渤海中部网采浮游植物种类组成和季节变化

Species Composition and Seasonal Variation of Netz-Phytoplankton in the Central Bohai Sea

中文关键词: 渤海中部  浮游植物  优势种  群落结构

英文关键词: Central Bohai Sea  Phytoplankton  Dominant species  Community structure

中文摘要:

      利用2013年5月、7月、11月和12月渤海中部41个站位的4次综合海上调查所获资料，分析其浮游植物群落结构的季节变化特征。共鉴定出浮游植物3门42属87种。其中，硅藻门33属72种，甲藻门9属15种，金藻门1属1种。渤海中部浮游植物优势种多为硅藻，部分甲藻也表现为优势类群。与历史资料比较发现，主要优势种发生了演替现象，往年优势种浮动弯角藻(Eucampia zodiacus)本次调查并未出现，斑点海链藻(Thalassiosira punctigera)首次以优势种出现，浮游甲藻的优势地位与往年相比日趋明显。浮游植物细胞丰度5月、7月、11月和12月平均为 200.14×104、16.32×104、7.43×104、12.77×104 cell/m3，与同期历史资料相比，5月偏高，这与萎软几内亚藻(Guinardia delicatula)的暴发有关，其他月份相对比较稳定。其群落结构特征中的多样性指数(H¢)和均匀度指数(J)均呈现7月>11月>5月>12月的趋势。Spearman相关性分析结果显示，与浮游植物细胞丰度相关度较高的环境因子是无机氮、磷酸盐、石油烃和N/P。

英文摘要:

      The community structure of phytoplankton could be affected by environmental factors, such as water temperature, salinity, total nitrogen, and total phosphorus. Changes in environmental factors may be associated with alteration in the community structure of phytoplankton. To investigate the consequences of oil spill in the Bohai Sea in 2011, here we analyzed features of phytoplankton community structure using data obtained in the comprehensive investigation at 41 stations within the central Bohai Sea in May, July, November and December 2013. The sampling and measuring methods followed the Specifications for Oceanographic Surveys and Specifications for Marine Monitoring. A total of 87 phytoplankton species were found, including 72 species of diatom in 33 genera and 15 species of pyrrophyta in 9 genera. There was another species of chrysophyta in 1 genus. Diatoms were the dominant phytoplankton species, while some dinoflagellates species also accounted for a large portion in the community. Compared to the historical data in the same season, there was an obvious shift in the community structure. Eucampia zodiacus, a previous dominant species, were not found in this survey; however, Thalassiosira punctigera appeared for the first time as a dominant species. The dominance of planktonic dinoflagellate became increasingly evident. The average cell abundance was 200.14×104 cell/m3, 16.32×104 cell/m3, 7.43×104 cell/m3 and 12.77×104 cell/m3 in May, July, November and December respectively. The cell abundance in May was higher compared to the historical data probably due to the outbreak of Guinardia delicatula, and in other month it was relatively stable. The diversity index and evenness index of the community structure followed the order July > November > May > December. The Spearman analysis revealed that changes in the nutrient structure of the central Bohai Sea was responsible for the shift in community structure, and that the spilled petroleum also might have affected the community structure. Because the phytoplankton community structure was generally consistent with results from other investigations, it was most likely unchanged after the oil spill in 2011.