南汇东滩邻近海域春夏季大型底栖动物群落结构分析

Community structure analysis of macrobenthos in the adjacent waters of Nanhui East Beach during the spring and summer seasons

为了评估长江大保护管理措施下,邻近海域生态系统的恢复状况,本研究利用2021年4月和2022年6月在南汇东滩潮下带2个航次的大型底栖动物调查数据,运用生物多样性和非度量多维尺度排序等方法分析了南汇东滩邻近海域大型底栖动物的群落结构特征,并结合历史研究结果进行了对比分析。结果显示:1)2个航次共采集到大型底栖动物44种,其中夏季(31种)>春季(28种),春季大型底栖动物的优势种为安氏长臂虾和葛氏长臂虾,夏季为安氏长臂虾;2)春、夏季物种多样性指数(H′)平均值分别为1.06和1.25,丰富度指数(d)平均值分别为0.94和1.50,均匀度指数(J′)平均值分别为0.56和0.44;3)NMDS和SIMPER分析结果表明,春季和夏季的大型底栖动物在22.63%和20.75%相似性水平上可分别分为3个站位组,且呈现显著的空间结构差异。与历史研究相比,南汇东滩邻近海域的鱼类种类数呈现一定的恢复趋势,甲壳类、多毛类和软体类等生物的种类数变化不显著,建议开展相应生境修复项目,恢复南汇东滩临近海域生态系统。

To assess the restoration of the ecosystem in the neighboring sea area affected by Yangtze River protection and management measures,we utilized survey data on macrobenthos collected from Nanhui East Beach subtidal zone in April 2021 and June 2022.By employing biodiversity analysis and NMDS(non-metric multidimensional scaling),we evaluated the community structure characteristics of macrobenthos and compared them with historical research findings.Our findings indicate the following:1)A total of 44 macrozoobenthos species were identified in both surveys,with 31 species observed in summer and 28 species in spring.During spring,Palaemon annandalei and Palaemon gravieri were the dominant macrozoobenthos species,while P.annandalei dominated during summer.2)The average Shannon-Wiener index values were 1.06 and 1.25 for spring and summer,respectively.The average Margalef index values were 0.94 and 1.50,and the average Pielou index values were 0.56 and 0.44 for spring and summer,respectively.3)Based on NMDS and SIMPER analysis,a similarity level of 22.63%and 20.75%allowed us to classify the macrobenthos into three station groups for spring and summer,respectively,revealing significant spatial structural differences.In comparison with historical research,fish species in the adjacent waters of Nanhui East Beach demonstrated a certain recovery trend,while crustaceans,polychaetes,and molluscs did not exhibit significant changes.We recommend implementing habitat restoration projects to restore the ecosystem of the adjacent waters of Nanhui East Beach.