南极普里兹湾表层沉积物中生物钡的含量与分布

摘要

利用中国南极科学考察第21和27航次采集的普里兹湾表层沉积物样品，分析了其中BBa的含量及分布特征，并讨论了控制其分布的相关因素。结果表明：分别利用直接扣除法和分步萃取法获得的BBa含量差别较大，直接扣除法获得的含量明显高于分步萃取法，这是因为扣除法获得的BBa中包含了大量的非生源钡，比如与样品中含砂量有密切联系的铁锰氧化物结合态钡，从而导致在该海域采用直接扣除法缺乏合理性。分步萃取法获得表层沉积物中BBa含量为104-445μg· g-1，平均值为227μg· g-1，呈现明显的空间分布差异，整体分布趋势为湾中心区域较高，浅滩及冰缘区较低。表层沉积物样品中BBa的含量及分布与BSi、OC以及上层水体的叶绿素a和初级生产力情况密切相关，说明上层水体的生物生产状况是BBa分布的主要控制因素。%We used the normative calculation and sequential extraction methods to determine the concentration of biogenic barium, and compared the results of the two methods .The concentration of biogenic barium calculated using the normative calculation method was much higher than the result from sequential extraction , which suggested that bari-um associated with Mn and Fe oxides contributed considerably to total barium .The concentration of biogenic barium based on sequential extraction ranged from 104 to 445 μg · g-1 , with an average content of 227 μg · g -1 .The highest levels of biogenic barium were recorded in the center of the bay , where the seawater is more stable , and lower values were found near the shore and over the ice shelf .Biogenic barium concentration showed a significant linear correlation with BSi and OC , and was also closely correlated to chlorophyll a concentration .This finding in-dicates that primary productivity of phytoplankton in the surface water column is the main environmental factor regu -lating the concentration and distribution of biogenic barium in Prydz Bay .