A combined acoustic and optical instrument for fisheries studies

The AOS system was developed through the merging of acoustic and optical technologies to further the quality of fisheries stock assessment. The system has been deployed from several ships (40 m to 75 m in length) over the past three years providing improved accuracy of acoustic target strength measures for commercial fish species and delivering biomass estimates of fish stocks. It has proven to be robust withstanding the harsh environment of pressure and temperature to depths of 1000 meters. The platform must also cope with exposure to significant impacts and vibration during deployment and recovery as the trawl net moves up and down the stern ramp of commercial trawlers. The system continues to be incrementally improved to gain better performance and to streamline post survey data analysis. These improvements come as a direct result of new measurement challenges identified through working with data sets collected by the instrument.