Continuous Monitoring of Fish Population and Behavior by Instantaneous Continental-Shelf-Scale Imaging With Ocean-Waveguide Acoustics

Abstract

Abstract : The long-term goals of this program are to (1) instantaneously detect, image and spatially chart fish populations over continental-shelf scales, (2) continuously monitor the areal densities and behavior of these fish populations over time, and (3) remote species classification, using a novel audible frequency acoustic system (300-5000Hz) referred to as Ocean Acoustic Waveguide Remote Sensing (OAWRS). The OAWRS ability to assess biological and behavioral characteristics at entire-population scales with high spatio-temporal resolution is an important technological step forward, and represents a new approach in the study of marine ecology and ecosystem-based fisheries management. The primary objectives of this proposal are: 1) Conduct a major multi-institutional offshore oceanographic experiment to explore the population distributions and behavior of living marine fish in the Gulf of Maine on and near Georges Bank with the new OAWRS technology. 2) To specifically monitor the temporal and spatial population densities of herring, a fish of major ecological and commercial importance, on the northern flank of the Georges Bank, where they are known to congregate in large quantities. 3) To test this new OAWRS technology with simultaneous line-transect methods using both conventional fish finding sonar (CFFS) and directed capture sampling with nets. 4) To use the OAWRS technology in conjunction with an official US National Marine Fisheries Service Survey, in particular the Annual Herring Survey in Georges Bank and the Gulf of Maine, to enable quantitative comparison. 5) To investigate the limits of taxonomic resolution inherent to the OAWRS system, and to use OAWRS imagery to assess the taxonomic limits of more conventional systems that rely upon sparse line-transect surveys that significantly under-sample fish populations in time and space.