Table_2_Macrobenthic community of an anthropogenically influenced mangrove associated estuary on the East coast of India: An approach for ecological assessment.xlsx

The Mahanadi Estuarine System (MES), with a complex network of freshwater channels, rivers, and mangroves, is a leading seaport in State Odisha on the east coast of India, but subjected to intense human activity in recent years. Such anthropic impingements are known to impact sediment-dwelling biota adversely. However, information on the macrobenthic community of the MES is not well documented yet. Therefore, the primary objectives of this study (February 2013-March 2017) were to address knowledge gaps on the macrobenthic community structure vis-à-vis local environmental conditions and to evaluate the extent of anthropogenic disturbances on macrobenthos. The results from 264 benthic grab samples (van Veen, 0.04 m2; 2 replicates × 12 GPS fixed locations × 3 seasons) revealed 73 taxa representing 64 genera and 48 families of macrobenthic fauna. The polychaetes (81.41%) and crustaceans (15.42%) were significant faunal groups that contributed mainly to the benthic population and diversity. Multivariate approaches using benthic community attributes and biotic indices (AMBI and M-AMBI) as proxy measures of environmental disturbances proved effective for appraisal. The correlations between the environmental parameters (temperature, pH, salinity) and community estimates were statistically significant. Hierarchical clustering analysis disclosed three major groups (Global R 0.70; p < 0.002) influenced by tolerant/opportunist species. The lower abundance, richness, diversity, and dominance of opportunistic species mark the signs of environmental stress. The community health status remained unbalanced, as indicated by AMBI scoring. M-AMBI analysis contributed best in differentiating areas exposed to diverse impacts and indicated polluted community health status with moderate ecological quality. Our results reiterate the effective use of macrobenthos as bioindicators for ecological status and monitoring. The findings could be utilized for future monitoring assessments, translated into valuable information, and designed into well-defined sustainable management strategies for the MES.

马哈纳迪河口系统（Mahanadi Estuarine System, MES）拥有由淡水水道、河流与红树林构成的复杂网络，是印度东海岸奥里萨邦的主要海港，但近年来遭受了高强度的人类活动干扰。此类人类活动扰动已知会对底栖生物产生负面影响。然而，目前关于该系统的大型底栖生物群落（macrobenthic community）的相关记录仍较为匮乏。因此，本研究（2013年2月—2017年3月）的核心目标为填补大型底栖生物群落结构与当地环境条件相关的认知空白，并评估人类活动扰动对大型底栖生物（macrobenthos）的影响程度。本研究通过264个底栖采泥样品（范维恩采泥器（van Veen grab），采样面积0.04 m²；每组设置2个重复样，共12个GPS固定采样点，覆盖3个季节）开展分析，共获取隶属于48科、64属的73个大型底栖生物分类单元。其中多毛类（81.41%）与甲壳类（15.42%）为主要的动物类群，主导了底栖生物的种群规模与多样性水平。以底栖生物群落特征与生物指数（AMBI、M-AMBI）作为环境扰动替代指标的多变量分析方法，被证实可有效用于生态评估。环境参数（温度、pH、盐度）与群落评估指标之间的相关性具有统计学显著性。层次聚类分析显示，研究区域可划分为3个主要类群（全局R=0.70；p<0.002），类群划分受耐污种/机会种的影响显著。机会种的丰度、丰富度、多样性及优势度降低，是环境压力的典型表征。AMBI评分结果表明，大型底栖生物群落的健康状态仍处于失衡状态。M-AMBI分析则可更好地区分受不同扰动程度影响的区域，结果显示群落健康状态已受污染，生态质量处于中等水平。本研究结果再次证实，大型底栖生物可作为生态状况监测与评估的有效生物指示物。该研究成果可用于后续的生态监测评估工作，转化为具有实用价值的科学信息，并为马哈纳迪河口系统制定科学合理的可持续管理策略提供支撑。