HYDROACOUSTIC REMOTE-SENSING FOR ARTIFICIAL HABITATS

Hydroacoustic assessment techniques are widely used in studies of fish abundance, distribution and behavior. Applications of these techniques for evaluation of artificial habitats is complicated by the near-bottom distribution of these fish. However, this problem can be overcome by fixed-location techniques. Fixed-location techniques are now widely used in situations such as hydroelectric facilities or nearshore water intakes, where the electronic equipment can be kept in a dry, secure location. In these situations, data on fish abundance, distribution and behavior have been collected 24 h.day(-1) for up to 17 months. In many of these studies, data collection is totally automated, with transfer of results to a central station via telephone lines. These remote techniques are readily applicable to artificial habitats that are close enough to shore for cable runs. Sites further offshore will require application of instrumented buoys.