Popis: |
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 interest-ing 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 tech-niques. 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 cor-relation to nocturnal illumination. |