New discoveries in Victoria's seabed

Ancient lakes, rare plants and strange holes have been discovered during a sonar survey of Victoria's seabed.

Scientists are giving coastal planners and managers an unprecedented view of the state’s marine national parks. A recent offshore survey has found new underwater formations that will keep coastal researchers busy for years to come.

Using new mapping technology, the Coastal Cooperative Research Centre (CCRC) has produced high-resolution images of prehistoric riverbeds, and never-before-seen underwater habitat. Deep depressions — which may represent old volcanos, ancient lakebeds, sunken coastal bays or other formations — have also been revealed. More research will be conducted to confirm their origin.

The sonar mapping and monitoring program will enable the Victorian government, universities and scientific institutions to build on knowledge about the state’s coastal ecosystems.

Parks Victoria’s manager of marine research Dr. Anthony Boxshall says the images reveal unprecedented detail of various habitats on the seabed.

“Of course, we know broadly what’s on the seafloor in the parks, but with this amazing detail we can better manage these important areas.”

New equipment and cutting-edge analysis from Perth-based Fugro Survey Pty Ltd are being used in the joint project with Parks Victoria and the Coastal CRC.

“Fugro is a world leader in collecting seafloor information from multibeam systems and preparing seafloor maps with the software developed right here in Australia,” said Cass Castalanelli, Fugro’s technical manager.

Sonar mapping equipment, mounted to a research vessel, can record a 50 to 200 metre-wide swath of seabed as it passes over the surface. Sound waves are converted into images by on-board computers to show the contours of the seabed. Special video equipment is then used to identify particular habitat types such as seagrass, kelp, rocky reefs or sand.

“Results from this project will enable marine park managers to witness the benefits of such management systems as monitoring sediment movement and mapping underwater habitats. In addition to environmental and resource applications, the project is also important to navigation in coastal waters,” said Professor Des Lord of the Coastal Cooperative Research Centre.

“The astounding results from this work in Victoria has led to similar mapping exercises commencing elsewhere in Australia and is attracting considerable international attention.”

Dr. Boxshall added that the wealth of seabed shapes and habitat now exposed is providing a rich field of study for geologists, engineers, biologists, park managers and anyone with interest in Victoria’s seabed.

Victoria has 13 marine national parks and the project will map 6 of the largest ones from Port Campbell to Point Hicks. The surveys will be completed by July 2006.

Supporting organisations include the University of Western Australia, Deakin University, Tasmanian Aquaculture & Fisheries Institute, Australian Maritime College, Victorian Partnership for Advanced Computing and the National Tidal Centre.

This project supports Australia’s National Research Priority No. 1, an Environmentally Sustainable Australia.