DEVELOPMENT OF A MULTIDISCIPLINARY SIDE-SCAN SONAR-BASEDENVIRONMENTAL ASSESSMENT TOOLIN SHALLOW MARINE WATERS

摘要

The Belgian coastal zone has been the subject of a multidisciplinary investigation as tornprovide data to support the implementation of a future marine protected area. Intensive fieldworkrnresulted in a spatially and temporally diversified dataset containing geologically and biologicallyrnrelated variables. Most data was gathered in a macrotidal shallow marine environment witnessingrnthe highest biological diversity known on the Belgian continental shelf. The depths vary between –rn17 and 0 m MLLWS; the sediments range from mud to gravel with a predomination of sands. Asrnsuch, the area was ideal for the set-up of time- and cost-efficient monitoring tools. Side-scan sonarrnwas the preferred remote sensing technique to study the nature of the seafloor in relation to thernlarge- and small-scale morphology and the ruling hydrodynamics. Acoustic habitats wererndiscriminated, mainly based on differences in reflectivity, texture and patterns; this was standardisedrnthrough the set-up of a table showing the relations of the imagery with the most importantrnenvironmental parameters. A prediction towards the preferred macrobenthic community wasrnincluded as the structural and functional role of macrobenthos is regarded important within thernmarine ecosystem. The interpretation of the imagery in terms of acoustic habitats was tested and itsrnphysical and biological meaning was evaluated along the Belgian coastal zone. This was aidedrnthrough a GIS-based quantitative analysis that also allowed an easy set-up of holistic habitatrnstructure maps. As such the acoustic habitat modelling is a tool for a scientifically sustainedrnevaluation of the coastal zone.