雷州半岛东南部海域春季大型底栖动物群落特征及其与环境因素的关系

根据2014年3月在雷州半岛东南部海域开展的海洋生态环境调 查数据资料,对该海域大型底栖动物群落特征进行了研究。研究区内共鉴定大型底栖动物39种,其中软体动物所占比例最大,其次为环节动物;彩虹蛤蜊(Mactra iridescens)、棒锥螺(Turritella bacillum)、粗帝汶蛤(Timoclea scabra)、西格织纹螺(Nassarius siguinjorensis)、红明樱蛤(Moerella rutila)和背毛背蚓虫(Notomastus cf. aberans)等6种为主要优势种。平均生物量和丰度分别为251.32 gm-2和 480.0个m-2;其平面分布趋势较为复杂,丰度大致呈现西南部高、东北部低的趋势;可划分为5个分布较为分散且差异明显的群落(R=0.951,P=0.001);各群落的优势种组成差异较大、更替率高。全海域底栖动物多样性水平较高,均匀度、丰富度和多样性指数分别为0.59、2.36和2.35,而各群落的多样性水平均较低。5个群落的ABC曲线均出现不同程度的交叉和重叠,表 明雷州半岛东南部海域底栖动物群落受到明显的扰动,稳定性较差;与环境因素相关分析表明,水动力作用、沉积物中铜(Cu)、铬(Cr)含量以及人为扰动是导致群落结构差异及不稳定的主要因素。

Relationship between macrobenthic fauna community and environmental factors in Southeast Leizhou Peninsula of the South China Sea

Based on the data collected from 13 sampling stations in Southeast Leizhou Peninsula of the South China Sea in March 2014, we examined the characteristics of macrobenthic fauna community. Thirty-nine species of macrobenthic fauna were obtained. The highest number of species were mollusca, followed by Annelida. The dominant species of macrobenthic fauna were Mactra iridescens, Turritella bacillum, Timoclea scabra, Nassarius siguinjorensis, Moerella rutila and Notomastus aberans. The average biomass and abundance were 251.32 gm-2 and 480.0 indm-2, respectively. The trend of spatial distribution was complicated, and the abundance was generally higher in southwest area but lower in northeast area. The results of cluster analysis and MDS showthat macrobenthic fauna community could be divided into five significantly different groups (R=0.951,P=0.001) and there was great difference of dominant species among the groups. Overall, the diversity of macrobenthic fauna community for the survey area was higher. The Pielou evenness index, Margalef species richness index and Shannon-Wiener index were 0.59, 2.36 and 2.35, respectively; however, the diversity was low for each group. ABC analysis for five groups shows that macrobenthic fauna community in the surveyed are a in spring was seriously disturbed, with poor community stability. The correlation analysis between macrobenthic fauna community and environmental factors show that hydrodynamic affects the content of heavy metals such as Cu, Cr in sediments and the disturbance is caused by human activity, which are the main factors affecting difference and instability of macrobenthic fauna community.