Southeast Asia has a relatively long tradition in mollusc culture. The mollusc species of commercial significance in this region are the blood cockles (Anadara granosa), the green mussels (Perna viridis), the oysters (Crassostrea spp.) and the horse mussels (Modiolus sp.). Mollusc production has been observed to fluctuate dramatically in recent years due mainly to the inconsistent seed supply from the wild, which varies geographically and annually. These variations are often associated with pollution and also the uncontrolled harvesting of adults irrespective of their sizes, which reduces chances of spawning among adults. Production of the above-mentioned species in Southeast Asia in 1997 amounted to 73 820, 62 073, 36 779 and 5 300 mt., respectively. The culture of these bivalves is still dependent on traditional methods of obtaining seeds from the wild and transplanting them to culture sites for grow-out. Culture techniques for these bivalves are basically the same all over Southeast Asia, except for minor variations in the use of structures and materials to suit the local conditions. Whilst efforts are geared towards developing new technologies to promote mollusc culture in the region, it is important to facilitate and stimulate environmentally acceptable developments and sustainable management practices. Although hatchery propagation techniques have been developed for these cultured and other non-cultured species, the technologies have yet to be taken up commercially. Some of the common problems confronted by the region, which varies greatly by species and location, are inconsistent seed supply, lack of suitable areas for expanding culture activities, poor post harvest handling techniques, demand levels being below production capacity, environmental pollution, vagaries of nature, low price and lack of access to export markets.

Details are given of the production of Penaeus monodon in the Philippines reared in brackishwater earthen ponds applied with different fertilizer combinations, namely diammonium phosphate, urea and chicken manure. Results show that the shrimp showed higher yields in fertilized ponds, but increasing the concentration of fertilizers did not give a marked increase in yield - the excess fertilizer was wasted.

The findings are presented of a study conducted to determine the economic feasibility of the pond culture of mud crab (Scylla serrata) at various stocking densities. Investments, costs, and returns are given for a 1 ha crab monoculture at 4 stocking densities - 5000, 10,000, 15,000 and 20,000. Results show that mud crab monoculture in brackishwater ponds is economically feasible at stocking densities of 5000/ha and 10,000/ha.

The toxic effects of sulphide are best understood in mammals and are generally similar in aquatic organisms. At the physiological level sulphide has 2 major effects on mammals: 1) local inflammation and irritation of moist membranes including the eye and respiratory tract; and, 2) cardiac arrest due to paralysis of the respiratory centres of the brain. The toxicity of sulphide to plants, macroinvertebrates, freshwater fish and marine fish is discussed in detail. It is concluded that the role of sulphide in mass kills of fish, shrimp and other animals in brackishwater earthen ponds, lakes and sea cages should be determined.

Following brief descriptions of the various phases in the natural life history of the milkfish (Chanos chanos), namely adults, eggs and embryos, larvae, fry and metamorphosis, juveniles and sub-adults, a summary is provided of the life history, providing also a schematic diagram.

An account is given of the fabrication and deployment of artificial reefs used in the SEAFDEC/AQD's Community Fishery Resource Management project, which focused on Malalison Island located in west Central Philippines. The project aimed to apply community-based techniques of fishery resource management through the collaboration of community organizations, biologists and social scientists. The 3 types of reefs (building blocks, concrete pipe culvert, and modified concrete pipe culvert) were deployed at Gui-ob reef covering an area of less than 1 ha.

An outline is given of aquaculture practices in Malaysia, Philippines and Thailand, which included freshwater, brackishwater and marine systems.

An outline is given of aquaculture and fisheries in Asia, providing information of use to students whose work can influence laws, rules, policy and regulations on aquaculture and fisheries, with the view in mind to sustainable aquaculture. In this issue, the following countries are examined: China, Indonesia, and Bangladesh.

Integrated farming has long been practiced in Malaysia, not only to provide protein requirements needed by the family, but also as a source of income. With fish being promoted on a larger scale, the Malaysian government is providing farmers with financial assistance and hands-on training on fish culture and rice production. Systems of fodder-fish integrated farming and fish-livestock farming in mine ponds are outlined.

Aquasilviculture can be defined as the integration of aquaculture with mangroves. Details are given of an example of aquasilviculture in the Philippines at Puerto Galera, Mindoro. The farm has 3 series of perimeter ponds stocked with tilapia, although milkfish, mudcrab and shrimp may be caught when entering the ponds incidentally.