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OYSTER FARMS

an oyster, ready to eat how to catch oysters oyster farming today

Pacific Oyster
How does an Oyster Grow
Oyster Farming Today
Smoky Bay
Denial Bay
The World's Your Oyster
Favourite Recipes

First Oysters for Sale

No one knows who collected the first oysters for sale in South Australia, but the first fisheries legislation was the Oyster Fisheries Act of 1853, and was in force four years before South Australia had a parliament. Oysters were supplied to the market in the early days of the colony from large beds of Clinton and Mangrove Point on Yorke Peninsula. An advertisement on 19 February 1849, in the Adelaide Times, said "To the lovers of oysters. Those who are admirers of this favourite shellfish can procure the best specimens of ‘natives’ at one shilling per dozen (if used on the premises) by applying at the establishment of the undersigned. If carried off the premises the price will be one shilling and sixpence per dozen. Good refreshments at Adelaide prices. Charles Osborne, Glenelg Hotel, Holdfast Bay, Feb 13th, 1849."

an oyster, ready to eat

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Port Lincoln and Coffin Bay were very prolific areas for the native oyster, Ostrea Angasi. Thirty sailing cutters were dredging in the Coffin Bay area by 1870 and it is believed the annual catch around that time was 700,000 dozen oysters. By 1859, many oyster dredging areas had been overfished, although dredging continued in a small way in the areas around Pt Lincoln.

During the 1920 and 1930s most fishermen fished for whiting in the summer months and dredged for oysters during winter. Oysters were much less prolific and of a smaller size than during the earlier years.

Despite attempts at conserving native oysters, the industry slowly died and by 1945 there was no record of any oysters being marketed. Over the years, people applied for leases to put down artificial native and Sydney rock oyster beds, but there is no evidence that any were particularly successful.

The first oyster farm in Coffin Bay had been growing the original Coffin Bay Oyster – the native oyster, Ostrea Angasi, for in excess of 25 years with an outstanding reputation for quality. In 1984, interest in expanding the oyster industry began to grow as the potential of the clean waters was recognised and seed supplies of the Pacific Oyster became reliable.

It was not until the Japanese oyster, Crassostrea Gigas, known as the Pacific Oyster, was introduced into South Australia from the Tasmanian hatcheries in the mid 1980s, that oyster farms as they are known today, began.

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The Oyster Industry of the Far West Coast

One of the unusual features of oyster farming in South Australia, particularly the Far West coast, is the amazing clarity of the sea water, when compared to where oysters are grown throughout other parts of Australia and the world.

This is mainly due to a marine environment that does not have any fresh water input via river systems, and seems to utilise natural upwellings of nutrients from the ocean itself. These nutrients assist in providing the right conditions for oysters to flourish.

the marine environment to catch oysters

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Oyster farming has been in existence in South Australia on a small scale since the late 1960s, but it wasn’t until the early 1990s that the industry began the initial steps to significant production. At that point the main growing areas were: Denial Bay (Ceduna), Smoky Bay, Streaky Bay, Coffin Bay, Cowell and Nepean Bay (Kangaroo island). Since then, oysters are also cultivated in areas of the Yorke Peninsula including Stansbury, Edithburgh/Coobowie, Port Vincent and Port Broughton.

How does an Oyster Grow?

South Australian oyster farmers purchase juvenile oysters, called spat, from oyster hatcheries. After oyster broodstock have been induced to spawn in the hatcheries, the spawn is mixed together and fertilises to become free-swimming larvae. After a period of time, the larvae attach themselves to finely crushed scallop shell. It is very important that this finely crushed shell is sieved to exactly the right size before being put in with the larvae.

After settlement, the larvae become very small juvenile oysters which are fed a special algal diet. Once the spat reach 2mm in size, they are transferred to a nursery where they are grown until they reach 4mm to 10mm in size, when they are sold to the oyster grower. They are then put into specially made small aperture plastic mesh trays and placed onto the oyster farm until they reach 15-20 mm in size.

From the spat trays, juvenile oysters are graded and placed into larger aperture mesh baskets. As the oysters grow, they are graded approximately 6 times before they are sold. Fewer oysters are put in the baskets at each grading to allow for maximum filtering of water. At full adult size, there may be only 40 – 60 oysters per basket.

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Oysters are principally cultivated in the inter-tidal range of the water column, which exposes them to air at low tide. This is done by placing them on man-made structures on shallow banks so they come out of the water at low tide. When the oyster industry first began on the Far West coast, growers used the "rack & basket" system, which consists of 2 wooden railings running parallel with plastic mesh baskets containing oysters placed across them. Since then, the industry now uses a range of growing systems, with the BST system, invented by 3 Cowell oyster growers, proving popular. This consists of plastic mesh baskets hung beneath taut plastic wire and from where growing heights can be adjusted easily.

basket of oysters

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An oyster eats as it breathes, by pumping water in and out of its valves. They tend to feed on algae and fungi, and an adult oyster (depending on size) can filter between 6 and 20 litres of water per hour. Water flow is very important, and so the size of the mesh aperture compared to the size of the oyster must be correct. Even when oysters have reached adult size (70 – 90 mm), they need to have a plump meat condition before they are marketed.

On average it takes two years for an oyster to grow from spat to adult size.

Oyster Farming Today

Locally, oyster farming began in 1985 in Denial Bay and 1988 in Smoky Bay. During the initial years of the industry, 105 ha of intertidal farms were allocated in Denial Bay and 85 ha within Smoky Bay, with individual farms having a maximum size of 10 ha. This has now increased to 165 ha (including 40 ha of subtidal or deepwater culture) in Smoky Bay and in excess of 200 ha in Denial and Murat Bays (Ceduna).

rack and basket used to catch oysters

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Production from these areas would currently exceed 1 million dozen oysters annually, accounting for approximately 40% of the state's production, with there being 30 different oyster growing operations, providing significant economic and employment benefits locally.

Oyster Growers at the Ceduna Oyster Fest

The tent where you buy your wonderful oysters at the Oyster Fest is organised by the Far West Zone of the South Australian Oyster Growers Association, and is predominantly manned by local oyster growers during the weekend. The oyster growers ensure that the very best quality oysters are set aside for the Oyster Fest, and sold at quite reasonable prices and served fresh for your enjoyment and satisfaction.

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"The World’s Your Oyster"

"The World’s Your Oyster" a book of 154 oyster recipes and information on oyster farming on the West Coast of South Australia, written by Sue Trewartha and Angie Bayly in 1993, you can contact Box 77, Ceduna, SA, 5690 for copy of the book. Cost $10 plus postage.

Some favourite recipes from "The World’s Your Oyster"

Oysters Kilpatrick

12 oysters

1 tspn Worchestershire Sauce

4 tblspn cream

˝ cup bacon pieces

freshly ground black pepper

Ľ cup grated cheese

Combine sauce, cream and pepper, spoon over oysters, top with bacon and cheese and bake in hot oven 8-10 minutes.

Garlic Cream Oysters

12 oysters

6 crushed cloves garlic

˝ cup cream

1 tbspn lemon juice

1-2 chicken stock cubes

Ľ cup water

freshly ground black pepper

Mix stock cubes in saucepan with water and add garlic, cream, pepper and lemon juice. Simmer until thickened, spoon over oysters and bake in hot oven 8-10 minutes.

Cactus Cream

12 oysters

1 tbspn butter

1 red capsicum

˝ cup cream

freshly ground black pepper

Melt butter and add chopped capsicum. Cook over low heat until soft. Stir in pepper and cream and simmer until thick. Spoon over oysters and bake in hot oven 8-10 minutes.

Ceduna Sunrise

12 oysters

1 tbspn butter

Ľ cup chopped almonds

5 tbspn Galliano liqueur

juice 1 lemon

1 tbspn chopped mint

freshly ground black pepper

1 tbspn lemon rind

Melt butter and when very hot, toss in almonds. Stir until golden, then add Galliano, rind and lemon juice. Simmer until thickened. Take off heat, add mint and pepper. Spoon over oysters and bake in hot oven 8-10 minutes.

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Surfers Choice

At the beach with no sauce ingredients available? Just throw your oysters in the shell onto a barbecue plate or on the coals. They are cooked when they open and are delicious! Murat Bay Magic

18-24 oysters

3 tbsp brandy

1 cup chopped mushrooms

freshly ground black pepper

1 tbsp butter cup cream

pinch nutmeg

Melt butter and cook mushrooms. Drain. Pour brandy over mushrooms, add cream and heat until sauce is reduced. Add oysters, pepper and nutmeg. Heat through, only for a few minutes till edge of oysters curl, and serve hot.

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Copyright (c) 2002 Last updated 18th November 2002