广西涠洲岛海域浮游植物群落结构季节变化特征及环境影响因素

Seasonal Variation Characteristics of Phytoplankton Community Structure and Environmental Impact Factors in the Weizhou Island,Guangxi

关键词:  涠洲岛  浮游植物  群落结构  季节变化  影响因素  布氏鲸

Key words:  Weizhou Island  phytoplankton  community structure  seasonal change  impact factors  Balaenoptera edeni

摘要:

为了解广西涠洲岛布氏鲸(Balaenoptera edeni)栖息海域浮游植物群落结构的季节变化特征及其环境影响因素，分析浮游植物群落结构季节变化与布氏鲸季节性迁徙的关系，于2022年1月(冬季)、4月(春季)、8月(夏季)和11月(秋季)对广西涠洲岛布氏鲸栖息海域的浮游植物进行系统调查。结果显示，全年共鉴定出浮游植物3门54属115种，物种组成以硅藻(93种)和甲藻(19种)为主。浮游植物种类组成季节差异不明显，但优势种更替显著，优势类群也发生较大变化，其中冬、春季以硅藻门(Bacillariophyta)为最具优势类群，优势种也均属硅藻门，而夏、秋季优势类群转变为硅藻、蓝藻和甲藻等多门类。浮游植物细胞密度也具有较大差异，春季最高，冬季次之，夏、秋季最低。浮游植物与环境因子的冗余分析(RDA)表明，营养盐、水温(WT)和盐度(S)是影响浮游植物细胞密度、优势种季节变化的主要环境因子。布氏鲸冬春季迁徙进入、夏秋季迁徙退出涠洲岛与浮游植物细胞密度季节变化吻合，作为初级生产者的浮游植物可能通过食物网的上行控制作用影响着顶级营养级海洋生物布氏鲸的迁徙。

Abstract:

In order to understand the seasonal variation characteristics of phytoplankton community structure and its environmental impact factors in the habitat of Balaenoptera edeni in Weizhou Island,Guangxi,and to analyze the relationship between the seasonal variation of phytoplankton community structure characteristics and the seasonal migration of B.edeni,the phytoplankton in the habitat of B.edeni in Weizhou Island,Guangxi were systematically investigated in January (winter),April (spring),August (summer) and November (autumn) in 2022.A total of 115 species of phytoplankton belonging to 54 genera and 3 phyla were identified throughout the year.The species composition was dominated by Bacillariophyta (93 species) and Pyrrophyta (19 species).The seasonal difference of phytoplankton species composition was not obvious,but the dominant species changed significantly,and the dominant groups also changed greatly.Among them,Bacillariophyta was the most dominant group in winter and spring,and the dominant species also belonged to Bacillariophyta.However,in summer and autumn,the dominant groups changed to be composed of Bacillariophyta,Pyrrophyta and Cyanophyta.The density of phytoplankton cells also changed greatly,with the highest in spring,the second in winter,and the lowest in summer and autumn.Redundancy Analysis (RDA) of phytoplankton and environmental factors showed that nutrients,Water Temperature (WT) and Salinity (S) were the main environmental factors affecting the seasonal variation of phytoplankton cell density and dominant species structure.The migration of B.edeni into Weizhou Island in winter and spring,and out of Weizhou Island in summer and autumn were consistent with the seasonal variation of phytoplankton cell density.Phytoplankton,as a primary producer,may affect the migration of the top trophic marine organism B.edeni through the upward control of the food web.