In this article it is proven that ultrasound can be used to harvest microalgae. The separation process is based on gentle acoustically induced aggregation followed by enhanced sedimentation. In this paper, the efficiency of harvesting and the concentration factor of the ingoing biomass concentration are optimized and the relevance of this process compared to other harvesting processes is determined.

This review provides an overview of aspects of the ecology of drifting and beach-cast macroalgae and marine angiosperms in respect to present and potential commercial use of that resource in Australia. It sets the scene with sections on industries that utilise macro-algae and seagrasses, the ecology of littoral and nearshore sublittoral ecosystems and the processes of deposition of beach-cast macro-algae and seagrasses on beaches. It then describes the major economic macro-algae and seagrasses that occur as beach-cast wrack, with an emphasis on known information on habitat distribution, geographical range, and harvesting issues. Gaps in scientific knowledge are pointed out.