IMOS - AUV SIRIUS CAMPAIGN: TASMANIA, MARCH 2009

Researchers: Williams, Stefan (Principal investigator) ,  Williams, Stefan (Principal investigator) ,  AODN Data Manager (Point of contact, Distributes) ,  Data Officer (Point of contact, Distributes) ,  Data Officer (Point of contact, Distributes)
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Brief description Tasmania (Barrett, Lucier - TAFI; Johnson, Ling - UTAS) The primary objective of this work was to describe biological assemblages associated with rocky reef systems in deep shelf waters on the Tasman Peninsula in SE Tasmania and in the Huon, Freycinet and Bruny Island Marine Protected Areas (MPA), providing a record of community composition at or near the time of designation of these MPAs. Detailed multibeam sonar bathymetry data were previously collected by Geoscience Australia (GA) to provide high-resolution digital elevation maps of the study areas. These maps were used to determine suitable AUV survey locations. At each location, multiple reefs were surveyed at a range of depths from approximately 50 m to 100 m depth. Dive profiles were designed to provide sufficient replication to quantitatively determine abundances of key species/features within depth strata, within reefs, between reefs (km to 100 km scale), and between differing levels of reef complexity. The AUV deployments were part of a multi-disciplinary experimental program to analyse the covariance of co-located fine-resolution seabed habitat data, provided by the EM3002 multibeam sonar coverage, and biological datasets collected at similar spatial scales by Remotely Operated Vehicles (ROVs), Baited Remote Underwater Video systems, towed video and the AUV. This program was undertaken with UTAS and GA as part of the Marine Biodiversity Research Hub, a collaborative program funded under the Commonwealth Government's Commonwealth Environmental Research Facilities Program. In addition, the AUV completed high resolution, full seafloor coverage day and night dives at St Helens in the North East to document nocturnal feeding habits of the sea urchin Centrostephanus rodgersii whose poleward extension has had a significant impact on kelp beds in the North East of Tasmania. Tasmania 03/2009 Scallop fisheries at Maria Island, Freycinet MPA; 9 dives over 5 days of operations; this trip ended prematurely with the grounding of the R/V Challenger. A shackle securing the anchor to the anchor chain gave way and the ship blew onto rocks, destroying the Ultra-Short Baseline (USBL) transceiver affixed to the ship that is used to track the AUV while it is underway. This equipment was replaced using funding from the University of Sydney and a claim has been lodged with the University of Tasmania to recover the costs as the ship was being operated by TAFI. A planned deployment in SA with SARDI was rescheduled as a consequence of this incident and we are looking into the availability of ship time to complete the proposed SA deployments.

Lineage Maintenance and Update Frequency: asNeeded

Lineage Statement: This data is provided by the IMOS AUV Facility and was collected by the University of Sydney's Australian Centre for Field Robotics aboard the TAFI Research Vessel R/V Challenger. The AUV Sirius undertook seafloor survey deployments along the Tasmanian Peninsula, at Port Arthur and in the Huon Channel between October 5th and 16th, 2008. This represents a first pass processing completed while onboard the ship. A more thorough revision may be available in the future. In all 19 dives were completed, in addition to a number of calibration dives which are not contained on this disk. Each mission has been processed to generate a dive report, dive tracks, geotifs and meshes. Multibeam and hydrographic data have been completed for some but not all dives. The structure of each dive summary is as follows: .pdf - a report outlining the dive. This shows some dive stats (date, time, depth, number of images, distance travelled, etc.), the raw mission profile, a depth profile, the hydrographic data and the reprocessed navigation data where available. .kml - this is a kml file of the vehicle path that can be loaded into Google Earth. _latlong.csv - this is comma separated value file containing a summary of the imagery collected by the vehicle during the dive. This is a result of the output of the renavigation and should be self-consistent where loop closures were identified. USBL and GPS observations have also been fused into the navigation filter. The csv file contains data for each image including the date and time, local northing and easting in metres, depth, latitude and longitude, roll, pitch, heading, altitude and the names of the two stereo images. hydro/ct.csv - a csv containing the conductivity and temperature measurements taken during the dive. These include the date and time, interpolated northing and easting, depth, latitude and longitude, conductivity, temperature measurements and salinity, pressure and speed of sound. hydro/eco.csv - a csv containing the ecopuck fluorometer measurements. These include the date and time, interpolated northing and easting, depth, latitude and longitude, chlorophyll-a, backscatter (red), cdom and temperature (note that this particular sensor does not measure temperature and this field is filled with a dummy value). i_gtif - this directory contains geotiffs of the left, colour images collected during the dive. These contain georeferencing tags generated by the navigation. If loaded into a GIS they should be displayed at the correct geographic location. The image footprint accounts for the field of view of the camera and the measured altitude of the vehicle, The encoding within each image is PNG and should be viewable in a standard image viewer. mb - this directory contains GRD files of the multibeam data, intensities and associated variances. mesh - this directory contains a mesh of the data based on the navigation and the stereo reconstructions. These can be viewed using the osgsight utility by loading the final.ive file. The mesh will show the local stereo surface with associated texture maps.

Notes Credit
Australia’s Integrated Marine Observing System (IMOS) is enabled by the National Collaborative Research Infrastructure Strategy (NCRIS). It is operated by a consortium of institutions as an unincorporated joint venture, with the University of Tasmania as Lead Agent.

Notes Credit
Australian Centre for Field Robotics (ACFR)

Notes Credit
Commonwealth Environmental Research Facility (CERF) Marine Biodiversity Research Hub

Data time period: 01 03 2009 to 31 03 2009

148.5,-39 148.5,-44 144.5,-44 144.5,-39 148.5,-39

146.5,-41.5

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text: uplimit=150; downlimit=50