山东烟台大沽夹河河口及邻近海域大型底栖动物群落特征

Characteristics of macrobenthic communities in the estuary of Dagujia River and its adjacent water areas in Yantai, Shandong

为了解烟台大沽夹河河口及邻近海域大型底栖动物群落特征及受干扰情况,于2012年9月在上述区域设置12个采样点进行大型底栖动物群落调查和分析。对采集的生物样品进行物种鉴定、计数和称重,利用生物统计软件PRIMER计算优势度指数(Y)、Shannon-Wiener多样性指数(H')、Margalef丰富度指数(D)和Pielou均匀度指数(J),并进行等级聚类(CLUSTER)、非度量多维标度排序(non-metric multi-dimensional scaling,MDS)及丰度/生物量曲线(abundance and biomass curves,ABC)分析。共采集和鉴定大型底栖动物89种,优势类群为多毛类。总平均生物量为18.02 g/m^2,软体动物贡献率最高;总平均丰度为2,165 ind./m^2,甲壳类贡献率最高。丰富度指数(D)、均匀度指数(J)和Shannon-Wiener多样性指数(H')分别为2.620±1.324、0.585±0.294和2.398±1.351。CLUSTER聚类和MDS标序结果表明,在30%的相似性水平,不同站位可分为5组,且不同组间差异显著。环境因子与群落分布特征相关性较大,其中最能解释群落丰度和生物量空间分布特征的环境因子为水温、盐度和总磷含量。ABC曲线表明该区域超过80%的采样点其大型底栖动物已受到中等到严重程度的扰动。结合历史资料发现,调查区域大型底栖动物群落物种呈小型化变动趋势,尤其是大沽夹河入海口处,物种组成单一,小型甲壳类占绝对优势。

A survey on macrobenthic assemblages was carried out in the estuary of Dagujia River and its ad- jacent waters in September 2012 （Yantai, China）, to investigate the macrobenthic community and disturbance from anthropogenic activities. The software package PRIMER was used to calculate four biodiversity indices and carry out CLUSTER, non-metric multi-dimensional scaling （MDS） ordination analyses, abundance and biomass curves （ABC） to analyze the community structure. A total of 89 macrobenthic species were identi- fied, of which the dominant group was polychaetes. The average biomass and abundance was 18.02 g/ms and 2,165 ind./ms, respectively, of which Molluscan species contributed most to biomass and Crustacean species contributed most to abundance. Three biodiversity indices, Richness index, Evenness index and Shan- non-Wiener index were 2.620 q- 1.324, 0.585 ＋ 0.294 and 2.398 q- 1.351, respectively. CLUSTER and MDS analysis showed that macrobenthic assemblages could be divided into five sub-groups based on Bray-Curtis similarity and significant difference was found within the sub-groups. The spatial distribution of abundance and biomass of the community was closely related to water temperature, salt and total phosphorus. ABC curves showed the macrobenthic assemblages suffered disturbance from moderate to severe extent due to anthropogenic activities. Further analysis shows community succession has occurred, seen through a miniaturi- zation tendency of individual body size, and decreasing number of species in assemblages as well as the dominant group changing to Crustacea in the estuary of Dagujia River.