摘要
生物硅是海洋硅循环及古海洋学的主要研究对象,主要由硅藻、放射虫、硅鞭藻和海绵骨针等硅质生物壳体组成。由于硅藻是海洋硅质生物以及海洋浮游植物群落的优势种群,故生物硅常被用作判断硅藻生产力甚至整个海洋初级生产力的重要指标。相对于硅藻的鉴定和统计分析,生物硅含量分析有其便利快捷的明显优势,然而生物硅组成的复杂性使其在现代海洋学及古海洋学的应用中存在一定的风险,但是目前有关生物硅含量与硅藻生产力的相关性及其对现代海洋和古海洋研究的影响尚未引起足够的关注。本文通过收集整理大量已发表的我国边缘海表层沉积物生物硅与硅藻的相关研究成果,在此基础上探讨了我国边缘海沉积生物硅含量与硅藻丰度的空间分布及其耦合性,及其对海洋生产力研究的指示意义。从现有的研究数据可以看出东中国海,主要包括东海和黄海,以及南海陆架浅海区表层沉积生物硅含量与硅藻丰度均无明显的空间变化规律,而南海表层沉积生物硅含量与硅藻丰度均表现为由陆架向海盆逐渐增加的趋势,与水深呈明显正相关关系。整个中国边缘海沉积生物硅含量和硅藻丰度的空间分布格局与现代水体初级生产力的分布格局差异明显,陆源输入的稀释作用对此起到了重要影响。通过进一步的分析发现,南海表层沉积硅藻对生物硅的贡献还存在明显的区域变化,表现为在陆坡及其邻近海盆区硅藻对沉积生物硅的贡献较大,而在深海海盆区放射虫及其他硅质生物对生物硅的贡献不容忽视。为了更好地利用生物硅、硅藻及其他相关参数研究边缘海硅循环及古海洋环境演变,未来需要更多地关注除硅藻以外的硅质生物,如硅鞭藻、海绵骨针等,对生物硅的贡献及其对海洋硅的生物地球化学过程的影响。
Biogenic silica(BSi), mainly composed of cell wall or skeleton of siliceous organisms, such as diatoms, radiolarians, silicoflagellates and sponge spicules, is important in the researches of marine silica cycle and paleo-oceanography. Since the diatoms are the dominant marine siliceous organisms and marine phytoplankton communities, BSi is always used as an important indicator of the diatom productivity. Compared with the diatom analysis, the measurement of biogenic silica content is more convenient and faster, though the complexity of the BSi composition may cause incorrect implication. So far, the correlation of BSi content with abundances of the diatom and other siliceous orga-nisms, and its specific implication for marine silica cycle and paleoceanographic research haven’t been paid enough attention yet. In the present work, we reviewed the published data of the surface sediment BSi content and the diatom abundance in China Seas, to understand the spatial distribution and coupling relation of the BSi content and the diatom abundance, and its implication. Previous work indicated no obvious spatial distribution pattern of BSi content and diatom abundance in the sediements of the Yellow Sea, East China Sea and shallow water of the South China Sea. A gradually increasing trend of the BSi content and the diatom abundance was found from the continental shelf to the deep basin of the South China Sea with the increased sea water depth. The spatial distribution pattern of BSi content and diatom abundance in the Chinese marginal seas is principally controlled by terrestrial input, which gradually decreases with depth, other than the primary productivity in the upper euphotic layer. Furthermore, it is found that the contribution of diatoms to the sediment BSi content in the South China Sea has obvious regional variation. The contribution of diatoms to BSi in the continental slope is prominent, while the contribution of the radiolarians and other siliceous organisms cannot be ignored in the deep basin of the South China Sea. In order to better use the BSi, diatoms and other related parameters to study the marine silica cycle and the paleo-ocean environment changes in the marginal sea, further research of other siliceous organisms, such as silicoflagellates and sponge spicules is necessary.
作者
梁宇钊
冉莉华
张兰兰
LIANG Yuzhao;RAN Lihua;ZHANG Lanlan(Key Laboratory of Marine Ecosystem Dynamics.Second Institute of Oceanogra phy,Ministry of Natural Re sources,Hangrhouu 210012,China;Key Laboratory of Marginal Sea Geology,South China Sea Institute of Oeanology,Chinese Academy of Sciences,Guangzhou 510301.China)
出处
《微体古生物学报》
CSCD
北大核心
2021年第1期112-130,共19页
Acta Micropalaeontologica Sinica
基金
国家重点研发计划(2016YFA0601101)
南方海洋科学与工程广东省实验室(珠海)创新团队建设科研经费共同资助。
关键词
硅藻
放射虫
生物硅
表层沉积物
中国海
diatom
radiolaria
biogenic silica
surface sediment
Chinese Seas
