The oyster pearl is one of the most enigmatic products of natural history. It is elegant, mysterious, and has been highly prized since time immemorial. But what makes these organic gems so precious? How did they come about? We will explore the nooks and crannies of pearl farming throughout history to find out how this beautiful cultivation method has evolved over the years.
Pearl Farming History
Pearls are almost as old as notable human history. As early as 4000 BC, there is already evidence of people using nacre or mother of pearl for ornamental purposes. Pearls are also mentioned in critical texts of the major organized religions, from the Bible to the Koran. These are also crucial indicators that pearls are being harvested even before the Japanese pearl farming efforts. It was during the time of Alexander the Great that the importation of pearls increased in what is now known as Europe.
When Christopher Columbus explored the world in the sixteenth century, he and other explorers also found that pearls were being harvested in South America and Central America. This discovery led to what is now called the Pearl Age of trade, which was undoubtedly triggered by the fascinated aristocracy in Spain and elsewhere.
Before the cultivation of pearls, thousands of fishers also set sail, looking for natural or wild-caught pearls. We know now that this is not an easy task at all, because finding natural pearls is slim even with better transportation at sea and better knowledge of which species of oysters provide the best pearls.
The initial wave of interest in pearls during the eras of European conquest led to the depletion of what is called the “pearl banks” that existed in the Americas and Asia. Like whales being hunted down for their blubber, oysters were caught in such large quantities that they were soon depleted. The natural pearl trade died a natural death, too, as early as the 1920s. The demand was so high that even nature could no longer keep up.
How are pearls harvested from oysters?
Oyster pearls are cultivated by farming species of oysters that produce great-looking pearls. The process begins with spat or oyster larvae that eventually grow to about fifteen centimeters after a few years. Oysters can be grafted repeatedly, for up to three times if needed. Pearl farms are very selective about their breeding programs – the genetic diversity of the oysters has to be maintained. They only add a small quantity of spat during the breeding season to bolster the oyster population they already have.
During the process of nucleation, a small piece of shell or mother of pearl is inserted into the gonad or sex organ of the oyster. Ideally, this triggers an immune reaction from the oyster. Nacre, or mother of pearl, is secreted by the oyster to coat the irritant. The nucleus of the pearl is eventually coated by more and more nacre, forming the pearl that we know and love. The process of forming pearls takes months at the very least, or years, for the highest quality pearls. Some oyster stocks are so old that third-generation grafts can be as old as ten years old. That’s how selective pearl farms are.
It is said that as the oyster grafts age, the pearls increase, but the quality decreases. So this is the main challenge for pearl farmers as their oyster broods age over time.
Aging oysters tend to produce pearls that have lower luster and shine than younger oysters. This probably has to do with the young oysters being more robust and can produce higher quality nacre than their aging counterparts. Pearl farms typically harvest during the colder periods of the year as the oysters tend to produce lustrous and better-looking nacre when the season is cold. Pearl farms are after this final layer of luster before they remove the pearls from the oysters.
However, the actual periods of harvest may vary from year to year, depending on the water condition, temperature, and other factors that may affect the quality of the pearls and the condition of the oysters.
How do pearls farms run nowadays?
Pearl farms around found throughout the world nowadays. There are pearl farms in Australia, French Polynesia, the Philippines, China, etc. The most critical locales for pearl production can be found in the Pacific. Juvenile pearl oysters or spat are either grown by larger pearl farms or collected from the wild. Hatcheries are there to ensure that genetic diversity is maintained, and the most robust spat is kept for future use. French Polynesia is fortunate to have a marine environment that allows hatcheries here to collect oyster spat from the wild. Other locales aren’t so lucky. When there is insufficient oyster spat in the ocean, full-time hatcheries become necessary to make the pearl farming sustainable.
In places like Australia, there are strict regulations on the collection of wild oyster spat, as there is a global effort to maintain a healthy ecology in the wild. This prevents the depletion of more robust wild oysters that can be used later on by the same industry to produce better spat and better quality pearls. Again, genetic diversity has a lot to do with this. Oysters in the wild will have better genetic diversity because pairings of oysters occur naturally. In pearl farms, genetic pairings’ choice is limited due to constraints in the supply of stock, so there will be less genetic diversity in pearl farms.
Oysters must also be of a certain age before it can be used for pearl farming. The pearl farmers must be patient in waiting for the oysters to reach the proper size before they are finally grafted. Cultured oysters have to be fed and tended just like any other livestock, and there is more at stake in the proper care of oysters because they can sometimes die due to unforeseen circumstances.
In French Polynesia, oysters that are one to two years of age (minimum) are considered for grafting and the birthing of pearls.