基于3种生物指数的三沙湾养殖活动底栖环境效应研究

为考察我国东海区最为典型养殖海湾三沙湾养殖活动的底栖环境效应，本研究根据2016年8月航次41个样品采集站位的数据，分析香农-威纳多样性指数（Shannon-Wiener index，H'）、海洋生物指数AMBI（AZTI's Marine Biotic Index）和多变量海洋生物指数M-AMBI（Multivariate-AMBI）在4种典型水域（网箱、海藻、鲍鱼养殖和无养殖水域）间的差异及其与沉积物环境因子（δ15N、δ13C、C/N比、总有机碳、总氮、总磷、硫化物、含水率和粉粒-黏粒比例）的相关性。结果表明，航次共采集74种大型底栖生物，H'介于0~3.51；物种多属环境敏感类型（AMBI方法中EGⅠ和EGⅡ生态组），AMBI指数介于0~4.13，M-AMBI指数介于0.30~0.77。3种生物指数的分布水平表明此海域总体底栖生态质量良好，仅在局部水域存在显著扰动。Kruskal-Wallis检验显示仅H'在不同类型水域之间存在显著差异（P<0.05），后续配对检验（Pairwise comparision）显示大黄鱼养殖水域H'显著高于海藻养殖水域（P<0.01）。基于斯皮尔曼秩相关系数（Spearman correlation coefficient）的相关性分析表明仅H'和M-AMBI指数分别与总磷存在显著相关性（P<0.05）。聚类分析（Cluster analysis）结果显示不同类型站位在聚类图中随机分布，聚类结果未体现出采样水域的差异性。综上，基于3种生物指数的分析结果显示三沙湾内网箱等典型养殖活动未对区域底栖生境质量造成显著影响。

Effects of mariculture activities on benthic environment based on analysis of three biotic indices in Sansha Bay

Based on the dataset obtained from 41 stations of a cruise in August of 2016, Shannon-Wiener index (H'), AZTI's Marine Biotic Index (AMBI) and M-AMBI (Multivariate-AMBI) were employed to investigate the potential benthic environmental impacts of offshore mariculture activities in Sansha Bay, a typical aquaculture bay in the East China Sea. The three indices of macrobenthic organisms from four typical waters (finfish, seaweed, abalone farms and non-farm area) were compared and the correlations between these indices and the typical environmental parameters (δ15N, δ13C, C/N ratio, total organic carbon, total nitrogen, total phosphorus, acid volatile sulfide, water content and silt-clay fraction) were analyzed. A total of 74 species of macrobenthic organisms were identified in this study, with H' of 0-3.51, AMBI of 0-4.13 and M-AMBI of 0.30-0.77. Most species were assigned to environment-sensitive type, i.e. the EGI and EGⅡ ecological groups in the AMBI method. The distribution of the three biotic indices indicated that the overall environmental quality of the Sansha Bay was good except for occasional noticeable disturbances occurred in partial areas. Kruskal-Wallis test showed that only H' differed among three typical waters (P<0.05), and supplementary Pairwise comparison showed that H' in cage farm area of Pseudosciaena crocea was statistically higher than that in seaweed farm area (P<0.01). Spearman correlation coefficient showed that significant correlation between indices and environmental parameters were occasionally present, only for H' and M-AMBI were significantly correlated with total phosphorus (P<0.05). Furthermore, cluster analysis revealed that sampling stations were randomly distributed, which did not correspond to differences of the farm categories. In conclusion, analysis of the three biotic indices indicated that the typical mariculture activities in Sansha Bay had no significant impacts on the quality of regional benthic habitats.