Reliable marine benthic habitat maps at regional and national scales are needed to enable the move towards the sustainable management of marine environmental resources. The most effective means of developing broad-scale benthic habitat maps is to use commonly available marine physical data due to the paucity of adequate biological data and the prohibitive cost of directly sampling benthic biota over large areas. A new robust method of mapping marine benthic habitats at this scale was developed based on a stratified approach to habitat classification. This approach explicitly uses knowledge of marine benthic ecology to determine an appropriate number of stratification levels, to choose the most suitable environmental variables for each level, and to select ecologically significant boundary conditions (i.e. threshold values) for each variable. Three stratification levels, with nine environmental variables, were created using a spatial segmentation approach. Each level represents major environmental processes and characteristics of the Australian marine benthic environment. The finest scale of benthic habitat is represented by seafloor physical properties of topography, sediment grain size and seabed shear stress. Water-column nutrient parameters and bottom water temperature depicted the intermediate scale, while the broadest scale was defined by seabed insolation parameters derived from depth data. The classifications of the three stratified levels were implemented using an object-based fuzzy classification technique that recognises that habitats are largely homogenous spatial regions, and transitions between habitats are often gradual. Classification reliability was indicated in confidence maps. Physical habitat diversity was evaluated for the final benthic habitat map that combines the three classifications. The final benthic habitat map identifies the structurally complex continental shelf break as an area of relatively high habitat diversity. Continental Shelf Research

Geoscience Australia carried out a marine survey on Lord Howe Island shelf (NSW) in 2008 (SS062008) to map seabed bathymetry and characterise benthic environments through colocated sampling of surface sediments and infauna, rock coring, observation of benthic habitats using underwater towed video, and measurement of ocean tides and wavegenerated currents. Subbottom profile data was also collected to map sediment thickness and shelf stratigraphy. Data and samples were acquired using the National Facility Research Vessel Southern Surveyor. Bathymetric data from this survey was merged with other preexisting bathymetric data (including LADS) to generate a grid covering 1034 sq km. As part of a separate Geoscience Australia survey in 2007 (TAN0713), an oceanographic mooring was deployed on the northern edge of Lord Howe Island shelf. The mooring was recovered during the 2008 survey following a 6 month deployment. lh_back_8m is a backscatter grid of the Lord Howe survey area produced from the processed EM300 backscatter data of the survey area using the CMST-GA MB Process.

The dataset contains three grids. Each of the ArcINFO grids is an output of a finescale hydrodynamic model, the Simulating WAves Nearshore (SWAN) model (Booij et al., 1999; Ris et al., 1999).The grids describe the modelled maximum orbital velocity (m/s) which can be used as estimation of seabed exposure in Jervis Bay.

Geoscience Australia carried out marine surveys in south-east Tasmania in 2008 and 2009 (GA0315) to map seabed bathymetry and characterise benthic environments through observation of habitats using underwater towed video. Data was acquired using the Tasmania Aquaculture and Fisheries Institute (TAFI) Research Vessel Challenger. Bathymetric mapping was undertaken in seven survey areas, including: Freycinet Pensinula (83 sq km, east coast and shelf); Tasman Peninsula (117 sq km, east coast and shelf); Port Arthur and adjacent open coast (17 sq km); The Friars (41 sq km, south of Bruny Island); lower Huon River estuary (39 sq km); D Entrecastreaux Channel (7 sq km, at Tinderbox north of Bruny Island), and; Maria Island (3 sq km, western side). Video characterisations of the seabed concentrated on areas of bedrock reef and adjacent seabed in all mapped areas, except for D Entrecastreaux Channel and Maria Island. Seabed sediment samples were collected by TAFI in August 2010 in a targeted area to the east of Tasman Peninsula. Samples were collected at 25 stations using a Van Veen grab, from which a 50 - 100 g sub-sample was taken and submitted to Geoscience Australia for analysis.

A number of terms used in this book are derived from the fields of biogeography and benthic ecology and these are defined in the glossary; the reader is also referred to the works cited at the end of this chapter for further information. Many of the case studies presented in this book refer to habitat classification schemes that have been developed based on principles of biogeography and ecology. For these reasons a brief overview is provided here to explain the concepts of biodiversity, biogeography and benthic ecology that are most relevant to habitat mapping and classification. Of particular relevance is that these concepts underpin classification schemes employed by GeoHab scientists in mapping habitats and other bioregions. A selection of published schemes, from both deep and shallow water environments, are reviewed and their similarities and differences are examined.

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 colocated 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. Sample diversity indices calculated in PRIMER (version 6) using the species level data from JBinfauna_species (25Oct10).xls.

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.

This report provides a description of the research activities completed during the CERF Marine Biodiversity Hub survey of southeast Tasmanian temperate reefs, aboard RV Challenger, as part of the Hub's Surrogates Program. The survey was undertaken as a collaborative exercise between the Tasmania Aquaculture and Fisheries Institute (TAFI, University of Tasmania) and Geoscience Australia (GA), and was completed in two stages during 2008 and 2009. This report describes the methods employed in the mapping and video characterisation of shallow-shelf temperate reef habitats across seven survey sites in southeast Tasmania. Preliminary results are provided of the analysis of multibeam sonar and underwater video data. Examples of the types of biota encountered in the towed video and stills photography, and initial interpretations of the benthic communities are also provided. In addition, initial results are presented from the deployment of an Autonomous Underwater Vehicle (AUV) to collect high resolution photographs of reefs and associated biota.

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.

Field and supplementary environmental data for the Marine Biodiversity Hub Description: The directory contains the following datasets. 1. Multibeam acoustic data (both backscatter and bathymetry) for three field areas: Jervis Bay, Carnarvon Shelf, and Southern Tasmanian Shelf. 2. Marine environmental data at the Australian continental scale. 3. Side scan data for three regions: Fitzroy, Jervis Bay and Keppel Bay. 4. CARS and Ocean Color datasets obtained from CSIRO. 5. AUV data for the Tasmanian survey (October 2008). These datasets were collected from various field surveys and project partners for the research of Marine Biodiversity Hub. Please contact the CERF project team for further information.