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An Abalone Diver leaves for the sea early in the morning. Abalone is a mollusc of the gastropod family. They inhabit offshore reefs in sheltered spots such as rock crevices and ledges and dense kelp beds. In its natural habitat the Abalone is usually well camoflaged with its hard shell often encrusted with various algal or seaweed species plus sponges, worms and sea squirts. The yellow-finned Leatherjacket, a predator of Abalone, waits for the Abalone to release it grip from the rock surface and then quickly flips it over. |
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Egg production in abalone is usually related to age. Adult individuals release up to 2million eggs into the water, possibly triggered by periods of higher water temperature. When fertilized the microscopic eggs develop into larvae, here compared with the size of a pinhead. These are dispersed via water currents around the reef topography. In areas of high water movement however, larvae are flushed from the reef. Successful settling can only be achieved over a couple of days. Abalone shells grow to considerable size. Even at a small size they clearly have the abalone shell shape. Researchers are developing ways of determining shell age by reference to growth rings in the shell. A small part of the nacre is removed and this exposed area is dyed pink. The shell is then studied under a stereo microscope. |
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Sea urchins also live in the same areas as abalone. They are competitors with abalone for the available food supply. Abalone do not go to areas where urchins have fed. These areas are called "White Rock" because of the effect that urchin have on the algal cover of the rocks. |
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Two abalone shark cats leaving the entrance. The entrance is constantly changing and so the diver must be very careful to avoid damage to the boat. Because of the shallow nature of the bar it is usually high tide when the return journey is negotiated. A local Fisheries Officer is greeted by a shelter on board a shark cat. The Fisheries Division must monitor the work of the abalone industry to ensure that the supply of abalone is maintained. They are on the lookout for unlicensed divers - poachers - and divers who are collecting underside abalone or more than their quota. |
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An abalone diver searches for abalone amongst the strands of kelp, a favoured habitat for abalone. The diving depth ranges from 10-30metres and the diver may be beneath the surface for up to six hours in any one day. The yellow line is the air hose which brings oxygen from the compressor on the shark cat at the surface. The bag of abalone will soon be sent to the surface using the floatation bag at the top of the slide. This technique avoids the need for continual re-surfacing, which could create problems with decompression, such as the bends. A long-term problem is also bone necrosis, or bone rot. |
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On returning to Mallacoota, the diver must have the day's catch weighed. This is important for two reasons. Firstly, the diver is paid on the weight of the abalone. In 1998 the price per kilogram was $35. Secondly, divers are only able to collect 20 tonnes of abalone per year. Therefore records must be kept of their catches and these are stored on computer by the Fisheries Division of the Department of Conservation and Environment. Unloading the abalone boat prior to weighing of the catch. The white bins are called to ab bins" and must, by law, be used for the storage of the abalone. They are light, durable and easy to clean. |
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On their arrival at the "Coop", as it is known locally, the abalone await processing. At this point most are still alive. The first thing to do is remove the animal from the shell and this is done in the "shelling room". For experienced workers the meat can be scraped out in a split second. The conveyor belt takes the meat into the main part of the "Coop" building. The empty shells are put in wire crates ready for further cleaning. |
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The abalone meat is seen here falling from the "rumbler". The rumbler is a rotating drum which assists in the cleaning of the abalone. The rotating action and abrasion removes any grit and residual gut that may still be on the meat after shelling. A load in the rumbler is rotated for about half an hour, before it is emptied into the vat of hot water below. On a busy day, when all of Mallacoota's divers have brought in catches, there will be about 4 or 5 "rumbles", the term used to describe the cleaning cycle for one load. Once the meat has fallen from the rumbler it is picked up by another conveyor belt and taken to the "picking trough". |
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Process workers stand at the picking trough and remove the mouth and/or gut of the abalone using a sharp, spoon-like object. Small nailbrushes are used to further remove grit from the "frill", or epipodium. The highest quality abalone, A grade, are the lightest in colour. They are placed on a small conveyor belt and travel down to the scales where they are weighed. The lesser quality abalone are darker in colour and are taken away for further grading. The abalone must be sorted into the lower quality grades of B, C and D. After grading they are returned to a vat of hot water On arrival again at the picking trough, they are placed on the conveyor belt which carries them to the scales. |
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The weigher must ensure that each can has the correct weight. This requires good judgement because the weight of each abalone varies. With practice the weigher becomes very skilled and can easily judge just how many abalones will make up the weight. Once the abalones for a can have been selected and weighed, they are placed in a compartment on the conveyor and move towards the canner. The group of abalone is placed in the can as they pass by the canning section. |
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The machine at the end of the conveyor seals the cans. Brine pours into the can from a small hose above the conveyor belt. Once canned they are stacked into the "retort basket", which is then lowered into the retort, a large pressure cooker. Usually the retort basket will contain cans of the same grade. However, when this is not possible, a plastic sheet is placed between the layers to delineate the different grades. The cans are stamped on the top as to whether they are A, B, C or D grade. |
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The retort basket is being removed from the retort, after the cooking of the abalone takes place. The retort supervisor must ensure that the abalone are cooked at the right temperature to avoid spoilage. Here is a general view of the factory, showing the rumbler ( background), empty cans and the picking trough. |
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The seals on the cans must be checked at random to ensure that no leaks occur. As well as quality control for the cans, the factory must be kept very clean because it is a food preparation centre. Gloves are worn by all of those who come into contact with the abalone before they are canned. |
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The shells must be cleaned after the meat is removed in the shelling room. Before 1988 this wasn't done and the shells were dumped at the local tip. However, now the shells are sold overseas. The cleaned shells are bagged, ready for export to China, where they are ground for use in medicinal mixtures. Some are also used for jewellery, because of the mother of pearl lustre on the inside of the shell. However, this lustre is not as brilliant as some other abalone species, such as the greenlip abalone. The Mallacoota abalone beds consist of blacklip abalone. |
