After reaching a production of 90,426 mt in 1994, production of black tiger shrimp (Penaeus monodon) in the Philippines has slowly declined and has dropped to only 35,493 mt, the lowest since 1987. Amidst the production failures besetting most of the farms in the country, a few farms man- aged to turn around once again and operate profitably with some even expanding their operations and are the subject of this study covering 40 farms. The common characteristics of the successful farms were found to be as follows: (a) easy access to clean seawater due to relatively deep nature of the shoreline, availability of saltwater from well, or adequate reservoir area to treat new water; (b) clean and compact pond bottom either because these are located above the tidal level or have been backfilled heavily with crushed limestone; (c) use of healthy fry by ascertaining fry condition through proper diagnostics; (d) adequate aeration; (e) good feed management; (f) use of bioreme- diators such as microbial inoculants (often referred to as probiotics), fish or both; (g) long dry-out period or alternating shrimp with tilapia or milkfish effectively limiting shrimp production to only one crop per year; and (h) adequate production-based incentives to technicians and workers. When standardized into 5 ha farms under three stocking density conditions, the economic performances are as follows at density levels of 5/m², 15/m², and 40/m², respectively. The returns on investment (ROI) are 106.7%, 66.0%, and 78.5%; the internal rates of return (IRR) 250%, 111%, and 142%; and finally a return on equity (at a loan/equity of 70:30) 355.8%, 220.1%, and 261.8%.

The Philippines remains one of the top eucheumatoid seaweed producers worldwide. However, the reported seaweed health problems affecting farms have been one of the reasons for the decline in seaweed production in the country. Outbreaks of “ice-ice” disease (IID), epiphytic pests, and grazing problems have significantly reduced biomass yields and compromised carrageenan quality, directly affecting the livelihood of tens of thousands of families dependent on seaweed farming. In this chapter, we listed seaweed health problems based on type-association with the host seaweed plant and highlighted factors contributing to farm problems. Additionally, recommendations are presented that are relevant to the protection of the long-term sustainability of the eucheumatoid seaweed farming industry in the Philippines.

Production by fishcage culture using marine/brackish water has increased drastically since the mid-1980s, when the technology for developing sea bass hatchery fry was established. In the 1990s, it grew further, due to the start of production of grouper and snapper hatchery fry. We conducted a comparative analysis of production by fishcage culture and patterns of fishcage culture in the Philippines, Thailand, and Malaysia, all of which are major producer of fish by fishcage culture using marine/brackish water in the Southeast Asian countries. We compared of fishcage culture management between the reference and current year and analyzes the average of the reference year (the year when fishcage culture started; the same hereinafter) and current year (2004). In terms of production of cultured fish by kind, sea bass showed a more than 50% decrease - from 67% to 32%, whereas grouper saw a nearly doubled ratio from 20% to 39%. Snapper remained almost the same, at 29% to 28%. Other fish (mainly rabbitfish, threadfin bream and grunter) saw an increased ratio from 5% to 16%. We compared the management of fishcage culture between the reference year and 2004. We looked into the ratio of production by type of fish and found that sea bass showed a decreased ratio to less than half from 67% to 32%; while grouper showed a near doubling of its ratio from 20% to 39%. Snapper remained almost unchanged, at 28% to 29%; and other kinds of fish increased their ratios from 5% to 16%. In terms of operating cost per kilogram for farming groupers, fishcage culture costs more than fishpond culture. Fishcage culture, however, is more convenient and productive than fishpond culture, and requires lower initial cost than fishpond culture, since the former does not require an initial outlay for constructing a pond or management of water quality. Accordingly, fishcage culture shows overwhelmingly higher production than fishpond culture.

Rotifers (Brachionus sp.) were cultured with various combinations of baker’s yeast, Nannochloropsis sp., Culture selco, and DHAPS with or without supplementation of arachidonic acid (triacylglycerol form). Rotifers were able to be enriched with emulsified- arachidonic acid supplemented to culture media. Considered the reciprocal ratios of arachidonic acid, EPA and DHA in rotifers, rotifers pre-cultured in Culture selco and then cultured in DHAPS had the best balance of essential fatty acids, and the optimum level of arachidonic acid supplementation to DHAPS appeared between 0% and 5%. A feeding test was conducted to investigate the effects of arachidonic acid on the broodstock performance of rabbitfish (Siganus guttatus), one of the commercially valuable species in mangrove areas. A diet with 1.5% of arachidonic acid supplementation appeared to affect negatively the reproductive performance of S. guttatus broodstock, perhaps due to the excessive supplementation. Considered together with results of mangrove red snapper in 2003, the optimum supplementation of arachidonic acid in broodstock diets might be around 0.5%.

This study is an investigation of the aquaculture methods used in brackish water fishpond culture mainly producing shrimp in the Philippines, Thailand and Malaysia. Extensive methods are practiced in the Philippines and Thailand (2 tons/ha and below for annual production of shrimp with no or few feeding method), while the intensive method is used in all the 3 countries (2 tons/ha and over for the annual production of shrimp with more feeding method). Most of the production of cultured shrimp relies on the intensive method. The yield of shrimp using the extensive method is relatively high in the Philippines, but small in Thailand due to declining water quality. With regard to the intensive method, the Philippines has a low death rate for monodon (Penaeus monodon) because it has adopted the Green water system as a measure against bacterial disease (luminous bacteria). On the other hand, Thailand and Malaysia have low survival rates owing to the lack of effective measures to prevent virus disease (White spot). For this reason, an increasing number of farms have changed their main cultured species from monodon to vanamei (P. vanamei) in Thailand and Malaysia. Consequently, the price of monodon has been falling as a result of high production of vanamei at lower prices, and the profits of monodon farms continue to decrease. If the cultivation of vanamei, which is a species introduced from South America, continues to increase, it is expected to have a negative effect on monodon farming. In order to protect monodon, a native species, it is necessary to focus on cultivating this species in Southeast Asia. In Thailand, there is a need to ensure the supply of good quality seedlings, since the quality of monodon seedlings has been deteriorating. In Malaysia, it is necessary to equalize the level of aquacultural techniques within the country because there is a disparity in techniques among fish farms. In the Philippines, both extensive and intensive methods are conducted in a sustainable manner.

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.

Edwardsiellosis is an acute to chronic systemic disease in fish characterized by exophthalmia, ascites, hernia, and severe lesions of the internal organs. It is caused by Edwardsiella tarda, a Gram-negative intracellular pathogen implicated in enormous economic losses of cultured seawater and freshwater fish species. E. tarda has a broad host range and geographic distribution, and possesses important virulence factors that enhance its survival and pathogenesis in hosts. This chapter discusses some of the recent research on edwardsiellosis in fish including the etiologic agent's identification, pathology, diagnosis, and virulence factors, and as well as novel strategies aimed at preventing and controlling the disease.

This project established a sustainable aquaculture industry for giant grouper in Vietnam and the Philippines through the development of captive breeding and larval-rearing techniques. Captive breeding innovations and larval-rearing techniques, developed through a collaborative Fisheries project, are sustaining the aquaculture industry for giant grouper in Vietnam and the Philippines. Groupers are vital to the live reef food-fish trade in South-East Asia, and the giant grouper is a high-value, fast-growing species with significant aquaculture potential. Establishing a sustainable giant grouper aquaculture industry is a high priority for the region, but research is hampered by the high level of investment required to hold and maintain giant grouper broodstock. Lack of commercial production is also due to limited knowledge about the giant grouper’s maturation and spawning behaviour, and low larval survival.