A series of short field surveys in Jervis Bay, New South Wales, were undertaken by Geoscience Australia staff as part of the Surrogates Program in the Commonwealth Environmental Research Facilities (CERF) Marine Biodiversity Hub. The aim of the Jervis Bay field work was to collect accurately co-located physical and biological data to enable research into the utility of physical parameters as surrogates for patterns of benthic biodiversity in shallow soft-sediment habitats. In this report the survey design and sampling methods are described; selected field datasets are mapped and discussed; initial results of the laboratory analysis of seabed samples are presented; and there is a brief description of the upcoming analysis of covariance of the physical and biological datasets. The major outputs of the survey work to date are: 1. High-resolution multibeam acoustic datasets for priority areas along the open coast of Jervis Bay (Beecroft Head to Drum and Drumsticks), within the Jervis Bay National Park; and within the southern bay around Darling Road, and in the bay entrance. 2. High quality underwater video footage of benthic habitats in the Darling Road study area acquired with Geoscience Australia's shallow-water towed-video system. The video was used to characterise benthic habitat types, relief/bedform types, and biota occurrence. Characterisations were collected in real-time along bi-directional (six offshore and four alongshore) towed video transects, and were subsequently processed and mapped into three ArcGIS map layers. 3. A set of broad-scale (bay-wide) widely-spaced, co-located sediment and biotic (infauna) seabed samples from the bay's soft-sediment habitats (polychaete mounds, drift algal beds, sand flats, and sand ripple and wave habitats); 4. Sediment samples for geochemical, biogeochemical and sedimentological analyses. 5. A new acoustic doppler current profiler was successfully trialed, and is now being used to collect seabed current data in the Darling Road study area. 6. A progress report on the survey work was presented at the annual CERF Marine Biodiversity Hub's Annual Science Workshop in October 2008.

Williams et al. (2009) report on new multibeam sonar bathymetry and underwater video data collected from submarine canyons and seamounts on Australia's southeast continental margin to 'investigate the degree to which geomorphic features act as surrogates for benthic megafaunal biodiversity' (p. 214). The authors describe what they view as deficiencies in the design of the Marine Protected Areas (MPAs) in the southeast region of Australia, in which geomorphology information was employed as a surrogate to infer regional-scale patterns of benthic biodiversity. This comment is designed to support and underscore the importance of evaluating MPA designs and the validity of using abiotic surrogates such as geomorphology to infer biodiversity patterns, and seeks to clarify some of the discrepancies in geomorphic terminologies and approaches used between the original study and the Williams et al. (2009) evaluation. It is our opinion that the MPA design criteria used by the Australian Government are incorrectly reported by Williams et al. (2009). In particular, we emphasise the necessity for consistent terminology and approaches when undertaking comparative analyses of geomorphic features. We show that the MPA selection criteria used by the Australian Government addressed the issues of false homogeneity described by Williams et al. (2009), but that final placement of MPAs was based on additional stakeholder considerations. Finally, we argue that although the Williams et al. (2009) study provides valuable information on biological distributions within seamounts and canyons, the hypothesis that geomorphic features (particularly seamounts and submarine canyons) are surrogates for benthic biodiversity is not tested explicitly by their study.

Understanding and predicting the bio-physical relationships between seabed habitats, biological assemblages, and marine biodiversity is critical to managing marine systems. Species distributions and assemblage structure of infauna were examined on the oceanic shelf surrounding Lord Howe Island (LHI) relative to seabed complexity within and adjacent to a newly discovered relict coral reef. High resolution multibeam sonar was used to map the shelf, and identified an extensive relict reef in the middle of the shelf, which separated an inner drowned lagoon from the outer shelf. Shelf sediments and infauna were sampled using a Smith McIntyre grab. The three geomorphic zones (drowned lagoon, relict reef and outer shelf) were strong predictors or surrogates of the physical structure and sediment composition of the LHI shelf and its infaunal assemblage. Infaunal assemblages were highly diverse with many new and endemic species recorded. Each zone supported characteristic assemblages and feeding guilds, with higher abundance and diversity offshore.

Disturbances characterise many natural environments - on land, a forest fire that removes a patch of old-growth trees is an example. The trees that first colonise the vacant patch may be a different species to the surrounding old-growth forest and hence, taken together, the disturbed and undisturbed forest has a higher biodiversity than the original undisturbed forest. This simple example demonstrates the intermediate disturbance hypothesis (IDH) that has applications in many natural environments. The application of IDH is significant for managers tasked with managing and conserving the biodiversity that exists in a given area. In this report we have used models of seabed sediment mobilisation to examine IDH for Australia's continental shelf environment. Although other disturbance processes may occur (eg. biological, temperature, salinity, anthropogenic, etc.) our study addresses only the physical disturbance of the seabed by waves and currents. Our study has shown that it is feasible to model the frequency and magnitude of seabed disturbance in relation to the dominant energy source (wave-dominated shelf, tide-dominated shelf or tropical cyclone dominated shelf). We focussed our attention on high-energy, patch-clearing events defined as exceeding the Shields parameter value of 0.25. Based on what is known about rates of ecological succession for different substrate types (gravel, sand, mud) we derive maps predicting the spatial distribution of a dimensionless ecological disturbance index (ED). Only a small portion of the shelf (perhaps ~10%) is characterised by a disturbance regime as defined here. Within these areas, the recurrence interval of disturbance events is comparable to the rate of ecological succession and meets our defined criteria for a disturbance regime. To our knowledge, this is the first time such an analysis has been attempted for any continental shelf on the earth.

The Marine Biodiversity Hub was funded by the Australian Government Commonwealth Environmental Research Facilities (CERF) between 2007 and 2010. The Hub was developed to improve the scientific knowledge available to support marine bioregional planning and addressed two fundamental questions: 1. How can we predict the distribution of marine biodiversity; and 2. How can we use this improved capability to conserve and manage biodiversity in a multiple-use environment? This talk focuses on the Surrogates Program, one of four research programs in the Hub. The Surrogates Program addressed the above questions by testing and developing physical variables as surrogates of marine biodiversity, with a focus on seabed environments. In the program, we employed a range of marine survey technologies to collect high-quality and co-located benthic physical and biological data at four selected areas in temperate and tropical waters. We also developed advanced spatial and statistical approaches to test the degree of covariance between the physical and biological data, identify ecological processes, and generate prediction maps. During a number of field campaigns, we deployed a range of instruments to collect data including multibeam sonar, sediment grabs, benthic sleds, towed-video/still images and Autonomous Underwater Vehicles. GIS, machine-learning models and the SWAN hydrodynamic model were used to derive and predict a large number of physical variables as potential surrogates. The effectiveness of the surrogacy approaches were examined using multivariate analyses and spatial modelling techniques. In general, we found that using physical surrogates to predict marine biodiversity is a cost-effective approach. The new knowledge of surrogates and seabed ecological processes directly supports the management of the Australian marine estate. Other major outputs of the Surrogates Program include: - Thirty-seven new and updated national-scale marine physical environmental datasets; - High resolution bathymetry of targeted areas, covering almost 2000 km2, plus 171 km of underwater video transects, 402 sediment grab samples and 232 epifauna samples; - New seabed exposure and fetch models/datasets; and - Peer-reviewed reports and papers in scientific journals. The success of the Marine Biodiversity Hub has enabled the Hub to be refunded for a further four years through the new National Environmental Research Program. In this, Geoscience Australia (GA) is collaborating with the University of Tasmania, CSIRO Marine & Atmospheric Research, Australian Institute of Marine Science, Museum of Victoria, University of Western Australia and Charles Darwin University; GA is also leading Theme 3 Project 1 which focuses on identifying the functions and processes of shelf and canyon ecosystems. The project is expected to further advance marine biodiversity research in Australia by investigating the role of large-scale physical features on the shelf in influencing patterns of marine biodiversity.

The overarching theme of this book (and for the GeoHab organisation in general) is that mapping seafloor geomorphic features is useful for understanding benthic habitats. Many of the case studies in this volume demonstrate that geomorphic feature type is a powerful surrogate for associated benthic communities. Here we provide a brief overview of the major geomorphic features that are described in the detailed case studies (which follow in Part II of this book). Starting from the coast we will consider sandy temperate coasts, rocky temperate coasts, estuaries and fjords, barrier islands and glaciated coasts. Moving offshore onto the continental shelf we will consider sandbanks, sandwaves, rocky ridges, shallow banks, coral reefs, shelf valleys and other shelf habitats. Finally, on the continental slope and deep ocean environments we will review the general geomorphology and associated habitats of escarpments, submarine canyons, seamounts, plateaus and deep sea vent communities.

Seabed sediment textural parameters such as mud, sand and gravel content can be useful surrogates for predicting patterns of benthic biodiversity. Multibeam swath mapping can provide near-complete spatial coverage of high-resolution bathymetry and backscatter data that are useful in predicting sediment parameters. The multibeam acoustic data at a ~1000 km2 area of the Carnarvon Shelf, Western Australia was used in a predictive modeling approach to map eight seabed sediment parameters. The modeling results indicates overall satisfactory statistical performance, especially for %Mud, %Sand, Sorting, Skewness, and Mean Grain Size. The study demonstrated that predictive modelling using the combination of machine learning models has several advantages over the interpolation of Cokriging. Combing multiple machine learning models can not only improve the prediction performance but also provides the ability to generate useful prediction uncertainty maps. Another important finding is that choosing an appropriate set of explanatory variables, through a manual feature selection process, is a critical step for optimizing model performance. In addition, machine learning models are able to identify important explanatory variables, which is useful in explaining underlying environmental process and checking prediction against existing knowledge of the study area. The sediment prediction maps obtained in this study provide reliable coverage of key physical variables that will be incorporated into the analysis of co-variance of physical and biological data for this area. International Journal of Geographical Information Science

A range of physical descriptors of the seabed can potentially be used as surrogates for defining patterns of benthic marine biodiversity, including bathymetry, geomorphology and sediment type. These variables can be mapped, described and sampled across spatial scales that are of value to the management of the marine estate by providing a template for monitoring benthic ecosystems. As part of a four-year program (2007-2010) funded by the Australian Government, Geoscience Australia led marine surveys designed to collect robust datasets for the analysis of surrogacy relationships between a suite of physical variables and benthic biota in select areas of the Australian continental shelf. This paper focuses on results of the 2008 Carnarvon shelf survey, located within a Commonwealth Marine Park and adjacent to the World Heritage-listed Ningaloo Reef (Western Australia). High resolution multibeam sonar mapping, underwater video and benthic sampling revealed a complex geomorphology of ridges, mounds and sandy bedforms. The largest ridge extends 15 km alongshore is 20 m high and interpreted as a drowned forereef. Smaller ridges are ~1 km long, oriented northeast and preserve the form of aeolian dunes. Mounds are up to 5 m high and form extensive fields surrounded by flat sandy seabed. These ridges and mounds provide hardground habitat for diverse coral and sponge communities, whereas the surrounding sandy seafloor is characterised by few sessile benthic organisms. Multivariate analysis of these relationships is used to develop predictive models of benthic habitats, demonstrating the utility of high resolution physical data for informing management of these ecosystems.

The Tasmanian Shelf survey was conducted on the Challenger in collaboration with the Tasmanian Aquaculture and Fisheries Institute between the 13-16th June, 2008 and 23rd February to the 14th March, 2009 (GA survey #0315). The survey was operated as part of the Surrogates Program of the CERF Marine Biodiversity Hub. The objective was to collect co-located physical and biological data to enable the robust testing of a range of physical parameters as surrogates of benthic biodiversity patterns. A total of 55 video transects were surveyed from five study areas (Tasman Peninsula, Freycinet Peninsula, The Friars, Huon river, and Port Arthur channel) in water depths ranging from 15-110 m. Video was recorded to mini DV tapes, and copied to digital format. For further information on this survey please refer to the post-survey report (GA Record 2009/043 - Geocat #69755).

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. The GA0309_0312_JervisBay2008 folder contains video footage; the GA0326_JervisBay2009 folder contains still images; and the files are the video characterisation datasets. Underwater towed-video footage and still images represent the raw data. Video characterisation datasets include substrata types and the presence/absence of benthic taxa.