Marine protected areas (MPA) are tools for integrated coastal management (ICM); they have gained worldwide acceptance as a strategy for resource restoration and conservation. Research must gauge the effectiveness of MPA implementation in promoting fisheries recovery. This study investigated the effectiveness of enforcement in the Sagay Marine Reserve (SMR), western Philippines, in promoting the recovery of abalone stock. Enforcement of protection in the SMR is accomplished through the bantay-dagat (sea patrol), which utilizes reef watchtowers to deter illegal activities. The abalone populations in two protected reefs (well-enforced protection) and two open access reefs (poorly enforced protection) in the SMR were surveyed using 50m x 2m belt transects. Abalone density was significantly greater, and abalone were larger, on protected than on unprotected reefs. However, we found that recruitment appeared limited at all sites, and that abalone tended to be sexually mature at small sizes. This may indicate that the population has been near a critical threshold, that recent climatic events may have suppressed recovery rates, and/or that enforcement and rule compliance was low and with continued poaching. Nevertheless, the results of this study agree with findings of other research that a properly enforced no-take MPA can promote recovery of local stocks. Moreover, the investment of funds by the local government in monitoring activities (in this case, watchtowers) is necessary to achieve MPA objectives.

In many Southeast Asian countries, coastal fishing villages are increasingly encouraging their inhabitants to start small-scale aquaculture as a way of reducing the labor involved in fishing and diversifying their sources of income. This study aims to conduct a comparative analysis of small-scale aquaculture in the Philippines, Thailand and Malaysia (hereinafter referred to as the ‘three countries’). Aquaculture plays a leading role as a secondary source of income in the Philippines, and is both a primary and secondary source of income in Thailand and Malaysia. Even if a highly productive method of aquaculture were introduced in the Philippines, however, it would not see much uptake because it would be prone to damage by typhoons. Thailand and Malaysia, however, which are unaffected by typhoons, have rapidly increased their mussel production thanks to the active introduction of highly productive aquaculture methods. Our search of the points that developing areas in the three countries have in common revealed that many people started small-scale aquaculture after the mid-1990s in advanced areas, and that most small-scale aquaculture operators say that shellfish are easy to culture and want to continue in the business.

Aquaculture of grouper including orange-spotted grouper suffers losses from viral nervous necrosis (VNN). This disease usually occurs in larval stage resulting in a high rate of mortality. It is conceivable that vertical transmission from subclinically infected broodstock fish to the brood is the major route of infection. However, there are only a few studies regarding the fish subclinically infected with VNN and the evidence for a causal relationship between subclinically infected adult fish and vertical transmission remains tenuous. The purpose of this study is to reveal the distribution of the virus in asymptomatically infected fish. Six healthy broodstocks of orange-spotted groupers with body weights ranging from 5 to 12 kg were used and 14 different organs were collected. Cell culture and PCR methods were used to detect the virus. Additionally, 8 wild juveniles with body weights ranging from 2 to 4 g were also analyzed. In our results, the virus was detected by means of PCR but not by the cell culture method. All the broodstocks and wild juveniles were positive in the PCR test except for one juvenile. The highest detection rate of the virus among organs was the brain. However, the virus gene was also amplified from organs other than the central nervous system (CNS). We hypothesize that the virus was latently retained in the CNS of subclinically infected fish and when the fish immune system was weakened such latent virus was released from CNS to the peripheral organs including the gonad. This mechanism might provoke the vertical transmission infection.

There has been little information on the importance of arachidonic acid (20:4n-6, ArA) in fish and other aquatic animals, although the importance of eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA) has been highlighted. The present study was conducted to investigate essential fatty acid composition, especially ArA distribution in mangrove organisms in the Philippines, Malaysia and Japan. The overall results revealed that ArA was not a minor component in mangrove organisms, and that the existence of ArA in mangrove organisms is widespread, irrespective of the differences in species, geography and environment. Both mangrove green and dead leaves were rich in linoleic acid (18:2n-6 LA) and linolenic acid (18:3n-3 LNA), which are respectively precursors of ArA and EPA & DHA, although ArA, EPA and DHA were not detected in these leaves. Mangrove invertebrates contained intermediate to high ArA. Especially, mangrove snails had very high ArA levels with low DHA levels, and thus the snails appeared promising as a new dietary source rich in ArA. Most of fishes in mangrove areas showed entirely higher ArA levels than EPA levels. As overall traits, ArA/EPA ratios of mangrove animals were higher than those of cold and temperate water species .The present results suggest that ArA may be nutritionally more important for egg and larval development, and that its supplementation in diets can enhance the development of broodstock management and fry production technologies in mangrove areas. The information of the present report can be used as a guideline for development of appropriate broodstock and/or larval diets in mangrove areas.

Aquaculture plays a predominant role in the Philippines, an archipelago of 7,150 islands with 36,300 km of coastline, 26.6 million ha of coastal waters, and 250,000 ha of lakes, rivers and reservoirs over which are spread 239,000 ha of brackish-water ponds and 14,500 ha of freshwater ponds. From a mere 25,500 mt valued at P33.1 million in 1950, aquaculture production has increased to 38.2 million mt valued at P35.4 billion in 2002, and employs some 258,500 persons. Aquaculture contribution to total fisheries’ production in the 1950-2002 period has similarly increased from 11.6 % to 38.2 % by volume, and from 15.4 % to 31.3 % by value. Next to yields of 894,858 mt of seaweeds and bivalves from mariculture, Philippine aquaculture was dominated in 2002 by brackish-water pond production of 246,937 mt, followed by 94,697 mt from marine and freshwater pens/cages and 70,425 mt from freshwater ponds. Notwithstanding its major contribution to the Philippine economy, aquaculture development has come with many environmental and social costs. Foremost among these is mangrove conversion to culture ponds, mainly for milkfish — around half of the 279,000 ha of mangroves lost from 1951 to 1988 were developed into culture ponds. Ninety-five percent of Philippine brackish-water ponds in 1952-1987 were derived from mangroves. Mangroves have contributed significantly to the well-being of coastal communities for centuries through products used for fuel, construction, fishing, agriculture, forage, and food items mainly fish, crustaceans and mollusks. Mangroves also provide a variety of ecosystem services such as coastal protection provided by a buffer zone during typhoons and storm surges, reduction of shoreline and riverbank erosion, stabilizing sediments, control of flooding and recycling of nutrients. Other environmental impacts are pollution of lake and coastal waters from intensive pond, pen and cage culture; dependence on fish meal and fish oil for feeds; use of chemicals and antibiotics; spread of parasites and diseases; excessive harvesting of wild seed and adults and loss of bycatch. Socioeconomic consequences have the greatest effect on rural communities — loss of mangrove goods and services, blocked access to coastal resources, navigational hazards, privatization of lands and waterways, fishery decline, food insecurity, rural unemployment and urban migration, social disruption and conflicts. The future sustainability of Philippine aquaculture depends not only on farm level practices but also on the integrated management of the coastal zone and government action to prevent or redress environmental and socioeconomic damage. Pond, pen and cage systems for growout need to reduce and mitigate negative impacts and become more environmentally responsible through the development and/or wider dissemination of available onfarm technologies. These cover water management (closed/semiclosed cycles with low to zero water exchange, reservoir/treatment-settling ponds, greenwater techniques), feed management (reduced fishmeal/fish oil levels, lower N, P in effluents), effluent management (biofilters using seaweed, oysters and external filters such as mangroves, sludge processing and disposal, fallowing), and reduced use of antibiotics and chemicals. Aquaculture needs greater integration, e.g. the polyculture of more than one species in the same pond, or aquasilviculture where fish/shrimp/crab culture is integrated with mangroves. Only one among the many uses of the coastal zone, aquaculture should develop within the framework of Integrated Coastal Zone Management (ICZM). For example, siting of aquaculture farms should be based on the ecological footprint of the farming technology, and farm density should not exceed environmental capacity of a given area. ICZM features coastal zonation based on carrying or assimilative capacity of the environment; valuation of alternative resource uses; buffer zones between aquafarms and villages, rice paddies, rehabilitation of mangroves and other degraded habitats; participation of various stakeholders, e.g. fishers, aquafarmers; protection of communal resources, rights and access of marginalized groups; and mechanisms for conflict resolution. The government should enforce existing laws; institute a clear national aquaculture policy with corresponding institutional arrangements such as resource use fees for land, groundwater use, and penalties to fund environmental rehabilitation and compensate socioeconomic damage and become mangrovefriendly by adopting silvofisheries (or aquasilviculture where crabs/fish/shrimp are reared at low density in mangrove ponds and pens) or integrating mangroves filter adjacent to intensive fish/shrimp ponds. All these require a paradigm shift from the short-sighted common exploitation of water, mangroves and other resources to the ecological footprint approach incorporating not only inputs such as feed and seed, but also outputs, e.g. effluent treatment facilities.

An ACIAR-funded project was conducted in the Rinconada Lakes area of the Bicol Region in the Philippines to improve fish cage management by fish farmers not only to improve economic returns but also to reduce the negative impact of aquaculture on the lakes’ environment The area is prone to devastating typhoons and other catastrophic events which have adversely affected the livelihood of the communities. The study consisted of stocking density and feeding trials with the cooperation of local fish farmers with the aim of shortening the culture period from the traditional 8-12 months as commonly practiced by fish farmers to enable multiple crops annually. This would enable them to harvest their stocks safely in at least one cropping prior to the advent of adverse climatic conditions. Training of the fish farmers and subsequent verification trials were also conducted as part of the study.