Visioning the Coral Sea Marine Park

While shallower areas of the reefs have been studied through SCUBA diving, little is known about the pristine plateau in the vast deeper waters, and scientists only have a general idea of its depth. The deep waters have only been visited several times before by the likes of Jacques Cousteau in the 1980s - down to 240 meters - and a German expedition to 800 meters in 2009. This expedition will provide a novel look down to 2,000 meters into the deeper waters, giving insight into the species that live there and gathering new seafloor maps to better understand the geomorphology (shape of the seafloor).

Very few deep-sea areas in Australia have been studied. Following two successful expeditions exploring the Western Australian coast, this voyage will expand the characterization and understanding of deep sea areas in the Coral Sea Marine Park. As demonstrated by the work done in Bremer Bay, Perth Canyon, and most recently the Ningaloo Canyons, Remotely Operated Vehicle (ROV) SuBastian can make a major impact in the discovery of new species, habitats, and in understanding key processes in these little-known ecosystems. In a country where there are few opportunities to explore the deep sea with a dedicated science ROV, this expedition will have a major impact in visioning the Coral Sea.

Features of the Reef Flanks
In addition to the broad-scale mapping and characterizing of a genuine marine frontier, the vision data collected from these deep-water marine life and their surrounding environments will allow scientists to develop an understanding of the physical and temporal changes that have occurred historically on the Queensland Plateau. The acquisition of baseline mapping and underwater vision data provides a unique window into both the geological past and the present day condition of mesophotic (twilight zone) and deeper cold-water coral ecosystems, allowing for marine park staff to manage and adapt policies for the future.

Preliminary mapping of the Queensland Plateau suggests the presence of many enigmatic seabed features, including numerous drowned reef pinnacles and long meandering channels on the plateau surface. The team aims to completely map, in detail, the steeper reef flanks using high-resolution multibeam mapping, and also target these enigmatic seabed features. Advanced mapping techniques provide the ability to uncover finer-scale features, such as wave-cut caves on the sides of these reefs, which can provide important insight into the past sea levels. Comprehensive mapping is critical to reveal the complete reef morphology from their base up to their shallower depths, and to understand the evolution of the reef system. The new multibeam data will greatly advance the characterization of Australia's massive and ecologically important marine estate. All data will be added to the Australian government databases and made publicly available.

Life Along the Reef Slope
In addition to obtaining a detailed map of deeper reef structures, ROV SuBastian will capture high-resolution imagery upwards along the steep reef slopes to examine how corals and other species group across large depth gradients. This data will be compared to previous work in the region to identify spatial patterns of deep-sea life. The observations in the Queensland Plateau can provide insight into the biodiversity patterns in similar environments.

Additionally, the ROV dives will help to determine the extent and depth of coral bleaching. Another mass bleaching event recently took place that resulted in scientists finding more thanhalf of the coral reefs bleached beyond the Great Barrier Reefin early March. This expedition will provide an opportunity to look at the mesophotic or deeper reef to see how extensive the bleaching is, and if these reefs could act as a potential refugia for the Great Barrier Reef.