2015-2020年乳山近岸海域春、夏季大型底栖动物群落结构及变化

Structure characteristics and variations of macrobenthic communities in coastal water of Rushan in spring and summer from 2015 to 2020

根据2015-2020年乳山近岸海域春、夏季调查资料,对比分析6年间大型底栖生物的种类数、生物量、丰度、生物多样性的变化趋势.乳山近岸海域春、夏季共鉴定出大型底栖动物115种,其中多毛类50种,软体动物20种,甲壳动物36种,脊索动物5种和其他类群4种.多毛类、软体动物和甲壳动物占总种数的92.2%,三者构成大型底栖动物的主要类群.大型底栖动物平均生物量为72.11 g·m^(-2),平均丰度376个·m^(-2),生物量以软体动物居首位(31.47 g·m^(-2)),丰度以多毛类占第一位(224个·m^(-2)).从生物多样性年际变化来看,2016-2018年Shannon-Wiener多样性指数表明乳山近岸海域存在轻度污染,其他年份为清洁海域.在6个调查年份中,共出现了20种优势种,优势种年际变化较大,多次出现的优势种只有7种,对研究区域大型底栖动物优势种的变化趋势进行分析,乳山近岸海域大型底栖动物优势种向多毛类、软体动物和甲壳动物占比均衡转变.

Based on macrobenthos collected in spring and summer from 2015 to 2020 in water of Rushan coastal area,the variation of the species,biomass,abundance and biodiversity were analyzed.115 species were identified,among which there were 50 species of polychaeta,20 species of mollusca,36 species of crustacea,5 species of chordata,and 4 other groups.Species belonging to polychaeta,mollusca and crustacea accounted for 92.2%of the total species,thus constituting the main population of macrobenthos.The average biomass of macrobenthos in Rushan was 72.11 g·m^(-2),and the average abundance was 376 ind·m^(-2).As to the quantity composition,mollusca had the greatest biomass(31.47 g·m^(-2)),polychaeta was the main contributor to the total abundance(224 ind·m^(-2)).The Shannon-Wiener species diversity index showed that the water of Rushan coastal area was slightly polluted from 2016 to 2018,while ecological quality was good in the other years.A total of 20 dominant species were identified,but only 7 species occurred repeatedly during the sampling period,compared with historical reports,the percentage of each group(i.e.,polychaeta,mollusca,and crustacea,etc.)turned to be closer,rather than polychaeta in dominant.