The Lord Howe Island survey SS06-2008 in April 2008 aboard the RV Southern Surveyor was a collaboration between the University of Wollongong and Geoscience Australia. The survey was also an activity of the Commonwealth Environment Research Facilities' (CERF) Marine Biodiversity Hub, of which Geoscience Australia is a partner, and will contribute to the revised Plan of Management for the Lord Howe Marine Parks. The objectives of the survey were to map the morphology and benthic environments of the shallow shelf that surrounds Lord Howe Island as well as the deeper flanks of this largely submarine volcano. Of particular interest was the apparent drowned reef structure on the shelf and the spatial distribution of seabed habitats and infauna. The data collected are required to better understand the history of reef growth at Lord Howe Island, which sits at the southernmost limit of reef formation, and links between the physical environment and ecological processes that control the spatial distribution of biodiversity on the shelf. The morphology of the flanks of the submarine volcano was also examined to reveal whether they provide evidence of major erosional and depositional processes acting on the volcano. This report provides a description of the survey activities and the results of the processing and initial analysis of the data and samples collected.

The term 'surrogacy' is used in habitat mapping with reference to the biophysical variables that can be mapped with a quantifiable correspondence to the occurrence of benthic species and communities. Surrogacy research can be defined as an empirical method of determining which easily measured characteristics best describe the species assemblage in a particular space and at a particular time. These characteristics act as predictors (with some known probability and uncertainty) for the occurrence of species assemblages in unexplored areas. Abiotic variables are, in general, more easily and less expensively obtained than biological observations, which is a key driver for surrogacy research. However, the suite of abiotic factors that exert control over the occurrence of species (its niche) is also a scientifically interesting aspect of ecology that provides important insights into a species evolution and biogeography. This chapter provides a review of surrogates used by case study authors and of the methods used to quantify relationships between variables.

Permeable, sandy sediments cover most of the continental shelf. The important role of pore-water advective flow on biogeochemical processes in these sediments has been highlighted in recent studies. Such flow can be driven by wave-action, water-density and interactions between topography and bottom currents, in addition to biological activity, and can create spatially complex and highly dynamic benthic environments in which processes vary on timescales ranging from minutes to months. It is well known that the patchiness of soft sediment (organic matter/bacteria, particle diversity, redox) is likely to be a major determinant of species diversity, but previous studies have not specifically defined patches based on a range of biologically-relevant physico-chemical variables, nor observed how patches change across time. This study, as part of the Surrogates Program in the Commonwealth Environmental Research Facilities Marine Biodiversity Hub, investigated temporal changes in the geochemistry, physical sediments and infauna of sandy sediments in Jervis Bay at two times.

Flythrough movie showing the bathymetry of Carnarvon shelf, highlighting benthic habitats at Point Cloates. The bathymetric image is derived from multibeam sonar collected in 2008 using a 300 kHz Simrad EM3002 system on RV Solander. Key features on the shelf include a prominent ridge at 60 m water depth and a complex area of smaller ridges and mounds across the inner shelf. The ridges and mounds provide hard substrate for diverse coral and sponge communities. The Carnarvon shelf is a study site for the Marine Biodiversity Research Hub, funded through the Commonwealth Environment Research Facilities (CERF) programme. Survey work was carried out as a collaboration between Geoscience Australia and the Australian Institute of Marine Science. Further information is provided in GA Record 2009/02.

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_4m is an ArcInfo grid of the Lord Howe survey area produced from the processed EM300 bathymetry data of the survey area using the CARIS HIPS and SIPS software.

Autonomous Underwater Vehicles (AUVs) have only recently become available as a tool to investigate the biological and physical composition of the seabed utilizing a suite of image capture and high-resolution geophysical tools. In this study we trialled the application of an AUV, integrating AUV image capture with ship-based high resolution multibeam bathymetry, to map benthic habitats and biodiversity in coastal and offshore waters of SE Tasmania. The AUV successfully surveyed a plethora of marine habitats and organisms, including high-relief kelp-dominated rocky reefs to deep mid-shelf reef and sediments that are otherwise difficult to access. To determine the spatial extent of these habitats within a broader-scale context, the AUV surveys were integrated with larger scale multibeam mapping surveys. The data collected using the AUV significantly improved our understanding of the distribution of benthic habitats and marine organisms in this region, with direct application to the management and conservation of these environments. Integrating the AUV data with the largescale mapping data provided the opportunity to quantify the relationships between the biological and physical variables, and to use thise data to develop predictive models of biodiversity across the region.

Geoscience Australia carried out a marine survey on Lord Howe Island shelf (NSW) in 2008 (SS06_2008) 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 wave generated 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. The "2461_ss062008" folder contains raw multibeam backscatter data of the Lord Howe Rise. The raw multibeam backscatter data were collected along survey lines using SIMRAD EM300 from aboard RV Southern Surveyor

Geoscience Australia carried out marine surveys in southeast 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. The "challenger" folder contains processed multibeam backscatter data of the South East Tasmania Shelf. The SIMRAD EM3002 multibeam backscatter data were processed using the CMST_GA MB Process, a multibeam processing toolbox codeveloped by Geoscience Australia and Curtin University of Technology.

This study tested the performance of 16 species models in predicting the distribution of sponges on the Australian continental shelf using a common set of environmental variables. The models included traditional regression and more recently developed machine learning models. The results demonstrate that the spatial distributions of sponge as a species group can be successfully predicted. A new method of deriving pseudo-absence data (weighted pseudo-absence) was compared with random pseudo-absence data - the new data were able to improve modelling performance for all the models both in terms of statistics (~10%) and in the predicted spatial distributions. Overall, machine learning models achieved the best prediction performance. The direct variable of bottom water temperature and the resource variables that describe bottom water nutrient status were found to be useful surrogates for sponge distribution at the broad regional scale. This study demonstrates that predictive modelling techniques can enhance our understanding of processes that influence spatial patterns of benthic marine biodiversity. Ecological Informatics

This introductory chapter provides an overview of the book's contents and definitions of key concepts including benthic habitat, potential habitat and seafloor geomorphology. The chapter concludes with a summary of commonly used habitat mapping technologies. Benthic (seafloor) habitats are physically distinct areas of seabed that are associated with particular species, communities or assemblages that consistently occur together. Benthic habitat maps are spatial representations of physically distinct areas of seabed that are associated with particular groups of plants and animals. Habitat maps can illustrate the nature, distribution and extent of distinct physical environments present and importantly they can predict the distribution of the associated species and communities.