by
Malcolm R. Mackinnon
The distribution of Lates calcarifer or seabass in Australia extends from the east coast of Queensland at a point slightly south of the Tropic of Capricorn, to the north and west as far as the northwest coast of Western Australia.
The most commonly used name for the species throughout its Australian distribution is barramundi.
To date there has been no commercial culture of the species in Queensland and the market is supplied entirely from natural stocks.
The species is highly regarded throughout Australia, both as a table fish and as an attractive angling species.
The commercial fishery is carried out by set gillnetting in estuarine and marine waters. Netting in freshwater is illegal. Only fish larger than 50 cm total length may be taken. Commercial fishermen are licensed and nets must carry identification details and must be attended at all times.
Fishing activity is usually most intense during the spawning season from late November to about March, when the spawners gather near the mouths of rivers.
Because of declining catches in recent years during the last two summers, a closed season was declared in the early to middle part of the spawning season. This was an attempt to protect stocks until most of the spawning activity had occured. Results of this measure have not yet become apparent in the fishery because of legal size restrictions, but some encouraging information has been obtained by biologists studying the population of one and two year old fish.
Seabass fishermen often operate in remote areas and may be either land-based or sea-based in their operations. The land-based fisherman typically uses four-wheel drive vehicles or trucks and operates his nets from a small aluminum boat. The catch is deep frozen immediately after processing in a mobile freezer unit, and is taken to marketing centres by light aeroplane, by land, or sometimes it is collected by boat.
The sea-based fisherman normally operates from a shallow draught vessel of 10–15 metres length with deep-freeze storage and a small boat to tend the nets.
Fishermen working in remote areas usually market their catch as frozen fillets, but fishermen operating closer to population centres may market their catch as whole degutted fish, either fresh or frozen.
The retail price of seabass is higher than most other finfish in Australian markets. I regret that I was unable to obtain fishery statistics for this species from Australia in time for this report.
Many of the species which have been mentioned by NICA staff and by various participants of this course also occur in Queensland. Queensland crustacean species which are highly priced on the retail market include penaeid shrimps (including Penaeus monodon and P. merguiensis) and the mangrove crab Scylla serrata. Queensland also has at least one species of large palaemonid prawn, which has until now been included in the species macrobrachium rosenbergii however, I understand the Australian form may soon be separated from the species rosenbergii.
Finfish which have been mentioned during the course and which occur in Queensland include Scatophagus argus, Chanos chanos, Lutjanus argentimaculatus, Plectropomus spp, and several grouper species.
Queensland has many large areas undeveloped and unpolluted coastline and mangrove swamps, so there is ample space for culture activity, however, the problems of isolation, distance from market, and lack of essential services make many areas less attractive. As fish culture activity, especially in fry production is very labour intensive and the relatively high cost of labour in Australia may be another factor acting against the success of future fish culture operations.
Much more information on such subjects as availability and cost of suitable feeds is needed before fish culture becomes a reality in Queensland.
by
Luk Wah Kee
1. INTRODUCTION
1.1 Present status of seabass industry in Hong Kong
Mariculture activities in Hong Kong were initiated about 10 years ago and started to proliferate during the last decade. A total of 1 553 mariculture units and 11 impoundments, covering an area of about 33 hectares distributed in about 50 locations, were recorded in 1980. Seabass or seaperch, locally known or Maang-Choe is rated second amongst the higher-priced fish. A live seabass of 25 cm TL costed in the region of HK$ 80 per kg (average price in December 1980)1. Though high in value, seabass is not however, an essential culture species in Hong Kong. In 1980, an estimated yield of 6 tonnes cage cultured seabass was reported representing only about 0.8 percent of the total annual yield.
1.2 Development potentials
As obviously revealed, by its high price, seabass is a very popular and well demanded food fish in Hong Kong. The strong preference for live fish especially the high-priced ones having a low supply such as seabass, provides an opportunity for further development in the culture of this species. One of the factors limiting its expansion is the supply of fry, which is either imported from Thailand or Taiwan (China). Local capture of seabass juveniles from the wild is very limited. Another factor being the lack of experience in rearing this species, especially during the earlier stages of development. This has discouraged local fish farmers in attempting to stock a large quantity of this fry. If these inherent difficulties could be sorted out for example, by means of induced spawning and extension of updated techniques to the culturist, an increase in seabass culture activities could be expected.
2. FISHERY FROM NATURAL WATERS
Accurate statistics of the production and value of seabass from natural waters are lacking at hand. However, catches of seed fish from the wild are negligible and an estimate of its potential requires further assessment.
3. PRODUCTION FROM AQUACULTURE
3.1 Seed production through hatcheries
No hatching activity for seabass has yet been reported in Hong Kong.
3.2 Production of marketable fish
An estimated yield of about 6 tonnes of caged-cultured seabass was reported in 1980, valued at about HK$ 480 000 (calculated at HK$ 80 per kg).
3.3 Method of production
Nearly all the seabass fry are imported from Thailand and Taiwan (China). They are usually stocked in fish cages made of polyethylene netting of various mesh sizes according to different size groups. They are fed daily usually in the morning, with chopped trash fish or pellets and reared to marketable size for sale to wholesalers or directly to floating restaurants.
4. FUTURE PROGRAMMES/PLANS
As pointed out in the previous section, the two major factors hindering the development of seabass culture are the supply of fry and rearing techniques. It is hoped that after the completion of the training course in seabass culture and larval rearing in NICA, basic techniques acquired therefrom can provide basis for further development and researches on this species such that the promotion of seabass culture industry in Hong Kong could be achieved.
by
Murtado Arsjad
1. INTRODUCTION
Jakarta province has a population of about 5.5 million people and is divided into five administrative municipalities (North Jakarta, West Jakarta, East Jakarta, South Jakarta and Central Jakarta).
As the capital of Indonesia with a large population and with a continuous influx of traders, businessmen and tourists, Jakarta province has become a major consumption and distribution centre for various commodities. This condition makes it a favourable market for fishery products.
2. FISHERIES OF JAKARTA PROVINCE
2.1 Organization of the Jakarta Fisheries Office (Fig. 1)
The Provincial Fisheries Office is technically under the Directorate General of Fisheries (DGF) and administratively under the provincial administration.
Fig. 1 Organization of Jakarta Province Fisheries Office
2.2 Fisheries activity
Right now, fishing activities are concentrated mainly in the coastal area with the use of gears such as gillnets, purse-seine nets, small nets, long lines, traps, etc. Fish caught are sardines, snappers, tuna, narrow barred Spanish mackerel, jacks, etc.
The Jakarta fisheries office is now encouraging offshore fishing to prevent overfishing in the coastal areas.
2.2.1 Fish culture
Most of the existing fish culture are done in fresh and brackishwater ponds. Milkfish is the main species cultured in brackishwater ponds and other species like the common carp, giant gouramy, catfish and tilapia are cultured in freshwater ponds.
More attention is now being given on coastal aquaculture. Experiments on grouper culture in floating fish cages are being done. Cages measuring 2 × 2 × 2 m with a mesh size of 2.5 cm are stocked with fish 150 grams in average weight and a stocking density of 20 fish per cage. Ten percent of total body weight of trash fish is given once a day.
3. PROGRAMME ON SEABASS AND GROUPER CULTURE
Marine fish culture is still a new undertaking in Jakarta province. Suitable marine finfish for culture such as grouper, seabass and rabbitfish are found in coastal areas. The occurrence of juveniles in certain places in the area has been identified. Based upon these observations, the Provincial Fisheries Service has started cage culture pilot projects during the last two years. This programme is given high priority by the Provincial Government. Seabass culture in cages is on initial stage of development with the use of fingerlings derived from the wild. The initial site for this project is at Kepulauan Seribu (Thousand Islands), a group of islets north of Jakarta (Fig. 2).
Fig. 2 Location of Mariculture Project in Jakarta
SCS/82/SBTC/EXP. 3
INDONESIA
by
Georgine A. Koraag
ABSTRACT
The paper described the role of the fisheries in Indonesia for the economic development of the country. The government agency which is responsible for the development of fisheries, its functions and organizational set-up was explained. The Directorate General of Fisheries (DGF) in its programme gives considerable attention to the development of seafarming, and budget allocation has been made available commencing 1982. On seabass culture in particular, the DGF has started a pilot project in the Riau Archipelago, an area where seabass fry/fingerlings are abundant and easily obtained from natural sources. It is anticipated that further development could take place.
SCS/82/SBTC/EXP. 17
INDONESIA
by
Purwanto Partoseputro
ABSTRACT
A general account on the fisheries of the Riau Province is briefly touched including both capture and culture fisheries. In the field of fish culture the Provincial Fisheries Service has recently started with the cage culture of groupers and seabass. Pilot projects for grouper culture and experimental culture for seabass are now underway. The ultimate objective is to encourage fishermen to engage in seafarming.
1 Only abstract available, full paper with author.
SCS/82/SBTC/EXP. 12
INDONESIA
by
Agung Raka Asmara Kusuma
1. INTRODUCTION
Bali is one of 27 provinces in Indonesia, famous to foreigners as “The Island of Paradise”. It is situated between latitude 7°54'S-8°30'S and longitude 115°26'E-115°43'E. The total land area is 5 070.549 km2 with a coastline of 470 km. It has a continental shelf of about 9 500 km2. The population in 1978 was about 2.5 million.
Because of its position, Bali has a typical tropical monsoonal climate, with a rainy season between October and April and a dry season from April to October. Bali is divided into 8 regions and the provincial capital is Denpasar. The regions are Gianyar, Klungkung, Karangasem, Bangli, Buleleng, Jembrana, Tabanan and Badung. All regions have some coastline except for Bangli.
Most Balinese are agricultural farmers, who also keep cows and pigs. Fish is cultured in wet ricefields (mix culture) or in ponds. The abundance of marine fish makes the people who live along the coast opt for fisheries as their major source of income.
2. THE FISHERIES OF BALI
Fisheries in Bali comprise of marine and inland fisheries. Fishing in Bali is done using traditional gears and crafts. The fishing gears include purse-seines, gillnets, small longlines, bamboo traps, hand lines, etc. The catches from marine waters are mainly Indian oil sardine (Sardinella spp). Bali strait, between Java and Bali island is a fishing ground for sardines. The other commercial fishes are skipjack tuna (Katsuwonus pelamis), Eastern little tuna (Euthynnus spp), narrow barred mackerel (Scomberomorus spp), shark (Sphyrnidae), frigate mackerel (Auxis thazard), lobster (Panulirus spp), etc.
Brackishwater fisheries are also conducted in estuaries, tidal flats and mangrove swamps with some species of seaweeds (Hypnea cervicornis, Gelidium spp, Gracilaria echinoides, Eucheuma serra, Eucheuma spinosun and Caulerpa racemosa); shrimps (Penaeus monodon, Penaeus merguiensis) and milkfish (Chanos chanos).
Inland waters have some species of fish for domestic consumption such as common carp (Cyprinus carpio), Puntius (Puntius gonionotus), Tilapia (Tilapia spp), giant gouramy (Osphronemus goramy), catfishes (Clarias spp), etc. The total catch in 1979 was 26 437 tons from marine fishing, valued at US$ 7 660 160. The area of inland waters is about 249 490 ha, producing 930.1 tons of fish valued at US$ 621 032.30 (in 1979).
The export in 1979, tuna and lobster 1981 tons, aquarium tropical fishes amount to 16 920 fish all valued at US$ 2 534 726.35.
In addition, one of the big fishing industries has a branch and fishing base in Bali. The fishing gear is longline for catching tuna. It is foreseen that the fisheries in Bali will become developed either in marine fishing or aquaculture.
3. THE SEABASS AND GROUPER CULTURE PROJECT IN BALI
3.1 Organization of unit doing work
The project for seabass and grouper culture is headed by the chief of fisheries office and the technical employees as staff. This project is only in the experimental stage especially on rearing of seabass and grouper in floating netcages.
Budget for this project comes from the local government and the Directorate General of Fisheries of Indonesia (DGF). Budget will be released beginning 1982 to 1983.
3.2 Location for development
The sites for experiments were identified by experts. There are three locations to be developed in the province:
These locations have salinity of 29–31 ppt and temperature of 28–29°C.
3.3 Activities of project
Development of coastal aquaculture in Bali has the following objectives:
The activities on marine culture have very important role in the future.
Seeds of seabass and grouper measuring 5–7 cm in length are collected from natural sources. These seeds will be cultured in floating netcages (3 × 2 × 2 m). In one cage, the stocking rate is 200–250 juveniles. At present, the activity consists of the collection of fish seeds.
SCS/82/SBTC/EXP. 18
INDONESIA
by
Rotlan Silitonga
1. INTRODUCTION
Lampung province is on the western side of Indonesia situated on the southernmost part of Sumatra island. It is divided into four (4) districts (kabupaten) with a total population of six (6) million people. The province is mainly agricultural and the people derived their incomes from planting coffee, pepper, cassava, clove and coconut. Aside from these agricultural products, parts of freshwater and brackishwater areas are being used to raise fish. Marine fish species are caught with the use of different fishing gears.
2. THE FISHERIES OF LAMPUNG PROVINCE
Fish production in Lampung province is still very low. Statistics show that in 1981, the total fish production of the province is only 37 000 tons of which 90 percent comes fron marine resources while barely 10 percent comes from both fresh and brackishwater fishponds. The fish consumption is about 10 kg per capita per year. Modern techniques on how to culture fish have not yet reached the fish farmers thereby the people make use of their age-long traditional practices of raising fish in both inland and brackishwater ponds, as well as in the capture of marine finfish.
The freshwater fishponds are stocked with carps (Cyprinus spp), giant gouramy (Osphronemus goramy), tawes (Puntius gonionotus), Nile tilapia (Tilapia nilotica) and catfish (Clarias spp). In the brackishwater fishponds, the dominant species being cultured are the milkfish (Chanos chanos), tilapia (Tilapia mossambica) and mullets (Mugil spp).
In coastal areas, marine fish such as the skipjack tuna (Katsuwonus pelamis), anchovies (Stolephorus spp), hairtails (Trichiurus spp), scads and grouper (Epinephelus spp) are caught with the use of hook and line, gillnet, cast net and fish coral.
3. SEABASS AND GROUPER CULTURE PROGRAMME OF THE PROVINCE
Seabass (Lates calcarifer) has been identified as one of the major finfish to be cultured in brackishwater fishponds. Half grown seabass are collected from the estuarine areas by the use of seines, gillnets and fish corals or traps. The identification of seabass fry is still very difficult for the fishermen, and so far mature breeders of about 4–6 kg fish have not yet been observed to abound in these vicinities. On the other hand, the grouper (Epinephelus spp) has been given the second priority to the seabass. Construction of cages for seabass and grouper to be raised in coastal areas is now on the developmental stage.
Programme of seabass and grouper culture in Lampung is a pilot project of the Directorate General of Fisheries of Indonesia. It is divided into three divisions, namely: finfish culture, shellfish culture and seaweed culture. The project is solely financed by the development budget of the country.
Based on the observations made by FAO/UNDP expert, several sites were recommended as suitable for the culture of seabass and grouper. The site for the pilot project is at Hanura village, Lampung. The main activities of the project are to serve as experimental and demonstration station for marine culture techniques before it is introduced to the fishermen.
SCS/82/SBTC/EXP. 8
INDONESIA
by
Ketut Sugama
1. INTRODUCTION
During the past few years, the landings for marine fish have stagnated due to the heavy exploitation of the fishing grounds in the Java Sea. The freshwater fish production, both from natural waters and pond culture contributed relatively small amount. While it is realized that the present fish production from marine sources form the biggest contribution to the total fish landings unfortunately, with the anticipated changes in sea regime in the near future, the total fish landings from marine waters would considerably be reduced. In this connection, the Directorate General of Fisheries currently focuses its attention to the development of coastal aquaculture in order to compensate for the reduction of marine fish products from natural waters.
Marine fish culture is still new in Indonesia. For this reason, the Government of Indonesia and the Government of Japan had agreed in 1979 on a technical cooperative programme for research and development of marine fish culture. With the financial support of the Government of Japan, a research laboratory was established to accelerate the research on marine fish culture in Banten Bay, West Java.
Banten Bay covers a coastal area of mangrove swamps, tidal flats and estuaries. There are many species of finfish and shellfish that are found to be suitable for marine culture in this bay. Among the finfish are rabbitfish (Siganus spp), grouper (Epinephelus spp) and seabass (Lates calcarifer), which could be developed for marine culture. Part of the area of mangrove swamp had been converted into fishponds. However, annual production from these sites is still low. The reason for this is that modern techniques of aquaculture have not yet been adopted by the aquaculturists.
2. ORGANIZATION AND FUNCTION OF FISHERIES RESEARCH AND DEVELOPMENT CENTRE (FRDC)
The FRDC is a national government agency directly under the Agency for Agricultural Research and Development (AARD). It has three divisions: Inland Fisheries Research Institute (IFRI). Marine Fisheries Research Institute (MFRI), and Technology Fisheries Research Institute (TFRI).
The central office of MFRI is at Jakarta. It has three branches one of which is located in Banten Bay, Serang, West Java. This is the Marine Culture Research and Development Project (MCRDP).
The main function of the MCRDP is to undertake research on marine fish culture for the improvement and development of culture techniques. To implement the above programme, the Japan International Cooperation Agency (JICA) has been dispatching long and short-term experts, providing the required machineries, equipment and expendable supplies, and implementing the training of Indonesian fellows in Japan.
3. PROGRAMME OF THE MARINE CULTURE RESEARCH AND DEVELOPMENT PROJECT
All research activities of the MCRDP are being done in Banten Bay. The programme includes basic fisheries biology research, finfish culture research and shellfish culture research. The activities on finfish programme are as follows:
Species survey. The objective is to identify the species of commercial importance, which are biologically suitable for culture effort.
Culture of juveniles and adults. The aim is to test the technical and economic feasibility of raising juveniles to marketable sizes.
Fry production. This is aimed at providing a year round supply of fish fry for the stocking of commercial farming operations.
Culture of food organisms. The objective is to provide food organisms for larval rearing.
4. RESULTS OF FINFISH CULTURE RESEARCH ACTIVITIES OF MCRDP
MCRDP biologists have observed and identified species in Banten Bay which are suitable for culture. According to their results, rabbitfish (Siganus spp), grouper (Epinephelus spp) and seabass (Lates calcarifer) should be given priority for research on finfish culture. In Banten Bay, siganid fry appear twice per year while grouper and seabass are still under observation. The fry of siganid were caught in a seagrass area around Banten Bay using beach seine net (50 metres in length, 1.5 m in depth and with mesh size 0.5 cm). Fry seasons occur from March to June and September to November. Eight species were found: Siganus canaliculatus, S. javus, S. vermiculatus, S. guttatus, S. virgatus, S. corallinus, S. crisosphylus and S. poelus. Siganus canaliculatus is the dominant species.
The siganid fry (2.75 cm TL) were stocked in floating netcages (2 × 2 × 2 m). Frame of raft were made of bamboo and floats of galvanized iron drums. The siganid fry were fed with different kinds of food such as ricebran, trash fish, waste vegetables and seaweeds in order to determine which food will support the highest growth rate. According to the preliminary experiments, the fry fed with mixed trash fish and 50 percent ricebran grows faster than those fed with other compositions of food. Within 8 months, the fish attains up to 150 grams body weight, 22 cm in TL.
Because of difficulties in collecting seabass fry in big numbers from natural waters, the MCRDP biologists are undergoing study on fry production of seabass. Spawners were caught from the mouth of Sekampung River in South Sumatra using trap nets and gillnets. Thirteen (13) spawners 3 to 9 kg in body weight were stocked in two 30-ton circular tanks for observations. Within the last six months, they have not so far spawned.
Induced spawning using 500 MU (mouse unit) gonadotropic hormone for each spawner was done in January 1982, but this was not successful. This training course would be very useful to improve the techniques on fry production of seabass in our MCRDP laboratory.
by
Ali Awang
1. INTRODUCTION
Seabass (Lates calcarifer) and some other related species such as grouper (Epinephelus tauvina/salmoides), red snapper (Lutjanus argentimaculatus) and spotted snapper (Lutjanus johni) are widely found in coastal waters of the west coast of Peninsular Malaysia. These are well-liked food fish and can fetch about M$4.00 to M$8.001 a kati (600 g) depending on the location and season. Traditionally, these fish are supplied to the market by fishermen who catch by fishing methods such as hooks and lines, traps and bottom drift gillnets.
The increasing demand for this fish has generated interest in the culture of these species and has prompted the Fisheries Division of the Ministry of Agriculture to offer assistance in promoting this practice especially to the lower income groups such as the coastal fishermen.
2. PRESENT SITUATION
At present, there are very few brackishwater grow-out ponds and floating cages in the west coast. The few existing ponds are insignificant but with a large untapped resources of virgin mangrove swamps available the expansion of pond culture in the future is quite promising.
In comparison to the pond culture, the growth of cage culture is relatively faster. These cages are mainly stocked with grouper since it fetches higher price than seabass or snapper. Since the wild seed supply of grouper cannot meet the demand, the cages are usually stocked with a combination of the above species.
3. SEED PRODUCTION
Inadequate supply of seeds is probably the main constraint in the expansion of this practice. The seabass seed are either caught from wild or imported from Thailand. With these methods of procuring seeds, either the number is too small or the cost of imported seeds is too high. Therefore, our Division is actively engaged in constructing hatcheries. Since Thailand is successful in mass production of seabass fry and Peninsular Malaysia is in close proximity, we hope that the borrowed technology will help us to solve the problem of seabass fry supply in the near future.
At the moment, we have two hatcheries in operation and another will be in operation soon. Their original activities are to produce Macrobrachium seed. The first hatchery at the Fisheries Research Institute, Penang is the oldest and it is now engaging in the production of Macrobrachium, marine shrimp and seabass seed. In 1980, the seabass seed production unit was set-up but difficulties were encountered in procuring breeder from the wild. This year, we are fortunate to obtain fertilized egg from one breeder during the tenure of Mr. Niwes Ruangpanit, FAO Consultant from NICA, Thailand, who was assigned in Penang. We managed to nurse about 200 000 larvae up to about 20 day old and from this short and brief experience, more or less we managed to identify our shortcomings in the mass production of seabass in our hatchery.
Besides the hatchery in Penang, we have another Macrobrachium hatchery at Port Dickson, in the state of Negri Sembilan, now in operation and another station at Lumut, in the state of Perak, which will be in operation soon. Probably, with some modification these hatcheries can be converted to be used in the seabass seed production as well.
Two more hatcheries in various planning stages are going to be built on the west coast of Peninsular Malaysia. One in the state of Johor and another at Pulau Sayak in the state of Kedah.
These hatcheries are going to be multi-purpose hatcheries where species to be cultured are seabass, marine shrimp and Macrobrachium
4. GROW-OUT POND STATION
In complement with the development of hatcheries, our Division has set up two demonstration and experimental pond stations. One station is at Gelang Patah in the state of Johor, which is now in operation and another at Ban Merbok, in the state of Kedah which will be in operation soon.
The main function of these stations is to promote the grow-out pond technology, and together with the development of hatcheries, it is hoped that the culture of marine fish in Malaysia will be enhanced in the future.
SCS/82/SBTC/EXP. 14
MALAYSIA
by
Daim Hadji Basrun
1. INTRODUCTION
Sabah is located in the northern part of Borneo island and it is one of the 13 states in Malaysia, consisting of only about 1 million people of different races and religions. Timber, oil, copper and agricultural and fisheries products are the main sources of the livelihood and also serve as the source of foreign exchange of the state.
Fisheries is very important to the economy of the state; the protein source for the daily diet of the people comprises of about 80 percent of fish protein. The fishery resources from the natural waters are still in surplus which enables the state to export some of her marine products such as shrimp to foreign countries like Japan and Taiwan (China). The present capture production appears to be still sufficient. Trawlers and traditional gears such as longlines, fish traps, gillnets are among the popular methods used by fishermen.
2. THE AQUACULTURE OF SABAH WITH EMPHASIS ON SEABASS
The aquaculture development programme has been started in the State since early 1960's with its Freshwater Section which was later followed by the Marine Aquaculture Section and only recently the Brackishwater Section was launched with its experimental culture of Penaeus monodon and Epinephelus tauvina in the brackishwater ponds and in cages, respectively. There is no development boom in aquaculture in the State due to the fact that there are still abundant supplies of natural resources and another factor being the lack of experience in this particular field. Therefore, fish farming is very limited especially on finfish culture. The seabass locally known as ikan sulunsung are not very common in the local market and are still not very well known by most people. Data on the fish landing records show some negligible quantity of this fish landed in the southeast part of the state.
3. DEVELOPMENT POTENTIALS OF SEABASS CULTURE
The development potentials for seabass culture in the State has yet to be surveyed. But some data that are available at hand now to support this are firstly, the availability of vast areas along the coastline still undeveloped which will provide ample space for development and future expansion of seabass culture; secondly, the geographical location of the State which is not very much different from that of Thailand; and lastly the indication of the presence of the fish under local environment.
4. PROGRAMME ON SEABASS CULTURE
As pointed out above, there is still little attention being given on the fish so that there is no special programme so far being made in its culture. However, at present some seabass are currently cultured in netcages in the Mengkabong Fisheries Station of Sabah and can be put into use to initiate work on this species in the future. The work on seabass culture if carried out can be in line with the policy of the Department of Fisheries of the state to develop coastal aquaculture as well as freshwater aquaculture in the State. The objectives of this policy are firstly to improve the methodology in aquaculture for the production of fish for local consumers as well as for export to earn foreign exchange; and secondly to extend the practice of aquaculture to increase earnings of the local fishermen as well as to provide them additional employment.
SCS/82/SBTC/EXP. 16
MALAYSIA
by
Azian Hasan
Known as the Integrated Fisheries Development Project of Besut this FAO/CIDA assisted project aims to make the District of Besut, Trengganu State, a model fishing community on the east coast of Peninsular Malaysia. Funds from the Canadian Government through the Canadian International Development Agency (CIDA) are used to finance the consultancy and other technical services and some facilities required to develop the ten fishing villages distributed along the 35 km coast facing the South China Sea.
As part of its programme to uplift their standard of living, the project encourages aquaculture practices among the fishermen. The pilot fish culture in floating cages started at Setiu Lagoon in 1976 rearing Lates calcarifer, Epinephelus tauvina and Lutjanus argentimaculatus proved to be technically feasible and gave rise to the idea that this method of marine fish farming be an activity to supplement the fishermen's income. In line with this objective subsidies, training and advice were given to interested fishermen. However, development of this work was dampened by the decline of seed supply from the wild.
The breakthrough made here (in Thailand) in the mass production of seabass fry has prompted the Fisheries Division to establish a small hatchery at Besut as a solution to the shortage of fish seed M$1.2 million has been allocated for the construction of this hatchery on a 9-acre (2.6 ha) site at Tanjung Demong in Besut. It also hopes to produce other marine fish and penaeid shrimp seed. So far, the layout and design have been finalized, tender called and contractor chosen for its construction. A master fish farmer, a biologist and a hatchery technician will be brought over by the FAO/CIDA to initiate production when the essential components of the hatchery are completed by the end of this year. Meanwhile, local staff are being recruited to make way for the technology transfer and future management of the hatchery.
SCS/82/SBTC/EXP. 2
PHILIPPINES
by
Dennis B. Araullo
1. INTRODUCTION
The Philippines is composed of 7 100 islands which is divided into three (3) regional groups of island namely: Luzon, Visayas and Mindanao. It has a total population of 48 million people in 1980. The fish consumption in the Philippines is about 25 kg per capita per year although the National Institute of Science and Technology (NIST) established that for adequate nutrition 36.5 kg per capita per year would be required.
For the year 1980, the fisheries industry contributed 4.4 percent to the Philippines gross national product (GNP) and provided direct employment of about 800 000 persons including the country's fish farmers.
For 1980, fish production has reached 1 672 254 metric tons, 5.8 percent more than 1979 production of 1 581 303 metric tons. The Philippines ranked 13th in world fish production according to a survey conducted by the Food and Agriculture Organization (FAO).
The bulk of the national fish production is being contributed by municipal fisheries1 comprising about 60.1 percent of the total fish production; commercial fisheries2 contributing 29.2 percent while fishpond production accounted for only about 10.7 percent.
Philippine marine waters cover a total area of 1 666 300 km2, five (5) times more than its total land area. However, fishing activity is confined to coastal and inland waters. Coastal waters account for 265 970 km2 from shore to depths of 200 meters. Of this total area, only 126 500 km2 are traditional fishing grounds.
The inland resources consist of 562 000 hectares which include freshwater and brackishwater swamplands and fishponds and other inland bodies of waters such as lakes, rivers and reservoirs readily available for direct harvest or culture purposes. There are 176 000 hectares of operating fishponds which are now being subjected to intensification efforts by using more inputs to increase productivity. The Philippines has 68 lakes with a total area of 200 700 hectares; river area of 31 000 hectares and 249 000 hectares of brackishwater areas part of which awaits further development into fishponds.
The varied shorelines of the Philippines including bays, estuaries, reefs and lagoons are the habitats of more than 2 400 species of fish although only 65 species are presently of high commercial value. The ten (10) major species of fish caught in Philippine waters are the roundscad (Decapterus macrosoma), sardine (Sardinella spp), yellowfin tuna (Neothunnus macropterus), anchovies (Stolephorus spp), slipmouth (Leiognathus equulus), bigeyed scad (Caranx crumenophthalmus), thread bream (Eleutheronema tetradactylum), short-bodied mackerel (Rastrelliger brachysoma), caesio (Caesio spp) and oceanic bonito (Euthynnus yaito).
2. ORGANIZATIONAL STRUCTURE AND FUNCTIONS OF THE BUREAU OF FISHERIES AND AQUATIC RESOURCES (BFAR)
The BFAR is a national government agency directly under the control and supervision of the Ministry of Natural Resources. It has thirteen (13) divisions at headquarters and thirteen (13) Regional Offices throughout the country. The Central Office divisions include: Fisheries Extension Division, Marine Research Division, Fish Propagation Division, Fish and Fishery Products Utilization Division, Fisheries Engineering Division, Fisheries Training Division, Technological Services Division, Fishery Licensing Division, Conservation and Law Enforcement Division, Finance Division, Administrative Division, Planning and Management Division and Legal Division.
Each region is composed of several provinces and cities, ranging from 5 to 9 provinces and 2 to 5 cities. The Bureau is headed by a National Director; a Division chief for each central office division; a Regional Director for each region and a Provincial Fishery Officer for every province.
The main function of the BFAR is to accelerate and promote the integrated development of the fisheries industry and to keep the fishery resources of the country in optimum productive condition through proper utilization, conservation and protection.
3. BFAR PROGRAMMES AND PROJECTS
The Bureau of Fisheries and Aquatic Resources has a yearly expanded Fish Production Programme (EFPP), a subset of the 5-year Integrated Fishery Development Plan. This serves as a guideline in carrying out the Bureau's functions. The Programme identifies objectives, strategies, production targets, projects, both private and public funding requirements for better development of the fisheries industry.
EFPP is divided into four sectoral development projects, namely: The Commercial Fisheries Development Project; the Inland Fisheries Development Project; the Municipal Fisheries Development Project; and the Fish and Fishery Products Utilization Project. The Programme also includes the proper conservation of the fishery resources as well as the administrative support services for more effective programme implementation.
4. BFAR MARINE FINFISH CULTURE PROJECT (SEAFARMING PROJECT)
Marine finfish culture is still a new industry in the Philippines. Although the country is quite successful in culturing freshwater fishes in fish cages/pens, more technological researches are indeed necessary to make marine fish culture a viable project. For this reason, the BFAR has launched the Seafarming Project in the early part of 1977. This project is a subset of the Municipal Fisheries Development Project. Under this undertaking, culture of different marine fishes in fish cages were given emphasis.
Because of the availability of fry and fingerlings, siganids (Siganus spp) and groupers (Plectropomus maculatus) were given priority for fish cage culture. For these species, there are two (2) types of fish cages that are being utilized presently: the floating fish cage and the submerged fish cage.
Inasmuch as this is only on experimental stage, BFAR biologists are using 1 × 1 × 1 m of floating and submerged fish cages, with the mesh size of 2 mm nylon net. The stocking rate per cage varies from 70 to 100 siganids or groupers in juvenile stage, measuring 2–2.5 cm in length. Stocking rate is gradually decreased depending on the ages and sizes of the fish. Grading of juveniles are being done at least once a month. Food and feeding methods are important factors affecting the growth and survival of the fish.
With regard to siganids, floating cages has been utilized. Not much problem is encountered on its feeding because siganids can be fed with algae, Enteromorpha. Although this algae may not give enough nutrients such as vitamins for siganids to resist diseases, it is usually supplemented with squash and raddish to supply them with vitamin and mineral requirements. Other supplement feeds used are Ipomea reptans (kangkong) leaves, banana peelings, gonads of sea urchin, hermit crabs, Ipomea batatas leaves and land snails. Ipil-ipil (Leucaena leucocephala) leaves was used before but it was discontinued because its nutritional value was found inadequate for the fish and it contains some toxic substance. Feeding was usually done every morning.
2 Pertains to commercial fishermen using fishing boats of more than 3 gross tons.
Based on observations in the above tests, siganids were very slow grower with an increment in length of only 5 mm per month. It was observed further that the growth rate was achieved at 15 ppt although siganids can tolerate salinity of as high as 30 ppt.
The groupers were cultured in submerged fish cages, about 5 meters deep. This method is more difficult to manage than the floating cages. Groupers were fed with ground trash fish at 6 to 10 percent of their body weight daily. To avoid cannibalism, grading of fry were done once every two (2) weeks. Just like the siganids, it was also observed that the grouper was also a slow grower. This might be attributed to insufficient supply of food as one of the factors. Being purely carnivorous fish, availability and high cost of trash fish as food was the major problem. A kilogram of trash fish used was almost equal the price per kg of grouper. Fish meal was likewise expensive.
Based on the observations of BFAR biologists, they concluded that due to lack of appropriate technology and good source of cheap food (e.g., trash fish) for these fishes, this type of aquaculture project is not economically viable at present time. However, BFAR continues its experiments and major emphasis is given on improving the food for these marine finfish. In the future, the author believes that because of the Training Course on Seabass Spawning and Larval Rearing, it may be advisable that the Philippines should shift its marine finfish culture effort to seabass culture.
SCS/82/SBTC/EXP. 13
PHILIPPINES
by
Romulo C. Aure
1. INTRODUCTION
The Philippine archipelago is composed of 7 100 islands and islets. It is divided into three regional groups of island, namely: Luzon, Visayas and Mindanao. It has 176 038 hectares of brackishwater fishponds of which more than ninety percent (90%) is devoted to the culture of milkfish, (Chanos chanos). The national average production of milkfish is still below one ton per ha per year. However, production levels of more than two (2) tons per ha per year have been achieved in Iloilo province, Panay island of the Visayas group, specially in the towns of Barotac Nuevo, Anilao and Dumangas.
Marketable seabass of 300 to 500 g in weight are occasionally harvested in brackishwater fishponds together with milkfish. The fry of seabass finds its way to the milkfish ponds during flooding which is usually done every fortnight when the water in the milkfish ponds are changed for freshening and for removal of metabolites. Other fish species such as the Nile tilapia (Tilapia nilotica) Mozambic tilapia (Tilapia mossambica), mullets (Mugil spp) and spadefish (Scatophagus argus) are some of the major species being cultured singly or in combination with milkfish.
2. PRESENT STATUS OF SEABASS CULTURE IN PANAY ISLAND
Aquaculture, fish farming, fish culture or the raising of fish in bodies of water has been an age-long industry in the Philippines. The island of Panay is one of the biggest producers of milkfish fry notably the coastlines of Antique province of this island. Milkfish fry gathering start from late February or early March of each year up to the month of November. Peak seasons for the first cropping or harvest are on the months of May and June through August, at the latest, and September to October as the second peak season for the second cropping. The supply of milkfish fry is year-round. Thirteen (13) provinces in the country have been identified as the spawning ground of the parent milkfish locally known as “sabalo”. During milkfish fry gathering, seabass fry are occasionally caught together with other species of fish which inhabit the coastal areas, mangrove swamps and the estuarine regions.
2.1 On-going research on seabass
The culture of seabass is still on its infant stage. Very few fry are collected from the natural environment which in effect does not warrant its culture either in brackishwater fishponds or in coastal areas. Identification of spawning grounds, scarcity of seeds and information regarding the biology of the fish are some of the major constraints in raising the fish.
2.1.1 Brackishwater Aquaculture Centre (BAC)
The Brackishwater Aquaculture Centre of the University of the Philippines is a national research station in brackishwater aquaculture. Its major thrusts are to conduct basic and applied research on acid sulfate soils, feeds and feeding, fry and fingerling survival, and fertilization.
BAC researchers have recently been conducting experiments on the rate of growth and survival of seabass at varying stocking densities and also on feeds and feeding for raising the fish to marketable size. The seabass is reared in both brackishwater ponds and in cages situated inside the pond. In the grow-out ponds, the fish at various stocking densities are fed with trash fish at 10 percent of the initial fish biomass, once daily, adjusted thereafter to 3 percent of its body weight during the last month of the culture period. Fish in cages are fed with pelleted diet composed of ricebran, trash fish, vitamin pre-mix, with high levels of protein and binders. The results of the experiment will be available before the end of 1982.
In another development, marketable sized seabass were
purchased from private fishpond operators for use in spawning
experiments. Live fish were bought at a price of 
60 to 70
per kg1 depending upon the size and quality of the live fish.
Tentative plan is to induce the fish to spawn by hormone injection
using either homoplastic glands or human chorionic
gonadotropin or a combination of both.
2.1.2 Southeast Asian Fisheries Development Centre (SEAFDEC)
The Southeast Asian Fisheries Development Centre is an international research institution funded by the five member countries namely Japan, Malaysia, Philippines, Singapore and Thailand. The main thrust of SEAFDEC's Aquaculture Department in the Philippines is to raise and propagate crustaceans such as the jumbo tiger shrimp (Penaeus monodon), white shrimp (Penaeus indicus), and the brown shrimp (Metapenaeus ensis). Aside from the crustaceans, SEAFDEC has also gained the reputation for having spawned the milkfish by hormone injection. In 1980, one of the senior researchers of SEAFDEC was able to induce the seabass to spawn by hormone injection. It was rather unfortunate because during that time, milt was not available so that fertilization of the eggs was not carried out. Like the BAC, SEAFDEC is also acquiring marketable size seabass for future use for induced spawning by hormone injection.
3. FUTURE PLAN UPON RETURN TO THE PHILIPPINES
To augment the fish supply for the growing population in the Philippines and to solve the protein deficiency of the people, research work in fisheries is necessary. Increased fish production in our natural waters and in culture ponds may eventually solve this perennial problem of the increasing population in terms of food and nutrition requirements. Research work on the fast growing species of fish for culture or rearing purposes should be undertaken. The Training Course on Seabass Spawning and Larval Rearing may be meaningless if the techniques acquired during the course will not be put into use. The significance or success of the course can be felt if and when research work on the seabass can be pursued or undertaken in participants respective countries.
3.1 Making of research proposal
Tentative plan is to submit research proposals on the following aspects of seabass work for initial implementation.
3.1.1 Survey of the potential spawning grounds of seabass
This will be carried out by making periodic visits to known spawning grounds (based on reports by fishermen in fishing villages) and to monitor the monthly occurrence of the spawners. Hydrobiological checks on dissoved oxygen, salinity, temperature, hydrogen-ion concentration, turbidity and water current are some of the parameters to be observed in the fishing ground in order to be able to assess the environment favoured by the spawners.
3.1.2 Stock assessment
The objective is to determine the quantity or abundance of broodstock in each spawning ground. This will be done by using the existing fishing gear(s) used in the locality and perhaps make necessary recommendations as to what types and kinds of gear is best to use. This is very important so that potential spawners to be collected will not be subjected to too much stress or killed. Quality of spawners is one aspect for the success of producing viable eggs during spawning activities.
3.1.3 Induced or artificial spawning of the seabass
The purpose of this is to insure the ready supply of seed stock to supply the needs of the fish farmers for culture purposes.
3.1.4 Research on culture and dissemination of information
Research proposal on fry to fingerling survival using the indoor and outdoor facilities and the rearing of fingerlings to marketable size in earthern ponds will follow after the preceding proposals have been successfully undertaken. Technology verification and dissemination of information to the end users shall likewise follow after thorough investigation about the seabass have been completed.
1 or Philippine pesos 8.30 = US$1 (June 1982).
SCS/82/SBTC/EXP.1
PHILIPPINES
by
Marcial B. Barrota, Jr.
ABSTRACT
Project Compassion, Inc., is a private, non-profit, humanitarian organization which was set up in the Philippines in 1975. Its present activities include: raising of food and cash crops, small household industries; better nutrition, family planning, better use of leisure time; fish farming as an alternative to small-scale fishing; and others. In fisheries, one of its thrusts is the development of agro-marine projects. In this field, a pilot brackishwater fish farm for the demonstration of aquaculture is being carried out. Using the training acquired in this course, it is planned to include seabass culture as an added activity which may be done with the brackishwater pilot fishpond project or as a new activity.
SCS/82/SBTC/EXP. 15
PHILIPPINES
by
Marlo E. Pacoli
ABSTRACT
The paper reports the issuance of Presidential Decree No. 43 in 1972, aimed at accelerating development of the fisheries industry in the Philippines. For the implementation of this Decree, the Fishery Industry Development Council (FIDC), a fisheries policy and planning body was created, under the Ministry of Natural Resources. Through the Council, the involvement of the different ministries and offices were better defined and coordinated. The FIDC thereafter promulgated development strategies and programmes on various aspects of fisheries. These included guidelines on production, fish utilization, conservation and management, extension services and research, financial assistance, concentration of resources, institutional linkages and fishery exports. Seafarming is one of the prominent programmes under the aquaculture production programme. In this subject, the development of seabass culture is included for pilot studies.
1 Only abstract available, full paper with author.
by
Tan Eng Leng
1. INTRODUCTION
Singapore's annual fish consumption is about 70 000 tons. Majority of the fish are mainly imported from neighbouring countries. Fish produced locally, i.e., from farming is still negligible. In view of this, the Aquaculture Unit in Singapore has taken steps to increase the fish production locally. Owing to the constraints in limited coastal waters, fish has to be intensively cultured in floating cages. This floating cage culture system was first introduced in early 1971. Preliminary studies on it was very encouraging. This floating cage system has been found to be commercially viable and high valued fish like the grouper (Epinephelus tauvina) about S$1 8–12 per 600 g, the seabass (Lates calcarifer) about S$ 8–9 per 600 g and the snappers (Lutjanus spp) about S$ 5–7 per 600 g and others associated fish can be cultured.
2. PRESENT STATUS
The viability of the cage culture system has led to the implementation of the Marine Fish Farming Scheme in March 1981. Fish farmers are required to apply for a licence in order to do such farming. Normally, fish farmers are allocated an area of 5 000 m2 (0.5 ha). To date 40 licences out of 60 proposed farms have been issued. These cage farmers purchased fish fingerlings from local fishermen and mainly import from overseas (e.g., Thailand and Malaysia). The cost of fingerlings vary depending on the size, i.e., about S$1.20 to S$3.00 per fingerling of which freight charges account for 10–40 percent. Presently, the high valued fish cultured are the grouper (E. tauvina) and seabass (Lates calcarifer) and the farmers are in various stages of development so that there is no production statistics available at this moment.
However, this cage culture system is not without problems. The main problems encountered are:
3. PROGRAMME
The Aquaculture Unit of Singapore is conducting experimental studies on grouper (E. tauvina) spawning and larval rearing. The seabass (Lates calcarifer) is also a popular fish and in March 1981, 60 000 of seabass fingerling have been imported. These fingerlings face the same problems as the grouper. The fingerlings available are usually the runts that have been culled from the fast-growers which are sold within the producing countries concerned. The supply of fingerlings is inconsistent and with the increasing freight charges seabass propagation in Singapore may warrant attention.
by
Somprasong Kantom
1. INTRODUCTION
The Samut Sakhorn Fisheries Station under the Department of Fisheries was set up in Samut Sakhorn province. It is responsible for four coastal provinces, namely: Samut Sakhorn, Samut Songkram, Samut Prakarn and Bangkok. In these four provinces exist the largest area for coastal aquaculture or about 80 percent of the total area or about 16 000 ha (100 000 rai). Most of these areas are used for extensive shrimp culture. The production obtained averages 61 kg/rai/year (380 kg/ha). In some of these areas, the fish farmers culture seabass but not so many as those doing shrimp culture. Besides coastal aquaculture freshwater fish culture has also been done in this area. The demand of seabass fry for rearing in grow-out culture in coastal areas and freshwaters in this region is about 1 000 000 fry as shown from collected data. The Fisheries Department is at present unable to supply this amount for the fish farmers. The hatcheries such as Rayong, Songkhla and Satul are very far from this culture area so that high expense in transportation will be incurred.
Fish farmers in these areas lack knowledge and some techniques in seabass culture, so the production and survival rate they get in grow-out culture are very low. Training courses on hatchery, nursery and grow-out culture of seabass are necessary for them.
2. PLAN FOR SEABASS HATCHERY
It is planned to establish a seabass hatchery in Samut Sakhorn. The purposes are: (i) to supply the fry needed in adequate amounts for this region, and (ii) to encourage the fish farmers on seabass culture in order to attain high production in the future.
The following hatchery facilities are going to be constructed:
Spawning tank. The 50-ton tank for seabass spawning is under construction.
Nursery ponds. Eighty (80) panlite receptacles with the size of 1 metric ton each will be acquired to be used for hatching eggs and nursing fish.
Tank for plankton culture. Ten (10) tanks with the size of 1 × 10 × 1 m for rotifer and Chlorella culture are under construction.
Water supply. Since the Fisheries Station is located near the mouth of the river, therefore the water is turbid; this cannot be used directly for the spawning process. There are 3 reservoir ponds with the size of 6 rai for sedimentation which can be provided with filter system.
3. SOURCE OF SPAWNERS
The spawners can be obtained from the grow-out cages that are set in the 6 rai ponds (0.96 ha) in the area, with 2 m deep water. Another ways to get spawners is to use gillnets that can be set at the mouth of Ta-cheen River.
4. NURSERY FOR SEABASS LARVAE AND FRY
While the spawning tanks and plankton tanks of the Station are still under construction, larvae and fry can be obtained from existing hatcheries; larvae with age of 10 days. This stage of fry are able to eat Artemia. After nursing the fry to 30 days, the fry can get to a length of 1.5 cm in length. These can be distributed to the fish farmers by selling them at Baht 1 per fry.
5. PROCEDURE OF CULTURE
To increase the production of seabass in ponds, the pond should be in small manageable size, area about 2 rai and 60 cm deep. The height of the dike is about 1 m. The ponds have to be cleaned up and dried and competitors eliminated by using 0.25 ppm teased cake. After cleaning the ponds, the water is allowed into the ponds and drained out again. After that with the gates properly screened, refill the water by opening the water gates at high tide. The depth of the water in the pond should be about 1 m. Before this, the fry were nursed at the size of 1–1.5 cm in length for 30 days in netcages. The size of the nursery netcage is 1 × 2 × 0.8 m with stocking rate of 400 fry per cage. The fry are feed with Acetes. They have to be graded every 3 days to prevent cannibalism. When the fry grow up to 4– 5 cm in length, Tilapia are chopped into suitable size of the mouth of the seabass. Tilapia are chopped into suitable size of the Sakhorn. The feeding rate is about 10 percent of the body weight of the fish per day. Feeding time is once in the morning and another in the afternoon. When the fry reach suitable size for stocking in the grow-out pond, the fish are sorted according to size and those of uniform size are released in the same pond until they get into marketable size. The fish will be reared in the ponds for 6–8 months, after which they may attain a weight of 500–800 g. Stocking rate is about 2 fish/m2.
SCS/82/SBTC/EXP. 11
THAILAND
by
Jate Pimoljinda
1. INTRODUCTION
The investigation on seabass (Lates calcarifer) along the coast of the Indian Ocean of Thailand had been carried out by the Phuket Marine Fisheries Station since 1969. The operation was conducted in the localities suspected to be nursery grounds of this species such as in swamps and ricefields along both sides of rivers where seawater is able to flow in. Measuring and weighing of fry were conducted and preserved specimens were also collected for further studies.
After the Brackishwater Fisheries Division was established in 1975, the Phuket Marine Fisheries Station was divided into two sections, the Brackishwater Fisheries Section and the Marine Fisheries Section. The project on seabass investigation and culture was then transferred to the Brackishwater Fisheries Section.
2. COLLECTION OF SEABASS FRY FROM NATURAL WATERS
It is already known that seabass spawners will spawn in estuarine areas during the early part of the rainy season. The eggs and larvae are usually drifted upstream by the incoming tide to the swamps and fields along both sides of the river which normally serve as the nursery grounds of seabass. When they grow up to the fingerling stage, they will migrate back into the sea. The collecting of seabass fry was therefore conducted before their seaward migration. Rectangular nets with dimensions of 1 × 5 m and 1 cm mesh were used to collect the fry and grading was done before packing and transporting.
3. REARING OF SEABASS FOR BROODSTOCK
The pond used for rearing seabass in the Phuket Station was constructed in the intertidal zone. The tidal range along this coast is about 3 meters, i.e., the difference between highest and lowest tide. The fry collected were trained to feed on trash fish before releasing them into the pond. Feeding was performed twice a day. About nine months later, the fish grew to about one kilogram in weight. Rearing of seabass in this pond was carried out for about two years, after that the fish were transferred to the concrete rearing tank of about 5 × 10 × 2 m at the Brackishwater Fisheries Section. In the meantime, this Section has succeeded in the propagation of the tiger shrimp, Penaeus monodon with high production. Interest was henceforth shifted to pay more interest in shrimp culture which was the main target of this Section. Due to lack of care, the matured seabass in the rearing pond died. Recently, however, the attempt on rearing seabass fry to be spawners was renewed using the cages at Ao Yon also in Phuket. These are reared until they could be used as spawners so that they could be transferred back to the concrete pond.
4. ARTIFICIAL PROPAGATION AND NURSERY ACTIVITIES
Several trials of hormone injection to the spawners had been attempted but were not successful. There were many causes of failures such as the gonad of spawners were not in the unsuitable condition for injection, lack of skill and technology or unsuitable environmental condition. However, it was found that the spawners in the rearing pond spawned by natural means in the following year but this was detected only when the fry have grown to about 1.5–2.0 cm in length and the survival rate was very low. After this incident, closer observations on the spawners were undertaken. Whenever spawning was detected, the eggs were collected from the spawning pond the following day by scooping them and putting them in the hatching tanks. Nursing of larvae was not yet successful because the fry all died few days later. The activity on seabass culture in the Brackishwater Fisheries Section is now confined to nursing of larvae collected from the hatchery at Satul Brackishwater Fisheries Station and from NICA.
5. CAGE CULTURE OF SEABASS AS A SMALL-SCALE FISHERY VENTURE
Trials on cage culture of seabass is being conducted since 1979 in Phangnga Bay, by the Small-Scale Fisheries Project as one of the activities of the cooperative project between the Department of Fisheries of Thailand and FAO/Bay of Bengal Project. The purpose of this project is to demonstrate and extend the knowledge and method to the local fishermen who are facing the problem of rapidly increasing cost of living and also the crisis of fuel oil situation for fishing operation. The seeds used in this experiment were supplied from NICA and Satul Brackishwater Fisheries Station. Trash fish has been used to feed the fry.
At present, cage culture is widely distributed particularly in Phang Nga Bay and the adjacent waters because of low investment and high profit. Phang Nga Bay is well-known as a place for tourism. In one small island named “Ko Pan Yeeh” there are many restaurants which serve the tourists with live fish, as well as with lobsters and crabs which are located near the cages. It is anticipated that the cage culture industry will continue to expand in this area.
