Pearling - The Western Australian Fishery

Western Australia has a valuable and successful pearling industry, worth around $200m annually, and is the world's top producer of prized silver- white South Sea pearls.

Wild pearl oysters are collected by divers in waters off the WA coast between Cape Leveque and Exmouth. They are seeded on the fishing grounds, allowed to recover for several months, then carefully transported to farms where the pearls are grown out.

The most sought-after species is the silver-lip pearl oyster Pinctada maxima, which produces the splendid silver-white South Sea pearl. Other species, producing pearls with different characteristics, are farmed on a much smaller scale.

Pearl oyster fishing has a lively history of boom and bust through the vagaries of weather, biology, fashion and technology. Oyster beds were heavily exploited in the late 19th century for mother-of-pearl shell, used mainly for buttons and inlay work, and naturally occurring pearls were an occasional bonus.

Australian and European vessel owners employed Aboriginal, Malay, then Japanese divers who were more proficient at depth and in full diving suits. Pearling took a heavy toll of crews and divers in earlier decades with hazards such as cyclones, marine predators and the bends (decompression sickness).

Pearling in Western Australia

The industry crashed in the 1920s and 1930s following the introduction of plastics for buttons and decoration but this calamity reduced fishing pressure on the stocks of wild oysters and allowed a valuable resource to recover.

Development of efficient seeding practices heralded the beginning of the cultured pearl industry in the 1950s and today WA produces pearls regarded as the world's best.

Sixteen licensees harvest P. maxima oysters and most farms are on the WA coast between Exmouth and the WA/NT border, though oysters are also taken to farms near Darwin and to the Monte Bellos Islands. There is also increasing interest in the production of half pearls and smaller round pearls from other pearl oyster species - Pinctada albina, Pteria penguin and Pinctada margaritifera.

Skilled divers work from sophisticated pearling boats which act as both fishing boats and floating operating rooms where oysters can be seeded, though some companies use separate vessels for fishing and seeding. After seeding, oysters are placed on the sea-bed in panels, which are turned regularly over the next two or three months to aid the formation of round pearls.

They are then taken to farms, and usually held in panels suspended from long-lines. Shells are regularly cleaned of barnacles and other marine growth.

Oysters are about three years old when captured and pearls take another two years to grow to desirable size and quality.

The best oysters may be seeded several times, with each pearl being larger than its predecessor.

Pearl culturing techniques are practised in Indonesia, Malaysia and Thailand using P. maxima , though the same pearl quality has not been achieved. The limited availability and rarity of the Australian pearl results in high prices for these luxury jewels.

Production from the WA pearling industry based on P. maxima has steadily risen and value of production in 1997/98 was estimated to be worth $189 million.

Informtation courtesy of the WA Department of Fisheries