长江口北支贝类放流滩涂区潮下带水域浮游植物分析

Analysis of phytoplankton in the subtidal waters of the north branch of the Yangtze River Estuary

2012年9月至2013年6月按季度对长江口北支贝类放流区外潮下带海域进行了浮游植物调查,共鉴定出浮游植物8门75属228种,其中硅藻门153种、绿藻门25种、蓝藻门21种、甲藻门14种、金藻门2种、黄藻门2种、隐藻门2种和裸藻门9种。不同季节浮游植物种类组成不同,春季6门31属73种,夏季5门34属106种,秋季7门61属111种,冬季5门27属63种。各季节丰度分别为春季3.78×10^5个/L,夏季7.93×105个/L,秋季3.72×10^5个/L,冬季1.14×10^5个/L。对浮游植物与水化因子进行CCA典范应对分析,结果显示悬浮物、浊度、营养盐对浮游植物丰度影响较大。由于贝类投放和环境因子的变化,生态修复前后浮游植物种类组成变化显著,各季节浮游植物种类数及丰度都有明显增加。

From September 2012 to June 2013,phytoplankton surveys were conducted in the outer and outer tidal zones of the north branch of the Yangtze River estuary.A total of 228 species of 75 genera of phytoplankton were identified,including 153 species of Bacillariophyta,25 species of Chlorophyta,21 species of Cyanobacteria,14 species of Dinoflagellates,2 species of Chrysophyta,2 species of Xanthophyta,2 species of Cryptophyta and 9 species of Euglena.There was obvious seasonal variation in the species composition of phytoplankton.There are 73 species of 31 genera and 6 phyla in spring,106 species of 34 genera and 5 phyla in summer,111 species of 61 genera and 7 phyla in autumn,and 63 species of 27 genera and 5 phyla in winter.The abundance of each season was 3.78×10^5 cells/L in spring,7.93×10^5 cells/L in summer,3.72×10^5 cells/L in autumn,and 1.14×10^5 cells/L in winter.The CCA model response analysis of phytoplankton and hydration factors was carried out.The results showed that suspended solids,turbidity and nutrient salt had great influence on the abundance of phytoplankton.Due to the change of shellfish and environmental factors,the composition of phytoplankton changed significantly before and after ecological restoration.The number and abundance of phytoplankton increased obviously in all seasons.