鸭绿江口近岸海域水质环境对冬季浮游动物群落结构的影响

定量分析滨海湿地近岸海域水质环境与浮游动物群落结构之间的关系对揭示海水水质环境健康状态具有重要意义。2019年12月在鸭绿江口湿地国家级自然保护区近岸海域开展了浮游动物和水环境因子调查,运用冗余分析和结构方程模型等方法探讨了水质环境对冬季浮游动物群落结构的影响。研究区共鉴定出浮游动物14种以及浮游幼虫5大类,桡足类最多占比52.63%;保护区不同功能分区间浮游动物群落结构总体差异不大,多样性指数、均匀度指数和丰富度指数平均值分别为1.34、0.51和0.59;浮游动物的种群分布与海水化学需氧量、溶解性无机氮、浮游植物群落多样性指数和铜元素含量关系显著;结构方程模型模拟结果表明,海水富营养化水平对浮游动物丰富度的效应系数为-0.26,具有显著的直接影响(P=0.01),重金属污染水平通过影响浮游植物丰富度(效应系数为-0.41,P<0.001)间接对浮游动物丰富度产生作用(间接效应系数为-0.2)。研究结果将有助于深化对海水环境和浮游动物群落结构协同演变过程的认识,为滨海湿地近岸海洋生态系统科学管理提供理论支撑。

Effects of the sea water environmental factors on zooplankton community nearshore of the Yalu River estuary in winter

Quantitative analysis of the relationship between the water environmental factors and zooplankton community nearshore of the coastal wetland is of great significance for assessing the sea water quality. Based on the investigation and sampling of the seawater and zooplankton nearshore of Yalu River Wetland National Nature Reserve in December 2019, the influence of environmental factors on zooplankton community structure was analyzed using Redundancy Analysis (RDA) and the Structural Equation Modeling (SEM). A total of 14 species of zooplankton and 5 groups of planktonic larvae were identified, of which the number of copepods was the highest with proportion of 52.63%. None significant difference of zooplankton community was detected among different subareas of the nature reserve. The diversity index, evenness index and richness index of zooplankton community in the study area were 1.34, 0.51, 0.59, respectively. Simulation result of the SEM showed that richness index of the zooplankton community was directly affected by the eutrophication status of the sea water with a coefficient of -0.26 (P=0.01), and was indirectly affected by the heavy metal pollution status with a coefficient of -0.2. This study provides useful insight for the relationship between sea water environmental factors and the zooplankton community, and provides basis for the scientific management of the offshore marine ecosystem of coastal wetland.