南极威德尔海冬季海冰叶绿素及其生态意义

2006年8-10月南极威德尔海冬季海冰考察,对海冰生物地球化学特征,包括叶绿素a、POC、C/N等的含量与垂直分布及其生态意义进行分析研究。结果表明,海冰叶绿素a含量普遍较高,平均总量233.8μg·l-1,范围14.7-1519.2μg·l-1,其中有57%以上的冰芯平均总量超过100μg·l-1。冰芯叶绿素a平均值为16.6μg·l-1,范围2.1-84.4μg·l-1,高出威德尔海区初冬海冰叶绿素a平均值的2.2倍,高出深冬时的7.5倍。海冰不同层次叶绿素垂直分布不均匀,底部有色层多位高值区。本文海冰R值83%,表明冬季冰藻具有较强活性,并处于初春旺发前期的活跃状态,不仅有利于暖季大量冰藻释放促成海域浮游植物水华与初级生产的迅速增长,并为浮游动物幼体的生长发育提供丰富饵料,确保海域生态系统的修复和可持续发展。

DISTRIBUTION AND ECOLOGICAL SIGNIFICANCE Of CHLOROPHYLL IN WINTER SEA ICE FROM WEDDELL SEA,ANTARCTICA

The investigation on sea-ice research was carried out in North-Western Weddell Sea,Antarctica,during the cruise of ANT/XⅢ-7 on board POLARSETEN in austral winter (Aug—Oct) of 2006. Biogeochemical parameters of Chlorophyll a,POC and C/N from sea ice cores were measured. The results indicated that the gross value of Chlorophyll a ranged from 14.7μg·l-1to 1519.2μg·l-1 with the mean of 233.8μg·l-1,and it was up to 100μg·l-1 by 57% ice cores. The concentrations of chlorophyll a ranged from 2.1μg·l-1 to 84.4μg·l-1 with the mean of 16.6 μg·l-1 per core,which was 2.2 times higher than that in the beginning of winter and 7.5 times higher than that in mid-winter in Weddell Sea. The mean value of R (chlorophyll a / gross of chlorophyll) was 83%. It indicates that stronger activation of ice algae cells are significant primary production in Antarctic sea ice in the winter. Also ice algae could lend great support to spring bloom of phytoplankton in waters. Therefore,it would largely contribute to the growth of marine larvae of zooplankton,and promote sustainable development of marine ecosystem in the Southern Ocean as well.