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The coastal zone between Guilderton and Kalbarri, north of Perth, Western Australia, is a highly dynamic area of high landscape and conservation values under increasing development pressures. Intensification of terrestrial and coastal impacts has highlighted the need to develop a georeferenced data base for land management. The Coastal Assessment and Restoration project aimed to document the natural resources and coastal developments to the region and to identify & assess threats to the coastal strip through the creation of GIS datasets. GIS datasets provide a key source of reference information which can be accessed by a number of stakeholders for future coastal planning and management and provide a basis for developing a risk management assessment of the coastal zone and a strategy for coastal managers in our climate change future. [ABSTRACT FROM AUTHOR]

Understanding of the processes regulating sediment transport, accumulation and erosion requires an appropriate mapping of coastal geomorphology, seabed sediments and benthic habitat distribution to allow management issues to be identified, understood and addressed. In this study multibeam echo-sounder data were used to map shallow water geomorphological features and the spatial distribution of benthic habitats, with the support of underwater imagery for ground truthing the acoustic data. At Geraldton, sediment analyses have revealed a dominant biogenic nature, with modern carbonate sedimentation linked to the seagrass and macroalgal carbonate factories colonising these shallow (< 30 m) coastal embayments. Whilst seagrasses are common on sheltered hardgrounds blanketed by fine sand, macroalgae were found on high energy limestone reefs. The distribution of sand bar and sheet systems is regulated by wave induced sediment transport with the influence of pre-existing seabed topography. Exposure to wave energy, seabed geomorphology and sediment characteristics is closely related to the distribution of benthic habitats and sand substrates, highlighting the value of an integrated analysis of these parameters. The capability of multibeam echo-sounder backscatter data to discriminate between seagrass meadows, macroalgal communities and sandy substrates was also evaluated and the acoustic response from the seabed was better explained by considering together seafloor geomorphology and biota type, as both these parameters influence backscatter strength. [ABSTRACT FROM AUTHOR]