Now showing items 1-4 of 4

    • Conference paper

      Biology and status of aquaculture for giant clams (Tridacnidae) in the Ryukyu Islands, southern Japan 

      K Iwai, K Kiso & H Kubo - In JH Primavera, ET Quinitio & MR Eguia (Eds.), Proceedings of the Regional Technical Consultation on Stock Enhancement for Threatened Species of International Concern, Iloilo City, Philippines, 13-15 July 2005, 2006 - Aquaculture Department, Southeast Asian Fisheries Development Center
      The Ryukyu Islands consist of many islands located between Kyushu in mainland Japan and Taiwan. The islands in the south-western area of the Ryukyu Islands belong to the Okinawa Prefecture. The Ryukyu Islands are strongly affected by the Kuroshio Current and are renowned for their coral reefs with high diversity of tropical and subtropical species. Giant clams traditionally have been utilized as fisheries resources for a long time in this area. According to fisheries statistics, catches of Tridacna crocea in Okinawa have decreased drastically during the last 30 years and currently are less than one tenth of previous catches. Fishing can easily deplete stocks of giant clams because the clams inhabit shallow waters and take at least three years to attain sexual maturity. Techniques for the mass seed production and aquaculture of three species (T. crocea, T. squamosa, and T. derasa) were established in Okinawa. Four hundred thousand seeds of giant clams of 8 mm shell length (SL) are supplied to fishermen for use in aquaculture or stock enhancement every year. This paper will review the (1) biology of giant clams, (2) present status of aquaculture of giant clams in Okinawa, and (3) other studies on giant clams in southern Japan.
    • Conference paper

      Coral culture and transplantation and restocking of giant clams in the Philippines 

      ED Gomez, PC Cabaitan & KC Vicentuan - In JH Primavera, ET Quinitio & MR Eguia (Eds.), Proceedings of the Regional Technical Consultation on Stock Enhancement for Threatened Species of International Concern, Iloilo City, Philippines, 13-15 July 2005, 2006 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Recently, the Pew Project (2001 to 2005) of the senior author entitled ‘Coral reef habitat and productivity enhancement through coral transplantation and giant clam restocking’ was implemented with the aim to improve the biodiversity and productivity of stressed coral reef habitats in 10 selected demonstration sites in the Philippines. These were meant to serve as models for other communities. Transplantation of corals and reseeding of giant clams were the approaches. Nubbins or small fragments from nearby large coral colonies and abundant solitary forms were transplanted to the target sites. Care was exercised to avoid or reduce any negative impacts on the natural source communities. Only cultured giant clams were used, specifically the threatened Tridacna gigas at sizes that would ensure their chances of survival in the wild (approximately 20-30 cm shell length). Following deployment, monitoring activities were undertaken, focusing on macro-invertebrates and fish, as well as the assessment of the survival and growth of experimental animals. Liaison work was done with local communities to raise their environmental awareness and to ensure their cooperation. This manuscript draws principally from results of the Pew Project. At present, two other restoration projects supported by the European Union and the Global Environment Facility Coral Reef Targeted Research Project are being implemented at the Bolinao Marine Laboratory of the University of the Philippines Marine Science Institute (UP-MSI) in Pangasinan. These projects are testing the efficiency of floating and standing coral nurseries in growing coral nubbins in addition to transplanting fragments or branches of corals to restore degraded coral reefs.
    • Conference paper

      Status and prospects of aquaculture of threatened echinoderms in the Philippines for stock enhancement and restocking 

      MFJ Nievales, MA Juinio-Meñez & HG Bangi - In JH Primavera, ET Quinitio & MR Eguia (Eds.), Proceedings of the Regional Technical Consultation on Stock Enhancement for Threatened Species of International Concern, Iloilo City, Philippines, 13-15 July 2005, 2006 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Echinoderms are either specifically targeted by gleaners and divers, or form part of the multispecies invertebrate fishery in many coastal areas in the Philippines. The existence of a local sea urchin market in northern Philippines (e.g., Pangasinan, La Union) benefits many coastal families that depend on this fishery for subsistence. In Bolinao, Pangasinan, over 40 families are reportedly dependent on this fishery. Major sea urchin species collected include Tripneustes gratilla, Diadema spp. and Salmacis spp. In the case of holothurian fishery, with over a century of fishery history for holothurians, at least 25 species mostly belonging to the families Holothuriidae and Stichopodidae are commercially important (Schoppe 2000). While there may be local consumption of both fresh and dried products, the latter are largely exported. Echinoderm fishery is dependent on wild stock. The high demand far exceeding supply, good global market prices and their biology (e.g., slow mobility, shallow water benthic habitat) render them vulnerable to overexploitation. The contribution of echinoderm products to the Philippine economy is substantial. The relative contribution of echinoderm products to the income and socio-economic well-being of fisherfolk who collect these invertebrates is undocumented. However, it has been noted that middlemen, especially local buyers who sell trepang in Manila and Manila-based traders-exporters monopolize the profits (F. Nievales, unpublished data). Products from both echinoderm groups remain in short supply in the country and so trading, limited only by declining natural stock, continues to be lucrative.
    • Conference paper

      An uncertain future for seahorse aquaculture in conservation and economic contexts 

      ACJ Vincent & HJ Koldewey - In JH Primavera, ET Quinitio & MR Eguia (Eds.), Proceedings of the Regional Technical Consultation on Stock Enhancement for Threatened Species of International Concern, Iloilo City, Philippines, 13-15 July 2005, 2006 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Seahorses (family Syngnathidae, genus Hippocampus) have set precedents globally. They were among the first marine fishes of commercial importance to be listed on both the IUCN Red List and CITES Appendix II. Overfishing and non-selective fishing are two agents in their depletion, so management is clearly needed. We here outline what is known about these fishes and their trade, before considering the potential role the culture and release could play in rebuilding wild populations.