枸杞岛海域春季异养浮游细菌和生态环境因子关系初步研究

Ecology study of the relationship between heterotrophic bacterioplankton and ecological environment in the area of Gouqi Island in spring

为了查明海藻场和贻贝养殖场中均以γ变形菌为优势种的异养浮游细菌发挥不同生态作用的环境条件是否相同,以2009年5月底栖海藻和养殖贻贝快速生长期的实验数据为基础,研究枸杞岛海域表层水体异养浮游细菌与生态环境因子之间的关系。结果显示:春季异养浮游细菌在海藻场海域、贻贝养殖区海域和过渡海域丰度均值分别为1.60×108个/L、1.21×108个/L和1.56×108个/L,水平分布为海藻场高于过渡区域高于贻贝养殖场,且藻场中细菌数量约为贻贝场中的1.33倍。海藻场中异养浮游细菌与叶绿素显著正相关,与铵盐也呈现一定的相关性,这主要归因于大型海藻主要利用硝酸盐而浮游植物与细菌共同竞争铵盐,导致铵盐浓度降低,铵盐成为影响异养浮游细菌生长的限制因子;过渡海域异养浮游细菌和铵盐显著负相关,与溶解有机碳呈正相关;贻贝养殖区中细菌与生态环境因子的关系不明显。因此,叶绿素、铵盐、溶解有机碳是枸杞岛海域春季藻场内外海域制约异养浮游细菌现存量的重要控制因子。研究亮点:本文以异养浮游细菌优势种均为γ变形菌的天然海藻区和人工贻贝养殖场为研究区域,首次在不同生境海域开展异养浮游细菌生态作用的调查,试图理清不同生态群落的存在对异养浮游细菌发挥生态作用的影响机制,为近岸典型生境中微食物环的构建提供依据。

Gammaproteobacteria were the dominant species playing different ecological roles in kelp beds and mussel farms.In order to demonstrate whether the environmental conditions were different in these areas,it was applied to study the relationship between heterotrophic bacterioplankton and environmental parameters during spring in the area of Gouqi Island.The results showed that abundance of heterotrophic bacterioplankton in the area of KSX,MSX and SX were 1.6×108 cells/L,1.21×108 cells/L and 1.56×108 cells/L separately.Horizontal distribution of heterotrophic bacterioplankton was that abundance in KSX was highest and 1.33 fold of number in MSX which was lower than in that SX.Heterotrophic bacterioplankton was positively correlated with chlorophyll a in KSX.It was limited positively by ammonium in KSX,because of algae depending on nitrate and the advantages of bacterioplankton absorbing nutrient and competing with phytoplankton;number of bacterioplankton was negatively influenced by ammionium and positively influenced by dissolved organic carbon in SX.Therefore,Chlorophyll a and ammonium and dissolved organ carbon were the key limiting parameters of heterotrophic bacterioplankton during spring around kelp bed area of Gouqi Island.