http://hdl.handle.net/10862/95 Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia and Prospects for Seafarming and Searanching, 19-23 August 1991, Iloilo City, Philippines Thu, 14 May 2026 09:42:07 GMT 2026-05-14T09:42:07Z https://repository.seafdec.org.ph:443/bitstream/id/817bb0a4-b733-4bd7-b8b0-44d4d6cbef7c/ http://hdl.handle.net/10862/95 http://hdl.handle.net/10862/100 Ecological impacts of seafarming and searanching Munro, John L. Lacanilao, F.; Coloso, Relicardo M.; Quinitio, Gerald F. Seafarming has ecological effects such as pollution and eutrophication of adjacent areas by excess food or by feces or modification of habitats by physical structures. More subtle effects on the communities result from heavy consumption of plankton or benthos by caged or enclosed farmed organisms and consequent reduction of availability of food to adjacent natural communities. Seapens, in which monocultures are reared, develop a radically different benthos from that in adjacent areas. Seafarms can become focal points from which pathogens and parasites can be spread.Searanching, in which stocks are enhanced by the addition of hatchery-reared recruits, has the potential to cause significant changes in the composition and stability of marine communities. Enhanced recruitment of a species will have negative effects on both its prey and its competitors but will enhance the biomass of its predators.Enhanced recruitment of a stock of apex predators will decrease the biomass of its prey and cause changes in the composition of the community. The effects of searanching are amenable to modelling, and the likely effects of proposed searanching schemes should be examined before these are implemented.The magnitude of the effects of searanching will depend on the degree to which the area is naturally saturated with recruits of that species and on the rate of exploitation. Poor management of the stock, resulting in under- or over-exploitation, will have highly destabilizing effects on the communities.Seafarming or searanching can have negative effects on the gene pools of natural stocks and result in changes in life histories or in behavior. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/10862/100 1994-01-01T00:00:00Z http://hdl.handle.net/10862/39 Shrimps Parado-Estepa, Fe D. Lacanilao, F.; Coloso, Relicardo M.; Quinitio, Gerald F. During 1988-1991, research at the Aquaculture Department of SEAFDEC on the shrimp Penaeus monodon has been directed towards a) the development of captive broodstock, b) the refinement of hatchery and grow-out techniques, c) the development of diets for the various stages of culture, and d) the prevention and control of diseases. Biochemical, morphological, and histological characterization of the male and female reproductive systems were conducted to provide basic information for the development of techniques for pond-reared broodstock. Studies on the refinement of hatchery techniques included determination of the environmental and feeding requirements of larvae and postlarvae to serve as basis for the improvement of management practices. Refinement of grow-out techniques included studies on the physiological response of this species to vital environmental factors and studies on the role of natural food organisms during culture. Nutrition studies have resulted in the formulation, testing, and improvement of diets for broodstock, larvae and postlarvae, juveniles, and subadult shrimps. Methods of prevention and control of the luminous bacterial disease, chronic soft shell syndrome, aflatoxicosis, monodon baculovirus (MBV) infection, and other relevant diseases have been investigated through the identification of causative agents and bioassay of possible chemo-therapeutants. Studies to improve larval rearing of alternative shrimp species such as P. indicus, P. merguiensis, and P. japonicus have likewise been pursued. Nutritional requirements of the white shrimp species were evaluated to develop suitable formulated feeds for the different culture stages. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/10862/39 1994-01-01T00:00:00Z http://hdl.handle.net/10862/2165 Proceedings of the Seminar-Workshop on Aquaculture Development in Southeast Asia and Prospects for Seafarming and Searanching, 19-23 August 1991, Iloilo City, Philippines Lacanilao, F.; Coloso, Relicardo M.; Quinitio, Gerald F. Documents the presentations at ADSEA '91, the 2nd Seminar-Workshop on Aquaculture Development in Southeast Asia. ADSEA '91 includes reviews of the status of the researches conducted by Southeast Asian Fisheries Development Center, Aquaculture Department (SEAFDEC/AQD) on the following cultured species sea bass, groupers, snappers, milkfish, rabbitfish, mullet, tilapia, carp, catfish, bivalves and the seaweed Gracilaria. Topics on aquaculture development in Southeast Asia and Japan were also discussed. The status and development of seafarming and searanching in different SEAFDEC member countries and their ecological, social and economic implications were also presented. The contributions of the selected participants during the meeting which are contained in this volume are cited individually. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/10862/2165 1994-01-01T00:00:00Z http://hdl.handle.net/10862/41 Seaweed: Gracilaria Hurtado-Ponce, Anicia Q. Lacanilao, F.; Coloso, Relicardo M.; Quinitio, Gerald F. This paper reviews the studies on Gracilaria/Gracilariopsis conducted from 1988 to 1991 by the Aquaculture Department, Southeast Asian Fisheries Development Center. It includes 114 species of macrobenthic algae collected in Panay, the nomenclature of Gracilariopsis heteroclada previously described as Gracilaria sp., and the biology, ecology, and farming systems of Gracilariopsis. Agar quality of the different species of Gracilaria and the effect of seasonal variation on the quality and quantity of agar produced from Gracilariopsis heteroclada were also studied. Sat, 01 Jan 1994 00:00:00 GMT http://hdl.handle.net/10862/41 1994-01-01T00:00:00Z