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

Page 8the bead in an even, uniform and attractive manner to create a pearl. For the first few weeksafter seeding the shell is kept inside a mesh bag in case it rejects the nucleus, which in thatcase can be recovered from the bag and re-used.A good technician will achieve low rejection rates (30% rejection would be considered good),and a high proportion of good-quality pearls. Pearl price is exponentially related to quality – agrade 1 pearl may be worth 10 or 100 times the value of a grade 2 pearl, so a small increasein the proportion of grade 1 pearls in a harvest makes a huge difference to the profitability ofthe farm. Pearl seeding technicians are costly, particularly the most skilled ones. The typicalcost of implanting pearl nuclei is around US$ 10 per shell. Since a typical mid-sized farmmay have 10,000 – 50,000 shells seeded each year, this represents a very substantialinvestment, and is a major barrier to entry into the industry.Harvesting of pearls typically takes place about two years after implantation. When a pearl isharvested, it is frequently possible to insert a new nucleus into the pearl sac in the gonad inplace of the harvested pearl, thus immediately commencing a second crop. Second andsubsequent pearls from the same oyster tend to be of better quality than first pearls becausethe pearl sac is already established. In addition, larger nuclei can be used, leading to aprogressive increase in pearl size and value. Some oysters can produce four or five pearlsduring their lives, and occasionally even more.The main difference between black-lip and white-lip pearl farming is in acquisition of shellfor implantation. White-lip spat are less abundant and settle less readily on spat collectorsthan black-lip, hence spat collection is not a major source of young oysters for this species.Traditionally white-lip were collected as young adults from the wild, but hatchery technologyfor pearl oysters has now developed to the point that juveniles of both white-lip and black-lipcan be produced in relatively simple hatchery facilities. Where wild stocks are unable toprovide sufficient white-lip pearl oysters for farm operations, hatchery-reared spat areincreasingly used.In general, black-lip pearl farmers prefer wild-collected juveniles over those reared inhatcheries, as they are reputedly more robust and are said to produce better-quality pearls.This is not universally true, however, and some users of hatchery-produced spat appreciatethe consistency of size and shape, which makes seeding easier. For wild spat collection to besuccessful requires a robust natural spawning stock to produce the juveniles, which in turnrequires that the natural stock not be excessively harvested, either for shell (which is anexport commodity in its own right) or for adults to be used for seeding. In areas where naturalstocks have been depleted, pearl farms can contribute to reproductive success by aggregatingconcentrations of breeding adults, and spat collection operations are often most successful inlocations close to existing farms. Nevertheless a rigorous management regime for wild adultsis required where spat collection is the basis of a pearl industry, no matter how many shell arebeing kept under culture, and both French Polynesia and Cook Islands have restricted orbanned the collection of adult pearl shell from the wild in islands where pearl farming ispractised.The pearl farming industries of French Polynesia and Cook Islands have evolved to showsimilar structural characteristics. A small number of large companies produce the majority ofthe pearls while larger numbers of smaller producers or family farms each produce smallnumbers of pearls, or simply collect and sell juvenile shell to the larger operators. Thissegmentation of the industry allows participation at different levels. Large investors withsubstantial capital, a long time horizon and a low aversion to risk can take the chance toimplant large numbers of pearl shell in the hope of substantial economic gain. At the sametime small operators with limited capital or those who are new to the industry can collect and