Pictures: Sustainable Pearl Farming

Black Pearls
Photograph by Andy Bardon
Laurent Cartier, a PhD candidate in environmental sciences at the University of Basel in Switzerland, inspects Tahitian black pearls at Kamoka Pearl, a small family-run pearl oyster farm in French Polynesia. The farm is on the palm-fringed atoll Ahe, in the Tuamotu Archipelago about 300 miles (480 kilometers) northeast of Tahiti.
Cartier (no relation to the international jeweler and store) studies the environmental impacts of the pearl industry, with a particular interest in how raising pearls can be made more eco-friendly.
Cartier launched www.sustainablepearls.org with National Geographic Emerging Explorer Saleem Ali, director of the Centre for Social Responsibility in Mining at the University of Queensland in Australia; and Julie Nash, a PhD candidate in natural resources at the University of Vermont. The group is planning a conference on sustainable pearls and is investigating developing a certification program that would signal to consumers that pearls are raised in a responsible way.
(See "The Rise of Eco-Friendly Pearl Farming.")
Cartier has been helping Kamoka Pearl develop and test environmental best practices. In one innovation, the farm eschews powerwashing of oysters because that common practice can cause nutrient loading in the water. Instead, Kamoka moves pearl oysters to shallow water periodically, where wild fish pick them clean.
—Brian Clark Howard
Published August 11, 2013
String of Oysters
Photograph by Andy Bardon
Madison Rose Whitman drops a string of pearl oysters into the water at Kamoka Farm. Since 2003, Kamoka has played host to many young people from around the world, who come to work as part of the World Wide Opportunity on Organic Farms (WWOOF) program. Kamoka has as many as 10 "WWOOFers" at a time. As on other farms, participants receive free room and board in exchange for their labor, as well as a chance to experience pearl farming.
"Usually people have the time of their lives," Josh Humbert, the farm's owner, said about WWOOFers. "We are kind of the ocean's version of organic farming."
WWOOF volunteers do whatever jobs need to be done around the operation, Humbert said, although the process of "grafting," or placing beads inside oysters, is left to the full-time staff, since it is skilled labor.
Published August 11, 2013
Cleaning Station
Photograph by Josh Humbert
Pictured are buoys used at Kamoka to anchor pearl oysters in shallow water, so fish can pick them clean.
Pearl oysters live for a few years, which is plenty of time for marine organisms like barnacles and sponges to encrust on them. When that happens, oysters tend to make smaller pearls, however, so farmers opt to periodically clean them.
Typically, workers haul the oysters up onto a boat and then blast them with water. The rinse water can overload lagoons with organic material, however, causing a "dead zone." If the rinse is kept and stored on land, it can form a smelly, festering pool.
Instead, Kamoka periodically moves their oysters to the shallows for a natural cleaning process.
Published August 11, 2013
Oyster Baskets
Photograph by Josh Humbert
Butterfly fish and moorish idols swim around oyster baskets at Kamoka. Pearl oysters are loosely packed into baskets or nets, which are hung vertically to a depth of around 20 feet (6 meters).
Kent E. Carpenter, a professor of biology at Old Dominion University in Virginia, recently conducted a study that suggests Kamoka's oysters are good for local fish populations, since they provide hiding spaces for small fish and some food in the form of encrusting organisms (learn more).
Published August 11, 2013
Family Business
Photograph by Andy Bardon
Patrick and Josh Humbert, father and son, sort through pearls at Kamoka. The farm was founded in 1990, by Josh Humbert's father and brother. A year later, half-way through college, Josh Humbert joined the business (he eventually became the sole owner, although Patrick still works there).
Published August 11, 2013
Oyster Surgery
Photograph by Josh Humbert
Surgical tools await an oyster who's mantle, once removed, will help to produce up to 30 pearls. A bit of the mantle will be implanted with a nucleus, or bead, into each of several other pearl oysters, to stimulate them to grow pearls.
Contrary to popular belief, according to Josh Humbert, there is rarely a grain of sand at the center of a pearl. Instead, natural pearls usually form when an oyster builds up mother of pearl (nacre) around worms that invade the animal's shell.
For beads, Kamoka uses bits of oyster shell.
Published August 11, 2013
Oyster Farmer
Photograph by Andy Bardon
Josh Humbert, owner of Kamoka, inspects a pearl oyster.
The process of inserting a bit of mantle and a bead into a pearl (grafting) is tricky work that takes time to master.
"It used to be that only a few people—mostly from Japan—knew how to do it and their secrets were very closely guarded," Carpenter said of grafting. "But eventually more people were trained, the secret got out."
Published August 11, 2013
Difficult Work
Photograph by Andy Bardon
A local Tahitian worker named Timi carefully removes a pearl from an oyster. Timi has been with Kamoka since 1993. Humbert says he pays his workers more than many larger scale pearl farms in the islands.
Published August 11, 2013
Placing Oysters
Photograph by Andy Bardon
Whitman places oysters into a mesh basket, which will get submerged for two years, allowing the grafted proto-pearls to develop into large, shiny objects of desire.
Published August 11, 2013
Underwater Farm
Photograph by Josh Humbert
Pearl oysters are spaced out much more than food oysters, which are often closely packed. That can cause waste to build up. If pearl oysters are packed too close, their pearls will be smaller and less shiny.
Published August 11, 2013