1 The major part of this paper dealt on the role of fisheries in the country and its status and prospects. Only relevant portions on this training course are reproduced here.
2 Assistant Fisheries Officer, Fisheries Department, P.O. Box 2161, Brunei.
Aquaculture in Brunei is at its infant stage. Fishes such as grass carp, big carp, and tilapia are being cultured and gave promising results. Inland fishermen are being encouraged to set up suitable fishponds and to the point that the Department of Fisheries supplies them with free fingerlings. Culture of freshwater fishes could greatly help in lowering the import of fishes. Majority of the population, however, favours marine fishes than the fresh water ones. As of now, mussel culture is also being undertaken and so far, gave promising results, too.
Seaweeds have potential economic value both as industrial products and as foods. As far as Brunei is concerned, neither any survey nor any serious works have been done on seaweed. Of course, there is always a possibility of seaweed utilization in Brunei. However, feasibility studies have to be conducted first. Though greater part of the Brunei coast (161 km) are exposed to South China Sea wind and the inner coastal region are very muddy and swampy, some parts may prove to be ideal for seaweed farming. The people have to be convinced, too, of the economic Importance of these seaweeds. This may, however, take a long time. In comparison with the other Asian countries and Japan, the status of seaweed in Brunei is at present negligible.
Aye Kyaw 1
1 Research Assistant, Research Department, People's Pearl and Fishery Corporation, Thakepa, Rangoon, Burma.
In Burma, seaweed (“cakenella nipae”) culture was first experimented by Kyi Swe (1972) at Kyaihkhame. Gracilaria edulis was cultured by Min Theim, et al (1974) at Setse. In January 1977, the Research Department of the People's Pearl and Fisheries Corporation materialized it into a pilot scale. This was with the joint cooperation of the Marine Biology Department of Moulmein College and Foodstuff Industry. The Mg. Shwe lay Gyaing (1718'N - 9420'E) Sandoway was the site chosen for the project.
The main aim of the project was to promote the experimental seaweed culture of Burma from primary research to pilot scale. This enabled them to assess the possibility of commercial production of seaweeds.
2. METHODS OF PLANTING
Two methods of planting of seaweeds are employed which follow the rule of constant level and constant depth. In the first method, the poles are fixed squarely at the bottom of the sea and the nets are attached horizon-tally 0.6 (2 ft) from the bottom. The second method is the long line float system making use of nets attached to the poles.
3. RESULTS AND DISCUSSION
3.1 Stock ground and planting stock
In the beginning of the experiment. Gracilaria edulis test plants were carried from Macotin Point within 36 hours. The southern parts of the Arakan coasts were surveyed thoroughly ranging from Mawche up to Gua. Finally, in January 1977, a rich stock ground of Gracilaria edulis was found in Andrew Bay, about 7 sea miles east of Mg. Shwe lay culture base. The Bay was once one of the richest Gracilaria edulis producing areas in Burma 40 years ago. During the Japanese invasion (1940–1945), the local people were said to have been selling hundreds and hundreds of bushels of that raw material to the invaders at kt - 10/c (Japan kyats at the time) per viss (3.6 lb or 1.6 kg).
Even now, G. edulis could still be found in many places such as Kyautchinatach, Myohaung, Kyeuetauh, Magyigyaing and all along the vicinity.
planting stocks were collected from these areas and transported by boat to Mg. Shawe lay culture belt. These were planted immediately on nets and fixed to the aforementioned systems.
Maintenance or stability of the systems is the problem of seaweed culture at Mg. Shawe lay. The bay is open to the north and south winds seasonally, thus suffering from the effects of storms and underwater current movements. For this purpose, fixed concrete base or anchor was considered. Nets made of polytheylene ropes 8 mm in diameter were found most reliable because of their strength and resistance to rot or decay in salty water. It was also discovered that spores released by cultured mature plants easily take root on them.
Eighteen plies of nylon woven nets (5 m × 2 m) were used for culture. To meet the growing weight of the plants, the nets were further folded into two. On each pair of knots, 4–6 cm, cuttings or fragments of seed plants were tied with plastic strings. According to the latest experiment, 204 of the test plants are sufficient to plant a net. It takes an hour for a person to plant the whole net.
4.1 Factors to be considered
Barnacles endanger the ropes and nets. They appear in small patches and grow up into a large community in no time. With the tidal movements of the sea, especially when storms rage, ropes running on their sharp edges easily snap leaving the whole system in a mess.
Filamentous algae, Nostoc, Microcoleus, and hydrozoans, etc. greatly inhibit the growth of plants. They cover the plants depriving them of nutrients and light. Acanthophora and Padina develop mostly during rainy season on cultured nets. Blue-green algae is dominant during winter months.
Among multi-cellular animals, sponges cause most harm to the growth of the Gracilaria. Once rooted, they grow much faster than the plants, thus, covering them completely. In the first year of the experimental culture, sponges were the chief factor that caused the death of the plants soon after they were being harvested.
For these reasons, it is a life-and-death necessity to clean and weed the nets, ropes and floats every other day at the first month of planting and harvesting.
4.2 Culture belt
In Burma, Gracilaria edulis grows most rapidly in waters with a salinity of 25 ppt and at temperature of 20–30°C. The substrate of Mg Shwe lay bay is sandy-loam. The pH of the water is 6–9. The depth of Mg. Shwe lay bay is 5 m during rainy months. It may be judged rightly that the exceedingly good results obtained in Mg Shwe lay Gyaing during the rainy season are due to diluting effect of rain on the high salinity of the seawater. The temperature during the said period is apparently low.
Three years of continuous field study have determined the seasonal cycle of Gracilaria edulis in this particular culture area. It begins to flourish at the approach of February and reaches its peak (full bloom) in July to August. It starts to deteriorate in mid-September and becomes pale and fragile in October. Growth then stops totally and remains till January. This period from October to January is called a “resting period”.
4.3 Measuring growth
Random samples are taken from: (a) the whole net, (b) the upper three rows, and (c) the uppermost row of some three rows of the LLF systems. Percentage cover is observed weekly for 10 consecutive weeks. It takes 2–3 months to reach a full grown size. The longest length recorded is 25 cm. It is apparent that G. edulis grows within the said period a hundred folds in weight and about 3–4 times in length.
4.4 Harvesting, drying and packing
At present, cultured Gracilaria are harvested once a month from April to September. Harvesting is by hand method. Two-thirds of the plants is cut off leaving longer stems for growth for the next harvest.
The harvested plants are washed, weighed and dried evenly on bamboo screens under the sun for a day or more, depending on the weather. The drying ratio is about 1:7. Dried raw seaweeds are then packed in Manila bags containing 10 viss (= 164 kg) each. So far the experimental culture has been able to produce 720 kg wet weight or 100 kg dry weight.
Three years of experimental seaweed (Gracilaria edulis) culture at Mg Shwe lay has shed much light on the technology of seaweed culture of Burma. The environmental condition of the bay is suitable during the rainy season. Spontaneous generation by spores is an achievement and of advantage in Burma's Gracilaria edulis culture.
V.S. Krishnamurty Chennubholta1
1 Scientist, Mandapam Regional Centre of Central Marine Fisheries, Research Institute, Marine Fisheries, P.O. Pin Code: 623520, Mandapan Camp, South India.
Forty percent of the population in India is estimated to be vegetarian. Seaweeds with its high nutritive value constitute a potential resource of valuable supplementary food.
India has a coastline of 5 698 km. Rocky and coral formations are found in Tamil Nadu, Grujarat states, and in the vicinities of Bombay, Karawar, Batnagiri, Goa, Vizhinjam, Varkala, Vishakapatnam, and in few other places like Chilka and Pulicat lakes, Andaman and Nicobar Islands. The coastal areas of Tamil Nadu and Grujarat states are the important seaweed growing regions of the* country.
2. SEAWEED RESOURCES
Some surveys have been made to estimate the resources of the seaweeds in the country which are as follows:
2.1. Quantities, of alginophytes
The standing crop of seaweeds at the northwest end of Kathiawar has been estimated by Sreenivasarao, et al. (1964). On a 0.015 km2 of reef area, they found 60 tons of fresh Sargassum or about 4 kg/m2. Hornell (1918) estimated the amount of fresh Sargassum washed ashore along the Kathiawar coast to about 100 tons annually.
In the Gulf of Kutch north of Kathiawar peninsula, Desai (1967) gave a very high estimate of 1 000 000 tons of harvestable brown algae per year corresponding to 10 000 t dry weight. Chauhan and Krishnamurty (1968), however, harvested 19 000 tons fresh weight of alginophytes, 12 000 tons of which were Sargassum. while investigating a good 10 km2 in the same area.
2,2 Quantities of agarophytes
Prasanna Varma and Krishnarao (1964) estimated the seaweed resources along the Pambian area in the Gulf of Mannar. In two areas covering 59 km2, only 0.5 percent had coral or rocky reefs with economically harvestable seawee resources. An area of 0.294 km2 has an estimated wet weight of harvestable Gracilaria at 334.9 tons, Gelidium at 18.9 tons and brown algae at 657.9 tons or agarophytes at 1.2 kg/m2 and alginophytes at 2.2 kg/m2.
In Palk-Bay, north of the Gulf of Mannar, Umamesheswararao (1968) estimated the standing crop of an area measuring 3.6 km2. The mean values he got for two years of investigation were:
|Fresh weight (in tons)||ka/m2|
From samplings in the Gulf of Kutch, Desai (1967) observed that 20 tons of dry Gracilaria can be harvested. A profuse growth of seaweeds has been observed in an area 800 m wide and 32 km long in the Gulf of Mannar between Mandapam and Tuticorin. The Gulf of Mannar is considered to be the richest ground for Gelidium in India.
Twenty thousand tons (wet weight) of Gracilaria and 2 000 tons of Gelidium or 3 000 tons and 300 tons dry weight respectively, can be collected annually from this area.
The total standing crops as revealed by discussions with seaweed collectors in the coastal villages of Ramnad and Tirunelveli districts and by the scientists of the Central Marine Research Institute are as follows:
|Agarophytes||5 000 t||20 000 t|
|Alginophytes||20 000 t||80 000 t|
3. USES OF SEAWEEDS
Seaweeds are rich in protein, vitamins and mineral contents. Green and red algae are rich in protein ranging from 20.12 to 25.48 mg/100 g. They are also rich in Vitamins A, B, C and E. The Vitamin C content in Sargassum myriocysum exceeds that of lemon. Vitamins A, B12 and B occurring in many seaweeds exceed in qualities than those occurring in other vegetable and animal matter. * Seaweeds are rich sources of colloidal carbohydrates such as agar-agar and algin which have a very wide industrial use. Agar-agar and algin are added to some food items, confectionary, dairy products, sweets, jellies, jams, desserts, ice cream, Pharmaceuticals, rubber making, in clarifying liquor, as a lubricant, laxative and in many other industries.- The most important use of agar is in bacteriology as a culture medium; while the algin is in textile industry.
In order to popularize seaweeds as substitutes for food and to maintain a continuous supply of raw materials to the ever-growing agar and algin industries, culture methods were developed as there is already depletion of these agarophytes and alginophytes in the natural environment by constant exploitation.
4. CULTURE WORK
In India, preliminary culture experiments were started by Thivy (1964) at Portander by tying small plants of Sargassum cinetum, S. vulgare, S. swartzii and Gelidiella acerosa to coir nets. In these experiments, plants of Sargassum cinctum with an initial height of 10 em had grown to a height of 37–52 cm within 40 days. Culture experiments on Ulva lactuca and U. rigida in the laboratory indicated that the apical and marginal portions show maximum increase (Kale and Krishnamurty, 1967) .
Experiments with Gracilaria corticata and G. edulis had shown that in former, the growth was slow during the first 45 days and a rapid increase from 1.8 to 5.5 cm was recorded during the next 45 days. In the latter, a growth of average 4.3 kg/m2 in 80 days was observed in the coir nets used for culture work. Cultured Gelidiella acerosa in coir nets yielded a fresh weight of 3 kg/m2 in 77 days from an initial seed material of 1 kg (Krishnamurty, C.G.S. et al. 1971).
At present, trials are underway to streamline a method by floating nets which could bring down the cost of production of seaweeds by culture practices. This also forms the future programme for the Institute.
5. THE WORK ON GRACILARIA AND OTHER SEAWEEDS
Gracilaria edulis and Gelidiella acerosa are the main agarophytes in India, and as such, they attract the attention of aquaculturists in the country.
5.1 Gracilaria edulis
Gracilaria edulis is being grown in coir ropes by longline rope method by seeding them in the twists and left in the inshore waters for further growth. An annual production rate of 3.5 kg/m of rope was obtained. Later, the ropes were fabricated in the form of nets and tied to wooden poles in the inshore waters. Here, the production rate was found to be three times the initial weight introduced in 60 days. The technology involved in the cultivation of Gracilaria edulis was transferred by the Central Marine Fisheries Research Institute, Cochin to interested fishermen in the coastal villages of Ramnad Diet in India under Land-to-Land Programme of Indian Council of Agricultural Research.
5.2 Gelidiella acerosa
Gelidiella acerosa has a very slow growth rate and the production rate obtained for this was three times in 77 days.
The method of cultivation is yet to be simplified to reduce the cost of production of seaweeds for which trials are underway.
5.3 Porphyra sp.
Cultivation of Porphyra in Japan by spores is a unique phenomenon in the world but full knowledge about spore germination of other seaweeds is lacking as the survival and viability of spores is very limited. In addition to this, it takes a lot of time for the spores to reach the plants of harvestable stage. Still, vegetative propagation (by fragments) is quicker and easier. In the Central Marine Fisheries Research Institute, Cochin, India treatments are underway to simplify the culture using the latter method, side by side with improving the techniques of spore culture.
6. POST-HARVEST TECHNOLOGY
The processing is done in the country itself as there are already nearly 10 factories manufacturing agar-agar in India. The leading one is M/S Cellulose Products of India. Grujarat is second with a branch at Tamil Nadu.
Agar in India sells at a rate of Rs 100 to 200 (i.e. US$12, $24) per kg depending upon the (quality) grade. The value of algin varies from Rs 60 to Rs 120 (US$7.5 to $15) depending upon the demand.
The agar and algin industries have been established in the country in recent years. Some private firms in Grujarat and Tamil Nadu states have started production of agar and algin utilizing the raw materials collected along the Indian coasts. In order to ensure supplies to this industry, export of raw materials is now prohibited.
During 1966–1968, the exports of agarophytes were as follows:
|1966||163 t||60 000|
|1967||198 t||200 000|
|1968||92 t||30 000|
9. QUALITY CONTROL
The Government of India desires that agar and algin manufactured in India conforms to the standards required by various industries;! In this connection, the Indian Standards Institute in Calcutta has divided the agar into three categories based on moisture, nitrogen and ash contents:
The quality of algin is determined by the viscosity in centipoise. Algin of very high viscosity is required for textile industry.
Culture of agarophytes should invariably be combined with agar production to make it economically feasible as cost of fresh or dry agarophytes fetches only low returns. Though the first year of staring may not bring profits, second year onwards profits may start accruing as the non-recurring expenditures would not be there from them.
Methods of cultivating Gracilaria edulis by rope method and the process of manufacture of sodium alginate were found to be economically feasible. The methods are patented and are available at the Central Salt and Chemicals Research Institute (CSMCRI), Bhavanagar and NRDC, New Delhi, respectively for the benefit of entrepreneurs.
Sreenivasa Rao, P.E., R.R. Iyengar and F. Thivy. 1964 Survey of algin bearing seaweeds at Adatra Reef, Grha. Curr. Sci., 33(15): 464–5.
Hornell, J. 1918 Report on the further development of fishery resources of Baroda State. Baroda.
Desai, B.N. 1967 Seaweed resources and extraction of alginate and agar. In Proceedings of the Seminar on Sea, Salt and Plants, edited by V. Krishnamurty, Bhavanagar. Central Salt and Marine Chemicals Research Institute: 343–351pp.
Chauhan, V.D. and V. Krishnamurty. 1968 An estimate of the algin bearing 1968 seaweeds in the Gulf of Kutch. Curr. Sci., 37(22): 648pp.
Prasanna Varma, R. and K. Krishna Rao. 1964 Algal resources of Pamban area. Indian J. Fish., 9(1): 205–11.
Umameheswarai Rao, M. 1968 The seaweed potential of the seas around India. In Proceedings of the Symposium on the Living Resources of the Seas around India, Cochin, 7–10 December 1968, Mandapam Camp, Central Marine Fisheries Research Institute: 31pp.
Thivy, F. 1964 Marine algal cultivation. Salt Res. Ind., 1: 23–28pp.
Kale, S.R. and V. Krishnamurty. 1967 The growth of excised pieces of thallus of Ulva lactuca var rigida in laboratory culture. CSMCRI Bhavanagar: 234–238pp.
Krishnamurty Chennubholta, V.S. 1977 Field cultivation of Gelidiella acerosa in inshore waters of Gulf of Mannar (Abstract). Proc. 9th Inst. Seaweed Symposium, Santa Barbara, California.
1Staff, Directorate of Resources Management, Directorate General of Fisheries, Jalan Salemba Raya 16, Jakarta, Indonesia.
Indonesia consists of more than 13 000 islands. It is geographically located between 90° to 140°E latitude and 5°N to 11°S longitude. Due to this location, Indonesia experiences a tropical climate.
I would like to tell you about my experiences on the seaweed survey in Indonesia. Actually, I have not visited the whole of Indonesia, but only some areas such as the provinces of Lampung, West Java, East Java, Central Java, Bali, West Nusa Tenggara, East Nusa Tenggara, South Sulawesi, East Kalimantan and Bengkulu.
At present, production of seaweeds in Indonesia is dependent only on wild stocks. I gathered these data by interviewing the fishermen and staff of local fisheries services, field observations and following up the development of seaweed culture.
From interviews with fishermen, I was able to gather some data like seaweed distribution, method of harvest, time of harvest, kind of equipment used, production and marketing. Field observations were made by surveying the bottom of the area, noting the species found, observing the direction of water movements, measuring the salinity and temperature, etc.
Seaweed farming/culture has been started by fishermen at Dabo and Aru islands (Mollucas province) since 1978, Later on, this spread out to Samaringa island, Bali province and Maumere district. In Bali province, they farmed Eucheuma spinosum using raft 5 m in length and 2.5 m wide, while in Maumere district, it is by bottom method. At present, farming at Samaringa island has been stopped due to low price of this seaweed. As of now, they turned to the wild stocks.
2. WORK ON SEAWEEDS
Seaweed is one of the exported commodities, which are harvested from the offshore and coral reefs of Indonesian marine waters. These seaweeds which have commercial value are the following: Eucheuma, Gracilaria, Gelidium and Hypnea (Table 1).
Production of these seaweeds are dependent on the wild and natural stocks. The supply is quite variable because the growth of these seaweeds is seasonal. During the season when westerly winds prevail, great volume could be harvested. Scarcity of seaweeds can be observed at the occurrence of big waves when most of the. wild stocks are destroyed. In this case, foreign demand could not be met, and for these reasons, there is a need to introduce farming techniques. The success of seaweed culture depends on factors like suitable suites, water movement, system and methodology, supply of seedstock, availability and cost of labour, and marketing.
Seaweed farming/culture in Indonesia is still at its research stage but not yet in commercial scale. These researches have been conducted in several areas of the country by the Marine Fisheries Research Institute (LPPL) and National Institute of Oceanology. From these research institutions, improvements have been made in terms of growing seaweeds.
In Aru and Dabo islands, province of Mollucas, seaweed farming is managed by a cooperative supported by the United States Agency for International Development (USAID). The Directorate General of Fisheries is planning to establish a pilot seaweed farm at Bali province in the near future. Funding through the United Nations Development Programme is being sought.
3. POST HARVEST TECHNOLOGY AND MARKETING
The method of harvesting in Indonesia is usually done by gathering all of the wild stocks in an area. This depletes the seaweed resource of an area. In this connection, some of the provinces formulated conservation measures. A law was passed against over-harvesting. In some places, however, the law was not followed.
Processing of seaweeds for export involves drying for two to three days. After drying, the seaweeds are placed in the sacks. Local businessmen purchase these from the fishermen and are responsible for their exportation.
In Mollucas and South Sulawesi alone, all of the Eucheuma produced are being exported to other countries. On the other hand, Gracilaria produced in Indonesia are processed for the production of agar and for food consumption though some are being exported.
The dominant species of Eucheuma in Indonesia is Eucheuma spinosum wherein carrageenan extract used for industrial purposes can be obtained. Extraction of carrageenan is not done in Indonesia. Processing plants for these seaweeds are in the United States, Denmark, France, Japan, Australia, etc. (Volume of export see Table 2).
Presently, Indonesia is still exporting raw materials of seaweed to foreign countries for the production of agar, algin and carrageenan. Besides Indonesia, the Philippines was successful in mariculture of Eucheuma. Ninety-five percent of the produce is exported to foreign countries as raw material.
Table 1. Production of seaweed (by province)
|15||West Nusa Tenggara||61||9||-||-|
|16||East Nusa Tenggara||89||571||179||445|
Table 2. Volume and value seaweed of exports
|Padang TL Bauyer|
DISTRIBUTION OF SEA WEED IN INDONESIA
Toga Muliater Pasaribu1
1 Staff, Directorate of Production, Directorate General of Fisheries, Jalan Salemba Raya 16, Jakarta, Indonesia.
Algae are commodity that can be obtained from the sea. It is well-known in the world commercial trade as seaweed.
Agar is produced from a seaweed Gracilaria verrucosa that can be found in the water of Pulau Jawa. At Pulau Sulawesi} Maluku and Nusa Tenggara, a species, of the genus Eucheuma is common. Carrageenan can be extracted from . it and is used as a stabilizing, gelating, and a thickening agent.
In 1973 before the Eucheuma farming was developed} the total world trade market for Eucheuma amounted to 14 000 tons. Indonesia contributed about 5 000 tons to this while the Philippine contribution amounted to about 300–400 tons (Mubarak, 1981). From 1974 onwards, Eucheuma farming in the Philippines has undergone a rapid development surpassing that of Indonesia.
Besides Eucheuma, there are other species whose extracts are widely used in Indonesia and these include Gelidium and Gracilaria.
Efforts to increase seaweed production have to be intensified by condicting researches and extension training programmes for the farmers.
2. EXTENSION TRAINING PROGRAMME
In Indonesia there are two research institutions engaged in marine research, namely:
National Institute of Oceanology (Lembaga Oceanology Indonesia, L.O.N.) under the Indonesia Council of Sciences (Lembaga Ilmu Pengetahuan Indonesia, L.I.P.I.).
Marine Fisheries Research Institute (Lembaga Penelitian Perikanan Laut, L.P.P.L.) under the Agency for Agricultural Research and Development (AARD), Ministry of Agriculture.
These two institutions cary put researches and investigations on the marine resources of the country.
The Directorate General of Fisheries in turn will take appropriate steps to extend the useful findings to the farmers concerned so that intensification of production can be assuredly achieved.
To do these, the Directorate General of Fisheries will have to resort to the following:
Training of field extension workers directly in the field by having demonstration ponds, floating cages and dialogues with farmers.
Training of farmers at the Sea Farming Development Centre will be implemented in 1982 on the theories and practical aspects of agriculture.
The above trainings will be financed by the Central Government. Air pioneers, those trained farmers are expected to explain and to' convey their knowledge to the other untrained farmers.
The results obtained fr6m these trainings will be monitored continuously by the Directorate General of Fisheries whereby further improvements can be made and carried out to ensure better future production. Further, extension programmes on sea farming in Indonesia will enhance the development of Seaweed-farming.
SCHEME: STRUCTURE ORGANIZATION FOR THE EXTENSION WORKER
1 Staff, Fisheries Services, Province of Bali, Jalan Patimura No. 77, Denpasar, Bali, Indonesia.
This is a report about the general development and production of seaweeds in Bali province. At present, most of the seaweed production in Bali province still depend largely on the collection from the wild stock. Seaweed has been farmed on a small-scale project since December 1978.
1.1 Background information
Bali province has an area of 5 632.86 km2. with a coastline of about
470 km. It consists of several islands namely Nusa Penida, Nusa Lembongna, Nusa Cenningan, Nusa Dua, Pulau Serangan and Pulau Menjangan. Geographically, on its west is the Bali Strait (Selat Bali) bordering the Java islands, Java sea on the north, Lombok Strait on the east, that borders the Lombok island (West Nusa Tenggara province), and Indian Ocean on the south.
Most of the coastal areas in Bali island are characterized by growing reefs. These are characterized by sandy bottoms and gentle slopes toward the sea, with the exception of the southern shore especially in the southern portion of the north of Bandung regency which is steeper in slope. There are many estuaries covering the southern area of the island.
The total population of Bali province is estimated to be 2 350 000. Most of them are farmers and about 7 percent are fishermen. Transportation and communication to any part of the island as well as to other islands are available.
1.2 Natural resources.
Seaweed has been known in the past as vegetables to the coastal people. In fact seaweed has been exported to China and Japan even before the Second World War.
The various types of seaweeds that have been utilized by the people in Bali province for their own consumption as well as raw materials for industrial purposes include the following: Hypnea, Gelidiella, Gelidium. Gracilaria, Eucheuma, and Caulerpa.
According to the National Institute of Oceanology, there are 37 species in Tanjung Benoa, Badung regency.
Most of these seaweeds are found along the coast of the island. Distribution of seaweeds can be grouped into the regencies, as shown in Table 1.
Table 1. Distribution of seaweeds in different regencies
|Regency||Collection Centre||Area (Ha)1|
|1.||Badung||Jimbaran, Pecatu, Husa Dua, Tanjung Benoa and Serangan||550|
|2.||Tabanan||Soka, Yeh Gangga and Kedungu||140|
|3.||Jembrana||Airkuning, Pengambengan and Candi Kusuma||450|
|4.||Buleleng||Temukus, Kubu Tambahan and Teluk Terima||300|
|5.||Karangasem||Candi Dasa, Fadang - Bali and Buitan||300|
|6.||Klungkung||Nusa Penida, Lembongan and Ceningan||300|
|7.||Gianyar||Lebih and Ketewel||150|
1 The reef is around 200–500 m in width.
2. PRODUCTION OF SEAWEED
2.1 Harvesting of natural stock
Most of the production of seaweeds in Bali province depends on the natural wild stock. The amount of seaweeds that have been produced are as shown in Table 2.
Table 2. Figures obtained from data of Fisheries Service, Province of Bali
Generally, the composition of the production of these seaweeds consists mostly of Gracilaria sp. Since l979, the production has increased especially in Badung regency as a result of Eucheuma spinosum culture. This species has been reponsible for the 60 percent increase in that particular year.
The harvesting season is carried almost throughout the year. Harvesting from natural stock consists of two types: (i) the seaweed is harvested directly from the substratum; and (ii) they are harvested from the shore as the waves brought them to the shore during west monsoon in the month of November to January.
2.2 Harvesting of cultured seaweed
Seaweed culture has been started in December 1978. The most important species being-cultured is Eucheuma spinosum. The culture has been pioneered by an Indonesian who works with Copenhagen Pectin, Ltd.
The seed stock of these species were obtained locally and also from Samaringga, Sumbawa island, Seribu archipelago. It appears that seed stocks from Samaringga and Sumbawa have the fastest growth rate.
In general, seaweed farming makes use of the floating method and monoline bottom method. At present, most of the local farmers are using monoline bottom method.
The total number of families engaged in the farming at Terora, Tanjung Benoa, is about 20 and they work on an area of about 2 hectares. On average, each has about 75 units of floating nets or monoline.
Harvesting is done almost monthly though there are instances that harvesting is carried out twice a month depending on the growth of the seaweed.
3. POST HARVEST AND MARKETING
3.1 Post harvest technology
After harvesting either from natural stocks or from culture, the seaweeds are cleaned and dried under the sun on the shore by the fishermen.
If the seaweeds are to be sold to the buyer, the seaweeds are further cleaned with freshwater before they are dried, with the exception of Eucheuma spinosum. Dried seaweeds are packed before sending them to Java, The products are further exported to the other countries.
Generally, the species of Hypnea sp and Gelidiella are processed by local inhabitants. These materials are dried in the form of sheets for local dishes.
Most of the seaweeds are mainly marketed to the other districts or islands, especially to Java (Surabaya and Jakarta). With the exception of Hypnea and Gelidiella, seaweeds are generally marketed for local consumption.
The sequence in seaweed marketing in Bali province can be illustrated as follows:
The Trader deals with outside buyers, for example in Surabaya, East Java and Jakarta, West Java. The seaweeds that are sold out to Java are used for local industries as well as for export to other countries.
Faazaz Bte. Abd. Latiff 1
1 Fisheries Officer, Fisheries Research Institute, Glugor, Penang, Malaysia.
The Malaysian Government looks at fisheries as a source of employment, food, and export. In this connection, the Government encourages aquaculture development. About 150 000 hectares of mangrove swamps and mudflats in West Malaysia may be suitable for this purpose. More than 4 000 hectares have already been taken up for the culture of cockles (J. Malaysian Economic Association, 1976). The rest are yet to be utilized for other aquaculture activities like seaweed farming.
2. SURVEYS ON THE POSSIBILITIES OF SEAWEED FARMING
Aerial and ground surveys were made by the South China Sea Fisheries Development and Coordinating Programme (SCSP) on the northwestern coasts of West Malaysia. A 240 km long shoreline between Langkawi Islands and southward beyond Pulau Pangkur appear to have & good potential for seaweed farming. Besides this, about 34 km of coasts in segments, could also be considered for farming. These areas are in Kuala Kedah, Alor Setar districts, Tanjung Dawai, west coast of Penang, Tanjung Piandang, Kuala Kurau, Port Weld and areas opposite Pulau Pangkur in Perak.
The survey also showed that two Gracilaria species are growing in abundance in the Middle Bank between Penang and the mainland. The substratum is of the very soft, non-sticky, dark grey mud which characterizes the soil type of Perak, Penang, Kedah and Perils shores.
Despite the findings from the survey, seaweed farming implementation programme for West Malaysia still remains as a proposal. The reasons for the slow development in seaweed farming can be attributed to:
Thus, before any seaweed farming can be developed in West Malaysia, the above problems have to be overcomed. This would require a combined effort and cooperation of the Government agencies, research organizations, universities and the private sector.
Here are some recommendations worth considering:
The Government should give priority to seaweed farming by providing financial aids and other incentives.
Training of skilled personnel in seaweeds for jobs as extension workers and practical farmers should be encouraged.
Extension services and training centres should be established.
Pilot scale projects on seaweeds should be undertaken as an intermediate step between research and private enterprise. Such projects could be used to test their economic viability for commercial application.
More aerial and ground surveys should be carried out to look for more suitable farming areas for the seaweeds.
Seek for expatriate technical assistance.
The World Bank, regional banks, national development banks and other financing agencies should be encouraged to recognize and support seaweed farming in Malaysia.
According to Doty (1972), implementation of farming of Gracilaria could probably be developed over a four-year period. Nevertheless, from his past experience, it is expected that it will take 5 years to exceed 500, the target number of families suggested. His proposal is summarized in the Working Paper Series of the FAO/UNDP South China Sea Fisheries Development and Coordinating Programme.
Seaweed farming has a promising future in Malaysian aquaculture. This could create more employment opportunities to the people to augment their incomes. In the long run, Malaysia could also become one of the agar producing countries from Southeast Asia.
Proceedings of the Seminar on the Development of the Fisheries Sector in Malaysia (June–December 1976). 1976
Doty, M.S. 1977 Seaweed resources and their culture in the South China Sea Region (SCC/77/Wp/60), South China Sea Fisheries Programme, Manila, Philippines.
Tenth International Seaweed Symposium, 1980 11–15 August 1980, Goteborg, Sweden.
1 Fisheries Assistant, Fisheries Department, Mailbag No. 107, Kota Kinabalu, Sabah, Malaysia.
Sabah is one of the states of Malaysia situated at the north of Borneo Island facing the South China Sea, Sulu, and Celebes Sea. A considerable portion of the population of Sabah, apart from the commercial fishermen, is dependent on fishing. Their methods of fishing are primitive utilizing fish-traps, spears, handlines and others which are usually uneconomical.
A small quantity of Eucheuma are found growing on reefs in Semporna area, southeast of Sabah and on reefs of offshore islands of the South China Sea in Kudat area, north of Sabah.
2. SEAWEED FARMING POSSIBILITIES IN THE COUNTRY
Seaweed farming possibilities in the State of Sabah can be divided into five areas;
2.1 Coast of Kota Kinabalu, including Labuan
The possibilities for the southwest coast of Kota Kinabalu are unknown.
2.2 Kota Kinabalu, northward and the offshore South China Sea islands
The northwest coast of Kota Kinabalu is devoid of reefs though the bay at Kota Kinabalu and up to the south of Pulau Gaya are largely reef-filled and would possibly be a good area for production of Eucheuma cottonii. However, its value for seaweed production is not realised due to heavy traffic of boats that come and go in this area. The value of seaweed production is overlooked. However, there is a real potential for the production of industrial seaweeds in this area. The offshore islands have not been surveyed closely but being surrounded by narrow reefs suggest that reef algae could be produced in minor quantities. Northward areas from Kota Kinabalu appear to be feasible sites for Gracilaria production and there may be some potentials, too, for alginate-producing seaweeds.
2.3 Balabac Straits
The Balabac Straits area abounds with reef suitable for the introduction of Eucheuma farming. However, there are problems to be solved, e.g. most of the reported stocks of Eucheuma are on non-inhabited reef areas. But there are many opportunities on the inhabited islands foe this seaweed and for alginate producers as well.
2.4 Muruda Peninsula and eastward including the northern and western shores of Danvel Bay and the Semporna Peninsula
2.5 The reefs and islands in the Semporna area
3. SEAWEED CULTURE PROJECT
The Sabah Government engaged the technology of Aquatic Resources Limited Company, headed by Dr. Maxwell S. Doty, for seaweed culture development on seaweeds particularly Eucheuma on behalf of the Fisheries Department. Sabah Fisheries Department has no experienced personnel or experts to do the research in seaweeds.
Initial development was started in August 1978. The work was confined in Semporna area which had greater number of coastal inhabitants. However, there are possibilities of extending the demonstration in Kudat area in the middle of this year. The work is still on experimental basis.
Several farmers have shown interest in seaweed culture and have begun planting Eucheuma. Later, their interests vanished because of heavy predation and shortage of seed stocks for replanting. Todate, there is no commercial production of seaweeds in Sabah.
by Tiburcio C. Donaire1
1 Fishery Biologist, Bureau of Fisheries and Aquatic Resources, Region VII, Cebu City, Philippines.
The Philippines is endowed with several kinds of seaweeds, both with economic and non-economic value. According to statistics, 3 000 to 4 000 tons of dried seaweeds reach the world market monthly from different sources in the world. The Philippines alone contributed 800 tons of seaweeds in the middle of 1960's and these included Eucheuma, Gracilaria and Gelidiella. Early in 1970's, this export figure decreased to as low as 400 to 500 tons. The main reaon probably was that the natural supply was exhausted. To this effect, in order to meet foreign demands, the Government initiated the establishment of pilot demonstration farms throughout the country. However, before that, a United States based company, Marine Colloids (Phil.), Inc. had already conducted surveys and test plantings in the different regions in the country. The company's development farm was established in 1969–1970 at Tapa-an Island, Siasi, and Sulu in the southern portion of the Philippines. Planting of 3 000 000 plants was not realized because of infestation of unknown organisms. In order to avoid great loss, the company forced to harvest the plants. After that calamity, the developmental research was temporarily stopped.
In 1972, the Ministry of Natural Resources (MNR) initiated a programme for the establishment of experimental farms throughout the country. Implementation of the programme, however, was realized only on the latter part of 1975. One of the objectives of the programme was to survey and conduct test plantings in some of the potential areas all over the country. Initial demonstration farms were established in Estancia, Iloilo; Caubian Island, Lapu-Lapu City, Cebu; and Sacol Island, Zamboanga City. Due to limited manpower coupled with hardship in the assessment and evaluation of the project's result, it was turned over to the Bureau of Fisheries and Aquatic Resources (BFAR) in late 1977. Data of the project were encouraging; growth rate of the plants were ideal, and the locations were suitable. However, the seasonality of the plants remained a problem. Retrials were made in one area to another until suitable areas were discovered. Observations were conducted as to the seasonality of the plants. It was found out that several factors must be considered in the selection of sites, namely:
- Water movement (current) - primary factor
- Water temperature (25°C to 32°C)
- Water depth (20 to 30 cm at low tide)
- Predation and competition
- Availability of seed stocks
- Labour requirement
- Marketing facilities and outlets
The success of the farm depends mostly on the above-cited criteria. However, besides environmental factors, one must consider the management aspect. The willingness to get wet, having an observant eye, initiative, creativity and, of course, capabilities in swimming are basic qualities one should possess in managing a seaweed farm.
2. THE CULTURE OF EUCHEUMA IN BOHOL PROVINCE
Eucheuma farming in Bohol province started as early as 1977. Wild variety of Eucheuma atriatum were used as seed stocks by the fish farmers. During this time, a foreign company, the GENU Products, Inc., based in Cebu City was on its way for its developmental research, Eucheuma spinosum and E. cottonii from Sitangkai, were introduced for farming. The suitability of the area as shown by the amazing growth rate of seaweeds, which were planted by the fishery folks in the island, encouraged the GENU Products Company, Inc. to establish its own farm in commercial scale at the said area. Aside from producing its own harvest, the company also engaged in buying dried seaweeds from the fishermen at reasonable price for export. This was the beginning of the seaweed industry in Bohol province wherein almost all of the inhabitants were engaged in farming. By 1979, the production of seaweed at that area reached to as high as 1 000 tons monthly. In effect, the supply out-weighed the demand, which consequently lowered the price of the seaweeds.
3. METHODS OF CULTURE
As early as 1975, two methods of farming were employed: the off-bottom and the bottom methods.
3.1 Off-bottom method
There are two types, namely: floating bamboo raft method; and the floating cage method.
3.1.1 Floating bamboo raft method is made up of six full length bamboo poles. The measurement depends on the measurement of the bamboo poles, but commonly it is 5 m × 5 m. It is formed into square where monofilament nylon lines are tied parallel to one side of the square bamboo raft. It can accommodate 130 to 140 plants per raft.
3.1.2 Floating cage method is made up of polarex net and bamboo poles. Polarex net serves as enclosure while bamboo poles serve as floats. Plants are placed inside the cage. The total weight of seed stocks inside the cage depends on the size of the cage. However, common cage measures 2 m × 5 m × 2 m and the total weight of seedlings for this cage ix 20 to 25 kg. After two or three months culture period, 80 to 100 kg of seaweeds could be attained.
3.2 The bottom method
The bottom method is classified into four types, namely: (i) broad-casting method; (ii) plot method; (iii) stakes and net method; and (iv) stakes and line method (monoline).
3.2.1 Broadcasting method - this is done by throwing the seed stocks to the farm area. This method is convenient but the distribution of seed stocks is not even. Seed stocks are also susceptible to creeping predators such as sea urchins and starfishes. Sometimes seed stocks are carried away by water current.
3.2.2 Plot method - seed stocks are arranged in plots. This method is labourious since eadh seedling is tied to a piece of stone and arranged in lines. Other disadvantages of this method are: cleaning of plants is difficult and grazers such as sea urchins and starfishes are abundant and are, hard to detect especially at the centre of the plots.
3.2.3 Stakes and net method - this method is made of one foot mesh net measuring 2.5 m × 5 m. Both corners of the net are tied to the pegged stakes. The net can accommodate more or less 300 to 350 plants weighing 50 to 100 g each. Cleaning of plants on this method of culture is quite hard especially at the centre of the net. Debris and other epiphytes easily gain attachment to the nets.
3.2.4 Stakes and nylon line method (monoline)- this is non-labourious and most economical method of culturing Eucheuma. Presently, in Bohol province, this method of culture is being employed. Maintenance of the farm is easy such as cleaning of the plants, removing of predators, replanting of missing plants, and harvesting. This method is inexpensive considering that this is made up of two stakes and ten meters of monofilament nylon No. 200. Stakes are pegged one meter apart from each other and ten meters in opposite side. A ten meter nylon line can be planted with 30–35 plants at a distance of 30 cm from each plant. The line is 20 to 30 cm from the bottom which is tied to the pegged stakes.
4. POST HARVEST TECHNOLOGY AND MARKETING
Harvesting is instituted every two to three months period. Farmers do not allow the plant to grow to as heavy as 10 kg for it will be destroyed by water current. Method of harvesting is either by full-harvest or by partial-harvest (Pruning). The latter is merely done by cutting some portion of the plants and remaining parts are left to grow and reproduce. However, it was found out to be time-consuming and the reproductive capacity of the remaining plants is very slow. Full harvest then is very common in this area. One hectare farm yields 3 tons of seaweeds per month or 36 tons annually.
Drying of the harvested plants takes 2 to 3 days, After three days of drying, these are rewashed to remove the salts and other foreign matters to ensure good price. A sack of dried Eucheuma to be sold weighs around 80 to 90 kg.
In Mandaue City, Cebu, semi-processing of dried seaweed is being under-taken by the Marine Colloids (Phil.), Inc. The semi-processed seaweeds are exported to Japan, Australia, United States, and Denmark where the final processing takes place for the production of carrageenan. This carrageenan is used by industries as stabilizing, gelling, thickening, emulsifying and binding agent.
Seaweed industry in Bohol reached its peak in 1979. Record showed that a total of 12 000 tons of dried Eucheuma had been exported from the province. However, aside from dried forms, hundreds of sacks of Eucheuma are sold fresh to the neighbouring provinces such as Cebu, Negros, Iloilo and some find their way to Mindanao. Fresh Eucheuma is eaten raw which is normally called “kinilaw” So far, there is no available data as to the amount of Eucheuma used for local consumption.
5. PROSPECTUS FOR A ONE HECTARE MODEL EUCHEUMA FARM
1. Budgetary estimate
|A.||Farm house of light materials (including the drying platform 20 m × 30 m)|
|Breakdown as follows:|
|40 pcs. Wooden post at 30.00/post||1 200.00|
|Lumber (assorted sizes)||4 000.00|
|60 kg G.I. nails (assorted sizes)||510.00|
|75 pcs. Bamboo poles (full length)||600.00|
|2 000 nipa singles||600.00|
|25 pcs. Matted bamboo (amakan)||200.00|
|10 pcs. Marine plywood||900.00|
|2 pcs. Plain G.I. sheets||96.00|
|3 bundles splitted rattan||21.00|
|5 gals. Marine||425.00|
|Labour for construction||600.00|
|B.||Service pumpboat with 7 HP Briggs and Stratton engine complete with accessories, spareparts and tools||3 000.00|
|C.||1 unit Skipp boat (3 m t. cap)||2 000.00|
|D.||1 unit Non-motorized banca (2 persons cap.)||250.00|
|E.||Maintenance and operation|
|Supplies and materials (itemized)|
|10 kg Monofilament nylon (#200 test lbs)||300.00|
|10 rolls Plastic straw (tie-ties}||150.00|
|8 ,000 pcs. Mangrove stakes (3 ft. long)||2 140.00|
|4 pcs. Diving masks with snorkel||360.00|
|1 unit Transistorized radio||129.00|
|1 unit Weighing scale (200 kg cap.)||200.00|
|1 unit gas lamp (Coleman)||420.00|
|2 pcs. Waterproof flashlinghts (5 batteries)||120.00|
|Iron bars, bolos, knife, bull hammer, etc.||500.00|
|4.5 m t. initial seedlings||3000.00|
|Others (fuel, rattan baskets sacks, etc.)||2 500.00|
|Note: Prices quoted 1979 (Rate 7.65 = US$1.)|
|1 Caretaker/Guard (fully-employed) - 20.00/day||7 300.00|
|1 Boat Operator/Diver (fully=employed) - 15.00/day||5 475.00|
|2 Labourers/Divers (partially-employed)||12 000.00|
|GRAND TOTAL||50 247.00|
2. Cash flow
|A.||In-flow||1st year||2nd year||3rd year|
|Harvest in kg|
22 500 kg
33 750 kg
33 750 kg
|Value in pesos||790 000.00||135 000.00||135 000.00|
|Total expenditure||50 000.00||31 485.00||31 485.00|
|C.||Cash balance from operation||39 753.00||103 515.00||103 515.00|
Doty, M.S. 1973 Euchexma farming for carrageenans. Sea Grant, Bulletin, The University of Hawaii Sea Grant Program, Honolulu, Hawaii; U.S.A.: 21pp.
Kraft, G.T. 1970 The red algal genus Eucheuma in the Philippines. (A Master's Thesis deposited in the University of Hawaii Library): 358 pp.
Kraft, G.T. 1969 Eucheuma procrusteanum, a new red algal species in the Philippines. Phycologia 8: 215–219.
Parker, H.S. 1913 (in press). The culture of the red algal genus Euchemna in the Philippines.
Trono, G.C., Jr. 1972 Seaweeds, one of the important marine resources of the Philippines. A seminar paper read on November 2, 1972 during the Gregorio T. Velasquez Lecture Series. Sponsored by the Alpha Chi Chapter of the Phi Sigma Society.
Cynthia S. Saratan1
1 Junior Fishery Biologist/Project Leader, Bureau of Fisheries and Aquatic Resources, Region I, FARNO 4, Makati, Metro Manila, Philippines.
Gracilaria, known as “gulamang dagat” in the Philippines, is commonly found in Bacoor Bay, Cavite province, Luzon. During dry Months, one often sees piles of these Gracilaria species being dried under the sun along the shores of the bay from Parañaque town to Cavite City.
The harvest of Gracilaria depends on wild crops. The supply is often insufficient to meet the growing demands for them as source of agar. Its production is, likewise, unpredictable depending upon climatic and other physico-chemical factors of the area.
With the development of culture and harvest methods plus improved drying and storing techniques, propagation of this important alga on a commercial scale can be a source of additional income for the people. It could also be a product by the country.
2. BACKGROUND INFORMATION.
Gracilaria culture project at Bacoor Bay was established in 1975 under the Ministry of Natural Resources (MNR). This was under the administration of Dr. Gavino C. Trono, Jr., as the Consultant and Special Disbursing Officer and with the supervision of Mr. Hollenbeck. For some reasons, the project was temporarily stopped but was reopened in February 1976 with Ms. Priscilla M. Torres as the project leader. In 1917, the project was transferred under the administration of the Bureau of Fisheries and Aquatic Resources (BFAR).
The farm site is located in Kaingin, Bacoor, Cavite. It occupies an area of one hectare which is equally divided into five parts of 2 000 m2.each. For field culture tests, each part is alloted for hollowblocks, adobe blocks, empty shells, off-bottom method treatment and one for control. The basis for the selection of the site were:
3. SPECIES AND BRIEF DESCRIPTION
Gracilaria found in certain areas in Bacoor Bay are called the “plastic type”. They are reddish-brown in colour with elongated thalli and few branch-lets. Some species are coloured green to brown and are usually found growing on stones and shells and sometimes mixed with obnoxious weeds such as filamentous green algae or lumot (Enteromerpha) and a seaweed locally called “balahibong pusa” (fur of the cat). Those obnoxious seaweeds are easily mistaken for Gracilaria and are sometimes purchased accidentally with the Gracilaria, unless detected by an experienced-eyed. The main physical difference can be noticed in the many branchlets growing from the main thalli in the balahibong pusa.
4. CULTURE METHOD
4.1 Bottom culture
This consists of improving the bottom or substratum by introducing materials such as adobe block, hollow blocks, empty shell to induce spore settlement and attachment. The data to be gathered from this set up are:
4.2 Off-bottom culture technique
This method is patterned after the culture of Eucheuma. The vegetative cuttings are enclosed in the tube formed nylon nets and suspended at different heights from the bottom.
This portion of the farm will remain as it is, a representative of the bay's natural condition.
5. NATURE OF WORK
Procedures: (See attached scale)
Results: This report covers the observations from the period of January 1977 to December 1978.
5.1 Off-bottom method
Experiments showed that Gracilaria cannot be propagated vegetatively through cuttings. The Gracilaria enclosed in tubular nets initially registered an increase in weight but after 2 to 3 weeks they started to disintegrate.
5.2 Bottom method
5.2.1 Artificial substrates versus control
The results showed that the setting of the attached Gracilaria can be enhanced by the introduction of artificial substrates. This is borne out by comparing the' production of seaweeds in the blocks with that of the control for both years.
In 1977, significant quantities of seaweeds were collected from the control portion. However, it could not be immediately ascertained whether these seaweeds have just been detached from the blocks and were carried by the water to the control area. This occured during the months of March and April when the seaweeds were still in large number. The fact that this did not happen during the time of maximum attachment of seaweeds was probably because the seaweeds at that time were still short and unentangled. Significantly, however, the same occurrence did not take place in 1978.
There was little production of seaweeds in the control portion in 1978 as compared to 1977 (see attached table). This was noticed even during the period of maximum production of seaweeds.
5.2.2 Pattern of attachment
There seems to be a distinct pattern in the periods of attachment of seaweeds on the substrates. For both years, germination started in May to July as red dot-like structures appeared which later developed into hair-like unbranched thalli. The rest of the months, from August to April of the following year represented the growing period. However, in September to December 1978, there was a reduction as to the amounts collected from the substrates. This could be attributed to the series of rather strong typhoons that passed the area which carried away the growing seaweeds and also due to lowered salinity of the water.
During this period, an increase in the growth of Gracilaria salicornia was observed on the blocks which somehow displaced the desirable type of Gracilaria.
For the two-year period, the months from January to March registered the highest production of seaweeds.
It was, likewise, observed that even with the artificial substrates, the distribution of seaweeds in the blocks was not uniform. Some of the blocks have very dense growth of seaweeds while the others were practically bare.
5.2.3 Attachment versus type of substrate
The highest attachment of seaweeds per square meter was recorded by the adobe blocks in 1977 (see attached table). Every month these blocks have always an edge over the other two types of substrates. It was followed closely by the hollow blocks, and empty shells which had the lowest production. This may be due to the concentration of cement used in making the blocks which somehow may have affected the rate of attachment of seaweeds.
6. POST HARVEST TECHNOLOGY AND MARKETING
Processing of raw materials has been reported on experimental basis. As of now, the country is not engaged in commercial processing of Gracilaria.
Gracilaria is both used as table food in the form of salad and as fertilizer and is also exported. Bacoor Bay gatherers rake gulaman and sell them fresh in the fishpond operators which are to be fed to milkfish. Sometimes they dry them under the sun and sell them to different private buyers/factories. There is no complete records of exact volume consumed and/or export of Gracilaria.
Average monthly production of seaweeds for each substrate
|Substrate||1 663.0 kg|
|May||No production record|
|June||No production record|
|July||No production record|
Benedicto V. Teruel2
1This report was delivered orally by the SEAFDEC participant during the course. It is regretted that no written report was submitted.
2 Administrative/Research Assistant, Southeast Asian Fisheries Development Center, Aquaculture Department, Tigbauan, Iloilo, Philippines.
Tan Eng Leng1
1 Assistant Primary Production Officer, Changi Fisheries Centre, Aquaculture Unit, 300-C Nicoll Drive, Changi Point, Singapore.
The marine algae play an important part in the ecology of the ocean. These marine algae are composed of the microscopic forms (phytoplankton) and the macroscopic ones known as “seaweeds”., Seaweeds are categorized into three major groups based on their dominant colour pigments: Chlorophyta (green algae), Phaeophyta (brown algae), and Rhodophyta (red algae).
2. THE ECONOMIC AND MARKET DEMAND OF SEAWEEDS
Seaweeds are source of food for human consumption and their extracts are used for industrial purposes in both developed and developing countries of the world.
Countries like Japan, Korea, China, the Philippines and others farm seaweeds for human consumption.. Among these countries, Japan has the largest produce with an annual value of over half-a-billion dollars. The Philippines ranks second as the largest exporting and consuming seaweed country.
Commercial extractions for algin, agar and carrageenan for industrial purposes form the basis of a multi-million dollar industry in some countries. Seaweeds that are rich in these extracts are Eucheuma, Gracilaria and Gelidiella. These extracts are used in food preparations such as in ice creams, puddings, salad dressings, cheese, fruit juices, and in dental molds, in brewing beer, and many others. These are also commonly used as fertilizers, animal feeds, dyes and as rich source of iodine. Agar is a medium used for culturing of bacteria and for canning purposes. Japan is the largest importer of agar (720 tons in 1972), followed by the United Kingdom, Federal Republic of Germany, and the United States. However, the major exporters of Gracilaria are the Philippines, Brazil, and Taiwan, China. Both the cost of raw materials and the extracts have increased in price significantly owing to the demand and limited supply caused by over-harvesting of the crop. For example, the price of agar in Japan increased by 50–100 percent in three years (1971–1973) and the raw material such as Gracilaria increased by 25 percent in 1972. The actual cost was $500 per ton in 1973.
The carrageenans are promising substitutes for agar for laboratory culture media because they are much cheaper than agar.
3. SEAWEED IN SINGAPORE
Studies on the ecology and productivity of seaweeds are not being carried out in Singapore. These are mainly due to the country's limited coastlines and project priorities like land extension programmes.
The increasing demand of seaweeds as food and for industrial purposes appears to be a profitable business for countries in the South China Sea Region. However, current business practices and farm methodology are not encouraging. With proper farm methodology and cloning of genetically desirable algal species, production in the region may be significantly increased. Singapore, being centrally located, with its sound infrastructure, and traditionally being a commercial centre appears ideal for supporting a processing plant for seaweeds.
Hale Pindole Amandakoon1
1 Aquaculturist, Ministry of Fisheries, Fisheries Research Division, Crow Island, Colombo 15, Sri Lanka.
Sri Lanka is an island country situated in the Indian ocean, southeast of India at latitudes between 6–10 degrees north and longitudes 80–82 degrees east. Its total land area is 6 510 km2 and has a coastline of 1 700 km. The estimated population, as of 1981, is approximately 15 million. There are about 121 500 hectares of brackishwater lagoons, estuaries, and mangrove swamps that would be available for aquaculture.
Seaweeds in Sri Lanka are mainly utilised for the production of commercially important agar. They are commonly known as Ceylon moss or locally called as “kandhaparsi” or “Sanchow pansi”.
In 1952, the Ministry of Industries and Fisheries became interested in the study of economically important marine algae. A systematic survey was carried out for agar producing seaweeds. Apart from few trials conducted by phycologists involved in the Research Division of the Ministry of Industries and Fisheries, no work in the culture of seaweeds has been initiated.
2. THE WORKS ON GRACILARIA
Due to their higher gel content and high abundance in the area, detailed investigations were done mainly on Gracilaria confervoides and G. lichenoides. G. confervoides was found in large quantities at Koddyar Bay, Trincomales while G. lichenoides was found at Puttalam lagoon, Mannar and some islands off Jaffna.
2.1 Gracilaria lichenoides
Sivapalan (1975), after cultivating G. lichenoides on an experimental plot in Puttalam lagoon at Kalpitiya, observed that the plants attained a length of 26–32 cm in 97 days with an average growth rate of 0.285 cm/day. It was eivdent then that about 2–3 kg (5–6 lb) wet weight of G. lichenoides could be attained per square meter area of coir net.
2.2 Gracilaria confervoides
In order to find the optimum conditions for the extraction of agar, a pilot test was carried out in the laboratory of the Fisheries Research Station using G. confervoides collected from Koddyar Bay, Trincomalee (Dunainatnam et al., 1972). Based on the several experiments done on this type, a method has been suggested to manufacture agar on a commercial scale.
Before the war, agar was mainly imported from Japan. During the war, small amount of G. lichenoides collected from Pallaithivu, an island about 7 miles from Jaffna was imported to India. Later an. export market was found for G. confervoides in Japan. But due to bad trade practices, the export trade was terminated.
Even though Sri Lanka has great potentials for seaweed industry, the lack of trained personnel in this field is a major constraint for its development.
Dunainatnam, M.J. 1972 Grevo and Wimaksin, Agar from Gracilaria confervoides and Gracilaria lichenoides from Ceylon. Bulletin of the Fisheries Research Station, Ceylon, Vol. 23, Nos. 1–2: 29–35pp.
Sivapalan, N. 1975 Cultivation of Gracilaria lichenoides in Puttalam lagoon. Bulletin of the Fisheries Research Station Sri Lanka (Ceylon), Vol. 26, Nos. 1–2: l-3pp.
1 Fishery Biologist, Brackishwater Fisheries Division, Department of Fisheries, Bangkok, Thailand
Plants from the sea has been used as vegetable raw materials like any other plants on earth. Every country in the region uses seaweed as food since long time. Nowadays, that science has been widely developed, there are new techniques and good instruments to prepare a source of agar and carrageenan from seaweed. Production of seaweed are mostly harvested from natural sources. The FAO/UNDP is an important agency with the foresight to start courses on training about seaweed farming in order to increase source of agar for food and carrageenan for industry. These good ideas are suitable for countries of every participant, including my country, Thailand.
Thailand's food production is about 80 percent from agriculture, some of which are exported to other countries. There is no problem about food, therefore production of seaweed has a little scope at present2. They are collected from natural fields, as there is no seaweed farming yet in the country.
2 This is apparently the participant's opinion but not necessarily of the Government.
Some local people eat Gracilaria. Sargassum, Caulerpa, but these are not popular because there are a lot of tastier, more delicious and cheaper items. Some fishermen harvest seaweeds from the seaside and take them to local markets for sale. For these reasons, it is high time that seaweed farming should be developed in Thailand.
Ho Hun Nhoung1
1 Biological Engineer, Ministry of Marine Products, Institute of Aquacultural Research, Haiphong City, Vietnam.
Vietnam had about 3 260 km. of coastline and has several hectares of swampy areas. At present, Vietnamese people living along the seashore construct ponds in these brackish areas for the cultivation of shrimps, fish and Gracilaria.
Gracilaria in Vietnam is largely distributed from north to south. There are 11 species of Graeilaria identified. Gracilaria verrucosa, G. blogettii, G. salicornia, G. cacalia, £. chorda, G. compressa, G. crassa,G. hainanensis. G. gigas, G. textorii, Gracilaria sp.
The economically important species are distributed in large number in three main regions such as: Haiphong, Channhoa, and Binhtrithien (Hue). The biomass of species collected from these areas range from 200–600 g/m2.
Even before studies on seaweeds were done, maritime people already collected Gracilaria for food, animal feeds, and extraction of agar. At the start of 1970 up to the present, studies were made on the biology of Gracilaria. Technology for the culture of Gracilaria was also developed. Gracilaria culture began at Haiphong and later at Binhtrithien. Today, people have already cultivated and harvested large amount of this particular seaweed annually.
2. TECHNIQUES FOR THE CULTURE OF GRACILARIA IN VIETNAM
2.1 Swamp culture
2.1.1 Ecological condition
2.1.2 Swamp bottom treatment
Before cultivating bottom was drained and let it dry from 7–10 days to kill undesirable algae. This is not made when there is no undesirable algae.
The area is divided into smaller compartments at usually 5 000 to 10 000 m2.
Good water supply and drainage systems are necessary.
Water depth 30–60 cm: 30–40 cm during non-sunny months
50–60 cm during sunny months.
Seed production is done after the method of vegetative reproduction. Seed size varies from 5–15 cm.
Stocking method - scattter seed for cultivation
Stocking density - 200 to 300 gram/m2
2.3 Seasons for culture
Winter and autumn seasons (September to December) are usually the best seasons which gives high production (70–75% of the whole year production). I spring - winter season (January to May), production is 25–30 percent of the whole year production.
2.4 Management and maintenance
Water is changed usually according to tidal period (once every 15 days, for three days)
Water level is maintained from 30–60 cm deep: 30–40 cm during non-sunny months or 50–60 cm during sunny months
If seaweeds are too dense, thinning is made
Partial hafvest is made when biomass reaches at about 800–1 000 g/m2
2.5.1 Two types of harvest techniques
Partial harvest - use of rakes and boats to collect the seaweeds.
Complete harvest - ponds are being dried up to 15–20 cm water level and seaweeds are collected by hand method. These are washed and transported by boat.
3. PRIMARY PROCESSING OF RAW MATERIAL
4. PROBLEMS IN SEAWEED CULTURE
Gracilaria culture in Vietnam has just recently been started. One of the biggest problems so far is the presence of harmful seaweeds. These harmful seaweeds are identified as Cladophora, Chaetomorpha, Enteromorpha, Polisiphonia, etc. Gracilaria species are found attached to these harmful seaweeds. This takes a lot of time and work in sorting out these harmful seaweeds from Gracilaria.