渤海浮游植物群落结构的季节变化及其环境影响因子研究

Seasonal variation of the phytoplankton communities and their environmental factors in the Bohai Sea

浮游植物在海洋生态系统中发挥着重要作用,浮游植物群落变化可以反映海洋环境的变化。渤海海域受人类活动影响剧烈,水体富营养化及赤潮问题日趋严重。本研究以渤海中部(37°70′-39°70′N,119°00′-121°51′E)为研究海域,于2016年12月和2017年2月、5月、9月采集浮游植物样品,对浮游植物物种组成、丰度、优势种及群落多样性等进行了研究。此次调查共确定浮游植物3门68属131种,具体为硅藻46属90种,甲藻19属37种,金藻3属4种。该海区的浮游植物群落结构和优势物种显示了一定的季节演替特征,冬季、春季和夏季硅藻占优,秋季硅藻和甲藻联合占优。与历史同期资料对比发现,具槽帕拉藻(Paralia sulcata)和圆筛藻属(Coscinodiscus)仍为该海域主要优势种,但某些硅藻类群如细线条月形藻(Amphora lineolata)、新月柱鞘藻(Cylindrotheca closterium)和圆海链藻(Thalassiosira rotula)优势度有所提高。营养盐的浓度和结构是渤海浮游植物群落结构差异的重要影响因子。本研究有助于了解渤海的生物多样性,可为渤海海域的生态环境保护和评价提供一定的参考。

Phytoplankton play an important role in marine ecosystems,and the changes of phytoplankton community can reflect changes in marine environment.The Bohai Sea is severely affected by human activities,and the problems of eutrophication and harmful algal blooms in the Bohai Sea are becoming more and more serious.A comprehensive survey was carried out in the central Bohai Sea(37°70′-39°70′N,119°00′-121°51′E)in February,May,September 2017 and December 2016.The taxonomic composition,abundance and diversity of phytoplankton communities and the distribution of dominant taxa were studied.A total of 131 taxa of 68 genera in 3 phyla were identified,including 90 diatom species in 46 genera,37 dinoflagellate species in 19 genera and 4 chrysophyta species in 3 genera.The community structure and dominant species in the survey area showed obvious shifts with seasonal changes.The dominant species in winter,spring and summer all belonged to diatoms,while those in autumn belonged to diatoms and dinoflagellates.By comparing the results with historical data,we found that Paralia sulcata and Coscinodiscus were the common dominant taxa in this area.However,the dominance indices of Amphora lineolata,Cylindrotheca closterium and Thalassiosira rotula were higher than before.Nutrient concentration and structure are the important factors influencing phytoplankton community structure.This study is helpful to understand the biodiversity of the Bohai Sea,and can provide some reference for the protection and evaluation of the ecological environment of the Bohai Sea.