2009年春季舟山海域大型底栖生物群落结构的生态特征

2009年4月对舟山海域13个站位的大型底栖生物群落结构的生态特征进行了调查,并结合2001—2008年浙江近岸海域生态环境监测数据资料,分析了该海域大型底栖生物的变化趋势及其生存环境现状。结果表明,调查海域共鉴定出大型底栖生物84种,其中多毛类31种,甲壳类25种,软体动物12种,鱼类8种,腔肠动物4种,棘皮动物和其它类各2种。2009年春季该海域大型底栖生物的生物量平均值为11.62g/m2,丰度平均值为208.5个/m2,生物多样性指数(H′)为1.64,丰度呈由近岸向外海递增的趋势。根据Bray-Curtis相似性系数聚类分析和多维尺度排序分析,该海域大型底栖生物可划分为3个群落,分别为群落Ⅰ:双鳃内卷齿蚕-织纹螺-孔鰕虎鱼群;群落Ⅱ:色斑角吻沙蚕-脊尾白虾群落;群落Ⅲ:葛氏长臂虾-织纹螺群。通过丰度/生物量累积k-优势度曲线分析可知,该海域大型底栖生物群落已受到中度程度的污染或扰动,群落结构不稳定。比较分析2001—2009年舟山海域大型底栖生物生物量和丰度变化趋势可知,个体较小、生长周期较短的种类逐步成为舟山海域的优势类群。

Ecological characteristics of macrobenthos community in Zhoushan sea area in spring of 2009

Ecological characteristics of the community structure of macrobenthos in Zhoushan sea area at 13 stations were investigated in April 2009.Combined with the data from ecological environment monitoring for the coastal areas of Zhejiang from 2001 to 2008,the change trends and present status of the living environment of them were analyzed.UIK Margalef’s species richness index(d),Shannon-Wiener index(H′) and Pielou’s evenness index(J′) of species were calculated separately;the community was divided according to cluster analysis by Bray-Curtis’s similarity coefficient and multidimensional scaling ordination;the community was analyzed by Abundance Biomass Comparison(ABC) method,and data were processed by computer.In the study,84 macrobenthos were identified in which 31 are polytraeta,25 crustacea,12 mollusc,8 fishes,4 coelenterate,and 2 echinozoa and others respectively.The average biomass of macrobenthos in the area in spring is 11.62 g/m2,average abundance is 208.5 ind/m2,and biodiversity index(H′) is 1.64,and the abundance have a trend of increase from nearshore waters to offshore waters.The dominant species are Exopalaemon carinicauda,Palaemin gravieri,Nassarius sp.,Trypauchen vagina,Aglaophamus dibranchis,Goniada maculate and Cossurella dimorpha.The macrobenthos in the area can be divided into three communities,that is,Community Ⅰ: Aglaophamus dibranchis-Nassarius sp.-Trypauchen vagina,Community Ⅱ: Goniada maculate-Exopalaemon carinicauda,and Community Ⅲ: Palaemin gravieri-Nassarius sp.CommunityⅠis located in the offshore area,its species number,abundance,biomass and Shannon-Wiener index(H′) is the highest in the three communities,while Community Ⅲ which is located in the nearshore areas is of poor habitat,low biomass,low inhabiting density and uneven distribution of quantity.The curves of Abundance Biomass Comparison show that the macrobenthos communities in Zhoushan sea areas have suffered moderate contamination or disturbance,and the environment quality is not well.Comparing the data from 2001 to 2009,it can be seen that the species of small body size and short life cycle are becoming dominant groups.