This report is part of a national overview of agricultural pollution in the Philippines, commissioned by the World Bank. The overview consists of three ‘chapters’ on the crops, livestock, and fisheries sub-sectors, and a summary report. This ‘chapter’ provides a broad national overview of: (a) the magnitude, impacts, and drivers of pollution related to the fisheries sector’s development with a focus on aquaculture; (b) measures that have been taken by the public sector to manage or mitigate this pollution; and (c) existing knowledge gaps and directions for future research. This report was prepared on the basis of existing literature, recent analyses, and national and international statistics, as well as extensive interviews. It did not involve new primary research and did not attempt to cover pollution issues that arise in the broader aquaculture value chain, relating for instance to processing, packaging and transportation, feed processing, or veterinary drug factories.

In 1977, scientists at the Southeast Asian Fisheries Development Centre (SEAFDEC) in the Philippines became the first anywhere to succeed in breeding milkfish (Chanos chanos) in captivity. The advance was made possible by an IDRC grant, approved in 1974, for a three-year project of research in the breeding and rearing of this important source of protein. The initial grant, for $826,000, was renewed for another three years in December 1978 in the amount of $421,100.

Previous studies by the authors have shown the feasibility of using copepods in the semi-intensive seed production of grouper Epinephelus coioides. Early-stage E. coioides larvae preferred to ingest copepod nauplii over rotifers, although their abundance is relatively low. Higher growth and survival were obtained in larvae provided with copepods than larvae fed with rotifers alone. In this study, the authors tested various fertilization techniques for the mass production of zooplankton in ponds. The zooplankton population increased from an initial density of 86–148 ind/L to 1,524–3,186 ind/L 9–12 days after flooding. Major zooplankton were identified as rotifers, copepods, including cyclopoid and harpacticoid spp., and cladocerans. The calanoid copepod Acartia tsuensis can be propagated in 1-ton tanks in mixed species of microalgae alone or in combination with baker’s yeast. Density of A. tsuensis increased from 60 ind/L at stocking to about 900 ind/L 3–5 days thereafter. A prototype collector for copepod eggs and nauplii was tested. The average daily numbers of eggs and nauplii collected varied (2,300–117,600), depending on the density of copepodids and adults in the holding container (1,000–8,000 ind/10-L container). Hatching rates of collected eggs ranged from 34 to 89%. Collected eggs may be stored at low temperature (4–10°C) for up to 7 days. Duration and viability of eggs stored at low temperature were highly affected by the presence of protozoans. A. tsuensis eggs survived freezing to –20°C (0.3–1.7%) only at the cleavage stage, suggesting the feasibility of cryopreservation. Use of pond grown zooplankton, particularly the calanoid copepods, for the seed production of grouper is discussed.

Luminous vibriosis is a devastating infection of penaeid shrimp larvae and juveniles causing heavy mortalities. To counter the bacterial pathogen, Vibrio harveyi, shrimp farmers in the Philippines modified their growout culture method of the black tiger shrimp, Penaeus monodon, juveniles and developed the greenwater culture technique. This culture method involves the use of pond water of all-male, saline-tolerant Oreochromis hornorum as rearing water for the culture of shrimp juveniles in ponds. Such a modified culture of P. monodon juveniles was found effective in preventing the onset of luminous vibriosis. Basic studies revealed that antiluminous Vibrio factors are inherent in the bacterial, fungal, and microalgal flora of the tilapia water, dermal mucus, and gut that singly or collectively inhibit the growth of V. harveyi, in vitro. The skin mucus studies of other brackishwater fish species showed that the siganids, Siganus guttatus, and red hybrid tilapia (Oreochromis niloticus × Oreochromis mossambicus), as well as sea bass, Lates calcarifer, are promising alternative fish species for this novel shrimp culture method. A review of pond-simulated studies in tanks and ponds, similarly, confirmed these findings and the impact of the greenwater culture technique on water quality, including its economic benefits to the farmer. The greenwater culture of shrimp can sustain the successful production of shrimp juveniles by inhibition of the luminous Vibrio. This culture method is also currently used in the growout culture of the white shrimp, Litopenaeus vannamei.

In tropical Asia, the two main species of penaeid shrimps that are widely cultured are the black tiger shrimp (Penaeus monodon) and the Pacific white shrimp (Penaeus (Litopenaeus) vannamei). The former species is indigenous in most Asian countries while the latter is indigenous in the Americas and was introduced to Asian countries in the late 1990s. In this chapter, only details of the economically-important microbial infections in Asia in these two penaeid shrimps are presented and arbitrarily grouped as viral, bacterial, fungal and parasitic diseases. Viral infections are divided further into two groups: DNA viruses; and, RNA viruses. The infections attributed to DNA viruses are: White Spot Disease (WSD) Disease, Penaeus stylirostris densovirus (PstDNV) previously known as Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) Disease, Penaeus monodon densovirus (PmDNV) formerly known as Hepatopancreatic Parvo-like Virus (HPV) Disease and Penaeus monodon nucleopoly-hedrovirus (PemoNPV) previously known as Monodon Baculovirus (MBV) Disease. The shrimp infections caused by RNA viruses are: Yellow Head Virus (YHV) Disease, Taura Syndrome Virus (TSV) Disease, and Infectious Myonecrosis Virus (IMNV) Disease. For bacterial diseases, the list includes Luminous Bacterial Disease, Non-luminous Vibrio Infections, and Acute Hepatopancreatic Necrosis Disease (AHPND). Fungal disease includes Larval mycosis, while parasitic disease includes the current emerging threat to the shrimp industry, the Hepatopancreatic Microsporidiosis caused by Enterocytozoon hepatopenaei (EHP).

This case study presents the successful practice of sustainable intensification of milkfish aquaculture in marine fish cages under semi-intensive grow-out conditions in the Panabo City Mariculture Park (PCMP) in Davao del Norte, Philippines. Established in 2006, PCMP became operational through the promulgation of a City Ordinance declaring 1 075 hectares of municipal waters in Panabo City as a Mariculture Development Zone/Park. The operations of PCMP were so successful that in just five years it became the third largest among the 63 operational MPs in the Philippines during 2011, with 86 private investors-locators operating a total of 322 units of cages. At present, a total of 372 units of fish cages are operating in the mariculture park (MP). A combination of factors contributed to the successful operation of PCMP, but the success is usually attributed to the effective partnership between the government (both local and national) and the private sector. The Comprehensive MP City Ordinance that governs the PCMP is strictly implemented and includes, among others, the tenurial rights and access to locators. Regulations on distances between cages are strictly enforced and security measures in the total area are jointly undertaken by the government and the locators. The national government, through the Bureau of Fisheries and Aquatic Resources-National Mariculture Center (BFAR-NMC), provides technical support in all aspects from stocking to harvest during the production cycle. BFAR-NMC staff conduct regular periodic sampling of the stocks and compute feeding rates for the stocks which are implemented by the technicians/caretakers. Likewise, BFAR-NMC staff regularly monitor the water quality of the MP and the health status of the stocks. Since it became operational in 2006, the PCMP did not report a single incident of mass fish kill, which indicates that the technical guidelines of MP operations are strictly followed. Workers are trained and organized into groups by BFAR-NMC such as caretakers, cage framers, netters, harvesters, fish processors, and others, and actively participate in discussions related to MP operations to ensure protocols are properly followed. Harvests of stocks are done by skilled workers trained by BFAR-NMC, all done in the “Bagsakan Center” or fish landing area and are well-coordinated. The support facilities in the fish landing area are provided by both the local and national government and the PCMP Producers Association. The operators provide complete data for their operations to BFAR-NMC for record keeping. The strong partnership between the national government through BFAR-NMC, the local government unit, the investors, as well as the acceptance and support from the community for the PCMP is the hallmark of its success.

The objectives of this study were to compare the performance of a Southeast Asian Fisheries Development Centre (SEAFDEC) formulated diet with a commercial feed for growout culture of grouper and to transfer technology on grouper diet developed at SEAFDEC to the industry. In the tank study, Epinephelus coioides juveniles were reared in 12 units of 150-litre tanks at 15 fish/tank with 4 replicates per treatment. Fish were fed the diets at a feeding rate of 5-6% of body weight (BW) and trash fish at 10-12% BW per day for 60 days. In the feeding trial, treatments were arranged in a randomized complete block design with size groups as block. 36 fish were stocked per size group. Formulated feeds were given twice a day for 120 days. In the tank study, the commercial feed resulted to significantly lower growth, survival and food conversion ratio (FCR) compared with the SEAFDEC diet and trash fish control. Results of the field trials at growout ponds did not show significant differences in growth performance, survival and FCR of grouper juveniles fed with the diets. Both the SEAFDEC diet and commercial feed conformed to the established protein requirement of juvenile grouper. In tank trials, the poor performance of commercial feed was attributed to the low protein content and deficiencies in essential amino acids as confirmed by analysis of the amino acid composition. Improvement in growth performance of fish given the commercial feed was achieved in field trials by increasing the dietary protein level and improving the amino acid composition to match that of the grouper juveniles.

This study was undertaken to determine the nutritive value of some of the more widely available protein sources in the diets for grouper juveniles, based on apparent digestibility coefficients for dry matter (ADMD) and crude protein (APD), feed conversion ratio (FCR), specific growth rate (SGR) and survival. A series of feeding experiments were conducted to determine the growth performance of grouper juveniles. Test diets were formulated for growth (4 replications/treatment) and digestibility experiments (3 replications/treatment). Each diet contained a test ingredient: white fish meal, white cowpea meal and ipil-ipil leaf meal (experiment 1); local meat and bone meal, soya protein concentrates and meat solubles (experiment 2); and imported meal and bone meal, blood meal and maize gluten meal (experiment 3). A feeding trial for each experiment was conducted for 85 days in a flow-through system with filtered and aerated seawater. 10 and 20 juveniles were stocked in each of 60- and 250-litre fibreglass tanks, respectively. White cowpea meal (20.5% incorporation), local (16% incorporation) and imported (19% incorporation) meat and bone meals could partially replace fish meal in the diets for grouper juveniles without affecting their growth. Low ADMD and APD values for the processed feed ingredients (meat and bone meal, soya protein concentrates and blood meal-based diets) could be associated with the processing methods used in its preparation, which could damage the amino acids and contribute to low nitrogen digestibility. Apparent digestibility coefficients and growth could be used as indicators of the nutritional value of the feed ingredients. However, the availability and optimal balance of amino acids must also be considered.

This study was conducted to improve the hatchery survival of Epinephelus coioides by verifying and incorporating laboratory-scale experimental results to a hatchery-scale operation. Nine units of 200 m² ponds were used to verify mass culture techniques for zooplankton. Three fertilization schemes were tested with 3 replicate ponds per fertilization treatment. To test copepod production in tanks, adults and copepodids were transferred into 6 production tanks at a density of 60 individuals/litre. Zooplankton in 3 of the tanks were fed daily with Nannochloropsis sp., Tetraselmis sp. and Chaetoceros sp., whereas zooplankton in the remaining 3 tanks were fed daily with half the amount of the mixture of algae and bread yeast. Larval rearing runs were performed from 2000-2002 to verify earlier experimental results. To propagate copepod nauplii in larval tanks, Acartia were inoculated in 4 larval rearing tanks, 2-3 days before stocking of grouper eggs or newly hatched larvae. Brachionus were added daily from day 2 to 18 at increasing densities. Artemia nauplii and metanauplii were fed to satiation from day 15 until metamorphosis. Pond-grown zooplankton was added in separate tanks from day 15 onwards as a supplement to Artemia. The population of copepods in ponds fertilized with various combinations of organic and inorganic fertilizers increased a week after flooding of ponds and fertilization. Zooplankton compositions in the treatments were Apocyclops, Oithona sp., Brachionus rotundiformis, Penilia and Pseudodiaptomus sp. Copepodids and adults of Acartia tsuensis fed a mixture of algae alone or in combination with bread yeast seemed to propagate well in tank conditions. Results suggested that bread yeast could be used in combination with algae for nauplii production of Acartia in tanks. Verification runs indicated that pond-grown copepods could be used as a supplement to Artemia. Larvae fed copepods and Artemia showed similar survival rates to those fed only with Artemia. Larval survival from days 5-15 was higher in larvae reared in 20-25 ppt compared to those reared in normal seawater. 39 out of 71 tanks were discarded in 2000, whereas 3 out of 12 and 8 out of 26 production runs were aborted in 2001 and 2002, respectively. Mean survival at harvest increased from 3.06% in 2000 to 5.33 and 10.39% in 2001 and 2002, respectively. Larvae in discarded or aborted tanks were positive for viral nervous necrosis (VNN).

The main objectives of this project were to study the lipid chain transfer from the egg stage through hatching and the patterns of lipid conservation or loss during starvation and feeding of larvae in order to elucidate the lipid metabolism of grouper (Phase 1); to determine the fatty acid composition of highly unsaturated fatty acid (HUFA) boosters and enriched live food organisms to enable the possibility of choosing food organisms that provide various dietary levels and ratios of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA) and arachidonic acid (ARA, Phase 2); and to determine the effect of Brachionus and Artemia, containing different levels and ratios of DHA:EPA:ARA, on the growth and survival of grouper larvae (Phase 3). Total lipids (TL) of samples were extracted and separated into neutral (NL) and polar lipids (PL). The samples collected in Phase 1 were floating neurula eggs, newly hatched (NHL) and unfed 4-day larvae; larvae fed with live food organisms for 25 and 35 days or starved for 3 days; and wild-sourced larvae starved for a week. In Phase 2, the samples collected were phytoplanktons, Brachionus cultured in phytoplankton for 4 days, Diaphanosoma celebensis and Pseudodiaptomus annandalei. In phase 3, larvae were fed Brachionus until day 14 and at day 25 with Artemia. E. coioides eggs contained high DHA, EPA and ARA, demonstrating their importance in larval development. Larvae primarily spent NL as energy, whereas PL was generally conserved. Wild grouper larvae had higher levels of PL than NL, whereas hatchery-sourced eggs and larvae contained higher levels of NL than PL. Based on the lipid content of wild larvae, high phospholipid diets were essential for larvae survival and normal development. A variety of products were effective in enriching the HUFA content (particularly ratios of DHA, EPA and ARA) of live food organisms. HUFA-enriched live food organisms enhanced the growth, survival and pigmentation in grouper larvae.