A rare look at a Tahitian cultured pearl farm

Photos and story by Amanda J. Luke

Editor’s Note: Robert Wan, one of the pioneers of the Tahitian cultured pearl industry, invited GIA to visit one of his cultured pearl farms in French Polynesia last fall. It was a once-in-a-lifetime opportunity to witness how these beautiful gems are created. We’ve tried to convey some of that for you on these pages. GIA would like to thank Robert Wan, his son Bruno, Eric Sichoix, general manager of Marutea Sud, and all of the people who hosted us on Marutea Sud and Tahiti for this rare experience.

Imagine you’re in an open-air concrete building on a cultured pearl farm in French Polynesia. It’s hot, flies are climbing all over everything, including you, and there is a distinct odor of fish in the air.

You take a spot next to a young man seated in front of a large oyster held open with a pair of pliers. He’s so focused on his job he doesn’t acknowledge your presence.

He picks up an extraction instrument and pulls a shimmering cultured pearl from inside the oyster.

It happens so fast it takes you a moment to realize you’ve just witnessed the birth of a new gem. What was once a rarity of nature can be produced by man, on a farm such as this, hundreds of times a day during the harvest season.

Pioneers of Tahitian Cultured Pearls

The Tahitian cultured pearl industry began as an attempt to create income for outer islanders who flocked to Tahiti in the early 1960s for work, said William Reed, a pioneer in Tahitian cultured pearl farming. Reed, who had experience running a marine biology station to rear cultured pearl oyster larvae in the Red Sea and Persia, was hired by the government in 1968 to help develop the Tahitian cultured pearl industry.

Although the remote lagoons of French Polynesia were perfect for growing cultured pearls, the stock of the wild Pinctada margaritifera, variety Cumingi, (black-lipped) oysters in the area was not sufficient to support a large number of cultured pearl farms, Reed said. He found a way to collect the fertilized oyster egg and sperm or larvae, called spat, on a large scale on the island of Mangareva, however, and established Tahiti Perles in 1973.

The set up was very primitive – no electricity, plumbing or running water – making it a challenge to live and work there. “There was no air transport to any of the islands, so we had to travel (and ship supplies) by boat,” he said. “Sometimes the boat came only every 3 months.”

He knew he needed even more resources to develop the growing, grafting and harvesting techniques necessary to establish a Tahitian cultured pearl market, so when businessman Robert Wan expressed an interest in investing, he sold him the whole farm.

“Robert was very adventurous and prepared to take the risks,” Reed said. “He really is passionate about his products, which is terribly important.”

Wan had met and was friendly with the grandson of Kichimatsu Mikimoto, the re-nowned inventor of cultured pearl grafting, and learned a lot about cultured pearl farming on his visits to Japan. He harvested the first Mangareva cultured pearls in 1977 and has been devoted to improving the quality of farming techniques and cultured pearls produced on his farms ever since.

“Day by day, with tenacity, we created an economic sector. It allowed French Polynesia to become known throughout the world through the beauty of the “Poe Rava” (black cultured pearl) and the grace of women wearing our pearls,” he said. “It really was a beautiful adventure.”

Step 1:  Spat Collecting


The official name of the black-lipped oyster that lives and breeds in French Polynesia is the Pinctada margaritifera, variety Cumingi. It releases eggs and sperm in the Southern Hemisphere’s summer (December-February), which fertilize and are called spat. Spat immediately seek something to attach to for protection from predators, like octopuses, crabs and fish, so the spat collectors are put in the water to catch them.

Spat collectors at Marutea Sud are made of black plastic that looks like long fringed rope (top, right). They are placed 10-15 ft. (3-4.6 m) in the water and checked within two months to see if the spat have attached. One spat collector can attract 30-100 baby oysters, according to Eric Sichoix, general manager at Marutea Sud. “Mother Nature determines the survival rate for baby oysters,” he said.

The water temperature is checked daily; it should be 25-26 degrees Celsius. If there is a temperature difference of 2 degrees or more, the lines are moved. The spat lines are cleaned (bottom, left) on a regular basis to remove all other shells, mollusks and seaweed (top, left) that compete for nutrients.

Spat are removed from the collector at about 1 1/2 years old and moved to a line. They are ready to be sorted for nucleation and mantle tissue donation when they are 2 1/2 - 3 years old. At Marutea Sud, 5 percent are selected as donors and 95 percent for nucleation.

Sichoix and Rino Moraro (left) check over lines of spat. They are 8-9 months old and 1-2 inches in diameter.

Step 2:  Breeding Young Oysters


The spat and oysters are hung on a long line system (left), marked by buoys on the top of the water, at 10-15 feet (3-7.5 m) below the surface.

The lines of spat and young oyster are cleaned through a machine (bottom, left) on a regular basis to remove all other sea life that weighs down the lines making it difficult for them to filter water, which they need to oxygenate and get rid of impurities.

Gabriel Hopara (top, right) is one of six divers at Marutea Sud who dive twice a day to check on nucleated oysters and repair lines. They are the “macho men” of the farm, according to Sichoix, because they work in shark-infested water.

Step 3:  Nucleation

Oysters are ready to be nucleated with a bead and mantle tissue when they are 2 1/2 - 3 years old. The process is similar to what happens in nature when an irritant (a parasite or shell bead nucleus) makes its way into the oyster. The oyster first tries to reject it, but if it can’t, creates a pearl sac around it, which secretes nacre that builds up in successive layers around the nucleus, thus creating a pearl.

The oyster is a living organism and the nucleation process is major surgery. The expert nucleator is precise and fast – the procedure takes less than two minutes. The oyster, plied slightly opened,  (below) is placed on a shell holder at eye level. The nucleator decides what size bead should be implanted, then carefully inserts first the mantle tissue, then the bead into the oyster’s gonad, a small pouch-like organ that produces egg and sperm. An expert nucleator can implant 600 oysters a day.

The bead nucleus is the core of a cultured pearl. Made from North American river mollusks, the shell is cut into strips, then cubes, then shaped, tumbled and polished. Mississippi River mollusk beads (top, left) are used at Marutea Sud.

Mantle tissue is a vital component of pearl culturing. Bruno Wan said that, along with water temperature, it is what determines the color of the cultured pearl, which is why his father still teaches workers how to select mantle tissue donors. The mantle tissue is cut in strips then square pieces (left); 24 pieces are harvested from each oyster.

Step 4:  Culturing

Nucleated oysters are placed in baskets in a holding area near the nucleation farm (top, left) for 45-50 days to heal and see if they reject the nucleus. Bruno Wan says 85 percent of their oysters retain the nucleus.

Two holes are drilled at the hinge (left) and then hung on a line. Five to 6,000 oysters can be put on lines in one day; each line is 400 meters long. There are millions of oysters in the lagoon at any given time, Sichoix said.

Oysters need to be cleaned of sea life on a regular basis (uncleaned oysters, above right) with pressurized water and by scraping with a knife (bottom, left).

Every cultured pearl farm has preferred methods of doing things, based on experience, Sichoix said. He likes to hang second nucleated oysters on panels instead of mesh pockets because he feels they protect the oysters better, make it easier to clean them, and because the bigger oysters need something more solid to hold onto.

Nucleated oysters stay in the water for two years. The nacre thickness that usually forms in that time is about 2 mm for a first-time nucleated oyster, which means that an oyster with a 6 mm bead may produce a 10 mm cultured pearl.

There are four harvests a year at Marutea Sud, usually between May and November.

The three photos above show the progression of a cultured pearl coming out of an oyster.
Based on the cultured pearl that is extracted and the health of the oyster, the nucleator determines whether it will be re-nucleated. If so, a bead is inserted into the already formed pearl sac. Not all oysters will be re-nucleated.

The first sorting for size and shape is done at the farm and then the pearls are shipped to Papeete , where a more precise sorting for quality and color is done. The colors of the cultured pearl come from the secretion of the pearl sac, and depending on the quantity secreted, results in colors that range from white and shades of gray, to black, bronze, green and purple.

The pearls are sold at five auctions each year: three in Hong Kong and two in Kobe, Japan.