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  • This is a collection of data in East Antarctica from Southern Elephant seal's between 2004 and 2009. The monthly data set has been further classified by polynya and year. Additionally, we provide a dataset of the polynyas contours defined following a criteria of 75% of sea-ice concentration for each individual month between 2004 and 2019. Data are provided in .mat format

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    Snook (Sphyraena novaehollandiae) commercial catch (in tonnes), commercial effort (in number of days fished), and commercial Catch Per Unit Effort (CPUE, in kg/day fished) by fishing season per NRE scalefish fishery fishing block for all gear types combined. The dataset was provided by the Tasmanian Wild Fisheries Assessments team at IMAS. Tasmanian wild fisheries stock assessments are conducted by the Fisheries and Aquaculture Centre of the Institute of Marine and Antarctic Studies (IMAS) on behalf of the Tasmanian Department of Natural Resources and Environment (NRE Tas). Under the Sustainable Marine Research Collaboration Agreement (SMRCA), IMAS conduct fishery assessments, provide expert management advice and undertake scientific research on Tasmanian fisheries issues for NRE Tas.

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    Phytoplankton indirectly influence climate through their role in the ocean biological carbon pump. In the Southern Ocean, the subantarctic zone represents an important carbon sink, yet variables limiting phytoplankton growth are not fully constrained. Using three shipboard bioassay experiments on three separate voyages, we evaluated the seasonality of iron (Fe) and manganese (Mn) co-limitation of subantarctic phytoplankton growth south of Tasmania, Australia. We observed a strong seasonal variation in a phytoplankton Fe limitation signal, with a summer experiment showing the greatest response to Fe additions. An autumn experiment suggested that other factors co-limited phytoplankton growth, likely low silicic acid concentrations. The phytoplankton responses to Mn additions were subtle and readily masked by the responses to Fe. Using flow cytometry, we observed that Mn may influence the growth of some small phytoplankton taxa in late summer/autumn, when they represent an important part of the phytoplankton community. In addition, Mn induced changes in the bulk photophysiology signal of the spring community. These results suggest that the importance of Mn may vary seasonally, and that its control on phytoplankton growth may be associated with specific taxa.

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    Locations of the Oysters Tasmania's Sensor Network. The sensor network provides real-time data on salinity, water temperature, and depth in shellfish growing areas in Tasmania. Oyster growers can access the sensor data via the ‘ShellPOINT’ portal (https://www.oysterstasmania.org/shellpoint.html).

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    In collaboration with the Tasmanian State Emergency Service, water level monitoring instruments were installed to enable the collection of data in four estuaries identified as being vulnerable to coastal and compound flooding: Derwent Estuary, Huon Estuary, Georges Bay, and Macquarie Harbour. These instruments recorded fluctuations in water levels due to the combined influences of tide, river discharge, and weather events. The effects of the January 2022 Hunga Tonga-Hunga Ha’apai tsunami following a significant submarine volcanic explosion was also recorded in three out of the four estuaries. The datasets, comprising reduced water level observations, predicted water level, and residuals, are available from the IMAS Data Portal. Water level observations of varying duration were recorded between November 2020 – November 2022 for 14 sites in four Tasmanian estuaries. This work was undertaken by Karen Palmer as part of a PhD candidature at the University of Tasmania under the supervision of Dr Christopher Watson, Dr John Hunter, Assoc Prof Hannah Power (University of Newcastle), and Dr Rebecca Harris.

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    Location of the Giant Kelp (Macrocystis pyrifera) outplant trial sites. This is part of a collaborative project between IMAS, The Nature Conservancy, CSIRO and NRM South to restore giant kelp forests in Tasmania.

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    Data pertain to analysis of GRACE time series of mass change in both gridded and basin format. The GRACE data are based on the COST-G solution obtained from http://gravis.gfz-potsdam.de/home. Both 50km regular gridded data and basin-level time series are included, as well as the SAM and ENSO climate indices on which the regressions were based. The gridded datasets provided here include derived quantities from the regressions such as trends, uncertainties, and regression coefficients in NetCDF format.

  • Diel partitioning of animals within ecological communities is widely acknowledged, yet rarely quantified. Investigation of most ecological patterns and processes involves convenient daylight sampling, with little consideration of the contributions of nocturnal taxa, particularly in marine environments. Here we assess diel partitioning of reef faunal assemblages at a continental scale utilizing paired day and night visual census across 54 shallow tropical and temperate reefs around Australia. Day/night differences were most pronounced in the tropics, with fishes and invertebrates displaying distinct and opposing diel occupancy on coral reefs. Tropical reefs in daytime were occupied primarily by fishes not observed at night (64% of all species sighted across day and night, and 71% of all individuals). By night, substantial emergence of invertebrates not otherwise detected during sunlit hours occurred (56% of all species, and 45% of individuals). Nocturnal emergence of tropical invertebrates corresponded with significant declines in the richness and biomass of predatory and herbivorous diurnal fishes. In contrast, relatively small diel changes in fishes active on temperate reefs corresponded to limited nocturnal emergence of temperate invertebrates. This reduced partitioning may, at least in part, be a result of strong top-down pressures from fishes on invertebrate communities, either by predation or competitive interference. For shallow reefs, the diel cycle triggers distinct emergence and retreat of faunal assemblages and associated trophic patterns and processes, which otherwise go unnoticed during hours of regular scientific monitoring. Improved understanding of reef ecology, and management of reef ecosystems, requires greater consideration of nocturnal interactions. Without explicit sampling of nocturnal patterns and processes, we may be missing up to half of the story when assessing ecological interactions.

  • Data to accompany publication on wild diet of southern rock lobster on the east coast of Tasmania. In this study we collected 64 lobsters and analysed the diet of each individual using stomach contents, stable isotope analysis and DNA identification of prey species in faecal samples.

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    Purple wrasse (Notolabrus fuciola) commercial catch (in tonnes), commercial effort (in number of days fished), and commercial Catch Per Unit Effort (CPUE, in kg/day fished) by fishing season per NRE scalefish fishery fishing block for all gear types combined. The dataset was provided by the Tasmanian Wild Fisheries Assessments team at IMAS. Tasmanian wild fisheries stock assessments are conducted by the Fisheries and Aquaculture Centre of the Institute of Marine and Antarctic Studies (IMAS) on behalf of the Tasmanian Department of Natural Resources and Environment (NRE Tas). Under the Sustainable Marine Research Collaboration Agreement (SMRCA), IMAS conduct fishery assessments, provide expert management advice and undertake scientific research on Tasmanian fisheries issues for NRE Tas.