Estimation of offshore fish passage at Mission by imaging sonar

For this project, we propose to use an Adaptive Resolution Imaging Sonar (ARIS) mounted on a fin-shaped metal body towed by the vessel to acquire data of fish images. This would allow for more accurate survey of offshore fish passage than the current mobile survey system at Mission Hydroacoustics (HA) site. The application of ARIS system will address two challenges that are difficult to resolve with the mobile split-beam system. These are (1) recognition of fish targets and (2) determination of fish’s swim direction. By directly measuring these two variables with an imaging sonar ARIS, we will obtain an accurate estimate of offshore fish passage, which has been identified as a limitation with current systems when estimating abundances at Mission.