Observations of marine life in the Indian Ocean by hydroacoustic water column imaging
Present day multibeam echo sounder systems have the capability to record, display, and log backscattered signals from the water column (WCI = water column imaging) in addition to the echoes from the seafloor. This extra information can deliver interesting insights into marine life in the upper water layers but it produces a huge amount of data which requires tremendous time and effort for processing and interpretation. To tackle this, a semi-automated approach has been developed which is based on the conversion of the data into images and applying available image processing techniques. That way the WCI data acquired during eight expeditions in the Indian Ocean had been processed and the relative biomass abundance along an extended North-South profile had been determined. In addition, the WCI data displayed interesting observations of the diurnal migration of zooplankton and revealed an amazing correlation to nocturnal illumination.
Indian Ocean | INDEX project | multibeam echo sounder | single beam echo sounder | WCI |biomass abundance | zooplankton migration
