• The collecting stations
  The first pearl fishers soon realised that they would have to give up diving, adult animals' sample, unequally trustworthy suppliers and find other means of obtaining regular supplies of pearl oysters for grafting purposes
  They began to use passive techniques for catching Pinctada margaritifera spat, using collectors to which mollusc planctonic larvae become attached. This technique consists of immersing a rope at a depth of 3m, which is stretched out between buoys and moored to pinnacles or dead weights placed on the sea floor. Along the whole rope, which can measure anything between 100 and 200 metres in length, collectors are installed which are held under the water by the action of the surface buoys. The composition of these collectors has evolved considerably from plant fibres (coconut fibres, for example) to modern synthetic materials (nylon mesh, greenhouse shades, etc.

    The collectors (or clutches, as they are sometimes called) must be made of rot-proof material and contain many little nooks and crannies in which the oyster spat can settle safely and develop out of the reach of predators. The numbers collected depend on the number of larvae present in the immediate marine surroundings. The success of the pearl farmers therefore depends on their ability to gauge whether the conditions are favourable to the oysters' fertilisation and reproduction.

• The choice of site and the harvesting of young Pinctada margaritifera
  The sites chosen for the collecting stations therefore should be located preferably in naturally well-stocked waters so that there is the best possible likelihood of contacts occurring between the animals' sexual substances. Places which are either too exposed to sea currents such as those occurring near the atoll channels or too sheltered, shallow and stagnant, are unsuitable. When choosing a site, it is also necessary to pick the appropriate date for installing the collectors. In the reproductive cycle of Pinctada margaritifera, the peaks in the spawning period coincide with the occurrence of thermal shocks. The seasonal changes which take place in April and May as well as in November and December under these latitudes are therefore excellent moments for setting up collectors.
  The oyster spat attach themselves to the collectors fifteen to twenty days after being spawned.

• The depth at which the station is immersed:
  The most efficient technique consists of first carrying out the collection at a depth of 1.5 to 3 metres, and then allowing the station to sink gradually under the weight of the developing oyster shells down to a depth of about 15 m. This procedure makes it possible in the first stage to protect the vulnerable young oysters from the predators on the sea floor, and subsequently to keep them mid-way between the bottom and the strong surface movements which are liable to detach them from the collectors.
  

• The immersion time:
  The young oysters are usually detached eight to twelve months after the fertilisation phase, when they have reached a diameter of at least 6 cm, which simplifies the subsequent handling operations and reduces the risk of mortality.

    The young oysters collected do not all belong to the genus Pinctada margaritifera. A large proportion of them (which it is not easy to quantify, because the variations from one spat collector to another and from one station to another are too great and cannot yet be properly controlled) are the competitive Pinctada maculata oysters, which exist in larger numbers than the margaritifera variety around the Polynesian atolls.

The increase in the production of Pinctada margaritifera:

To compensate for the ever-decreasing adult oyster catching quotas imposed and to satisfy the demands of the flourishing new cultured pearl industry, the oyster farmers have successfully adopted and  developed the spat collecting technique. The number of collecting concessions granted has been increasing steadily since 1977  (see graph). The Tuamotu-Gambier islands have occupied a leading position in terms of oyster spat collection since 1991. These islands accounted for an increasingly large proportion of this activity in 1991, 1995 and 1996, and the atolls on the whole are now responsible for around 80% of all the Pinctada margaritifera available on the market. 

The distribution of oyster collecting  concessions among the atolls:

Four atolls have achieved a particularly high rate of oyster collection: Ahe, Arutua, Takapoto and Takaroa. The overall pattern of development of the collecting activites reflects the attempts made in this sector to redistribute the production points to  be able to satisfy the pearl producers' growing needs for young oysters, while compensating for the fact that the most over-worked atolls have exhausted their stocks, while others have no Pinctada margaritifera at all because they are not part of this variety's natural habitat.The island of Takaroa, for instance, which once had as many as 176 concessions, has lost 33 of them since 1991; whereas other atolls have benefited from the re-distribution, especially those situated near the main consumer centres, such as Nihiru, which is near Makemo. Some of the higher islands were prospected in 1991-1992: Mopelia in the Society Islands joined forces with the other pearl collecting atolls and by 1996, had 201 concessions entirely devoted to this activity, which send their produce to the Tuamotu atolls.

Aquaculture, a new experimental oyster spat production technique:

The most noteworthy attempt at aquaculture as an alternative means of producing Pinctada margaritifera on the Polynesian Territory was launched as the result of a public initiative, the Pinctada reseach programme, which is conducted by the Department of Marine Resources (SRM) and financed by the Terrritory, the French State and the European Community.This research is being carried out at the Rangiroa hatchery. 

The aims of this hatchery are manifold. First, as suggested by the name of the centre in question, it is planned to learn how to control the reproductive processes of Pinctada margaritifera with a view to producing spat "in captivity", as it were. The research carried out at the hatchery is not simply intended to provide an alternative to the usual spat collection procedures, but also to improve the productivity and the quality of the oysters produced so that they will be stronger and more able to withstand being handled. As the result of the reproduction cycle which ended at the hatchery in December 1996, 200 000 seed oysters aged two months were obtained. The scientists working at the site have calculated that at the age of six months, the mean survival rate of the oysters is approximately 50%.  32 000 of the seed oysters thus obtained were sold to four pearl growers in Rangiroa, and grafted once they had reached a suitable size. In 1998, the research centre transferred some of the spat which had hatched on the premises to other atolls. No data are available as yet on the results of the ensuing pearl harvest..