2011年夏季南大洋普里兹湾颗粒态生物硅的分布与变化特征

利用中国第27次南极科学考察期间获得的颗粒物样品，对南大洋普里兹湾海域水体中颗粒态生物硅的含量及分布特征进行了初步研究，分析了该海域颗粒态生物硅与营养盐、浮游植物以及颗粒有机碳之间的关系，同时结合历史数据对比了颗粒态生物硅的年际变化情况。研究结果显示：在2011年夏季普里兹湾表层水体中颗粒态生物硅含量在0.76-19.72μmol/ dm3之间变化，平均为6.06±4.55μmol/ dm3。在表层水体中的分布趋势是67°S以南的湾内区域颗粒态生物硅含量明显高于67°S以北的湾外区域，最大值出现在普里兹湾陆架区。在垂向分布上，P3断面水体中颗粒态生物硅含量随深度增加而减少。根据不同年份即24，25，26，27次南极科学考察期间获取的数据对比分析显示，颗粒态生物硅含量虽存在一定的年际差异，但是在普里兹湾的分布趋势基本一致。颗粒态生物硅含量的变化特征与硅酸盐相反与叶绿素a、颗粒有机碳相似。

THE DISTRIBUTION AND CONTENT OF PARTICULATE BIOGENIC SILICA IN SURFACE WATERS OF PRYDZ BAY,SOUTHERN OCEAN,DURING THE AUSTRAL SUMMER OF 2011

To characterize the correlation among PBSi and plankton, nutrients and POC, the contents and distributions of PBSi in the upper surface waters of Prydz Bay, Southern Ocean, were investigated during the CHINARE-27 cruises. Results show that the contents of PBSi ranged between 0.76—19.72 μmol/dm³, the average content of PBSi was 6.06 μmol/dm³, and the distribution of surface PBSi had significant regional characteristics. The concentrations were higher in the southern area of 67°S than in the northern area. The distribution of PBSi and Chl a and POC show similar patterns, and PBSi had a negative correlation with silicate. In the vertical direction, the mole ratio of Si/C decreased with increasing depth. This trend indicated a higher rate of PBSi dissolution, or lower rate of organic matter remineralization rate in the upper 200 m.