Data from multibeam echosounder surveys taken as part of the Ningaloo Outlook project were classified into various seafloor cover types according to their hardness, rugosity and depth. The classifications were validated with towed video ground truth where it was available. This dataset describes two AOIs which are explicitly part of the Ningaloo Outlook Deep Reefs project. Substratum classifications were applied using multibeam backscatter angular response curves along with rugosity as input to a maximum likelihood classifier. See original metadata record(s) and associated attached documents for accuracy estimates, alternate classification techniques, and additional surveyed areas. https://doi.org/10.25919/kssa-5b46 https://doi.org/10.25919/kttc-x397 https://doi.org/10.25919/8m65-7k26

This study compared the individual and combined effects of two introduced marine species in SE Tasmania - the northern Pacific seastar (Asterias amurensis) and the European green crab (Carcinus maenas) - and investigated their impact on native invertebrate fauna using in situ caging experiments. Both species predate upon bivalves, and this study assessed the biological interaction between these introduced species and native bivalve species - allowing the impact of multiple exotic predator species to be investigated in one system. The cage experiments have 5 treatment groups, including all combinations of presence (single animal) and absence of seastars and crabs, and a control with neither. Predator activity (number and type of bivalves consumed) was recorded after 8 weeks by suction-sampling each cage and counting and identifying fauna.

The SeaMap Tasmania project undertook mapping of seafloor habitats across the nearshore Tasmanian coastline (0-40 m) - the first state to compile a statewide asssimilated benthic habitat dataset. This initiative comprised of collating aerial photography (from archives), acoustic mapping, and conducting underwater video surveys and field-based visual observations. From this, 1:25,0000 scale habitat maps were created for shallow coastal water to within 1.5 km of the coastline (or 40 m depth, which ever was arrived at first). This record provided access to the raw video and associated annotations from video transects, which were subsequently used as validation (ground-truthing) for habitat mapping. A submersible digital video camera was deployed at selected locations around the Tasmanian coastline. These samples were used to verify the aerial photography and echo sounder substrate classification and obtain more detailed information on biological assemblages. Transects were undertaken from the LWM (Low water mark) to 80 metres in depth or 1.5 kms from shore. Positional information was recorded for each video drop as a series of DGPS coordinates and also as a direct overlay of the DGPS output (position, date and time) onto the video.

The SeaMap Tasmania project undertook mapping of seafloor habitats across the nearshore Tasmanian coastline (0-40 m) - the first state to compile a statewide asssimilated benthic habitat dataset. This initiative comprised of collating aerial photography (from archives), acoustic mapping, and conducting underwater video surveys and field-based visual observations. From this, 1:25,0000 scale habitat maps were created for shallow coastal water to within 1.5 km of the coastline (or 40m depth, which ever was arrived at first). Depth information was collected via acoustic methods and used to discriminate seafloor habitat type, in combination with scanned aerial photographs and towed video transects providing ground-truthing information. See 'Lineage' section of this record for full methodology and data dictionary. This data is also available via the Seamap Australia National Benthic Habitat Layer - a nationally consolidated benthic habitat map. https://metadata.imas.utas.edu.au/geonetwork/srv/eng/catalog.search#/metadata/4739e4b0-4dba-4ec5-b658-02c09f27ab9a