Now showing items 1-10 of 10

    • Conference paper

      Aquaculture industry profile and trends 

      WG Yap - In Fishlink 2001, 29-31 May 2001, Iloilo City, Philippines, 2001 - University of the Philippines Aquaculture Society, Inc.
    • Conference paper

      Cultivation of live feed for the rearing of sugpo (Penaeus monodon) larvae 

      WG Yap - In E Styczynska-Jurewicz, T Backiel, E Jaspers & G Persoone (Eds.), Cultivation of Fish Fry and Its Live Food. Proceedings of a Conference, 23-28 September 1977, Szymbark, Poland, 1979 - European Mariculture Society
      Series: European Mariculture Society Special Publication; No. 4
      The sugpo, Penaeus monodon, is a very important prawn species in Southeast Asia. It is extremely euryhaline and fast growing. Interest in the farming of this prawn species is very high. Unfortunately, the supply of natural fry is not sufficient. It is, therefore, necessary to develop the technology of breeding them in captivity and producing sufficient seed material. The Southeast Asian Fisheries Development Center, Aquaculture Department in Tigbauan, Iloilo, Philippines, operates a hatchery to produce fry for experimental rearing in brackish water ponds and for various laboratory studies.
    • Conference paper

      Culture of tilapia in saline water 

      WG Yap - In Fishlink 2001, 29-31 May 2001, 2001 - University of the Philippines Aquaculture Society, Inc.
    • Article

      Perna viridis (L.) 1758 as the correct name for the Southeast Asian green mussel (Bivalvia:Mytilidae) 

      AL Young & WG Yap - Philippine Journal of Science, 1984 - Science and Technology Information Institute
      The Southeast Asian green mussel is Perna viridis. The wide separation of the retractor mussel scars in the adult shell and the special set of teeth on the posterior shoulder of the larval shell definitely place the green mussel under the genus Perna ritzius.
    • Article

      Population biology of the Japanese little-neck clam, Tapes philippinarum, in Kaneohe Bay, Oahu, Hawaiian Islands 

      WG Yap - Pacific Science, 1977 - University of Hawaii Press
      The Japanese little-neck clam, Tapes philippinarum, an introduced species in Kaneohe Bay, Oahu, Hawaiian Islands, has a thriving population only in a U5-hectare mud flat after heavy fishing triggered depletion in six other beds within the bay. Monthly gonad examination of the clams suggested that spawning occurs at a low level throughout the year with a peak from January to February. This observation is corroborated by the appearance of new recruits in the monthly sample from April to June and by their presence at low levels at other times of the year. Size-specific fecundity, determined indirectly from differences in the length: dry weight relationships of ripe and spent clams, ranges from 432,000 eggs in a 20-mm clam, increasing exponentially to 1.35 x 106 eggs in a 40-mm clam.

      Estimates of the population of clams 11 mm and larger, which were 3.09 x 106 in 1970 and 3.4 x 106 in 1972, show a growth of 5 percent per year during the 2-year period; monthly quantitative sampling showed no evidence of population growth after 1972. A survivorship curve obtained from the monthly samples gave a total instantaneous mortality of z = 0.2005. The age-specific mortality agrees with the age-frequency of the empty shells collected from the bed, with a correlation coefficient of 0.9345 with 4 d.f. The condition of the empty shells indicated that 57 percent of the mortality is attributable to crab predation, mainly by Thalamita crenata, which constitutes 70 percent of the experimental crab catch in the clam bed. Sixty percent of the broken shells were 19.5 to 30.4 mm in length; in experiments with predation by T. crenata, 96 percent of those eaten fell within the 14.5 to 30.4 mm size range. The difference between the lower limits of the size ranges can be attributed to the size structure of the clams during the survey period. The experimental population had an artificially maintained size structure. Experimental exclusion of predators over a limited area suggested that crab predation regulates clam size structure but not clam density.
    • magazineArticle

      SEAFDEC AQD: Facilities and activities 

      RR Platon & WG Yap - World Aquaculture, 2002 - World Aquaculture Society
      As an R & D complex in aquaculture that can conduct replicated studies in marine waters, brackish water and freshwater, be it in aquaria, large tanks, earthen ponds or cages, there are not that many institutions in the world like the SEAFDEC Aquaculture Department (AQD). SEAFDEC AQD is one of four departments of the Southeast Asian Fisheries Development Center, a regional treaty organization with headquarters in Bangkok, Thailand. Starting with six countries when the SEAFDEC treaty was signed in 1969, SEAFDEC now includes Brunei Darusalam, Cambodia, Indonesia, Japan, Malaysia, Myanmar, the Philippines, Singapore, Thailand and Vietnam. The other three SEAFDEC departments are the Training Department (TD) in Thailand, the Marine Fisheries Research Department (MFRD) in Singapore and the Marine Fishery Resources Development and Management Department (MFRDMD) in Malaysia. Among the four departments, the Aquaculture Department, established in 1973 and hosted by the government of the Philippines, is the largest.
    • Article

      Settlement preference of the brown mussel, Modiolus metcalfei, Hanley and its implication on the aquaculture potential of the species 

      WG Yap - Fisheries Research Journal of the Philippines, 1978 - Fisheries Research Society of the Philippines
      A study on the settlement preference of M. metcalfei was made in Banate Bay, Iloilo, using four types of materials as spat collectors. During the six-month study period, not a single Modiolus spat was found in any of the materials tested. Spats were found attached to the posterior half of living adult mussels collected for related studies. Tests with empty Modiolus shells and bamboo fish corrals as spat collectors showed negative results indicating that settlement response in the brown mussel is elicited by the presence of living animals.
    • Conference paper

      A strategy for sustainable mariculture 

      WG Yap - In FM Yusoff, M Shariff, HM Ibrahim, SG Tan & SY Tai (Eds.), Tropical Marine Environment: Charting Strategies for the Millennium, 2002 - Malacca Straits Research and Development Centre (MASDEC), Universiti Putra Malaysia
      From merely growing shellfish and macroalgae along the freinges of the sea, man is naw growing marine fish in cages thus expanding the range of mariculture. While the farming of shellfish may have its own set of problems it is the growing of fish that particularly poses more serious problem. This is especially true since high value fish which invariably are carnivores are the preferred species. Depending on the hydrography of the site, the species culture, culture method, stocking density, feedtype, and husbandry practices marine fish farming has the potential of greatly increasing the organic load of the immediate waters. the use of chemicals such as therapeutants, vitamins, pigments, and anti-foulants futher adds to the pollution. If the rate and manner of development is left to market forces its sustainability may be jeopardized. Areas that are semi-enclosed are often preferred and can rapidly become subject to overcrowding to the extent that its carrying capacity is exceeded. In addition conflicts between growersand other users can arise thus adding a social dimension to the problem. Sustainability of mariculture can be better assured if the development is not haphazard. The concept of zoning and planned development which is now the standard appeoach on land can wery well be applied in the sea. The open waters can be zoned as to type of aquaculture allowable. Beyond zoning, growers can be induced to set up their cages in semi-exposed or even exposed areas where th hydrography is more ideal for growing fish by providing an infrastructure for mariculture. Such infrastructure may consist of nothing more than mooring facilities for deep-watercages and, where necessary, floating breakwaters. With proper spacing of the mooring points, even the density of the cages in an area can be regulated. This will effectively lower start-up cost since growerswill be spared the expense of installing mooring. This will make it possible to broaden the participation to those with limited access to capita such as small-sscale fishers. Users can be charged mooring fees much as ships are charged berthing fees. Service in the form of security may also be provided. this can be complimented by onshor facilities such as a landing area, feed depot, ice plant, cold storage and processing plant. Such an area can be operated like a marine version of an aindusrial park and can aptly be referred to as a mariculture park. This model of mariculture development is being tried in the philippines.
    • magazineArticle

      Towards sustainable aquaculture in the ASEAN region 

      RR Platon, WG Yap & VT Sulit - Fish for the People, 2007 - SEAFDEC Secretariat
    • Conference paper

      Viewpoint on formulating policies for sustainable shrimp culture 

      WG Yap - In Bangkok FAO Technical Consultation on Policies for Sustainable Shrimp Culture, Bangkok (Thailand), 8-11 Dec 1997, 1999 - Rome, Italy: Food and Agriculture Organization of the United Nations
      Series: FAO Fisheries Report No. 572
      An examination is made of all the negative impacts attributed to shrimp culture, particularly to intensive culture, considering also remedial measures recommended to ameliorate their ill-effects and discussing the implications and practicability of the suggested measures. The following impacts are covered: loss of mangrove ecosystems; organic loading and pollution; nutrient enrichment and eutrophication; the use of bio-active materials; longevity and toxicity of chemicals to non-target species; development of antibiotic resistance; species introduction and spread of disease; decline in natural stock of shrimps and other species; water and soil salinization and land subsidence; privatization of resources; competition for land, credit and commercial products; decline in domestic food crops; and, the 'fish meal trap'.