What is Pearling? - A Pearling FAQ
The farming of the gold or silver lipped pearl oyster (Pinctada maxima) for pearls and associated products forms Australia's largest aquaculture sector. Western Australia is the largest pearl producer, with the industry being valued at over $120 million in 2003. Pearls from the silver lipped pearl oyster are commonly called South Sea pearls.
The following is a series of questions - and answers - that are frequently asked about pearls and pearling.
- Are pearls found naturally in the oysters in the sea?
- How are pearls grown?
- Where are wild pearl oysters found and how are they cultivated?
- How are the oysters caught?
- Why are some pearls more valuable than others?
- Where are the pearls sold?
- What are the environmental impacts of pearl oyster fishing?
- How much water space is taken up by pearl farms in the North West of WA?
- Can the public access these lease areas?
- Do the public have the opportunity to comment on pearl farm lease applications?
- How important is the pearling industry to WA?
- How can I enter the pearling industry?
- Are there any other pearls aside from South Sea pearls grown in WA?
Are pearls found naturally in the oysters in the sea?
Yes, but in very rare cases. However, in the past all pearls were found in the wild.
In 1910 there were nearly 400 pearling luggers and more than 3,500 people fishing for pearl shells in the waters around Broome. In those days, pearling concentrated on the pearl shell itself, which was used for buttons and inlay. Pearl fishers were sometimes lucky to find the rare and elusive round pearl.
How are pearls grown?
Pearls are grown commercially by placing a bead (called a nucleus) in the pearl oyster gonad, which causes an irritation to the animal. The oyster forms a sack around the nucleus (which is usually a small bead of mussel shell) and lays down lustrous, thin films of nacre around the nucleus to ease the irritation, thus forming a pearl. The nacre is the same colour as the pearl oyster.
In modern pearl production, the seeding process results in cultured pearls of various shapes - from the perfectly round to irregularly shaped pearls (“baroque”) to half-round pearls (“mabe”), made by fixing hollow plastic shapes to the oyster's shell wall in its last year of production. Irregularly shaped natural pearls with no artificial nucleus are known as “keshi” or seedless pearls.
It takes two years for a farmed pearl oyster to produce a pearl of commercial value and size. After that first pearl, each oyster only takes one year to produce a pearl.
The best pearls come from contented healthy oysters, and the operations of pearl farms are designed to minimise stress on them. This involves moving the oysters while tides and temperatures are fairly stable, hanging them from panels in the water column to keep them flushed with nutrients and to carry wastes away, and cleaning them of marine parasites and algal growth on a regular basis.
Farming pearl oysters is a lot of work, much of it labour intensive. Tending the oysters is a continuous process, aimed at keeping pearls developing smooth layers of nacre on the nucleus to minimise blemishes caused by stress.
Every healthy oyster has a helper, a tiny pea-crab that lives unharmed inside it, sharing debris that the oyster sucks in and probably keeping it clean. The fate of the crab once the oyster dies is a mystery, but its presence seems essential for the oyster's well-being and seeding technicians are careful not to harm it.
Most of the trained technicians who seed oysters are Japanese, but some are Australians. These technicians travel the world, working for six to eight weeks at each farm.
Producers expect to seed an oyster four times in its life, seeding it first at about two years old for round pearls. In its last year, a pearl oyster will be used for mabe (half-shell) production.
Theoretically, the longer a pearl has to develop, the thicker and deeper the coating of nacre and the higher quality of the pearl, but there is a limit to what is practical. Producers aim for smooth round cultured pearls, although the quirks of the keshi and baroque pearls offer jewellers most scope.
Where are wild pearl oysters found and how are they cultivated?
Wild pearl oysters are collected by divers in waters off the Western Australian coast between Cape Leveque and Exmouth. The main fishing grounds are around Eighty Mile Beach near Broome.
The oysters are seeded on the fishing grounds, using large vessels holding shells in tanks. The oysters are then allowed to recover from the seeding operation for several months, on the ocean floor in net panels. They are then carefully transported to sheltered waters of the pearl farms, where the pearls are 'grown-out'.
The net panels of seeded pearl oysters are suspended on a floating line system from the surface of the sea on pearl farms. The oysters remain in the panels for up to two years as the pearls grow. During this time, the oysters (which are bivalves) feed by extracting nutrients from the water column.
Unlike other forms of aquaculture, no artificial feeds or chemicals are required. The panels and lines are regularly cleaned to remove algal growth.
How are the oysters caught?
The oysters are caught by divers, using surface air systems. They work from vessels on oyster shell grounds and hand pick the shells, which lay on the seabed covered with sand. Pearl divers are very experienced in finding the right-sized pearl oyster without disturbing other shells or marine organisms.
The most sought-after species is the silver lip pearl oyster Pinctada maxima, which produces the splendid silver-white South Sea pearl. This oyster grows best in the wonderfully clean waters around Broome in WA.
These pearls are white in colour, with brilliant lustre.
Why are some pearls more valuable than others?
Different types of pearls fetch very different prices, depending on their rarity and quality. Only about 20 per cent of the whole pearl harvest is completely perfect over all the different shapes and sizes, the rest usually have some kind of flaw or blemish.
Those that are blemish free sell for an enormous amount of money, perhaps $15,000 a pearl wholesale, and the very large size perfect ones can sell for more.
Where are the pearls sold?
For many years the Japanese dominated the pearling market, but times are changing. Japan is no longer the sole market for Western Australian pearls.
Now, only about half of the pearls get sold to Japan direct, and maybe another 10 per cent indirectly. Marketing experts predict North and South America will prove a big market for Australian pearls in the future.
The market in Europe prefers pearls of a creamy rosy colour, while America likes silver white and pink pearls, as does the Australian market.
Pearls are sold individually for use in jewellery or as pearl strands, worn around the neck of many women throughout the world.
Western Australian pearls are known as some of the best in the world because of the high number of round pearls, their large size, brilliant lustre and silky smoothness of the surface.
What are the environmental impacts of pearl oyster fishing?
Pearl oyster fishing has very little impact on the environment and is considered to be the most benign fishing method in commercial fishing. Divers 'hand pick' oysters, without touching the sea floor.
There is no fishing gear used and no levers to remove the shell from the sea floor. Shell are placed in baskets around the divers' necks and sent to the surface for grading.
Pearl oyster stocks are managed by a quota system that sets a maximum number of shells that can be caught by the industry in any year. The quota is set by researchers at a level that ensures the stocks of oyster are sustained over the years.
This quota is closely monitored by the Department of Fisheries through observers on the catching vessels and sophisticated stock assessment research paid for by industry.
The environmental impacts of pearl farms are considered to be negligible.
How much water space is taken up by pearl farms in the North West of WA?
There is a strict limiting formula on the area that a pearl farm can cover, based on the shell quota held by any company. Because the pearl oyster fishery is quota-based, there is a natural limit in the area that can be covered by pearl farms by applying the formula.
Pearl farms cover a tiny percentage of the North West/Kimberley region. The total area covered by 110 pearl leases is 184.774 sq nautical miles. Assuming that pearl farms will only occur in a water depth of between 0 and 20 metres, this represents only a small fraction of the area available within the fishery.
The figures below show the percentage area of each zone, between 0 to 20 metres, that is covered by pearl farm leases.
Zone 1 0.6 per cent
Zone 2 1.1 per cent
Zone 3 3.4 per cent
Zone 4 1.6 per cent
Pearling longlines only occupy a portion of each lease at any one time, therefore the area actually used by pearling is an even smaller area.
Can the public access these lease areas?
Yes. A pearl lease is not exclusive in use to a pearling company and allows other water users to move through the lease area. Navigation markers and other channel markers must be placed around the farm to enable safe navigation.
The pearling companies have developed a protocol to assist other water users to better understand the way to access pearl leases areas for their own activities.
Do the public have the opportunity to comment on pearl farm lease applications?
Yes. Pearl farm lease applications are subject to a major public and environmental process requiring significant data preparation and consultation. The process is managed through the Department of Fisheries which coordinates any 'inputs' from other government departments.
How important is the pearling industry to WA?
The pearling industry can contribute over $200 million per annum to the WA economy in the value of exports alone, and over $600 million dollars in wages, gear purchases and fuel, etc, to the local WA economy.
Over 2,000 people are directly employed in pearling industry.
How can I enter the pearling industry?
There is currently a limit placed on the number of quota units available in the pearl oyster fishery to sustain the wild oyster stocks. To enter the fishery, a person would need to purchase a minimum of 15 wildstock quota units from an existing licensee and obtain a pearling licence from the Department of Fisheries.
Under legislation, you need to have a pearling licence or a hatchery licence to hold a pearl farm lease.
There are a variety of jobs in the pearling industry, ranging from diving and boat handling to farm management, pearl production, sales and marketing.
Are there any other pearls aside from South Sea pearls grown in WA?
Around 40 licences have been issued for the culture of non-maxima pearls, commonly known as Western Australian black pearls.
You can tell the difference between WA black pearls and those from the Pacific by the differences in colour. A batch of pearls from the Pacific will look grey, green and black, whereas the overall impression of product from the Abrolhos Islands is silver, green, peacock and aubergine.
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