WAMSI Node 1.1.3 - Marmion Benthic Survey 2007

Full description

In May-June 2007, an "autumn bloom cruise" was conducted on the National Marine Facility, Southern Surveyor, led by Peter Thompson. The voyage was conducted in three legs, with a the first conducted from May 10th to May 15th focused on benthic habitats. Benthic based operations were performed over two transects near Perth at 31.71ºS and 31.76ºS from 115.63ºE to 115.15ºE with stations at depths of 30, 40, 50, 75, 100 and 150m. Acoustic swath mapping of the sea-bed was conducted during the entire voyage; at each of the 12 study sites, benthic sled dredges, sediment grabs, benthic video and CTD casts were completed.

Additional information for this dataset may be available via the original MarLIN metadata entry:
https://marlin.csiro.au/geonetwork/srv/eng/catalog.search#/metadata/810ec955-0f24-4706-bd11-0423e2775eb8
Lineage: The dredges were by a large heavy epibenthic sled, 1.2m wide with net catch 15mm stretched mesh. Thirteen dredges comprised 6 over reef or rock sediment (from 30-75m depth) and 7 over soft sediment (from 40-150m depth). Animal and plant samples were photographed, identified, catalogued, counted and weighed. Thirteen videos were captured- 1 at each station of 30, 40 and 150m depth and 2 continuous tows from 50-100m depth. Extra videos were also performed between 35-50m depth to target a range of habitat heterogeneity identified from the swath imagery. The series of towed videos ranged from a distance of 470m to 5.9km, with a total distance of 32.5km of benthic footage. Video was manually described into 15 categories based on sea-bed type and associated plants and animals and their densities.

Data
Details of operation deployments and results of benthic dredges reside in an Oracle database; extracts have been saved as Excel spreadsheets with further analysis. Videos are stored on original DVCAM tapes and as .wmv files; analysis is in an Excel spreadsheet. Swath data is a series of .xyz, .all and .txt files.