It is concluded from the present survey that the environment of selected places in Kepulauan Riau is satisfactory for the culture of groupers, rabbitfishes, snappers, seaperch, milkfish, oysters, mussels, conchs, clams, marine shrimps, mangrove crab, swimming crabs, seaweeds but not for freshwater species such as tilapia and Macrobrachium. However, the culture of snappers, seaperch, milkfish, conchs, marine shrimps, mangrove crab and swimming crabs, is not recommended because of various constraints discussed in Section 2.
This section will discuss various factors concerned with production and marketing as a basis for projecting the profitability of farming the selected species. This discussion is necessarily in general terms since only two of the selected species have been farmed in Kepulauan Riau. Completion of the aquaculture trials described in Section 4 will provide a more reliable basis for projecting profitability. Species groups with the best potential for aquaculture development on the basis of environmental suitability are as follows:
Oysters of the species Crassostrea glomerata are widely distributed although abundant only in a few areas. Native stocks are considered to be sufficient for collection of seed.
Adequate areas are available in bays free from domestic pollution for hundreds of oyster farms (Annex II).
Culture systems have been well-developed elsewhere but must be tested to verify their applicability in the local environment. Systems used in the Philippines and those used in New Zealand and Australia appear to be the best for the Riau Islands.
Natural food supplies (phytoplankton) are considered to be adequate in all areas surveyed and excellent in areas with drainage from the land. Oysters should reach marketable size in 6–8 months.
Fishermen and their families, living in small villages throughout the area, provide an adequate labour supply for starting oyster culture. The transmigration programme could bring new families to this area and many of them could become oyster farmers.
The logistics of oyster farming are not limiting because of the ease of boat transportation largely through protected channels between islands. The product, oysters in their shells, can withstand at least three days out of the water, allowing adequate time for harvesting, packing, transport to Tanjung Pinang and Singapore and sale to consumers.
Markets for oysters are excellent. Singapore alone could absorb all of the oysters that might be produced by several hundred one-hectare farms. It is also possible to pack oyster meats, removed from their shells, in retail sized jars and transport them via boat to Jakarta. Shucked oysters kept on ice will remain in good condition for up to 10 days allowing sufficient time for shipment and sale to consumers.
It is difficult to project the profitability of oyster culture in the Riau Islands without figures on cost of production and marketing and the sale price of the product. However, there are over 1 000 family oyster farms in the Philippines operating under similar conditions and most of them are successful. Therefore, their is a high probability that small-scale oyster farming in the Riau Islands would be economically viable. This, of cource, assumes that aquaculture trials described in Section 4 are successful and that government provides seed initially and trains potential oyster farmers.
Groupers are caught by small-scale fishermen throughout the Riau Islands for a well-established market. Six small farms are in production using seed (juveniles) from natural stocks caught by traps, nets or handlines. Growth is excellent and the fish can be marketed in four months.
Methods for farming groupers have been developed and applied in Hong Kong, Singapore, and elsewhere in Indonesia. The major problem is to get enough seed at an acceptable price. Aquaculture trials described in Section 4 address this problem.
Food must be provided regularly to groupers held in cages or net pens. This is usually scrap fish caught by the fish farm operator who is also a part-time fisherman or purchased from others. Both availability and cost of food are important. The eventual solution for highly industrialized large-scale farms is pelleted feeds but the small-scale farmer must rely on low-cost locally-available natural feeds.
Labour for small-scale grouper farming is usually provided by the operator, who may also be a fisherman, and by his family. Larger farms may require part-time, non-family labour which is usually available. Frequently fish farms can be located at or near an existing village which simplifies the labour problem. The transmigration programme could bring new families to this area many of which could become fish farmers.
The logistics of fish culture in the Riau Islands are favourable. Most areas are within a few hours of Tanjung Pinang or Singapore via boat. Individual fish farmers could easily deliver their product directly to the population centres and purchase needed supplies and equipment.
The market for groupers is excellent and a uniform sized product of high quality from fish farms delivered at opportune times should bring top prices.
The profitability of cage culture of groupers in Indonesia as discussed by Chan (1981) indicates a substantial return on investment. The Riau area is especially attractive because of the adjacent Singapore market which will be supplemented by the planned industrialization of the north western side of Batam Island.
The major problems of grouper culture are seed and feed supplies. Until these are clarified, it is difficult to project the potential for expanding grouper farming in the Riau area. These problems are addressed in the aquaculture trials described in Section 4.
Hundreds of places in Kepulauan Riau are suitable for grouper farms. These are in protected channels between the islands with good circulation and shallow water for cages suspended from fixed wooden structures or deep water for anchoring floating cages (Annex II).
The siganids are often recommended for seafarming because of the availability of seed, their low-protein food requirements and the well-established market. They adapt easily to culture in net cages or pens and reach market size in less than a year. The major problem is high mortality of larger size fish under certain conditions from unknown causes.
Siganid farming could be attractive in the Riau Islands since juveniles are available locally, labour is available in fishing villages and the environment is ideal for the construction and operation of fish farms. Siganids are in demand throughout the year at moderate prices, 400–1 000Rp/kg, and during the Chinese New Year holidays in January or February at several times these prices.
The profitability of siganid farming is difficult to project because of the lack of commercial experience in the Riau area and the threat of mass mortality from unknown causes.
The development of siganid farming is given a lower priority rating than oysters or groupers. However, when the mortality problem is solved, siganid culture could become a major seafarming activity in the Riau Islands.
Siganid farms could be located in hundreds of places where there are protected channels between the islands with good circulation and shallow water for fixed enclosures on deep water for anchoring rafts (Annex II).
Methods for farming Eucheuma spinosum and other species for their phycocolloids or for use as food are well-known and have been applied in the Philippines and in other places. Several areas in the Riau Islands appear to be suitable and have natural stocks of E. spinosum.
The major problem of tropical seaweed farming is the low price of the product. Reportedly there is a world oversupply at this time so the companies processing seaweeds have drastically reduced the price paid to seaweed farmers and to the harvesters of wild stocks. Seaweed farms in the Philippines are in serious financial difficulty and no new farms are being started.
It is recommended however, that seaweed farming be included in the long range planning for aquaculture development in Indonesia. There is a strong possibility that the worldwide marketing situation will change and that the present low price will stimulate demand and develop new uses for phycocolloids. This, in turn, could increase the price to the producer and make seaweed farming economically viable especially for remote areas.
Areas apparently suitable for seaweed farming include Pangkil Karas Besar, Mantang, Telang Berat and Telang Kecil Islands (Annex II).
Methods for culture of the green mussel are well-known and some farming has already begun in Indonesia. However, no green mussels were found in Kepulauan Riau during the present study and no one contacted knew of any local populations of this species.
Green mussel farming is economically viable in several areas in Southeast Asia. There are nearly 700 small mussel farms in the Philippines, most of which are successful.
Mussel farming in the Riau area would require purchasing seed from Jakarta or transplanting a brood stock which might eventually produce a self-sustaining population. Many places in the Riau area appear to be suitable for mussel culture but this should be verified by test plantings.
The market for mussels is just developing in Indonesia, and even Singapore, but is well-established in other areas such as the Philippines.
Therefore, it is recommended that mussel farming be included in the long range planning for aquaculture. The aquaculture trials described on Section 4 would provide a sound basis for evaluating the potential for mussel farming in the Riau area and selecting locations for trial plantings.
Although the environment appears to be suitable for selected aquaculture species, only grouper and oyster farming can be given serious consideration at this time.
Groupers are present in the Anambas Islands and substantial quantities are shipped to Tanjung Pinang and Singapore. Production could be increased by growing groupers from juvenile to market size in cages or pens. Culture methods are well-known and farming has begun in the Riau Islands.
Many protected areas suitable for grouper farming in cages supported by fixed structures or by anchored rafts occur in the Anambas Islands. Fishing villages, close to many of the areas, could provide the labour supply needed to build and operate the farms. Recommended areas are Telok Niulwan and Telok Ulu Mangar on Matak Island, with a government demonstration farm at the DGF Fishing Base near Tarempa on Siantan Island. Telok Kuala on Jemaja Island would also be a satisfactory area and it is likely that suitable places could be found in the vicinity of Letong (Annex II).
Fish are relatively abundant in the area and several of the low-valued schooling species might be used as food for groupers. There is even the possibility of using small tuna as food for groupers when the price drops during periods of heavy landings.
Juvenile groupers are present and presumably could be captured by the fishing methods used in other areas. Local fishermen might need demonstrations and training in the fabrication and use of wire mesh trap and other gear.
The logistics of fish farming would be more difficult than in the Riau Islands because of the distance to markets and the infrequent shipping schedules. However, a farmed crop could be harvested just before departure of a ship for Tanjung Pinang or Singapore. With adequate ice, the fish should reach the consumer in good condition. The principal disadvantages are the cost of shipping supplies to Tarempa and fish to Tanjung Pinang and Singapore.
There is no sound basis for evaluating the economic viability of grouper farming in the Anambas Islands at this time but the experience of the six new farms in the Riau area during the next two years, and the information provided by the aquaculture trials described in Section 4 will be helpful.
Oysters, Crassostrea glomerata, are moderately abundant in several places and are used for food in the fishing villages. No oyster culture has been tried. The results of the aquaculture trials described in Section 4 would be needed to evaluate the potential for oyster culture in the Anambas Islands.
There is a strong possibility that seed can be collected at Tarempa harbour or at the DGF Fishing Base. Seed could then be provided to fishing villages for culture to marketable size. This would also increase the number of spawners in those areas and could lead to local collection of seed.
Growth rates appeared normal for wild populations and the oysters sampled were in good condition and had excellent flavor. Oysters in aquaculture systems could be expected to grow more rapidly and reach a larger size than wild stocks.
The logistics of oyster farming are not expected to be limiting. Oysters remain alive for at least 3 days after harvesting, allowing enough time for shipment to Tanjung Pinang or Singapore and delivery to the consumers. With refrigeration, they will last longer.
The areas with the best potential for oyster culture are Telok Ulu Mangar and Telok Niulwan on Matak Island, Telok Baruk on Siantan Island and Telok Kuala on Jemaja Island. A government operated demonstration farm at the DGF Fishing Base near Tarempa on Siantan Island is also recommended.
The probability of economically viable oyster culture in the Anambas Islands is low at the present time. However, if oyster culture in the Riau Islands is successful, the same methods could be applied in the Anambas group with a good chance of becoming economically viable.
