http://hdl.handle.net/10862/1783 Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia Thu, 09 Apr 2026 11:27:05 GMT 2026-04-09T11:27:05Z http://hdl.handle.net/10862/475 Mangrove-friendly aquaculture studies at the SEAFDEC Aquaculture Department Triño, Avelino T.; Primavera, Jurgenne Garcia, Luis Maria B. The SEAFDEC Aquaculture Department studies on mangrove-friendly aquaculture (MFA) can be categorized under two models: a) mangrove filters where mangrove forests are used to absorb effluents from high-density culture ponds, and b) aquasilviculture or the low-density culture of crabs, shrimp and fish integrated with mangroves. In a study using the first model, shrimp pond effluents were retained in an enclosed mangrove area prior to release to receiving waters. Nutrients and other water quality parameters, and bacterial levels were monitored in the untreated effluents and post-mangrove water. In the second MFA model, mangrove pens and ponds installed in old growth and newly regenerating mangrove sites in Aklan, central Philippines were stocked with mud crab Scylla olivacea/S. tranquebarica and shrimp Penaeus monodon. Investment costs, survival and production, and cost-return analysis for the pens and ponds are reported in the paper. Aside from the aquasilviculture trials in collaboration with local government units, other activities in the Aklan mangrove sites are the survey and mapping of the 75-ha area in Ibajay, construction of a treehouse, and the educational use as field site by Coastal Resource Management trainees of SEAFDEC Aquaculture Department and field biology students of the University of the Philippines in the Visayas. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/10862/475 2001-01-01T00:00:00Z http://hdl.handle.net/10862/470 Research on marine fishes Toledo, Joebert D. Garcia, Luis Maria B. Research on marine fishes at SEAFDEC/AQD from 1995 to date was mostly on milkfish Chanos chanos. Studies focused on the refinement of broodstock and seed production techniques to improve egg and larval production as well as to eliminate morphological deformities in hatchery-bred fry. A verification study with former shrimp hatchery operators demonstrated the technical and economic viability of the AQD-generated milkfish hatchery technology. Production and efficiency of semi-intensive grow-out in ponds were enhanced by the use of formulated feeds and appropriate feeding scheme. Milkfish farming in the Philippines was critically reviewed and recommendations to sustain milkfish culture production were made. Tobacco dust and metaldehyde formulation were proposed as alternatives to organotin-based pesticides in controlling the population of pond snail. The growth hormone of milkfish has been isolated and purified. Addition of highly unsaturated fatty acid (HUFA)-rich oils in the diet did not improve the quality of spawned eggs of grouper Epinephelus coioides. A protocol for the intensive larval rearing of grouper was developed based on the results of several studies. A semi-intensive seed production method using copepod nauplii during the early feeding stages was also developed as an alternative to intensive method. Metamorphosis of larvae was significantly accelerated by exogenous thyroid hormones. Nutritional studies to reduce the amount of fish meal in grouper diets are in progress. Groupers grown in ponds or cages harbor a variety of parasites. Biochemical criteria to assess the quality of spawned Asian sea bass Lates calcarifer eggs was characterized. Diaphanosoma or other copepods may be an alternative or supplemental live prey to Artemia during sea bass larviculture. A practical diet for sea bass culture was developed. Studies to determine the essential amino acid requirements of sea bass are about to be completed. The effects of immuno-stimulants in sea bass are presented. Induced and natural spawning of mangrove red snapper Lutjanus argentimaculatus in concrete tanks or floating net cages has been documented. An improved larval rearing method has been developed using screened rotifers during the early feeding stage of the larvae. Exogenous thyroid hormones have advanced metamorphosis of larvae. A practical diet for snapper is under development. Research on rabbitfish Siganus guttatus were geared to developing tools for growth enhancement. Pituitary growth hormone (GH) has been cloned, allowing the production of recombinant rabbitfish GH. Rabbitfish prolactin, somatolactin have also been purified. Studies on marine ornamental fish focused on two species of seahorses, Hippocampus kuda and H. barbouri, and on blue tang Paracanthurus hepatus. Progress on the biology, breeding, and seed production of seahorses are presented. Successive natural spawnings of blue tang in concrete circular tank have been recorded. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/10862/470 2001-01-01T00:00:00Z http://hdl.handle.net/10862/1807 Developments in seaweed farming in Southeast Asia Simbajon, Ronald S.; Ricohermoso, Maximo A. Garcia, Luis Maria B. During the last thirty years, seaweed farming has progressed in the region comprising the Association of Southeast Asian Nations (ASEAN). Farm production reached a high of 146,500 mt of dried seaweeds in 1997 from an initial harvest of 500 mt in 1973. In 1997, the ASEAN region produced about 90% of the world s production of carrageenophyte seaweed, providing raw materials for the US$35O million world carrageenan market. Two species of carrageenophytes, Kappaphycus alvarezii (=Eucheuma cottonii) and Eucheuma denticulatum (=Eucheuma spinosum), constitute the base of the seaweed industry in the region. K. alvarezii is predominantly farmed in the Philippines and Malaysia while E. denticulatum is dominant in Indonesia. Vegetative propagation is still applied in all farmed species of carrageenophytes, while the monoline method remains the most popular method of farming. Non-traditional farming areas have been established in central and northern Philippines and in Sabah, Malaysia. The culture technology has been developed for Gracilaria sp.; however, no up-to-date reports on production are available. Seaweed farming has become one of the most important sources of livelihood for at least 100,000 coastal families in Southeast Asia, contributing apparently to the reduction of blast and cyanide fishing and to the relative improvement of peace and order in seaweed farming areas. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/10862/1807 2001-01-01T00:00:00Z http://hdl.handle.net/10862/472 Research on crustaceans Millamena, Oseni M. Garcia, Luis Maria B. Crustacean research at the SEAFDEC Aquaculture Department in 1994-1999 focused on two commercially important species: the tiger shrimp Penaeus monodon, and the mud crab Scylla serrata. Research on tiger shrimp dealt with broodstock development, refinement of shrimp culture systems, and health management. Broodstock development aimed to develop a technology for a sustainable supply of good quality captive broodstock through selective breeding. Initial efforts identified polymorphic stocks with low disease prevalence as base population and development of screening protocol to assess their health status using non-lethal procedures. Improvement of reproductive performance through studies on nutritional requirements and sperm quality was also conducted. To refine shrimp culture systems, emphasis was placed on the physiological requirements of tiger shrimp, including salinity adaptation and osmoregulatory capabilities, improvement of formulated diets, and development of culture systems that are compatible with the environment. In shrimp health management, disease problems in various culture systems with emphasis on luminescent vibriosis and some viruses were defined. The quality of hatchery-reared post-larvae compared with those caught in the wild was assessed. Research on the mud crab Scylla serrata started late in 1996. Studies were conducted on all culture phases: broodstock, hatchery, nursery, and grow-out. Broodstock development emphasized the development of an appropriate maturation system and a suitable maturation diet. The influence of eyestalk ablation and dietary history on reproductive performance was assessed. The completion of the mud crab life cycle in captivity was attained in 1997 when spawns from pond-reared females were further reared to produce second-generation broodstock. In the hatchery, larval rearing based on previous trials on feeding schemes, salinity tolerance, and water conditioning hastened progress in larviculture and formed the basis for large-scale production of mud crab juveniles. Research has shown the feasibility of direct stocking of crab megalopae in hapa nets in nursery ponds. In grow-out culture, studies have been done on the effects of stocking density, monosex culture, and practical diet development for the mud crab. Practical diets, formulated using local materials as ingredients, with or without vitamin and mineral supplementation, were found to be economically feasible for mud crab culture in ponds. Grow-out culture in mangrove pens appears to be an environment-friendly alternative to the usual open pond culture system. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/10862/472 2001-01-01T00:00:00Z