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  • Infauna are rarely considered in biodiversity assessments of coral reefs and surrounding areas despite their importance in these ecosystems regarding nutrient cycling, bioerosion, and other ecological processes. We surveyed infaunal assemblages in three areas (Mandu, Point Cloates, Gnaraloo) along the Carnarvon Shelf, Western Australia, a region that supports Ningaloo Reef, a relatively pristine coral reef protected by the Ningaloo Marine Park and new proposed Commonwealth marine reserve. Infauna were sampled with a Smith-McIntyre grab and sieved through 500 µm. Environmental data were collected (depth, seabed reflectance, sediment characteristics (grain-size, carbonate, kurtosis, sorting)) so that abiotic factors associated with infaunal assemblages could be identified. A total of 423 species and 4036 individuals were recorded from 145 grabs, with a large percentage (41.7%) represented by rare species (<2 individuals per species). Assemblages were dominated by arthropods, annelids, and molluscs (92.2% of species, 90.2% individuals) and scavengers, suspension feeders, and deposit feeders (25.3% of species, 51.2% of individuals). Assemblages were significantly different among all three areas, but the most distinct assemblages were recorded from the southernmost area of Gnaraloo. Infauna varied significantly with depth and sediment composition (mud and gravel), although these relationships were weak, possibly due to a combination of the assemblage diversity and the high numbers of rare species. Results from the current study broadly quantify infaunal diversity in the region and identify potential spatial and environmental patterns which will help inform future marine management plans, including providing baseline information about communities that can be used to assess potential future impacts and efficacy of protected areas in soft sediment habitats adjacent to coral reefs.

  • This study was undertaken as part of a program to collect baseline data from the seabed environments over the Van Diemen Rise, which comprises a series of carbonate platforms and banks in the eastern Joseph Bonaparte Gulf, northwest of Darwin. Samples were collected during a survey on board the RV Solander in August and September 2009. The state of saturation for the different carbonate minerals (aragonite, calcite, high-magnesium calcite) was calculated for each sampling site from the ratio of the ion activity product and the solubility product. The carbonate ion concentration used for the ion activity product was calculated from total alkalinity and pH. The solubility products of the carbonate minerals were derived from literature data, e.g. the solubility for high-magnesium calcite as a function of the mol% MgCO3 was based on experimental results by Plummer and Mackenzie (1974, American Journal of Science vol. 274, p. 61-83). The calculated average state of saturation was 1.4 (range: 0.8-1.9) for high-magnesium calcite, 4.2 (range: 3.4-4.6) for aragonite, and 6.4 (range: 5.1-6.8) for calcite. Values close to 1 suggest the mineral is in thermodynamic equilibrium with ambient water, which is the case for high-magnesium calcite. In contrast, aragonite and calcite are distinctively supersaturated. Given the near-equilibrium state of high-magnesium calcite, this mineral phase will likely be lost over a time scale of decades as ocean acidification progresses. This ongoing process will alter the sediment composition significantly given the high abundance of high-magnesium calcite. This study supports the concept of using high-magnesium calcite as an indicator for the progression of ocean acidification where surface sediments have been sampled and preserved over time.

  • The Marine Biodiversity Hub was funded by the Australian Government Commonwealth Environmental Research Facilities (CERF) between 2007 and 2010. The Hub was developed to improve the scientific knowledge available to support marine bioregional planning and addressed two fundamental questions: 1. How can we predict the distribution of marine biodiversity; and 2. How can we use this improved capability to conserve and manage biodiversity in a multiple-use environment? This talk focuses on the Surrogates Program, one of four research programs in the Hub. The Surrogates Program addressed the above questions by testing and developing physical variables as surrogates of marine biodiversity, with a focus on seabed environments. In the program, we employed a range of marine survey technologies to collect high-quality and co-located benthic physical and biological data at four selected areas in temperate and tropical waters. We also developed advanced spatial and statistical approaches to test the degree of covariance between the physical and biological data, identify ecological processes, and generate prediction maps. During a number of field campaigns, we deployed a range of instruments to collect data including multibeam sonar, sediment grabs, benthic sleds, towed-video/still images and Autonomous Underwater Vehicles. GIS, machine-learning models and the SWAN hydrodynamic model were used to derive and predict a large number of physical variables as potential surrogates. The effectiveness of the surrogacy approaches were examined using multivariate analyses and spatial modelling techniques. In general, we found that using physical surrogates to predict marine biodiversity is a cost-effective approach. The new knowledge of surrogates and seabed ecological processes directly supports the management of the Australian marine estate. Other major outputs of the Surrogates Program include: - Thirty-seven new and updated national-scale marine physical environmental datasets; - High resolution bathymetry of targeted areas, covering almost 2000 km2, plus 171 km of underwater video transects, 402 sediment grab samples and 232 epifauna samples; - New seabed exposure and fetch models/datasets; and - Peer-reviewed reports and papers in scientific journals. The success of the Marine Biodiversity Hub has enabled the Hub to be refunded for a further four years through the new National Environmental Research Program. In this, Geoscience Australia (GA) is collaborating with the University of Tasmania, CSIRO Marine & Atmospheric Research, Australian Institute of Marine Science, Museum of Victoria, University of Western Australia and Charles Darwin University; GA is also leading Theme 3 Project 1 which focuses on identifying the functions and processes of shelf and canyon ecosystems. The project is expected to further advance marine biodiversity research in Australia by investigating the role of large-scale physical features on the shelf in influencing patterns of marine biodiversity.

  • This dataset contains species-level identifications of polychaetes collected during survey SOL5117 (R.V. Solander 30 July - 27 August, 2010). Animals were collected from the Joseph Bonaparte Gulf with a Smith McIntyre grab, with a few specimens from a benthic sled. Species-level identifications were undertaken by Chris Glasby and Charlotte Watson at the Museum and Art Gallery of the Northern Territory (MAGNT) and were delivered to Geoscience Australia on the 6 June 2013. See GA Record 2011/08 for further details on survey methods and specimen acquisition. Data is presented here as delivered by the taxonomist, and Geoscience Australia is unable to verify the accuracy of the taxonomic identifications. The data file contains two spreadsheets: - 'species list' includes all polychaete species as identified at the MAGNT, including family, abundance, and comments from the taxonomists. It also contains phyla-level identifications for non-polychaete specimens that were mistakenly sent to the MAGNT with the polychaete samples. CG = Chris Glasby; CW = Charlotte Watson - 'Stations' includes location and depth for each station at which grabs and sleds were deployed.

  • Dense coral-sponge communities on the upper continental slope at 570 - 950 m off George V Land have been identified as a Vulnerable Marine Ecosystem in the Antarctic. The challenge is now to understand their likely distribution. Based on results from the Collaborative East Antarctic Marine Census survey of 2007/2008, we propose some hypotheses to explain their distribution. Icebergs scour to 500 m in this region and the lack of such disturbance is probably a factor allowing growth of rich benthic ecosystems. In addition, the richest communities are found in the heads of canyons. Two possible oceanographic mechanisms may link abundant filter feeder communities and canyon heads. The canyons in which they occur receive descending plumes of Antarctic Bottom Water formed on the George V shelf and these water masses could entrain abundant food for the benthos. Another possibility is that the canyons harbouring rich benthos are those that cut the shelf break. Such canyons are known sites of high productivity in other areas because of a number of oceanographic factors, including strong current flow and increased mixing with shelf waters, and the abrupt, complex topography. These hypotheses provide a framework for the identification of areas where there is a higher likelihood of encountering these Vulnerable Marine Ecosystems.

  • Lord Howe Island in the southwest Pacific Ocean is the subaerial remnant of a Late Miocene hot-spot volcano. Erosion of the island has formed a shallow (20 - 120 m) sub-tropical carbonate shelf 24 km wide and 36 km long. On the mid shelf an extensive relict coral reef (165 km2) surrounds the island in water depths of 30-40 m. The relict reef comprises sand sheet, macroalgae and hardground habitats. Inboard of the relict reef a sandy basin (mean water depth 45 m) has thick sand deposits. Outboard of the relict reef is a relatively flat outer shelf (mean depth 60 m) with bedrock exposures and sandy habitat. Infauna species abundance and richness were similar for sediment samples collected on the outer shelf and relict reef features, while samples from the sandy basin had significantly lower infauna abundance and richness. The irregular shelf morphology appears to determine the distribution and character of sandy substrates and local oceanographic conditions, which in turn influence the distribution of different types of infauna communities.

  • Deep sea environments occupy much of the sea floor, yet little is known about diversity patterns of biological assemblages from these environments. Physical mapping technologies and their availability are increasing rapidly. Sampling deep-sea biota over vast areas of the deep sea, however, is time consuming, difficult, and costly. Consequently, the growing need to manage and conserve marine resources, particularly deep sea areas that are sensitive to anthropogenic disturbance and change, is leading the promotion of physical data as surrogates to predict biological assemblages. However, few studies have directly examined the predictive ability of these surrogates. The physical environment and biological assemblages were surveyed for two adjacent areas - the western flank of Lord Howe Rise (LHR) and the Gifford Guyot - spanning combined water depths of 250 to 2,200 m depth on the northern part of the LHR, in the southern Pacific Ocean. Multibeam acoustic surveys were used to generate large-scale geomorphic classification maps that were superimposed over the study area. Forty two towed-video stations were deployed across the area capturing 32 hours of seabed video, 6,229 still photographs, that generated 3,413 seabed characterisations of physical and biological variables. In addition, sediment and biological samples were collected from 36 stations across the area. The northern Lord Howe Rise was characterised by diverse but sparsely distributed faunas for both the vast soft-sediment environments as well as the discrete rock outcrops. Substratum type and depth were the main variables correlated with benthic assemblage composition. Soft-sediments were characterised by low to moderate levels of bioturbation, while rocky outcrops supported diverse but sparse assemblages of suspension feeding invertebrates, such as cold water corals and sponges which in turn supported epifauna, dominated by ophiuroids and crinoids. While deep environments of the LHR flank .

  • Biophysical dispersal models are rapidly developing into a powerful and sophisticated means of investigating the interface between oceanographic and biological processes. By coupling ocean physics with larval behaviour, it becomes possible to study expected dispersal patterns, assess the potential impact of rare and/or catastrophic events, evaluate the sensitivity of the system to changes in larval characteristics or behaviour, and project these impacts over time. Potential applications include: examining the influence of vertical movement, studying the effects of different navigational strategies, analysing the effects of a defined reproductive season, and assessing the consequences of applying different survivorship functions. The development and implementation of these types of models will be addressed, and examples from Southeast Asia and Australia will be provided.

  • Geoscience Australia carried out marine surveys in Jervis Bay (NSW) in 2007, 2008 and 2009 (GA303, GA305, GA309, GA312) to map seabed bathymetry and characterise benthic environments through co-located sampling of surface sediments (for textural and biogeochemical analysis) and infauna, observation of benthic habitats using underwater towed video and stills photography, and measurement of ocean tides and wave-generated currents. Data and samples were acquired using the Defence Science and Technology Organisation (DSTO) Research Vessel Kimbla. Bathymetric mapping, sampling and tide/wave measurement were concentrated in a 3x5 km survey grid (named Darling Road Grid, DRG) within the southern part of the Jervis Bay, incorporating the bay entrance. Additional sampling and stills photography plus bathymetric mapping along transits was undertaken at representative habitat types outside the DRG. This folder contains the images derived from benthic samples taken on the surveys GA0312, GA0315 and GA0309 aboard HMS Kimbla. These images formed the first point of reference in identifying subsequent specimens to save wear and tear on the specimens put aside as reference material. Four phylum folders exist within the main folder: Annelida, Crustacea, Echinodermata and Mollusca. The crustacea folder contains further folders, breaking the images into finer groupings. Images of taxa that do not fit in the four phylum folders are loose in the main folder.

  • Physical sedimentological processes such as the mobilisation and transport of shelf sediments during extreme storm events give rise to disturbances that characterise many shelf ecosystems. The intermediate disturbance hypothesis predicts that biodiversity is controlled by the frequency of disturbance events, their spatial extent and the amount of time required for ecological succession. A review of available literature suggests that periods of ecological succession in shelf environments range from 1 to over 10 years. Physical sedimentological processes operating on continental shelves having this same return frequency include synoptic storms, eddies shed from intruding ocean currents and extreme storm events (cyclones, typhoons and hurricanes). Modelling studies that characterise the Australian continental shelf in terms of bed stress due to tides, waves and ocean currents were used here to create a map of ecological disturbance, defined as occurring when the Shield's parameter exceeds a threshold of 0.25. We also define a dimensionless ecological disturbance ratio (ED) as the rate of ecological succession divided by the recurrence interval of disturbance events. The results illustrate that on the outer part of Australia's southern, wave-dominated shelf the mean number of days between threshold events that the Shield's parameter exceeds 0.25 is several hundred days.