Abstract
This project provides an overview of methods, data processing techniques, and equipment used to make passive acoustic measurements in tidal channels. The acoustic field is measured in these energetic environments to characterize the natural noise field, quantify contributions by tidal energy and other human deployed devices, and to detect and localize vocalizing marine animals, the latter being the primary objective of interest in this project. No commercially available, purpose built acoustic monitoring systems have been designed for operation in turbulent tidal channels, estuaries, or rivers, despite a growing body of underwater acoustic field work being carried out in the context of environmental impact assessment of tidal energy extraction. However, a number of technologies designed for more benign oceanographic conditions have been experimentally deployed in high flow environments, including conventional cabled or autonomous hydrophone and analogue-to-digital instrument packages, internally recording hydrophones with digital interfaces, autonomous and cabled hydrophone or vector sensor arrays, and integrated hydrophone and data processing systems for marine animal detection. Flow noise, natural ambient noise, sensor size and geometry, and deployment method all have an effect on the detection efficiency of the passive acoustic systems. Experimental results and system performances are compared across all instrument package types, deployment methods, and study areas.