Seafloor mapping – the many uses of multi-beam sonar

Scientists on board a federal fisheries research vassal in Alaska’s Pribilof Islands are using multi-beam sonar to survey and map seafloors. According to ecologists, mapping this vital crab habitat is an important step in preserving deteriorating king crab populations. The primary goal of current mapping pilot project is to test the usefulness of multi-beam sonar […]
Scientists on board a federal fisheries research vassal in Alaska’s Pribilof Islands are using multi-beam sonar to survey and map seafloors. According to ecologists, mapping this vital crab habitat is an important step in preserving deteriorating king crab populations. The primary goal of current mapping pilot project is to test the usefulness of multi-beam sonar systems for finding “shell hash” (deposits of crushed crab shell believed to be important in the survival of young crabs). In the past efforts to monitor, crab populations and record vital habitats were limited to trawl and pot surveys. Although these surveys could inform ecologist which habitats were being used as nursery grounds for immature crabs they could not provide much needed information regarding the habitat itself. Today’s current multi-beam sonar technology has the potential to drastically transform ecologist’s ability to monitor and preserve critical habitats of declining sea species. These technologies, however, do not come without a cost. According to Michelle Ridgway, the ecologist in charge of the shell hash project the systems currently being tested cost over $3,000 an hour to operate. After the initial data is, collected Ridgway will compare the newly collected sonar imagery to seafloor samples, side scan sonar imagery, and remotely operated vehicle video that have already been collected to help interpret the acoustic backscatter images. http://www.alaskajournal.com/stories/062609/fis_img9_001.shtml