Mapping the middle: Developing and testing multi-beam acoustic techniques to study the oceanic water column

The fact that sound waves travel long distances, while light is extinguished within the upper several meters,means that acoustics allows us to see under the ocean surface. The challenge in using acoustic surveyingtechniques remains the identification and interpretation of the sources of scattering. Multi-beam systems allowthe creation of three-dimensional acoustic images and have been used-with increasing sophistication-fordecades to map the seafloor. The marine science community is just starting to use multi-beam systems and theyare showing promise in classifying water column scatterers and their distributions, be they fish schools, frontalstructures, plumes or bridge pilings. McGregor GeoScience Ltd., with their expertise in and infrastructure formapping the seafloor with multi-beam systems, is interested in tapping into this new market. To our knowledgethere is no group in Canada, in industry or academia, working on or offering services in multi-beam mappingof the water column. This proposal teams a Dalhousie research group with expertise in the interpretation ofwater column scattering with McGregor GeoScience Ltd.'s expertise in multi-beam acoustic data collection andanalysis to explore the potential of multi-beam surveying of the ocean water column for the benefit ofMcGregor and marine science (including fisheries management) in Canada.