Hiệu quả các hình thức nuôi thương phẩm hàu Thái Bình Dương (Crassostrea gigas) tại vịnh Bái Tử Long

After 10 months of grow-out  culture of Pacific oyster  (Crassostrea gigas)  in Bai Tu Long Bay (Quang Ninh) with three forms: strings, trays and culturing bags with the results as follows: oysters cultured in  strings reached 63.9 ± 0.80mm in  shell length,  106 ± 2.29mm in  shell  height (8.3 ± 1.08mm/month); 107 ± 1.72gr in body weight (10.4 ± 1.49gr/month), fatting rate of  24.2 ± 0.31% with survival rate of  72.5 ± 1.54%; cultured in trays: the oyster reached average size of  63.2 ± 1.08mm in length (4.9 ± 0.78mm/month in average); 101.8 ± 1.26mm in height (8 ± 0.92mm/month in average); 100.4 ± 1.31gr in body weight (9.7 ± 2.54gr/month), fatting rate of  24.3 ± 0.85% with survival rate of  72.5 ± 1.54%; cultured in bags: 58 ± 1.38mm in length (4.4 ± 0.76mm/month in average), 92.5 ± 1.04mm in height (7.1 ± 1.20mm/month in average), 86.2 ± 0.73g in body weight (8.5 ± 1.81g/month in average), fatting rate of 23.9 ± 0.60%,  with survival rate of  61.3 ± 1.40%.  The above results showed that the growth and survival rate of oysters cultured in strings and trays have been significantly higher than those in bag cultured type (P<0.05).