东海、黄海近代沉积物中生物硅含量的分布及其反演潜力

Biogenic silica distributions in recent sediments of the East China Sea and the Huanghai Sea and implications for productivity reconstructions

以东海、黄海2006年4月、10月航次采集的沉积物样品为研究对象,结合沉积物中生物硅（BSi）含量的空间分布特征进而讨论BSi的反演潜力。研究发现,调查海域表层沉积物中BSi的含量介于0.018%~2.516%,平均值为0.726%,柱状沉积物中BSi的含量波动较小,相对稳定。整体而言BSi含量与相应年代的浮游植物现存量变化的趋势相近。经一元线性分析发现BSi含量与硅藻生物量的相关性显著。为进一步证实由BSi含量反演古生产力的有效性和可信度,采用Tun-nicliffe等的方法探讨了BSi含量在沉积物中的稳定性,调查结果表明,近150 a来BSi几乎没有降解,能够稳定地保存于沉积物中。综上可以初步判断沉积物中BSi含量可作为古生产力指标来反演古生产力的潜力。

Surface and core sediment samples were collected during cruises in the East China Sea and the Huanghai Sea in April and October of 2006 to study the spatial distributions of biogenic silicon（BSi） in sediments and to evaluate its potential for productivity reconstructions.The results show that the BSi content of surface sediments is 0.018%~2.516%,averaging 0.726%.The vertical distribution profiles reveal that the BSi content is relatively stable,in accordance with the variations of the contemporary living phytoplankton biomass.A linear regression analysis method was adopted to prove that the BSi content has a positive relationship with the living phytoplankton biomass.To further confirm the applicability and credibility of the reconstruction potential of BSi,the method of Tunnicliffe et al.was used to study the stability of BSi in sediments.The survey indicates that there is almost no degradation of BSi in sediments over the past 150 a.Therefore,it is concluded that BSi in sediments may be used as an index to reconstruct paleoproductivity fluctuations.