The Tahitian Black Pearl -- Black Pearls From Tahiti

		MODERN  PEARL  FARMING             Much has changed since those early days.  After the oyster population was almost decimated, the Tahitian government's Department of Fisheries enacted regulations and conservation measures. In 1960 only four or five natural Pearls were found in all of French Polynesia. Efforts then began to produce cultured Pearls to revitalize the Pearl industry.                        In 1966, at Manihi atoll, Jacques and Hubert Rosenthal, grandsons of Leonard  Rosenthal, the "Pearl King", established the first black Pearl Farm in French Polynesia: the Societe experimentation Perliere de Manihi.  Today there are several Pearl farms throughout French Polynesia.  Some operate as cooperatives and some are owned by independent investors.             These farms actually "raise" a "crop" which is the black-lipped   oyster (Pinctada Margaritifera), producer of the "Black Pearls of Tahiti".    These oysters are grown at the farms from D-shaped larvae to spats to   adult oysters which can live up to thirty years, attain a diameter of 6-8   inches and a weight of 11 pounds.                          When the oyster is large enough, it is grafted.  The graft is a tiny   bead ball made from the shell of freshwater mussels from the   Mississippi River and it acts as the seed or nucleus of the Pearl-to-be.    The nucleus comes in various sizes which are selected to correspond   with the size of the oyster.  The nucleus is inserted with a piece of   epithelium  from a "donor" oyster into the reproductive organ (gonad) of   the oyster.  The epithelium is the mantle tissue which secretes nacre in   concentric layers around the nucleus to produce a Pearl.                          After the graft is completed, a hole is drilled into the oyster's shell   and the oyster is hung on a rope.  There are 10-20 oysters placed on a   rope.  The oysters are returned to one of the farms growing platforms   and suspended under water for two to three years while the pearls are   forming.                         The usual success rate of the grafting ranges from 25-40%, rarely   higher, and will vary according to atoll, location within the lagoon,   technicians' skill, the percentage of oysters which reject their nuclei and   various unpredictable circumstances such as hurricanes.