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Long
before foreigners arrived in Tahiti, native people used the
oyster shells they had collected for making various
instruments, ornaments, and above all, for fishing lures and
hooks. On the other hand, pearls were not held in high esteem,
no doubt because of the difficulty of piercing holes in them.
Today, the Territory has high hopes of the economic future of
the pearl.
At the beginning of the 19th century almost 1,500 tones of the
world oyster shell production were used for the button-making
industry. About 1850, supplies waned, partly because local and
foreign ships raked the oyster beds mercilessly. At that time
the lagoons were so rich in excellent pearl oysters that men
could collect hundreds of kilos per day, standing in water
only waist deep.
For decades, the production remained the same, for as the
easier areas became exhausted, men dived deeper and deeper for
their catch. The button industry started to use polyester in
1955 and prices fell, but gradually, a more permanent but less
spectacular demand developed because it was impossible to
imitate the beauty of real mother-of-pearl.
Pearl fishing used to be organized at special times or diving
seasons. A diver could go down deeper than 40 meters a hundred
times a day. All this effort was concentrated on
mother-of-pearl, as natural pearls were hardly ever found.
The population of whole islands would migrate temporarily to
atolls which were often deserted for the rest of the year.
After having escaped the perils of natural selection, the
oyster attaches itself to various inanimate supports. In fact,
it is a form of defense reaction that produces the pearl.
When
faced with a foreign body, a small parasite or a grain of
sand, the secreting organ of the shell, the mantle, isolates
the intruder by forming a layer of mother-of-pearl which will
then give birth to a pearl or a half-pearl. It was by
observing this reaction that the Japanese perfected their
pearl-culture techniques which are now used throughout French
Polynesia.
In the course of what can rightly be called a surgical
operation, the grafter introduces a small bone marble or
nucleus into a special part of the three to four year old
mollusk, and it plays the role of the intruder; next, the
oyster is hooked on to a platform several meters deep for a
few years.
As pearl production has meant that more and more living pearl
oysters ready for grafting are needed, the Territory's natural
stocks have been subject to intense harvesting and most of the
lagoons have come close to total depletion.
Yet in 1870, the French government had sent a biologist to
investigate the reasons for diminishing supplies and to
suggest a remedy, at a time when divers were still collecting
200 kilos a day. This scientist stated that it should be
possible to raise oysters by grouping spats on supports placed
in the water when the reproduction season is at its peak.
What's more, a conclusive experiment was carried out at that
time. However, it was not until 1954 that the Fisheries
Department brought technical assistance. This method, widely
practiced in the Tuamotu Islands, has increased
mother-of-pearl production.
Unfortunately, another danger threatens the industry today in
the form of a disease which attacks the pearl oyster.
According to ORSTOM research scientists, pollution of some
oyster bearing lagoons could be responsible for this disaster.
Other biologists blame the use of resistant marine paints used
to protect boats from corrosion.
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