IMAS Metadata Catalogue
oceans
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These data were collected on the RV L'Astrolabe (platform code: FHZI) from 28/02/2004 to 04/03/2004 on a trip from Dumont D'Urville to Hobart. Maximum photochemical efficiency of photosystem II (PSII), also called maximum quantum yield of PSII (Fv/Fm), has become one of the most widely utilized fluorescence parameters in phytoplankton research. It represents the potential photochemical efficiency, which is the probability that the light energy captured by the photosynthetic apparatus is being utilized as photochemistry. Fv/Fm has been shown to have an instant response to variations in physical and chemical properties and is interpreted as a diagnostic of the overall health or competence of phytoplankton. Together with the absorption cross section area of PSII and chlorophyll concentration, it can be used to measure primary production (Cheah et al. 2011, Deep Sea Research). Seawater from 3 m depth was supplied continuously from the ship’s clean seawater line. FRR fluorescence yields were measured continuously at 1 minute intervals in dark-adapted state (! 15 minutes dark-adaptation) using a flash sequence consisting of a series of 100 subsaturation flashlets (1.1 μs flash duration and 2.8 μs interflash period) and a series of 20 relaxation flashlets (1.1 μs flash duration and 51.6 μs interflash period).
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This dataset contains oceanographic profiles of dissolved iron (DFe) at the Southern Ocean Time Series collected during voyages IN2018_V02 and IN2019_V02 aboard RV Investigator, CSIRO Marine National Facility. Profiles of DFe were collected using a 12-bottle trace metal rosette (TMR; Seabird Scientific) equipped with acid washed, externally sprung Niskin bottles (Ocean Test Equipment). GEOTRACES cleaning, sampling, analytical and intercalibration procedures (Cutter et al., 2017) were followed where possible. Full sampling and analytical details for these profiles can be found in Ellwood et al., (2020a) and Ellwood et al., (2020b)
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This record provides an overview of the scope and research output of NESP Marine Biodiversity Hub Project D4 - "Expanding our spatial knowledge of marine biodiversity to support future best-practice reviews". For specific data outputs from this project, please see child records associated with this metadata. -------------------- This project will fill data gaps and evaluate methods relevant to the ongoing spatial management of seafloor biota across the Australian marine domain. The objective is to prepare Australian, State and Territory governments for future best-practice reviews of Australia’s marine bioregionalisation that can be used to improve marine spatial planning and management initiatives (e.g. marine bioregional plan and marine protected area reviews, environmental impact and natural heritage assessments). The project will incorporate results from field trips to unexplored offshore areas of Australia’s marine domain and communicate biodiversity values of the AMP network to the Australian public. Planned Outputs • Report evaluating the usefulness of phylodiversity (genetic diversity) to spatial marine planning • Report outlining extensions of known statistical approaches to be able to utilise available mixed-resolution biological data (including museum and historical data) for the production of best-evidence bioregional maps • Report evaluating the usefulness of connectivity (current) models to spatial marine planning • Report including description and images of deep-sea biological communities of the east coast, including the CMR network, on a scheduled November 2016 expedition of the NMF ‘Investigator’ (mid 2016-7). This survey will result in significant media opportunities to promote the values of the CMR network. • Report including description and images of banks, seamounts and pelagic aggregations within the Cocos Keeling/Christmas Island territories. This would require a successful application for ship-time on the NMF ‘Investigator’ • Report investigating the possibility of downscaling biogeographic maps to the typical scale of areas of conservation concern (1-100 km) by utilising emerging fine-scale bathymetry (provided by the shelf mapping project), acoustic and water movement data
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Redmap is a primarily a website that invites the community to spot, log and map marine species that are uncommon in their region, or along particular parts of their coast. The information collected is mapped and displayed on the site, demonstrating, in time, how species distributions may be changing. Sightings are divided into two categories – those with a photo that can be ‘verified’ by a marine biologist, and sightings without photos that we call community sightings (anecdotal). All the information collected, with and without photos, is mapped and will be used in the following years to map out a ‘story’ of changes occurring in our marine environment. The main data collected includes the species sighted (normally selected from a list comprising preselected species of interest), the location, date/time and activity being undertaken. Other optional information gathered include biological data such as sex, size and weight and environmental data such as water depth and temperature and habitat. This record is associated with live data (and will subsequently change over time) and spatial elements have reduced accuracy. It is also subject to a three year embargo (ie. does not contain data less than three years old). If you wish to discuss obtaining a citable, static dataset, that is current and/or contains accurate spatial elements, please see Point of Contact.
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Declining atmospheric CO2 concentrations are considered the primary driver for the Cenozoic Greenhouse-Icehouse transition, ~34 million years ago. A role for tectonically opening Southern Ocean gateways, initiating the onset of a thermally isolating Antarctic Circumpolar Current, has been disputed as ocean models have not reproduced expected heat transport to the Antarctic coast. Here we use high-resolution ocean simulations with detailed paleobathymetry to demonstrate that tectonics did play a fundamental role in reorganising Southern Ocean circulation patterns and heat transport, consistent with available proxy data. When at least one gateway (Tasmanian or Drake) is shallow (300 m), gyres transport warm waters towards Antarctica. When the second gateway subsides below 300 m, these gyres weaken and cause a dramatic cooling (average of 2–4°C, up to 5°C) of Antarctic surface waters whilst the ACC remains weak. Our results demonstrate that tectonic changes are crucial for Southern Ocean climate change and should be carefully considered in constraining long-term climate sensitivity to CO2.
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Thorium-234 samples were collected to determine the particulate organic carbon (POC) export fluxes in two East Antarctica polynyas, Dalton and Mertz. The samples were collected along the water column using the CTD deployed at several stations. The seawater Th-234 data was used in combination with POC:234Th ratios obtained from particulate samples collected using in situ pumps in order to derive the POC fluxes. This record describes Th-234 and U-238_data: sample ID, depth, CTD file, station ID, latitude and longitude, Th-234 concentration and its uncertainty, U-238 concentration and its uncertainty. See linked record for associated POC data from Aurora Australis Voyage 2 2016/17.
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This study considered a range of water-column and sediment (benthos) based variables commonly used to monitor estuaries,utilising estuaries on the North-West Coast of Tasmania (Duck, Montagu, Detention, and Black River). These included: salinity, dissolved oxygen, turbidity, nutrient and chlorophyll a levels for the water-column; and sediment redox, organic carbon content, chlorophyll a and macroinvertebrate community structure amongst the benthos. In addition to comparing reference with impacted estuaries, comparisons were also made across seasons, commensurate with seasonal changes in freshwater river input, and between regions within estuaries (upper and lower reaches) - previously identified in Hirst et al. (2005). This design enabled us to examine whether the detection of impacts (i.e. differences between reference and impacted systems) was contingent on the time and location of sampling or independent of these factors. The data represented by this record was collected in the Duck Bay.
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The Oliver and Holbrook (Journal Atmospheric and Oceanic Technology, 2014), or OH14, data set provides spatially and temporally homogeneous measurements of sea surface temperature (SST) variability at high resolution on the continental shelf around Australia.
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These data were collected on the RV L'Astrolabe (platform code: FHZI) from 28/12/2002 to 02/01/2003 on a trip from Hobart to Dumont D'Urville. Maximum photochemical efficiency of photosystem II (PSII), also called maximum quantum yield of PSII (Fv/Fm), has become one of the most widely utilized fluorescence parameters in phytoplankton research. It represents the potential photochemical efficiency, which is the probability that the light energy captured by the photosynthetic apparatus is being utilized as photochemistry. Fv/Fm has been shown to have an instant response to variations in physical and chemical properties and is interpreted as a diagnostic of the overall health or competence of phytoplankton. Together with the absorption cross section area of PSII and chlorophyll concentration, it can be used to measure primary production (Cheah et al. 2011, Deep Sea Research). Seawater from 3 m depth was supplied continuously from the ship’s clean seawater line. FRR fluorescence yields were measured continuously at 1 minute intervals in dark-adapted state (! 15 minutes dark-adaptation) using a flash sequence consisting of a series of 100 subsaturation flashlets (1.1 μs flash duration and 2.8 μs interflash period) and a series of 20 relaxation flashlets (1.1 μs flash duration and 51.6 μs interflash period).
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The ETAS (Eastern TASmania) model is a high-resolution (~2 km in the horizontal) ocean model for eastern Tasmania, providing three-dimensional estimates of daily temperature, salinity, and circulation over the 1993-2014 period. This dataset consists of eastward (u) and northward (v) currents organised into yearly files.