A plan for Antarctic krill survey with a scientific broadband echosounder onboard R/V Kaiyo-maru in the CCAMLR Division 58.4.1 during 2018/19 season

To investigate the utility of broadband sound for Antarctic krill acoustic surveys, we will conduct echo sampling with a scientific broadband echosounder EK80 (Simrad-Kongsberg) during a dedicated krill survey for CCAMLR Division 58.4.1 during 2018/19 season by Japanese research vessel, Kaiyo-maru. The echo sampling will be performed during targeted RMT1+8 tows. Spectra of volume backscattering strengths will be obtained from the sampled echoes and their characteristics will be investigated. Further, orientation and length distributions will be inferred from the measured spectra with theoretical acoustic scattering models. The survey and analysis plans are presented in this paper.