctic krill Euphausia superba Dana, 1850 were investigated using samples collected by a commercial fishing vessel. This dataset allowed comparison between seasons, years (2013–2016), and different fishing locations. Quantities of omega 3 fatty acids 20:5n-3 and 22:6n-3 (mg/g dry mass; DM) were highest in autumn and decreased through winter to reach a spring low. Quantities of the flagellate marker 18:4n-3 and diatom marker 16:1n-7c were variable and did not display the same seasonal fluctuations. In summer, krill had high percentages (% total fatty acids) of 20:5n-3 and 22:6n-3, total PUFA, and low 18:1n-9c/18:1n-7c ratios, indicating a more herbivorous diet. Krill became more omnivorous from autumn to spring, indicated by increasing ratios of 18:1n-9c/18:1n-7c and percentages of Σ 20:1 + 22:1 isomers. Bacterial fatty acids (Σ C15 + C17 + C19 isomers) were minor components year-round (0.9–1.8 %). Seasonal levels of herbivory and omnivory differed between years, and levels of specific fatty acid ratios differed between fishing locations. The fatty acid 18:4n-3 was a major driver of variability in krill fatty acid composition, with no obvious seasonal driver. This is the first study to report krill fatty acid data during all four seasons over consecutive years. This large-scale study highlights the value of using fisheries samples to examine seasonal and annual fluctuations in krill diet and condition.