Abalone in Iceland
Abalone - in Japanese: Awabi - are marine snails. They belong to the phylum Mollusca, which includes clams, scallops, sea slugs, octopuses and squids. Abalone join other snails, whelks and sea slugs in the class Gastropoda, which have one shell - also known as univalves - as opposed to clams with two shells, known as bivalves. Abalone belong to the family Haliotidae and make up the genus Haliotis. Worldwide, more than one hundred species of abalone have been identified, of which about ten are being harvested or grown for commercial purposes.
Abalone breed through broadcast spawning. In culture, spawning is controlled by the water temperature - andby light. The egg hatches as a microscopic freeliving larva, which drifts with the currents for about a week. It then settles to the bottom, sheds the swimming hairs and begins to develop the adult shell form. If a suitable habitat is located, it will grow to juvenile- and adulthood. At six months of age, the spat begins to consume kelp and becomes a juvenile (diagram above).
Abalone are nocturnal - active at night. In nature, they contend with a variety of predators throughout their lives. Eggs and larvae are consumed by filter feeding animals. Juveniles are preyed upon by crabs, lobsters, predatory snails, starfish, octopuses and fish. Adults are removed by large fish, seals, sea otters and the most effective of all predators - man.
Weaned-on-kelp juveniles - WoK's - feed on brown algae and continue to do so throughout their adulthood. In culture, they consume 3 to 5% of their own weight per day and convert the food at a rate of 1:10 to 1:20. Abalone grow to market sizes of 80 to 100 mm shell lengths and 80 to 150 gram live weights in some two-and-a-half to four years from the date of spawning.
In late 1988, three separate lots of Red Abalone juveniles (Haliotis rufuscens ), of shell lengths ranging between 20 and 45 mm, were brought to Iceland from a grow-out facility in California, USA. The purpose of the excercise was to test the species' ability to thrive in an intensive mari-environment created through geothermally heated seawater from drilled wells (diagram in the box above) and gauge its growth expectations if fed the locally available diet.
The tank-to-tank transit time of twenty-five hours was composed of the packing process and several hours on the road in California, two commercial flights of five hours' duration each, transfers at two airports (Los Angeles and New York) and, finally, clearance through customs in Iceland including a half hour's travel by road to the experimental marifarm of the Marine Research Institute (MRI) at Grindavik in the southwest of Iceland (map above).
Mortality in the two first transfers was high. In the last one, however, a 100% survival was attained. Hence, it could be insisted that the techniques of moving live abalone over extended distances and periods of time had been mastered. The comparatively high initial mortality may, in its own way, have been a natural selection of strong individuals, resulting in a surviving stock of strong and healthy Red Abalone animals ('survival of the fittest'). The present appearance of the stock, in which a number of individuals display shell lengths of 125-150 mm (5" to 6") and live weights of 450-500 gr (16 to 18 oz), certainly supports this theory (pictures below).
Monitoring of shell lengths, weights and the consumption of kelp indicate that growth rates and feed conversion ratios are comparable to those experienced in culture elsewhere in the world. Temperatures in the quarantine were maintained around 15 degC, considered optimum. The animals were fed Laminaria digitata , which occurs in abundance around Iceland. Supplementing the brown algae diet with Palmaria palmata (dulse) and Alaria esculenta at a rate of 10 to 20% was found to increase growth rates, improve the colour of the shell and be conducive to good health and general wellbeing among the animals.
For the feeding trials, kelp was harvested from shore in a nearby creek at low spring tide and stored in running seawater for one month at a time (between spring tides) at 7 degC. No deterioration was observed in the quality of the kelp during this storage time. However, it is anticipated that for a commercial size project seaborne harvesting from a specially equipped vessel must be employed.
Gravidity is common at all times in the Red Abalone colony and has been detected in individuals as small as 40 mm shell length. Spawning can thus be induced throughout the year. During the later half of 1991, the MRI produced several age groups of all-Icelandic ('native') juveniles, the largest of which are presently ~65 mm (2,5") long at 50-55 gram (~2 oz) live weight (picture above).
Following the successful feeding trials on Red Abalone and with the breeding techniques well under control, it was found that this animal is not in great demand in the Orient - the oldest, largest and most traditional of abalone markets in the world. Oriental traditions in preparing and eating seafood differ very much from those elsewhere in the world. In Japan, some species are even consumed live. It is also a common knowledge that Orientals attach various kinds of superstition to a number of food items. So do, for instance, the Japanese by longstanding traditions believe that abalone possess Aphrodisiacal powers.
It was found that there is a distinct preference in Japan for a local abalone called Ezo Awabi (Haliotis discus hannai ), the only species eaten live in that country. It fetches prices in Tokyo up to three times those paid for Red Abalone. Ezo Awabi seeks a habitat similar to that desired by Red Abalone, its US cousin, although it prefers a fraction higher temperature (18 degC instead of 15 degC). Growth rates and feed conversion ratios in culture are comparable for the two species and so is the demand for seawater and airation flow rates, indicating that the cost of commercial production might be similar.
Hence, it was decided to bring Ezo Awabi to Iceland and subject it to the same tests and scrutiny as Red Abalone had been earlier. Meantime, however, more stringent ordinances by the Ministry of Fisheries, governing the import of live marine organisms, required that a rather sophisticated quarantine be devised and located away from the Red Abalone colony (Keldur on the map). The design relies on experience gained during the feeding trials on Red Abalone and employs a watersaving system (diagram below).
A sand filter removes solids (excrements and fragments of kelp) from the recirculated water, whereas a biofilter denitrifies waste substances from the animals dissolved in the water and acts as an airator. An intensive airation is provided separately for every abalone tank. Apart from substantially reducing the seawater consumption, the system cuts demand for heating to a bare minimum. The rate, at which effluent is discharged to the environment, is equivalent to that of the make-up water, thus reducing the demand for disinfection.
The Ezo Awabi test animals were transferred from a farm in Matsuyama City in the south of Japan to Reykjavik in two lots (October and December 1992). Three commercial flights took each lot via Haneda (domestic) and Narita (international) airports of Tokyo and the International Airport of Copenhagen to Iceland. This time, the tank-to-tank transfer lasted for some 42 hours. Much like in the earlier instance, the survival rate in the first attempt was not quite satisfactory but turned out 100% in the last one. In spite of the logistics of these operations being rather complicated, they worked out very well.
Conditions in the quarantine did not facilitate reliable feeding trials on Ezo Awabi. However, observations of the animals confirm that the two species - Red Abalone and Ezo Awabi - behave much in a like manner in culture. Meanwhile, the Ezo Awabi stock has been released from 'intensive care' and moved to MRI's at Grindavik. Now that Red Abalone has been successfully bred in
Abalone are nocturnal - active at night. In nature, they contend with a variety of predators throughout their lives. Eggs and larvae are consumed by filter feeding animals. Juveniles are preyed upon by crabs, lobsters, predatory snails, starfish, octopuses and fish. Adults are removed by large fish, seals, sea otters and the most effective of all predators - man.
Weaned-on-kelp juveniles - WoK's - feed on brown algae and continue to do so throughout their adulthood. In culture, they consume 3 to 5% of their own weight per day and convert the food at a rate of 1:10 to 1:20. Abalone grow to market sizes of 80 to 100 mm shell lengths and 80 to 150 gram live weights in some two-and-a-half to four years from the date of spawning.
In late 1988, three separate lots of Red Abalone juveniles (Haliotis rufuscens ), of shell lengths ranging between 20 and 45 mm, were brought to Iceland from a grow-out facility in California, USA. The purpose of the excercise was to test the species' ability to thrive in an intensive mari-environment created through geothermally heated seawater from drilled wells (diagram in the box above) and gauge its growth expectations if fed the locally available diet.
The tank-to-tank transit time of twenty-five hours was composed of the packing process and several hours on the road in California, two commercial flights of five hours' duration each, transfers at two airports (Los Angeles and New York) and, finally, clearance through customs in Iceland including a half hour's travel by road to the experimental marifarm of the Marine Research Institute (MRI) at Grindavik in the southwest of Iceland (map above).
Mortality in the two first transfers was high. In the last one, however, a 100% survival was attained. Hence, it could be insisted that the techniques of moving live abalone over extended distances and periods of time had been mastered. The comparatively high initial mortality may, in its own way, have been a natural selection of strong individuals, resulting in a surviving stock of strong and healthy Red Abalone animals ('survival of the fittest'). The present appearance of the stock, in which a number of individuals display shell lengths of 125-150 mm (5" to 6") and live weights of 450-500 gr (16 to 18 oz), certainly supports this theory (pictures below).
Monitoring of shell lengths, weights and the consumption of kelp indicate that growth rates and feed conversion ratios are comparable to those experienced in culture elsewhere in the world. Temperatures in the quarantine were maintained around 15 degC, considered optimum. The animals were fed Laminaria digitata , which occurs in abundance around Iceland. Supplementing the brown algae diet with Palmaria palmata (dulse) and Alaria esculenta at a rate of 10 to 20% was found to increase growth rates, improve the colour of the shell and be conducive to good health and general wellbeing among the animals.
For the feeding trials, kelp was harvested from shore in a nearby creek at low spring tide and stored in running seawater for one month at a time (between spring tides) at 7 degC. No deterioration was observed in the quality of the kelp during this storage time. However, it is anticipated that for a commercial size project seaborne harvesting from a specially equipped vessel must be employed.
Gravidity is common at all times in the Red Abalone colony and has been detected in individuals as small as 40 mm shell length. Spawning can thus be induced throughout the year. During the later half of 1991, the MRI produced several age groups of all-Icelandic ('native') juveniles, the largest of which are presently ~65 mm (2,5") long at 50-55 gram (~2 oz) live weight (picture above).
Following the successful feeding trials on Red Abalone and with the breeding techniques well under control, it was found that this animal is not in great demand in the Orient - the oldest, largest and most traditional of abalone markets in the world. Oriental traditions in preparing and eating seafood differ very much from those elsewhere in the world. In Japan, some species are even consumed live. It is also a common knowledge that Orientals attach various kinds of superstition to a number of food items. So do, for instance, the Japanese by longstanding traditions believe that abalone possess Aphrodisiacal powers.
It was found that there is a distinct preference in Japan for a local abalone called Ezo Awabi (Haliotis discus hannai ), the only species eaten live in that country. It fetches prices in Tokyo up to three times those paid for Red Abalone. Ezo Awabi seeks a habitat similar to that desired by Red Abalone, its US cousin, although it prefers a fraction higher temperature (18 degC instead of 15 degC). Growth rates and feed conversion ratios in culture are comparable for the two species and so is the demand for seawater and airation flow rates, indicating that the cost of commercial production might be similar.
Hence, it was decided to bring Ezo Awabi to Iceland and subject it to the same tests and scrutiny as Red Abalone had been earlier. Meantime, however, more stringent ordinances by the Ministry of Fisheries, governing the import of live marine organisms, required that a rather sophisticated quarantine be devised and located away from the Red Abalone colony (Keldur on the map). The design relies on experience gained during the feeding trials on Red Abalone and employs a watersaving system (diagram below).
A sand filter removes solids (excrements and fragments of kelp) from the recirculated water, whereas a biofilter denitrifies waste substances from the animals dissolved in the water and acts as an airator. An intensive airation is provided separately for every abalone tank. Apart from substantially reducing the seawater consumption, the system cuts demand for heating to a bare minimum. The rate, at which effluent is discharged to the environment, is equivalent to that of the make-up water, thus reducing the demand for disinfection.
The Ezo Awabi test animals were transferred from a farm in Matsuyama City in the south of Japan to Reykjavik in two lots (October and December 1992). Three commercial flights took each lot via Haneda (domestic) and Narita (international) airports of Tokyo and the International Airport of Copenhagen to Iceland. This time, the tank-to-tank transfer lasted for some 42 hours. Much like in the earlier instance, the survival rate in the first attempt was not quite satisfactory but turned out 100% in the last one. In spite of the logistics of these operations being rather complicated, they worked out very well.
Conditions in the quarantine did not facilitate reliable feeding trials on Ezo Awabi. However, observations of the animals confirm that the two species - Red Abalone and Ezo Awabi - behave much in a like manner in culture. Meanwhile, the Ezo Awabi stock has been released from 'intensive care' and moved to MRI's at Grindavik. Now that Red Abalone has been successfully bred in