marine algae for feeding Geo-duck larvae at Vandon, quang ninh province Nguyen Thi Hoai Ha, Luu Thi Thuy Giang, Le Trung Thuy, Tran Hai Linh, Nguyen Quang Huy 1, Ngo Trinh Khang2 Microalgal Technology and Enviromental Biology Lab., Institute of Microbiology and Biotechnology,Vietnam ietnamNational University - Hanoi Building E2, 144 XuanThuy Road, Caugiay District, Hanoi Center of Aquaculture Breeding farm, Vandon district Halong Bay, Quang Ninh province, Vietnam 1,2 Corresponding author: hoaiha@vnu.edu.vn, nguyenhoaiha@yahoo.com Tel: (84-4) 7547 488, Fax: (84-4) 7547 407 Introdution Quang Ninh is a north-east province with about 250 km coast line, and approximately 2000 islands in a wide range of sizes This provides a large water surface area, tidal flats and promontories, where many valuable and rare marine species habit One of them is Geo-duck (Tuhai) Geo-duck is a bivalve species, commonly in Halong Bay At present, the species is a special food with high nutrient Fisher exploitation is usually from nutural resource As the result, Geo-duck clam resource is decreasing seriously Therefore, researches on biological characteristics of Geo-duck for sustainable development and conservation of this resource is demanded For people of North Vietnam, Geo-duck culture is almost a new job They usually collect large individuals while small ones will be rejected into seabed In order to help fishers and businessmen obtain fundamental knowledge of artificial production of seeds along with culture, we establish a process of Nanochloropsis, Isochrysis, Chraetoceros, Chlorella, marine algae culture Biomass are gathered by simple method Fresh, high value nutrient food resoure is provided on the spot These conditions will facilitate Geo-duck cultivation which is in the process at Van Don district, Halong Bay, Quang Ninh province, Vietnam The cooperator team works at Vandon district Airm & Objectives • Screeming of marine microalgal species with defined classification, high nutrient value and suitable for Geo-duck larvae at different stages and good for biomass large scale production • Seaching media and utimate culturing condition for the on-spot production at a large scale to meet the demand of richnutrient microalgal species to Van Don field-culture area up to 10 m3 in mass ACTIVITIES AND APPLlCATION OF MARINE ALGAE AT VANDON The maine algae inoculated in plastic bags and tanks Geo-duck larvae cuture tank 48 days age Geo-duck larvae CONCLUSION Geo-duck cuture tubes Geo-duck harvest • Providing marine microalgal as fresh quality source of food for the 5000 artificial breed Geo-duck larvae • Completing a process for the production of marine microalgal culture on the spot, bringing economical benifit to enterprises as well as people in the area REFERENCES ACKNOWLEDGEMENTS The authors wish to thank Institute of Microbiology and Biotechnology for suport Many thanks also to go Center of Aquaculture Breeding farm, Vandon district for supplying marine microalgae and funding Mylchreest, R 2003 2003 Geoduck and horse clam integrated fisheries management plan Fisheries and Oceans Canada, Vancouver, British Columbia Brown, M R., 1991 The amino acid and sugar composition of 16 species of microalgae used in mariculture Journal of Experimental Marine Biology and Ecology, 145: 79-99