Sophisticated sonar for marine habitat mapping

Sophisticated sonar for marine habitat mapping

Map of seafloor habitat types on Wellington’s south coast.

NIWA vessels’ multibeam sonar capabilities offer a rapid, accurate means of mapping marine habitats, with myriad applications.

NIWA recently applied this technology to map 46 square kilometres of seafloor habitats in and around the proposed Taputeranga Marine Reserve on Wellington’s south coast, in conjunction with Victoria University and the Department of Conservation.

Combining the shallow water capabilities of survey launch Pelorus and RV Kaharoa enabled the team to map close to the shoreline and cover the entire sub-tidal area. The vessels used a high resolution multibeam echosounder to provide unsurpassed detail of the seafloor, even distinguishing between coarse and fine gravel substrates.

This technology offers a quick and cost-effective method of seafloor mapping that can be combined with targeted dive surveys to produce detailed seabed habitat maps. These can be used to monitor the effectiveness of marine reserves, mataitai, and taiapure through ‘before-and-after’ or ‘inside-and-outside’ comparisons of marine habitats in and around reserves.

Research subject: Coasts