WBL/85/WP - 34
NOTES ON THE STATE OF THE MARICULTURE PRACTICES
IN THE RIAU ARCHIPELAGO
(THE SOUTH CHINA SEA OF INDONESIA)

by

Tatan Sujastani ¹⁾
Achmad Sudradjat ²⁾

1) National Proyect Leader, GCP/INS/CAN - Indonesia Fisheries Development Project Phase II.

2) Chief, Coastal Aquaculture Research Station, Tanjung Pinang.

I. TECHNOLOGY

1. The mariculture activities in the Riau Archipelago District, i.e. the South China Sea Region of Indonesia, consist of rearing practices for finfish, bivalves, seaweeds and crustaceans. The majority of fishermen in this area, however, conduct finfish per-or cage-culture (where in the INFIDEP works with). The system is of planted woostakes (nibung-palm tree) for a range of 4 to 10 m². The inner-sides are covered with layers of net (or sometimes cage-wiring) webbings, stretching right down to the bottom, but without touching the sea-bed. A floating net-cage technology was introduced as a demonstration of the project's mariculture experiments here which was imitated by the fishermen. The finfish species are Plectrophomus leopardus and P maculatus, both locally called “sunuk”, Epinephelus tauvina or “kerapu”, Lutjanus sanguineus, L. malabaricus, and L.johni or “kakap”. The species of Caesio erythrogaster or “ekor kuning” is accidentally kept, and Siganus spp. or “dingkis” as reared only for the Chinese New Year period. Bivalves and other moluscs are collected from the natural beds, whereas the culture practices for these are in a research experimental stage for Crassostrea cuculata and Crassostrea iredalei.

   Seaweed culture is not yet developed but experiments have been conducted since 1978 to study the viable grounds for Eucheuma spinosum. The culture of crustaceans at sea has not been practised.

2. The reguired inputs for the production are coastal grounds, materials for construction of pens or cages such as wooden staken and plates (“nibung palm” or others), net-webbings, lines and floats, fish seeds (fries or juveniles), feeds (trash fishes or by - catches), boats and labour. The “nibung palm” trees, labour, operational needs are locally available. The degree of availability in terms of quantity and quality is not yet studied ; the requirement for fish seeds (fries, juveniles) for finfish cage culture development is becoming the major limiting factor, since the uncertaintly of supplies is recognized.

3. All those mentioned inputs (in No. 2) are mostly shared with other fishing activities, such as those with stationary trap fisheries and other coastal fishing activities, The trash fishes (by cathes) are also used for feeds in animal husbandry.

4. The total live fish production in the Bintan area in 1984 was 23.000 kg (24 ton).

   The productions per unit are as follows:

   Size of cage (m2)	Yields/cage/6 months (kg)	Number of cage in July1984 (units)
   4	260	10
   8	350	30
   10	410	13

   The production within a 6 months period is usually yielded from 2 – 3 harvests for export to Singapore.

5. Only a few fishermen in this area have acquired knowledge and skill to operate their culture business.

6. Up to the present the cultured stock is well protected (by law and regulations). There is no epidemic or diseases known as far which disturbed the activities. The climatic conditions in the area is fair, therefore there has not yet been reported damage on mariculture sites due weather.

7. The technical as well as the socio-economical studies on the magnitude of viable sizes of a finfish farm have not yet been conducted. The existing practices in the area show that the limiting factor for size is the capital availability. As the common small scale cage (pen) operator operates a unit that cost less than US $, 500 whereas the stronger owners mostly operates unit that coast around US $ 2,500. (for detail See Appendix).

II PRODUCERS

1. The 1984's finfish culture operating were 30 entrepreneurs. The target for PELITA IV projected by the GOI is 60.

2. The objectives of the fisheries development project are to lift up the income of the existing fishermen as well as to provide the job opportunities in line with the increase of production. The mariculture as a segment is directed toward the existing fishermen involved in catching (fishing) activities.

3. The existing finfish culture operators are mostly fishermen, including owners of fishing gears, fishery product traders and also those who loan or provide capitals for the surrounding fishing community.

4. The observation shows that the living standard of mariculturists are better.

5. The owners of mariculture units usually provide materials for the operators especially traps. The catches (especially the fish seeds or juveniles) have to be sold to these owners (with set prices). The daily activities are conducted by the family members, and if necessary (mostly) are assisted by labourers ( usually fishermen ).

6. An avarage household mariculture operators is around 5 persons.

III COSTS AND INCOME

1. See Appendix

2. The specific credits or loan for mariculture investment/production is considered a necessary factor and very important for the development in the area. The formal channel has not yet been available, wherein the fishermen acquired their needs from the private sources (such as loans from owners, or entrepreneurs, etc.)

3. The private sources such as local-money-lenders, or fishing entrepreneurs (or owners) provide almost all requirements for mariculture activities through loans or credits in kinds.

4. The prices of the finfish cage culture products to the producers are :

   1).	Plectropomus spp	:	Rp. 6.500,-– 8.500,-/kg
   2)	Epinephelus spp.	:	Rp. 2.500,-– 4.000,-/kg
   3)	Lutjanus spp.	:	Rp. 2.500,-– 3.000,-/kg

   Those prices were quite stable during 1984.

5. Yes, See Appendix (for No. 1).

IV. DISTRIBUTION AND CONSUMPTION

1. 100% of finfish cage culture products are sold
2. Sold as live - fish
3. Plectropomus are exported to Singapore.
   Epinephelus are mostly sold to local restaurants, few are exported. (see Appendix).
4. The group (s) who control the distributions are fish traders (collectors) who stationed (live) in the remote islands.
5. If, the production is high, there will be a problem in marketing in Singapore (a kind of bottle nect?) due to existing high live fish stocks here.
6. The prices which are paid by the local consumers are :

   (1)	Plectropomus (rarely bought)	:	Rp. 6.000,- – 8.000,-/kg.
   (2)	Epinephelus & Lutjanus	:	Rp. 2.500,- – 4.000,-/kg.

APPENDIX A

REMARKS

1. Seed Supply. Fish-seeds are collected and caught by ( as by-catch) taps (made of wire-webbing) yields 0,3 kg/unit / week with an approximate weight of 0.25 kg/individual.

2. The present demand (Singapore market) of live-fish (products of mariculture practices) is those that having weight of around 0.7 kg/individual. The approximate rearing mortality was 5 %.

3. 4 rolls of wire webbing is utilized for 40 units traps. These traps are operated 10 units per (each) day for a 4 days setting.

4. Wire-webbing material (for traps) lasts within 6 months, net webbing (polyethylene materials) lasts for 2 years, wood materials last for 2 to 3 years; boat (dug out, and small motor boat) lasts for 3 – 4 years.

APPENDIX B

Marketing of Plectropomus

Marketing of Epinephelus & Lutjanus