http://hdl.handle.net/20.500.12066/4958 Mon, 25 May 2026 13:29:08 GMT 2026-05-25T13:29:08Z http://hdl.handle.net/20.500.12066/5041 Responsible aquaculture development in Southeast Asia: Proceedings of the seminar-workshop on aquaculture development in Southeast Asia Garcia, Luis Maria B. This publication documents the proceedings and outputs of the tri-annual seminar-workshop on Aquaculture Development in Southeast Asia (ADSEA). This seminar, ADSEA 99, reviewed the recent developments in aquaculture and provided a forum to discuss strategies to ensure further development of responsible aquaculture in the region. It specifically covered the following: 1) assessment of the progress and development of aquaculture technologies in the region, and research and development in the Department since 1995; 2) review of recent advances in sustainable and responsible aquaculture elsewhere in the world; and, 3) identification of strategies for sustainable and responsible aquaculture in the region. The contributions of selected participants during ADSEA '99 appear in this present volume. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/20.500.12066/5041 2001-01-01T00:00:00Z http://hdl.handle.net/20.500.12066/5040 Environmental impacts of marine fish farming and their mitigation Wu, R. S. S. Garcia, Luis Maria B. The environmental impact of marine fish farming depends on species cultured, culture method, stocking density, feed type, hydrography of the site, and husbandry practices. In all cultured systems, however, a very large percentage of organic carbon and nutrient input into a marine fish culture system as feed may be lost into the environment through feed wastage, fish excretion, faeces production, and respiration. The high pollution loading have caused considerable environmental concern in many countries, especially in water with limited carrying capacity. Furthermore, the use of chemicals (therapeutants, vitamins, pigments, and antifoulants) and the introduction of pathogens and new genetic strains have also raised environmental concerns. Despite the high pollution loadings, results from various studies show that some 23% of C, 21% of N and 53% of P of feed input into the culture system is being accumulated in the bottom sediments and the significant impact is normally confined to within 1 to 1.5 km of the farm. The major impact is on the sea bottom, where high sediment oxygen demand, anoxic sediments, production of toxic gases, and a decrease in benthic diversity may result. Decreases in dissolved oxygen and increases in nutrient levels in the water are normally confined to localized areas, and it is unlikely that fish farming activities will cause eutrophication over large areas. There is also no good evidence to support the suggestion that fish farming would increase the incidences of harmful algal blooms, nor that the present use of therapeutants, vitamins and antibiotics, and the introduction of pathogens and new genetics strains would pose a significant threat to the environment. Practical ways to mitigate environmental impact of fish farming include keeping stocking density (and hence, pollution loadings) well below the carrying capacity of the water body. Computer simulation and hydraulic models have been applied to estimate maximum stocking density in which water quality could be maintained in a sustainable manner. Pollution loading and environmental effects can also be significantly reduced by improved feed formulation and integrated culture (using macroalgae, filter-feeders and deposit-feeders). Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/20.500.12066/5040 2001-01-01T00:00:00Z http://hdl.handle.net/20.500.12066/5039 Biological hazard possibly produced by aquaculture and its control Inui, Yasuo Garcia, Luis Maria B. Blooms of Neterocapsa circularisquama, a novel dinoflagellate, have been causing mass mortality of both wild and cultured shellfish in embayments at the western part of Japan since 1988. Physiological and epidemiological studies suggest that the alga has been partly dispersed with the movement of shellfish in aquaculture activities. A recent outbreak of an epizootic iridovirus in red sea bream (Pagrus major) has caused extensive damage to marine fish culture in Japan. A research group at the National Research Institute of Aquaculture (NRIA), collaborating with prefectural fisheries research laboratories and an R&D company, clarified the etiology and developed a diagnostic method and a commercial vaccine. Penaeid acute viremia (PAV), a synonym of white spot syndrome, caused catastrophic loses in kuruma shrimp (Penaeus japonicus) culture in Japan. An epidemiological study of the research group at NRIA and the prefectural fisheries research laboratories strongly suggests that the causative virus was newly introduced to Japan from imported shrimp seeds for aquaculture. The group clarified the etiology and established diagnostic methods. Based on their studies, NRIA proposed a protocol to check the virus during larval culture and before seedlings are shipped. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/20.500.12066/5039 2001-01-01T00:00:00Z http://hdl.handle.net/20.500.12066/5038 Community-based coral farming for reef rehabilitation, biodiversity conservation and as a livelihood option for fisherfolk Heeger, Thomas; Sotto, Filipina B.; Gatus, Joey Ll.; Laron, Criteta Garcia, Luis Maria B. The present condition of marine resources in the Philippines is critical and a majority of coastal communities live below the poverty line. If it continues, the progressive degradation of coral reefs and overexploitation poses a dangerous trend. Coastal resource management strategies are facing a new challenge: the integration of social, economic and natural sciences in future concepts to reverse the current status of ecosystem destruction and improvement of the people s living conditions. Hence, the primary objective of the coral farm is to provide alternative livelihood to fisher families from their resources on a sustained basis. The second objective is the rehabilitation of degraded reefs. Currently coral colonies of 64 species are taken through fragmentation from the wild. After 6-12 weeks (depending on the species) of grow-out in the farm, the fragments were deployed at the rehabilitation site at an average of 2 fragments per square meter (=12.5% cover). The survival of fragments is high at 84%, despite the fact that some coral colonies were placed in unsuitable substrates by the fisherfolk. More trainings have to be conducted improve their knowledge of coral biology and community structure. The net cost of rehabilitating a one-hectare reef is U$2,100 for 12.5% cover. Additional profit from coral marketing is used for community projects identified by the folk. In this case, coral farming may be an option for livelihood and a cost-effective tool for reef rehabilitation. Mon, 01 Jan 2001 00:00:00 GMT http://hdl.handle.net/20.500.12066/5038 2001-01-01T00:00:00Z