广东大亚湾甲藻孢囊及其与锥状斯氏藻赤潮的关系

1999年12月至2001年1月,在大亚湾澳头海域用沉积物捕捉器(Sediment trap)及TFO重力采泥器对甲藻孢囊进行每月一次的周年监测,并同时研究了浮游植物的季节变化.结果显示,晚秋孢囊形成率最高(3.48105 cysts/m2d),冬季形成率较低,年平均为1.28105 cysts/m2d.锥状斯氏藻(Scrippsiella trochoidea)是大亚湾沉积物孢囊中的绝对优势种,除个别季节外,其形成率一般占孢囊总形成率的50%以上.2000年8月至9月,该海域发生了一次较大规模的锥状斯氏藻赤潮,最高细胞密度达4.0104 cells/mL.赤潮中后期,锥状斯氏藻孢囊包括暂时性孢囊和休眠孢囊大量形成,孢囊的形成减少了水体中营养细胞数量,是赤潮消退原因之一.  

SEASONAL DYNAMICS OF DINOFLAGELLATE CYSTS IN SEDIMENTS FROM DAYA BAY,THE SOUTH CHINA SEA ITS RELATION TO THE BLOOM OF SCRIPPSIELLA TROCHOIDEA

To investigate the distribution of dinoflagellate cysts and the relationship between cyst and motile cell,water samples and sediments both from TFO corer samples and from sediment traps were collected monthly at 4 stations in Daya Bay,South China Sea,from Dec. 1999 to Jan. 2001. A total of 31 different cyst types were recorded. Cysts of calcareous Peridiniales mainly Scrippsiella trochoidea were the most dominant species in surface sediments at four station, which occupied from 47% to 58%. While others only occurred within restricted periods scarcely. Results from experiment on sediment trap revealed that the highest production rates(up to 3.48105 cysts/m2d)was in late autumn,while the lowest in winter. A dense bloom of Scrippsiella trochoidea broke out from Aug. 2000 to Sept. 2000 in studied sea area,and significant high concentrations of its cysts including resting cyst and temporary cyst were observed. The highest production of temporary cyst happened during the period of the bloom. however,more resting cysts were produced at the end of the bloom. This result suggest that large encystment(both resting and temporary cysts)of Scrippsiella trochoidea appeared to result in bloom termination,while the high cyst concentration in surface sediment in Daya Bay provide richseed bedfor the motile cell in upper water column and also the possibility of the occurrence of bloom.