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

Suitability of Habitats for Growth of Black-Lip and Silver-Lip Pearl OystersTable 1. Type, total area and characteristics of the coral reef and lagoon habitats associated with each of the CookIslands (Wells 1998).Island Type Area Characteristics of Reefs and Lagoons(km 2 )Manihiki Atoll 5.2Penrhyn Atoll 9.8 Many isletsOuter reef has buttresses, surge channels and deep water nearby. Corals arebest-developed at the south-east end of the lagoon, where waves wash over thereef. Lagoon is about 5 km in diameter and has a maximum depth of 72 m.Two large islets in north-east and west and many small islets at southern endof lagoon.Rakahanga Atoll 4.0Rarotonga High, volcanic 67.0Small lagoon surrounded by reef with two main islets to north and south andseven smaller islets in between them.Fringing reefs are 400-800, 100-200m and 50-100m wide on the south, west andnorth and east coast, respectively. Reef edge is almost continuous. Reef flatsare shallow and covered with sand. Algal ridge is present on the reef.Mangaia Low, volcanic uplifted 71.0Mauke Low, volcanic, raised 18.4Mitiaro Low, volcanic 22.3Atiu Moderate, volcanic, 28.2raisedFringing reef with narrow living reef flat, steep outer reef slope that levels offto a wide terrace at a depth of 30-40 m depthSurrounded completely by a 50-100m wide reef flat dominated by hard reefrock pavement. Outer reef slopes gently to depths of 8-15 m, and then steeplyto 80 m, with few shelves.Fringing reef with narrow living reef flatFringing reef with narrow living reef flat, except on the north side where thereis no reef flat.Takutea Low, lying elongated 1.3 Surrounded by reefsand cayManuae Atoll with two flat coral 22.0sand islets.Palmerston Atoll 2.6Aitutaki Triangular volcanic cone 106.0forming an almost atollShallow closed lagoon surrounded by continuous reef with a single narrowboat passageElongated lagoon with eight islets surrounded by reefLarge (66 km 2 ), shallow (75% < 4.5 m deep) lagoon. Triangular barrier reef, 600-1700 m wide. Steep outer edge on south and east sides and intermediate slopeon west side. Small patches of reef in south and south-west of lagoon.SuwarrowPukapukaAtoll with a nearcontinuous rim and 22isletsTriangular atoll withthree islets at the apicesand several sand banks.Atoll is surrounded by a well developed algal ridge and 100-800 m wide reefflat. Patch reefs < 100 m diameter occur in the central lagoon and small patchreefs around its western edge. Lagoon has 10 km diameter, maximum depth of80 m and covers 133 km 2 . A wide, 10 m deep pass in the north-east allowsgood exchange of water.Atoll is surrounded by a closed reef, except for an artificial passge at NW end.Lagoon is 8 km x 3-5 km and ranges in depth from 10-50 m.Nassua Oval, flat sand cay Narrow reef flat