2.3.
LIVE FISH: CAGE CULTURE
The demand for live fish both in Sabah and for export has grown rapidly over the last few decades and high prices are paid. There are a small number of fish cages close to the Semporna mainland, but no hatcheries in the vicinity. None of the cages is located in the the proposed Park, but all the fish kept in cages are brought in from the wild (i.e. not true mariculture), with some being caught in the proposed Park.
2.3.1. Types of cage culture
Komilus et al. 2000 report that there are two types of cage culture in Semporna, one dealing with adults (holding cages), the other with individuals that have yet to reach marketable size (cultivating cages). Holding cages: the fish are mainly for export and the average length of time the fish are held in cages is 2-10 days. The marketed size is commonly between 0.5 to 1.5 kg.
Cultivating cages: the fish are fed and grown over periods ranging from 3-12 months (occasionally more). The stocking size ranges from 0.1 to 1.0 kg while the marketed size is between 0.5-1.5 kg. Operators involved in culture may then sell fish to those involved in holding (particularly if the operators are small-scale farmers/fishermen).
The fish are fed with trash fish obtained from local trawlers, with feeding rate depending on the availability of trash fish and total body weight. Market size fishes are fed at 2 - 4% body weight/day. In 1999, there were at least 3 active marine cage culture operators based near Pulau Bum-Bum. In contrast, there were at least 8 operators in 1998 with 18 cages (8,200 m3 total size) in full operation. Some of the operators were forced to close down in late 1988 due to unfavourable fingerling supply (Komilus et al. 2000).
2.3.2. Capture methods and target species
The target species are mainly groupers, wrasse and lobsters. Most of the fish are caught using portable or static traps (e.g. bubu; kelongs). There are also reports of illegal use of cyanide as an ‘anaesthetic’, but this is done covertly and is difficult to detect. The SIP diving team saw live fish being caught with a hookah system (compressed air supplied from a surface compressor), but it was not clear if cyanide was being used.
| Common name | Scientific name |
| Greasy grouper | Epinephelus coiodes |
| Dusk tail grouper | Epinephelus bleekeri |
| Leopard coral trout | Plectropomus leopardus |
| Mouse grouper | Cromileptes altivelis |
| Vermillion grouper | Cephalopholis miniatus |
| Tomato rock cod | Cromileptes sonneratti |
| Green wrasse | Choerodon schoeleinii |
| Bigeye kingfish | Caranx sexfasciatus |
| Napoleon wrasse | Cheilinus undulatus |
Table 15. Marine cage culture species in Semporna (from Komilus et al. 2000)
© S. Daly
2.3.3. Fish culture production and economic value
The annual yield from marine cage culture operations in Semporna ranged from 8 mt in 1994 to 7.19 mt in 1998, with a peak of 24.7 mt in 1997. The corresponding wholesale values were RM 0.32 million, 0.24 million and the peak of 1.15 million in 1997 (Komilus et al. 2000). Price of individual fish depends on size and species. The most expensive are the panther grouper Chromileptes altivelis and the bumphead wrasse, Cheilinus undulates.
|
Family/species |
Price RM/Kg |
| SERRANIDAE Cephalopholis miniata Cromileptes altivelis Ephinephalus tauvina Plectropomus areolatus P. laevis P. leopardus P. maculatus P. oligacanthus Variola albimarginata |
10.00 50.00 28.00 32.00 32.00 20.00 18.00 20.00 |
| LUTJANIDAE Lutjanus argentimaculatus L. bohar L. gibbus L. rivulatus L. sebae Symphorus nematophorus |
2.50 3.50 2.50 32.00 3.50 15.00 |
| LABRIDAE Cheilinus undulatus |
50.00 |
| CARANGIDAE Alectis ciliaris Carangoides gymnostethus C. fulvoguttatus |
2.50 (only large size) |
Table 16. Price list for some live fish marketed to Semporna. Source of information: Pulau Bodgaya (Kg Boheybual), Pulau Boheydulang (From Suliansa, 2000).
2.3.4. Constraints
Komilus et al. 2000 report that among the problems and constraints identified in marine cage culture operations in Semporna are the following:
Fish disease
Common disease occurrence mainly reddish skin, abdominal inflammation,
red boil and others include fin rot involving Myxobacter sp. and
Vibrio sp. and Brooklynella sp.
Social conflicts
Theft and poaching from marine cage culture operators is common in the
SIP area. At present, all the farms had arranged for a night watch to
resolve the problem.
Fry supply
Shortage of fingerlings is an acute problem with total reliance on the
capture of wild fingerlings from offshore reefs, including those within
the proposed park. SIP area.