Benthic habitat mapping with multibeam sonar in Newman Sound, Terra Nova National Park, Newfoundland

Abstract

The objective of this thesis is to characterise and map the benthic habitats of Newman Sound, a fjord in Terra Nova National Park, eastern Newfoundland. A multibeam sonar system was used to collect bathymetric and acoustic backscatter data. As backscatter is a function of seafloor substrate, interpretations were made about the distribution of substrates, and these were tested by groundtruthing. Benthic sediments were collected using a Peterson grab and video images were collected with a tethered drop camera, SCUBA divers, and a remotely operated vehicle. A seismic sub-bottom profiler was also used. Nine substrates were identified, and each supported a distinct assemblage of invertebrates and algae, which were classified into eleven habitats. The distribution of substrates and habitats were mapped in a Geographic Information System (GIS). The results indicate that this methodology can effectively map fjord habitats and successfully identifies areas of conservation value.