First trial of multibeam echosounder ME70 mouted on YOKO-MARU

The YOKO-MARU is newly built last December that is a research vessel belongs to Seikai National Fisheries Research Institute. She equipped the new multibeam echosounder SIMRAD ME70 which is expected to be active in future research. East China Sea is one of important fishing area of small pelagic fishes, sardine, anchovy, chub mackerel, and jack mackerel, and YOKO-MARU investigate around this area. Because of research results of acoustic surveys are important informations for decision of TAC (total allowable catch), it is required to investigate more accurate. Though echo-integration survey is the standard method of abundance and biomass estimation, fish avoidance reactions from vessels cause uncertainty sometimes in a survey for small pelagic fishes especially. To observe this behavior, horizontal and vertical scanning multibeam sonar have been employed. Also multibeam echosounder ME70 has vertical scanning acoustic beam, and it is able to scan widely under a vessel. Moreover, ME70 is a calibrated, so we can use quantitative information from target fishes. In this study, we introduce our first trial using ME70 and discuss future work of acoustic survey by YOKO-MARU.