芝罘岛污水排放对大型底栖动物群落的影响

Effects of Sewage Discharge on the Macrobenthic Community Offshore Area of Yantai, Shandong Province

关键词:  烟台芝罘岛  大型底栖动物  群落结构  污水排放  环境因子

Key words:  Yantai Zhifu Island  macrobenthos  community structure  sewage discharge  environmental variables

摘要:

[目的]分析芝罘岛附近污水排放对该海域大型底栖动物群落结构的影响,为近岸海区生物多样性保护的可持续和海洋环境生态监测利用提供科学依据。[方法]于2012年9月在芝罘岛附近海域设置10个站位对大型底栖动物群落进行调查和分析。采用生物统计软件PRIMER6.0计算Shannon-Wiener多样性指数(H')、Margalef物种丰富度指数(D')和Pielou物种均匀度指数(J'),并进行等级聚类(CLUSTER)、MDS标序及ABC曲线分析。[结果]共鉴定出大型底栖动物63种,其中多毛类35种,软体动物13种,甲壳动物11种,棘皮动物3种,其他类群生物1种,优势类群为多毛类。总平均生物量为8.30 g/m²,软体动物贡献率最高;总平均丰度为618.67 ind./m²,多毛类贡献率最高。Shannon-Wiener多样性指数(H')、Margalef物种丰富度指数(D')和Pielou物种均匀度指数(J')分别为3.173±0.102,5.469±0.417和0.965±0.007。Pielou物种均匀度指数(J')与盐度呈显著正相关关系(P<0.05),而Shannon-Wiener多样性指数(H')和Margalef物种丰富度指数(D')与12个主成分环境因素均无显著相关性。CLUSTER聚类分析和MDS标序结果表明,在60%的相似性水平上,不同站位可分为3组,且不同群落组间差异显著。离排污口最近的Z2站位以丝异蚓虫为主的多毛类占绝对优势,且优势种表现出小型化趋势。[结论]水深、溶解氧与总氮含量是影响该海域大型底栖动物群落空间分布的关键环境因子,与底栖动物丰度、生物量的相关性较大。ABC曲线显示该海域部分站位的底栖动物群落受到中等程度的扰动。结合历史材料发现,调查区域大型底栖动物群落物种呈小型化趋势,物种组成单一,多毛类占绝对优势。

Abstract:

[Objective] Analyzing the impacts from the sewage discharge on the macrobenthic community provides scientific basis for sustainable development of biodiversity conservation in coastal areas and marine environmental monitoring.[Methods] A survey was carried out in September 2012 on 10 sampling stations at the water areas near to Zhifu Island,offshore area of Yantai,Shandong province.Community characters,three biodiversity indices,CLUSTER,non-metric multi-dimensional scaling (MDS) ordination analysis,abundance and biomass curves (ABC) analysis were calculated and analyzed by software PRIMER 6.0.[Results] A total of 63 macrobenthic species were identified,including 35 species of Polychaetes,13 species of Molluscan,11 species of Crustacean,3 species of the Echinoderm,one species of other groups,of which the dominant group was Polychaetes.The average biomass and abundance was 8.30 g/m² and 618.67 ind./m²,respectively,of which Molluscan species contributed most to biomass and Polychaetes contributed most to abundance.Three biodiversity indices,Shannon-Wiener index,Richness index and Evenness index,were 3.173±0.102,5.469±0.417 and 0.965±0.007,respectively.Pearson correlation analysis showed that Evenness index was significantly positive related to salinity.However,the Shannon-Wiener index and Richness index were not significantly related to the 12 environmental variables.CLUSTER and MDS analysis showed that macrobenthic assemblages could be divided into three sub-groups based on 60% similarity and significant difference was found between different sub-groups.The species composition of station Z2 nearest to the sewage discharge point was dominated by polychaetes and it showed a miniaturization trend.[Conclusion] The environmental variables such as water depth,dissolved oxygen,and TN influenced the spatial distribution of macrobenthos,and they were significantly related to the biomass and abundance.ABC curves showed that the macrobenthic community at some stations had been suffered moderate disturbance from anthropogenic activities.Comparing with the previous researches at same water areas,it is found that the macrobenthic community has went through a miniaturization tendency of individual body size and decreased number of species,and that the dominant group is changing to Polychaetes.