Stimulating investment in pearl farming in ... - World Fish Center

Suitability of Habitats for Growth of Black-Lip and Silver-Lip Pearl Oysters Final, June 2008Fringing reefs occur along the coastline of the Northern Territory. The shallow, turbidwaters of the eastern Arafura Sea, however, are not conducive to growth of corals, hencemost of these reefs are shallow. The development of reef increases to the west and reachesmodest diversity in the vicinity of Essington Peninsula.On the coast of Western Australia, there are substantial areas of coastal fringing reefs atNingaloo Reef, in the Dampier and Monte Bello archipelagos and in the Kimberley region(Figure 1b). Ningaloo Reef is the largest fringing reef in Australia (230 km long). The reefsof the Dampier Archipelago, situated off the Pilbara coast are the best known reefs on thewest coast. The marine environment in this archipelago ranged from muddy inshore toclear offshore waters, all mixed by strong tidal currents. The reefs of the Kimberley coast arepoorly documented, probably because they are exposed to turbid waters and large tidalfluctuations. In the north-west, there are 'shelf-edge atolls', Scott Reef, Seringapatam Reefand Rowley Shoals, and an atoll-like structure consisting of a large sedimentaryaccumulation with reef patches, Ashmore Reef. The only true atoll in Australian waters isthe Cocos (Keeling) Atoll in the eastern Indian Ocean. There are also coral reefs and areas ofcoral growing on rocky reefs in the Houtman Abrolhos Islands, 400 km north of Perth. TheHoutman-Abrolhos Islands is a small archipelago of 122 low-lying islands situated near theedge of the continental shelf at latitudes of 28°15' to 29°00'S. Three of the islands are ofcontinental origin and have extensive sand dunes, whereas the others are composed oflimestone. The Abrolhos has the southernmost development of coral reefs in the IndianOcean and is one of the highest latitude coral reef systems in the world.4.2 Cook IslandsThe Cook Islands are located between 8 º and 23º S and 156º and 167ºW and are divided intotwo disjunct groups: the Southern and Northern Cook Islands (Figure 2). The Islands of theSouthern Group differ in form, structure and relief and include one high mountainous,volcanic island (Rarotonga), four low volcanic, raised islands surrounded by fossil reefs(Mangaia, Mauke, Mitiaro, and Atiu), a low lying elongated sand cay surrounded by coralreef (Takutea), two atolls (Manuae and Palmerston) and a near atoll with a volcanic core(Aitutaki). The volcanic islands are surrounded by fringing reefs. The Northern Groupconsists of five atolls (Suwarrow, Penrhyn, Manihiki, Rakahanga and Pukapuka) and oneoval flat sand cay on a coral foundation (Nassau). A brief description of these islands basedon the information in Wells and Jenkins (1988) is presented in Table 2.4.3 FijiFiji is one of the largest and most scattered groups of archipelagos in the South Pacificregion, consisting of about 844 high islands, cays and islets, located between 15-23º S and177-178º W (Vuki et al. 2000). The islands are divided into seven main groups: Rotuma,Vanua Levu and associated islands, the Lau Group, the Lomaiviti Group, the Yassawas, VitiLevu and associated islands and Kadavu and associated islands (Wells and Jenkins 1988)(Figure 3). The main archipelago accounts for 87% of the total land mass and includes thetwo largest islands, Viti Levu and Vanua Levu, and three other large islands, Taveuni,Kadavu and Gau. Most of the islands are volcanic and formed from molten rock that cooledand solidified below the surface of the earth.Coral reefs are well developed and found around all the island groups. Many of the reefsystems are complex, consisting of barrier, platform and patch reefs (Wells and Jenkins1988). Coral reefs vary in size from patch reefs less than 50 m long, to the 100 km long CoralCoast fringing reef system on Viti Levu and the 370 km long broken barrier reef chain of theThe Ecology Lab Pty Ltd – Marine and Freshwater Studies Page 13