Abstract

Seabeds of the global oceans are covered by sediments and rocks that provide habitats for diverse benthic flora and fauna. These sediments and rocks vary in morphological forms and textural properties. Accurate information on seabed substrate is key for effective ocean management. Especially, mapping seabed morphological forms and textural properties is an important scientific field of marine geology and geomorphology. Also, it would provide key information for the understanding of marine biology and ecology, as well as oceanography.

In the last two decades, multibeam acoustic remote sensing has become the preferred seabed mapping tool, mainly because it can simultaneously collect co-registered bathymetry and backscatter data. Modern high-frequency multibeam echosounders transmit and receive backscatter signals from hundreds of narrow-angle beams which enlighten small footprints on the seabed. They can produce bathymetry and backscatter data with a spatial resolution around 2% of water depth, which enables us to map the seabed with great detail and accuracy. In this presentation, I will describe the key processes and techniques used to analyse the multibeam data. I will also present a few case studies of multibeam acoustic remote sensing for the mapping of seabed properties and benthic biodiversity. The aim of the presentation is to demonstrate the great potential of multibeam technology for the advance of marine science.