深层海洋浮游植物研究综述

Phytoplankton in the deep sea,a review

对深层海洋(>200 m)浮游生物的研究是我国海洋浮游生物研究的前沿,已有的深层海洋浮游生物知识是我国相关研究的基础。浮游植物需要阳光进行光合作用,大多数浮游植物沉降到深海中会死亡,但有些浮游植物却能在深海中生存。综述深层海洋中存活的浮游植物的研究进展,为我国的研究提供参考。在深层海洋发现的浮游植物(>2"m)种类不多,共有18种,最深分布在4000 m,颗石藻的丰度大于硅藻和甲藻,最大丰度为2220个/L,出现在500 m。在1911—1985年期间,曾经发现橄榄绿细胞,由于研究手段有限,一直没有对其进行分类学研究。1985年以后的研究怀疑这些橄榄绿细胞就是聚球藻蓝细菌,聚球藻蓝细菌在太平洋、大西洋和地中海的几个站位能分布到2750 m,在深层海洋的最大丰度为3.5×105个/mL,出现在800 m。在许多海区200—700 m发现有浮游植物色素荧光的高值,但对引起高值的原因尚不清楚。浮游植物生物量在深层海洋的垂直剖面研究不多,已有的研究表明浮游植物生物量在300 m以深为0.001—0.1"g C/L,且其随深度增加而降低。

The study of deep sea （〉200 m） plankton is the frontier of marine biology and ecology research in China. Summarizing existing knowledge of deep sea plankton is important to Chinese research in this field. Most phytoplankton will die when they settle out of the euphotic zone. However, some phytoplankton manages to survive in the deep sea despite of the darkness. This review synthesized the research of living phytoplankton in deep sea. Phytoplankton needs sunlight to carry out photosynthesis. There were only 18 species of phytoplankton found in the deep sea with the maximum depth of 4000 m. The abundance of coccolithphore was higher than that of diatoms and dinoflagellates. Maximum abundance of coccolithphore in the deep sea was 2220 cells/L in the depth of 500 m. In the years 1911-1985, the olive green cells were found in deep seas. There was no extensive taxonomic definition of olive green cells due to limited research devices. After the year 1985, the olive green cells was deemed as Synechococcus spp., which was found in 2750 m. Maximum abundance of Synechococcus spp. found in deep sea was 3.5 ×105 cells/mL at a depth of 800 m. In situ fluorescence profiles in the deep sea found tertiary phytoplankton pigment maxima in 20-700 m depth. However, we are not sure what organisms caused the fluorescent maxima. There was little information about the biomass of phytoplankton in the deep sea. In the limited studies, phytoplankton biomass （0.001-0.1μg C/L） decreased with depth from 300 m to the bottom.