Myanmar has extensive mangrove forests in Ayeyarwady Delta, Rakhine, and Tanintharyi, but these have been drastically reduced due to paddy rice cultivation. Today, only 382,032 ha remain. Myanmar is only now starting to modernize shrimp farming. Current government policy supports and encourages foreign investment in shrimp culture.

Cambodia has 435 km of coastline with 85,000 ha of mangrove forest. A big part of the mangrove area is in Koh Kong province (63,700) where intensive shrimp culture activity is also concentrated. Shrimp (Penaeus monodon) farms occupy 850 ha, producing 450 tons/yr (1995). But lately, production decreased by 20% due to diseases and self-pollution. The government has since placed restrictions on shrimp farming.

Silvofisheries is a form of integrated mangrove tree culture with brackishwater aquaculture. It is a form of low input sustainable aquaculture. This integrated approach to conservation and utilization of the mangrove resource allows for maintaining a relatively high level of integrity in the mangrove area while capitalizing on the economic benefits of brackishwater aquaculture. Silvofisheries is being promoted in Indonesia as part of a mangrove rehabilitation, conservation and management program. Pond-based silvofisheries follow three design models: (1) the basic “empang parit” model that is essentially identical to an extensive aquaculture pond with maintenance of mangrove trees on the central platform; (2) modification of the basic model to include a dike constructed around the treed central platform so that the water level within the mangrove area and the open water perimeter culture area can be controlled separately; and (3) further modification of the second model to completely separate the open water culture area from the mangrove area by a gated dike with the pond culture area consolidated to a square or rectangular shape at the end of the enclosed diked area. The ratio of mangrove tree to open water culture area is 8:2 to 6:4. In addition, various methods of minimizing the costs associated with pond construction are being considered. This includes the cultivation of mangrove crabs (Scylla sp.) in pens. The State Forestry Company in Indonesia has successfully developed and implemented silvofisheries sites (e.g., 6,000 ha in West Java-Cikiong with 1,508 farmers; 5,300 ha in Blanakan with 2,060 farmers). A conditional lease program with non-government organizations providing technical assistance to farmers has been successful. This program exemplifies what can be accomplished in mangrove rehabilitation and management within a controlled and enforced program. Production and financial return from silvofishery varies with the system, site characteristics, the level of energy input (mainly from mangrove litter - green manure) and utilization by cultured species, among other factors. Annual profit of up to $2,000/ha/yr for a milkfish and shrimp polyculture silvofisheries system has been reported. There is a need to refine data and analysis, since all costs are often not included, and revenue projections are often based on expected production rather than actual production. Farm interviews in West Java showed a range in gross income from $313 to $946/ha/yr while net profit per individual farm (1.5-10 ha farm size) ranged from $943 to $1,558/farm/yr. There was greater production effort per unit area by farmers with smaller farms. Individual silvofishery farmers often combine incomes from multiple sources. The application of silvofisheries practices requires reasonable measures of caution as with any activity in an environmentally sensitive area as the mangroves. Additional important considerations in the development of silvofisheries as part of an activity within the mangrove ecosystem include the issues of land ownership, integrated coastal zone planning and development, comparative economic assessment, systems models, optimizing use of inputs, selection of mangrove tree and aquaculture species, better understanding of trophic production and food web utilization, and improvement of economic return.

Although Japan has large-scale aquaculture, there is no aquaculture development in mangrove areas because the total area is small (553 ha) and strictly protected. Mangroves are preserved in comparatively good condition. Future development of aquaculture in mangrove areas is considered small-scale. Rather than aquaculture, Japan practices enhancement and management of wild fisheries. Tourism is another industry that would have an important role in mangrove utilization. But basic research on mangrove ecosystems is essential prior to determining policies for utilization of mangrove areas. International cooperative research work is important to encourage mangrove-friendly aquaculture and protect the environment.

The paper describes some mangrove-friendly aquaculture activities that are practiced in Malaysia. Among these are the culture of cockle and oyster, semi-intensive culture of tiger prawn, fish cage culture, and pen culture of mud crab. Policies, regulations, future directions and priority areas in research and development that can contribute to sustainable mangrove utilization are discussed.

SEAFDEC Aquaculture Department (SEAFDEC/AQD) is mandated to develop human resources and disseminate and exchange information in aquaculture. Towards this direction, AQD’s recent thrusts are focused on the verification, packaging, and commercialization of the technologies developed through research. AQD disseminates and exchanges information on aquaculture research and technology through training, extension services, community-based projects and mass media. Through these strategies, AQD aims to reach out to more clientele which include among other sectors the private industry, research and academic institutions, regional and international organizations, policy-makers, non-government organizations, resource managers, SEAFDEC member-countries, local and national government and the fisherfolk. For the past two years, the scope of training courses and extension services of AQD have been expanded from technological viability to sustainability i.e., technological feasibility, economic viability, environmental sustainability and social equity. To attain sustainable aquaculture the following elements were considered: status of technology, conditions of the coastal resources, socio-economic attributes of the community and other stakeholders and institutional arrangements on sustainable aquaculture. Starting 1997, subjects on mangrove-friendly aquaculture and coastal resource management were incorporated into the curriculum of training courses. These courses are the following:

• Third Country Training Program on Coastal Aquaculture and Resource Management for trainees from Asian countries
• On-site Training on Sustainable Aquaculture and Coastal Resource Management in Vietnam
• Sustainable Aquaculture and Coastal Resource Management for extension workers and fishery school teachers

In terms of technology verification and extension, the culture of mudcrab (Scylla sp.) was tested in mangroves or tidal flats with existing mangroves in two different sites (Puerto Princesa, Palawan and Kalibo, Aklan) in collaboration with local government units and the fisherfolk. These activities started in 1997 and will be replicated in other areas of the country. Also in 1997, AQD published and distributed an issue on integrated farming with aquasilviculture in its SEAFDEC Asian Aquaculture newsletter. In 1998, AQD produced a 12-minute video on Conserving Mangrove Resources.

Recent statistics of fishery production in the Philippines reveal outputs that are either declining (municipal fishery) or levelling off (commercial fishery and aquaculture). These trends are, in part, a reflection of the serious effects of unregulated economic activities in the coastal zone. The degradation of coastal ecosystems means a loss of livelihood among many communities of impoverished fishers as catches from municipal waters have declined over the years. Considering that mangroves, seagrasses, and coral reefs are vulnerable to anthropogenic perturbations, several development strategies are presented to meet the twin issues of ecosystem conservation and food security for coastal fishing communities. Mariculture, searanching, habitat alteration and restoration are a few of these strategies. Our recent experience in village-based reef resource management in Mararison Island, central Philippines may likewise be a viable option in the management of shoreward ecosystems (mangroves and seagrasses). In particular, the establishment of a marine reserve in the island may find some relevant applications in mangrove management and development.

Mollusc research at the Aquaculture Department of the Southeast Asian Fisheries Development Center started in 1975 and focused on two commercially important mangrove-associated bivalves, the slipper-shaped oyster (Crassostrea iredalei) and the green mussel (Perna viridis). Studies conducted were on spatfall forecasting to increase collection of seeds from the wild; improvement of farming techniques; seed production in the hatchery; bivalve sanitation; and transplantation. These studies have led to the development of a suitable spat collector for oyster and mussel; promotion of the raft culture method for oysters and mussels to prevent siltation of growing areas, including a low-cost raft design for this purpose; refinement of transplantation techniques to increase production and to grow osyters and mussel in suitable areas without natural populations; and desgin of a prototype low-cost depuration unit. A socio-economic study of oyster and mussel farming practices in Western Visayas provided information on current farming practices and profitability. A study done on the use of green mussel as biofilter in a semi-intensive shrimp pond showed that shrimp stocked with mussels grew faster than those without. A study on the biology and fishery of the "imbao" Anodontia edentula, another mangrove-associated bivalve, is ongoing. Spawning has been achieved in the laboratory and larval stages monitored were first polar body, 2-cell stage, morula, ciliated gastrula, trocophore, veliger, and pediveliger.