长江口潮间带底栖生物生态及变化趋势

基于长江口3个区域潮间带(崇明东滩、南汇边滩和嵊山岛)监测数据，对长江口区域潮间带底栖生物生态现状及变化趋势进行评价。结果表明，2019年长江口海域泥相和岩相潮间带共鉴定大型底栖生物9门57种，软体动物、甲壳类和多毛类构成主要类群。崇明东滩、南汇边滩两个泥相潮间带底栖生物平均栖息密度分别为96.4个/m~2和160.4个/m~2,平均生物量分别为68.42 g/m~2和45.71 g/m~2;嵊山岛岩相潮间带平均栖息密度和生物量分别为488.9个/m~2和763.72 g/m~2。各断面多样性、丰富度和均匀度指数分别位于1.36—3.24、0.75—2.88和0.48—0.77,泥相潮间带低潮区生物多样性优于中潮区和高潮区，岩相潮间带中潮区生物多样性最好。聚类分析可见长江口海域潮间带底栖生物分为泥相和岩相2个大组群，物种分布存在明显的分潮区现象，高潮区站位成群或与个别中潮区站位成群，低潮区站位成群或与个别中潮区站位成群，表明底质类型和潮汐是影响潮间带大型底栖生物群落结构的主要因子。近30年来，崇明东滩和南汇边滩底栖生物种类数存在一定波动，嵊山后陀湾断面生物种类数明显下降；3个区域潮间带...

Ecological evaluation and variation trend analysis of macrobenthos in intertidal zone of Changjiang Estuary

Using macrobenthos monitoring data of 3 intertidal zones (Chongming eastern shoal, Nanhui nearshore and Shengshan Island being CM, NH and SS for short) in Changjiang estuary, biodiversity dynamics were evaluated in this study. The results showed that 9 phyla and 57 species of macrobenthos were identified in the intertidal zone of the Changjiang Estuary in 2019, and molluscs, crustacea and polychaeta were the main groups. The CM and NH were muddy intertidal zones, SS was rocky. The average density was 96.4 ind/m², 160.4 ind/m², and 488.9 ind/m² in CM, NH and SS, the average biomass was 68.42 g/m², 45.71 g/m² and 763.72 g/m² in the three areas. There were 3 sections in every area. The diversity, richness and evenness index were in 1.36-3.24, 0.75-2.88 and 0.48-0.77 with every section. The biodiversity of low tide zone was better than that of middle and high tide zone in muddy intertidal zone, but the middle tide zone was the best in rocky intertidal zone. All the macrobenthos were divided into two groups-muddy and rocky. Different species distributed in high, middle and low intertidal zones. Some species in high intertidal zone formed groups with very view in middle intertidal zone and some species in low intertidal zone formed groups with very view in middle intertidal zone. It showed that the sediment environment and tide were the most significant factors to affect community structure of intertidal macrobenthos. During the past 30 a, the species number of macrobenthos undulated in CM and NH, but decreased in SS; the average density and biomass were decreased in 3 areas, which should be related to wetland reclamation, species invasion, human over fishing and pollution.