Abalone

This is when fleet has access to the ocean through a very shallow bar. This is Rex and John heading out on a fine Autumn day.(bar is now closed.Ocean access ramp used)

Acknowledgements:

Mallacoota P12 College, Abalone Fishermans Co-Op, Adobe Flats

Articles and picutres from many sources, thank you all if I have missed you.

Abalone are located on the seabed on rocks. They can reach 30 years of age and are harvestable from approximately 6 years on. They are seaweed feeders, hence their Australian name: Mutton Fish. Abalone graze the seabed as sheep graze paddocks. They have a heavy muscular foot on the bottom of the shell, which is the edible part. The life of the abalone begins in a free drifting planktonic state. When they get too heavy they sink to the bottom, and if they are lucky, strike a suitable reef. In the juvenile stage they are light fearing and hide under boulders, rocks and in caves. As they grow larger, abalone become light loving and settle in more open and accessible areas, thus making room for the next group of youngsters.

They are not in danger of being fished out because there are strict conservation rules applying to size, licence limitations and daily quotas.

The first fleet of abalone divers with compressors came to Mallacoota around 1963. At the height of the fishing there were over 100 divers working from the port. The catches were shelled at sea and the meat brought home in 10 gallon rubbish bins.

Fortunes were made and lost, a mini-Klondike! As other areas opened up for diving the numbers dwindled until today there are 26 divers fishing from Mallacoota. With staff at the Co-op, and dependants, the industry supports around 250 people.

Our area extends from Lakes Entrance to the NSW border. The reefs are nearly all inshore. Divers go down to depths ranging from 10 feet to 90 feet, and prise the abalone off with a crowbar-like tool. They are checked for size and the little ones carefully put back.

Diving Dangers

The dreaded bends, where nitrogen bubbles circulate in the bloodstream and lodge in the joints, causing much pain, deformities, and sometimes death
Bone necrosis (also called Silent Bends), which eats the bones away like leprosy
Dehydration with the ensuing loss of concentration. (As the water is very cold the divers urinate excessively)

It is an interesting spectacle to see the abalone fleet cross the treacherous bar; either early in the morning between 7 and 9, or on their return between 2 and 5. Watch from the lookout area over the Mallacoota entrance.

Abalone are processed at the Co-op in three ways: canned, snap-frozen in the shell, or snap-frozen as meat only. They are now brought in, in the shell. The Co-op over the years has eliminated most middle-men and we ship directly. The markets are all Asian countries with the main export to Japan. They are considered a great delicacy and are supposed to have aphrodisiac properties. (Watch out how many you eat).

Depending on the species, abalone largely tend to occupy offshore reefs, staying within the sheltered reef topography. Such sheltered areas include rock crevices and ledges, or dense kelp beds, that provide protection from strong currents as well as predators.

In its natural habitat, the abalone is usually well camouflaged, with its hard shell often encrusted with various algal or seaweed species, plus sponges, worms and sea squirts.

The abalone is a mollusc of the gastropod family.

Egg production in abalone is usually related to age. Adult individuals release up to 2 million eggs into the water, possibly triggered by periods of higher water temperature. When fertilized the microscopic eggs develop into larvae, the size of a pin head. These are dispersed via water currents around the reef topography.

In areas of low water movement, e.g., under ledges in deep offshore areas, the larvae may settle and continue their life cycle relatively close to the parent. In areas of high water movement however, for example an exposed headland, larvae are flushed from the reef. Successful settling can only be achieved over a couple of days. The chances of larvae finding a favourable habitat, such as large boulders and thick kelp, are higher in an area of low water movement.

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.

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.

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 undersize abalone or more than their quota.

Abalone divers search for abalone amongst the strands of kelp, a favoured habitat for abalone. The diving depth ranges from 10-30 metres and the diver may be beneath the surface for up to six hours in any one day. They have an air hose which brings oxygen from the compressor on the shark cat at the surface.

The bag of abalone will be sent to the surface using the floatation bag at the top. 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.

On returning to Mallacoota, the diver must have the day’s catch weighed at the Co- Op.This will come off their yearly quota. Records must also be kept of their catches and these are stored on computer by the Fisheries Division of the Department of Sustainability & Environment.

The abalone arrive in white bins called ” ab bins” which must, by law, be used for the storage of the abalone. They are light, durable and easy to clean. A special tag seals a grid over each bin.

On their arrival at the “Co-op”, as it is known locally, the abalone await processing in large cool rooms. At this point they are still alive.

Processing

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. This is done in a rotating drum called a rumbler .

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 until this is removed. before it is emptied into the vat of 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”. Here process workers will remove the mouth and/or gut which still remains. Process workers stand at the picking trough and remove the mouth and/or gut of the abalone using a sharp, spoon-like object. Small nail brushes are used to further remove grit from the “frill”, or epipodium . At this point preliminary grading of the abalone occurs. The highest quality abalone, A grade, are the lightest in colour. Once selected they are sorted by a machine into different weights. They are then either frozen on trays or processed by the weighers at the scales where they are weighed. The lesser quality abalone are darker in colour and are placed in separate bins and crates to be taken away for further grading.

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. Brine pours into the can from a small hose above the conveyor belt.A machine at the end seals the cans. Once canned they are stacked into the “retort basket”, which is then lowered into the retort, a large pressure cooker.

The retort basket is 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.

There are many other ways the abalones can be processed: frozen whole on shell, cryo packed, and so on, depending on the particular order being done.

The following page has photographs taken in the early 1990s.

Abalone Culturing

Abalone culturing has been carried out overseas for some years now, in places like Japan, the USA, Mexico and Taiwan. They culture different species to those found naturally in Australian waters. In Japan they grow the abalone for the re-stocking of reefs. China grows abalone

to what is called a “cocktail” size, ready to be eaten by the consumer.

Research has shown that the Australian species have very high growth rates ideally suited to abalone culture. Australia has some other advantages too, like clean ocean water, available coastal land for the tanks and plenty of seaweed, the main food of abalone. But it is still a very complex process to culture abalone.

First the adult abalone must be induced to spawn. This is done by putting 3 or 4 of the same sex in a small container and adding either peroxide or ultra violet irradiation b encourage their spawning. As soon as one spawns then the others follow soon after. The female eggs collect on the bottom of the container. The sperm and eggs are mixed and after fertilization the larva develop overnight. These make for the surface light and can easily be removed to the larval rearing tanks after 3-7 days.

From there they go to the juvenile settlement tanks. These are tanks with special settling surfaces – often sheets of plastic – which have algae growing on them. The larvae settle on the plastic and graze on the algae. Six weeks later the growing abalone are removed and put in the grow-out tank. There they stay for two years when they have grown to a commercial size of 60-80mm.

For Australian abalone culture to be a success then a good, cheap artificial food to mix with natural foods is required to maximize growth rates. Although there is plenty of seaweed naturally, it just could not be harvested sufficiently to cope with the demand in the tanks.

Anatomy

Issues

Poaching is an increasingly serious problem for the Victorian industry. The article “Poachers dive on big abalone profits” illustrates some of the tactics being used by poachers to avoid detection and capture.

Poaching is at its worst in the Central Zone, closest to the processors in Melbourne. But Mallacoota and the Eastern Zone also have problems, particularly with the New South Wales border being so close. Poachers from New South Wales bring their boats just past Cape Howe, enabling them to quickly return across the border – beyond the Victorian Fisheries Officers’ jurisdiction – before apprehension. Even so, a number of poachers have been caught. Penalties have included fines, loss of gear and confiscation of their boat. But the financial rewards for poachers are very large and the chance of being caught relatively slight because of the small number of Fisheries Officers, the large expanses of water and the isolated nature of much of Victoria’s coastline. Also, as the number of divers has declined, there are now less people in a position to see poachers and report back to the Fisheries Officers.

Virus

Abalone Virus:
http://www.abc.net.au/stateline/tas/content/2006/s2363422.htm
http://www.vada.com.au/Virus/Virus.htm

Recipes

Abalone Patties

5OOg Finely minced abalone
1 Tbsp chopped parsley
3 Tbsp breadcrumbs
1 Egg
1 Tbsp chopped onion
Salt and pepper

Mix ingredients together and form into patties, dip into an egg mixture of two eggs, 2 tbsp plain flour, 1 tbsp cooking oil and a dash of soy sauce. Then roll in breadcrumbs. Place patties in refrigerator to firm for 30 minutes before cooking. Lightly fry in moderate pan until golden brown either side.

Sauteed Abalone

2 Beaten eggs
1 Clove of garlic
I Tbsp chopped parsley
6 Abalone, pounded 1/4 Tsp of thyme
1/3 Cup of parmesan cheese
Olive oil, lemon, salt, pepper, bread crumbs

Mix eggs, garlic, cheese, herbs, salt and pepper. Dip abalone in this mixture and then in crumbs. Fry in oil in a moderately hot pan until golden brown on both sides. Serve with salad.

Chinese Abalone

6 Cleaned abalone
2 Tbsp of soy sauce
1 Thsp of vinegar
2 Tbsp of sugar
3 Slices of fresh ginger 3mm thick

Place all of the ingredients in a pressure cooker and cover with water. Cook gently for 40 minutes. Turn off and allow to cool with the lid on. Remove the abalone from the cooker and cut them into 3mm slices. Remove the ginger from the remaining liquid and stir the sauce until it thickens slightly. Pour this into a dish and allow to cool. Dip the abalone slices into the sauce and enjoy.

Source: Mothers’ Club Cookbook of Mallacoota Higher Elementary School

Fresh Abalone – Mallacoota Style

Sure fire method for preparing and cooking fresh abalone (Mallacoota Style!).

Requirements: bread board; sharp knife, bowls for abalone meat, meat tenderiser, several sheets of newspaper and an apron.

Wash thoroughly to remove any grit and sea sand.
Cut off the head, which is a dark lump at the end of the ab. See drawing! The head makes good fishing bait. Cut head off, taking as little meat as possible. All else is edible.
With a sharp knife, cut the abalone in half through the frills, producing two schnitzels of white meat.
Using several sheets of newspaper as a base pound the sliced abs thoroughly. Find a level place outside ie. a log or an even concrete area. Apart from the fact that the pounding takes some space, small portions of the flesh will fly up from the operation and they stick like glue wherever they land. Hence outside the house, please! Pound until they go ‘splat’ instead of ‘thump’. The surface should be slightly pulpy and the abalone very malleable. Do not do to the ‘see through’ stage.
Using a heavy frypan, heat to a very high temperature with a little oil, or oil and butter. Garlic or onions may be added for flavour. Cook one (1) minute only on either side. Serve with vegetables as available. Eat at once. Bon appetite!
If they are not tender!!?? You didn’t tenderise them enough or you cooked them too long.

Abalone may also be dipped in breadcrumbs if you wish.
Source Peter Kurz

Critters That Live on and With

Seaweeds

It may seem curious to the newcomer in this field that seaweeds are associated so closely with the rocky coast. Most of the land plants prefer soil. Why are the plants of the sea not to be sought chiefly on sandy or muddy bottoms, even if the boisterous sandy surf beaches be excluded?

The answer is that there is a fundamental difference between the true seaweeds (the algae) and most kinds of land plants. The typical condition of a land plant is that it is differentiated into root, stem, and leaves, and the leaves extract oxygen and carbon dioxide from the air, whilst the roots absorb dilute watery solutions of mineral substances from the soil.

The marine alga is a very lowly kind of plant that can scarcely be compared with these highly developed land plants. It has no true roots, and to prevent any mistakes about the nature of its parts (whether flat and branched, or simple and thread-like) the botanist speaks of the whole thing as a thallus and of its separate parts as fronds. You may say that you have seen things very like branched roots when examining the base of the bigger seaweeds at low-water mark. The answer to this is that they are merely holdfasts-anchors with adhesive discs for attachment to the rock. They do not absorb anything from their strong foundation, but merely hold on and sustain the seaweed in place, withstanding the ordinary surf. The seaweeds obtain food materials and oxygen for breathing from the sea-water. They need light, however, like most land plants. So if we put two and two together it is not difficult to understand that on the whole a rocky foundation offers the most desirable locality for seaweeds. On quiet sandy estuarine shores one may also find a few seaweeds, but only a few thrive on sand and it will be noticeable that even there many make use of stones, and even the shells of animals, for a foundation.

In sheltered areas along the coast and in many of the estuaries, there are dense beds of marine plants but these are sea-grasses and not seaweeds.

There is an enormous range in the size of seaweeds, from the almost m icroscopic (depending upon our classification) to huge seaweeds, the giant kelps, over ninety metres in length. Our only approach to the latter is found in the extreme south of New South Wales and in Victoria and Tasmania where the bull kelp and species of Macrocystis may reach lengths of up to nine metres or more. Seaweeds seem to prefer cooler water for their fullest development. They are not excluded from tropical areas, but the pastures of brown weeds are thickest in temperate seas, where colder sea-water wells up from below.

The true seaweeds are listed under a fairly simple scheme of classification, as blue-green algae ( Cyanophyta ), which are usually small and inconspicuous, requiring hand-lens and microscope their identification, red algae ( Rhodophyta ), brown algae Phaeophyta and green algae ( Chlorophyta ) It is correct to say that the frond colours of the algae of these three groups do reflect the of names of the groups. Whilst, however, there are algae of the purest brown, green and red colours, there are all sorts of shades and tints! A botanist bases real classification on structure, life history and reproductive conditions, rather than on colour. There a certain relationship between the three big sub-divisions of algae, their colour and their mode of life. Green algae generally frequent the shallower zones, brown the intermediate and red the lowest light levels. There are exceptions!

The following are my untrained identifications, if I am incorrect, please let me know! Edna

Sponges

Notwithstanding that there is much that is scientifically interesting about sponges, the great difficulty in naming the different kinds seems to have repelled the younger zoologists of recent years. Nor do the rather drab, dried specimens (and those preserved in spirit are worse still) in the museums do much to encourage the amateur, who can at least proudly display to his admiring friends his shells or his butterflies. The colour of the living sponge can be beautiful but it is evanescent, and to name most of them one must investigate the minute internal structure with a microscope after applying various technical processes to the material.

Things wouldn’t be so bad if these shore sponges had some individuality in shape or in visible structure. Most frequently, however, they occur as irregular growths of living tissue, the nature of which would puzzle a philosopher. The whole mass can scarcely be regarded as one individual, and is usually called a colony, but it is impossible to define the bounds of separate individuals in such a colony. Sponges that live in deeper and moderately still water often do grow into regular and characteristically shaped masses and many of the deep-sea sponges, which may be cup- or vase-like, or have a stalk, are more easy to name than the common rock-encrusting species of our Australian shore zones. The shore sponges are accommodating in their growth habits. They may grow on rock or on other firm objects such as large mollusc shells, and are even found on living crabs. Specimens of one and the same species will vary in shape and size according to the conditions under which they are living, and it is this variable nature that puts an end to any hope of an easy technique in naming specimens.

There are three or four kinds of Australian shore sponges that are very common and that always present the same colour and the same nature of surface. But to name these correctly (with scientific nomenclature) we cannot do what the English shore collector does-turn to a description based on long usage and on the knowledge of past sponge experts. To name the local species with certainty one would have to face up to a re-examination of all the specimens in the collections of Australian and South Pacific sponges made by collectors of bygone days and named and housed in museums scattered all over the world.

Circumstances might have been entirely different if some of the early collectors on Australian shores had described the living sponges, for we find their colours are definite and practically constant. This, together with a statement about the nature of their habitat, would have enabled us to give some of them scientific names, but past workers do not seem to have bothered about details of this kind. Most of our named sponges were collected and described in the last century and are now scattered as drab specimens in museum collections, so it is difficult to relate them to our living intertidal species. Also, it should be noted that it is only in recent years that sponges as a group of animals have received much attention from zoologists.

More recently sponges from southern Australia have been described but in general they are from deeper water. We must content ourselves, therefore, with just a little general information about the sponges of our seashore, and photographs of a few of the more obvious ones.

A circumstance that is very unfortunate when one has to write a few words about the sponges of the seashores is the familiarity of the man in the street with the bath sponge. In consequence, everyone thinks he knows what a sponge looks like. Alas, nothing could be farther from the truth. As noted earlier, the bath “sponge” is only the skeleton of a sponge, and the very nature of this skeleton, which makes it of commercial value, is on the whole rare in the sponge world. Most sponges in any condition, alive, dead, or in skeleton form, are totally unfitted for scrubbing the human body, because their tissues contain spicules of lime or silica like tiny splinters of glass.

We might point out here that it was not until the middle of the nineteenth century that even scientists ceased to dispute as to whether a sponge was animal or plant.

It would be interesting to know what resident of the shores of the Mediterranean first came to find a use for that species of sponge whose skeleton forms the bath “sponge”, and how the discovery came about at all. Sponges have been used at least since the time of the ancient Greeks and Romans, and the Mediterranean Sea at its eastern end is still the source of the world’s best commercial sponges. But these do not live in the intertidal zones )f the seashores.

A sponge is the simplest form of cell republic in the animal world; indeed, it is of such a low grade in the animal kingdom as to be little more than a mass of cells. Organs such as liver, intestine, heart, or nervous system as we know them in animal bodies are not developed. There is nothing in a sponge, in fact, that really corresponds to the mouth of an animal, and no blood system or even a nervous system. The bulk of a sponge is largely space, a system of canals and chambers, all lined by cells and separated by cells. But the cells are alive and specialised to a certain extent. On the surface are hundreds of little pores, ostia, that open into the canal system, and through these water enters the sponge and circulates through the passages and chambers until it leaves by much larger openings. These latter are the obvious apertures or oscula that one may easily see on the surface of most sponges. The water current is kept up by the waving of delicate processes (flagella) of special cells that line the chambers of the sponge. Each of these cells has a curious collar-like structure, and so they are known as collar-cells. Our interest in this fact will be appreciated when it is pointed out that in the entire animal kingdom such cells are found in only one other group, the Protozoa-the uni-cellular lowest group of animals.

Thus a live sponge is a mass of “flesh”, perforated with chambers and canals in every direction, and adapted like a sieve for filtering its food from the sea-water. It lives and feeds by causing streams of sea-water to enter its body, bringing microscopic specks of organic matter or tiny living creatures that are captured and digested. The water also brings oxygen for respiration. Some sponge species are more solid than others, with a very tough consistency, whilst other species are much less compact and are easily compressible even in the live state. The shape varies considerably even in a single species, depending to a great extent on where it is found. On an open ocean coast exposed to heavy wave action, sponges tend to be low and encrusting, and are best developed under overhangs and cave-like areas. In more sheltered waters the same species may grow in quite a different shape.

When a supporting skeleton is added to this mass of living cells the result is a sponge. And it is in the composition of this skeleton that sponges show their greatest variation. This is the basis of the classification of this group of animals consisting of some few thousand species!