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Toward the Sustainability of Oyster Aquaculture in Kinmen Island, Taiwan. 黃守忠、謝蕙蓮、陳章波 Shou-Chung Huang a , Hwey-Lian Hsieh a , Chang-Po Chen a,b a Research Center for Biodiversity, Academia Sinica, Taipei, Taiwan b Institute of Fisheries Sciences, National Taiwan University, Taipei, Taiwan.
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Toward the Sustainability of Oyster Aquaculture in Kinmen Island, Taiwan 黃守忠、謝蕙蓮、陳章波 Shou-Chung Huanga, Hwey-Lian Hsieha, Chang-Po Chena,b a Research Center for Biodiversity, Academia Sinica, Taipei, Taiwan b Institute of Fisheries Sciences, National Taiwan University, Taipei, Taiwan
Outlines • Oyster cultures in Kinmen: “Rock oysters” vs. “Hanging oysters” • A research project in 2003 -Background -methods -results -conclusions • Suggestions for sustainable oyster aquaculture in Kinmen
Rock oysters Hanging oysters
Background • Production declines in the past two decades. • 1982: 1255 tons • 1992: 521 tons • 2002: 227 tons • Fishermen reported mass mortality in summer and fall in recent years.
Questions • Did mass mortality really occur? • What factors affect oyster’s growth & mortality? Food seston, phytoplankton Parasites flat warms, oyster drills Water T, S, DO Oysters Sediment silt, organic % Disease
Study sites 北山 湖下 水頭
Temperature Salinity DO Seston (~= SS) Chlorophyll a Particulate organic carbon Particulate organic nitrogen Shell length Mortality ratio Condition index (CI) Respiration rate Excretion rate Approaches Environmental parameters Oyster parameters Study period: late July to early December 2003 Sampling frequency: every 2 to 4 weeks
Conclusions • Winter monsoon started in late September and resulted in poor growing environments for oysters in Kinmen. • Mass mortality did not occur, but conditions of hanging oysters began to deteriorate in October, right after winter Monsoon started. • Rock oysters performed better than hanging oysters with lower mortality and higher growth rates during winter Monsoon season. • The poor adaptation of hanging oysters was resulted ,we hypothesized, from importing their spats from southwest coasts of Taiwan.
Suggestions • Active management • Adjusting rearing and harvest time • Rotation of culture locations
Suggestions • Active management • Adjusting rearing and harvest time • Rotation of culture locations • Environmental monitoring • Pollution watch on Jiulong river
Jiulong River Xiamen Kinmen
Suggestions • Active management • Adjusting rearing and harvest time • Rotation of culture locations • Environmental monitoring • Pollution watch on Jiulong river • Improve marketing, esp. the rock oysters • Open oyster farms for tours • Need more studies!!!
Thank you & a major help from our research assistant Ms. Yeh Hsin-Yi