Nucleation, or How to Perform Oyster Surgery

Nucleation, or How to Perform Oyster Surgery with Spey
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A natural pearl is a rare thing indeed: it might take 1,000 oysters before one reveals a lustrous gem within. To meet the insatiable need of the stylish the world over, it is therefore critical that man steps in to encourage production and prevent overexploitation of the crafty mollusk. This is the art of culturing, or farming oysters and mussels for the production of pearls. The end result is a brilliantly sustainable gem, but nucleation (the foundation of this process) demands absolute precision and a whole lot of luck. To understand nucleation, we must start at the very beginning (a very good place to start).

Most are familiar with the legend of how a pearl is formed – that tale of a grain of sand entering the shell of an oyster. Most often in nature, it is a parasite or infection and not a grain of sand that is the true progenitor of the pearl. Even then, no pearl is guaranteed; let alone a pearl of the radiant beauty requisite to be welcomed into the Spey collection of jewels. Man is then left to simulate this irritant by implanting a small bead nucleus into the soft tissue (the gonad, if you must know) of the oyster. All nucleation is reliant on this bead nucleus. Typically these are small, polished balls of recycled mollusks’ shells. The primary source for these nuclei, accounting for over 90 percent of the supply, is the lower Tennessee River. Shells are first cut into strips and then further into cubes, before being shaped, tumbled and polished into perfect spheres.

The nuclei are then exported to pearl-producing strongholds like Japan, Australia and French Polynesia. There, pearl farmers would have been slowly preparing the oysters for the major surgery to come. Months before nucleation, pearl farmers work to gradually decelerate the oysters’ metabolic processes by transferring the stock to slower-moving waters with just enough nutrients to sustain general health. Timing also coincides with the autumn and winter months, as cooler water temperatures tend to sedate mollusks. All of this is meant to coax the oyster into a more relaxed, stable state, so that it may be better equipped to survive the stresses of nucleation.

At this stage, expert technicians are brought in to perform the nucleation. Think of them as skilled oyster surgeons. Nucleation demands more than just prying a shell open, adding a bead nuclei, and then tossing the oyster back into the ocean. The job of a nucleator demands both precision and speed, returning the oyster to the water as quickly as possible. The shell must be opened first. A technician might induce the mollusk to open its shell, or rather relax its tight muscles, by either slightly raising the water temperature or moving the oysters from close quarters to open space. Forcing open the shell might kill the mollusk, so when a slight opening is conceived, the technician inserts a small plastic or wooden wedge to hold the gap.

The nucleator then mounts the mollusk with a gentle clamp, holding it steady for the work ahead. A small slit is cut into the gonad (the mollusk reproductive organ) using dentist-reminiscent steel instruments. A nucleus of just-the-right size for that particular oyster, along with a small piece of mantle tissue, is inserted into the cavity. The mantle tissue acts as a stimulus to pearl formation, being lined with the epithelial cells that secret nacre. Once the implant is complete, a nucleator might rub some of the mollusk’s own mucus or a special antibiotic across the area, to prevent infection and encourage healing. Depending on the level of experience, a technician might nucleate between 300 and 600 mollusks per day.

Now the pearl farmer waits, as nucleation can be a fickle game. With luck, the mantle tissue grows around the nucleus to form a pocket, or pearl sac, and then continues wrapping layer-after-layer of lustrous nacre for years to come. The immediate few weeks following surgery are critical, so to better the mollusk’s chance of survival, the implanted oysters are kept in a secluded, calm-water area of the farm and monitored frequently. Over half of these oysters will expel the nucleus or perish due to complications from the surgery. Periodic x-rays indicate whether any given oyster is still turning a pearl within. Three to five years or more later, the pearls are harvested and fashioned into fabulous Spey pearl jewelry. A pearl is an oyster’s greatest triumph, but one that comes after much toil and care. The luster is well worth the wait.

Image: Surgical implantation of a bead nucleus in an oyster, Halong, Vietnam. Credit: Nikitabuida.