During her expedition to The Great Barrier Reef in November-December 1987, Captain Cousteau’s exploration vessel “Calypso” was equipped with the small 2-man submersible SP-350. Deployment of the submersible during several dives down to a depth of ca. 250 m allowed to gather firsthand information on the morphology and the living assemblages of the deep fore reef slope in the northern Great Barrier Reef and at Osprey Reef in the nearly Coral Sea. Although no samples could be collected during the dives, direct observations of the substratum were possible, complemented by photographs and video recordings.
The main focus of the project was on depth distribution, of scleractinian corals. They showed a relatively rapid decrease in diversity and abundance at around ca. 60 m, and disappeared completely at approximately 150 m deep. Such a decrease in species diversity and abundance was mirrored in some other groups, particularly sponges and encrusting calcareous algae. Conversely, antipatharians and even more so octocorals, largely dominant in the 60-150 m depth bracket, could be observed down to our 250 m depth limit.
About the presenter
Professor Michel Pichon, Biological Oceanographer, University Professor, is an expert on coral reefs, which he has studied for more than 48 years. He was research leader of several coral reefs research teams, operating in most major reef areas in the Red Sea, the Indian Ocean (Mascarenes, Comoros, Madagascar (Thesis), Maldives and the seas around Arabia), and in the Pacific Ocean.
He has been based for more than 22 years in Australia, first at James Cook University, Townsville, then as Deputy Director, Australian Institute of Marine Science. He then did work principally on the Great Barrier Reef, with his students and Australian colleagues, but also elsewhere in the Pacific in cooperation with American and Japanese teams. He has published more than one hundred scientific papers in international scientific journals, mostly on coral reefs, and four books on the reef corals of Australia’s Great Barrier Reef. He is a board member of the International Society for Reef Studies.
He now lives in Australia, where he is a Tropical Marine Consultant and Honorary Research Associate at the Museum of Tropical Queensland, in Townsville.