枸杞岛贻贝养殖区大型底栖动物群落结构及与环境因子的关系

大型底栖动物物种组成及其群落结构能间接反映贻贝养殖区底栖生态状况。基于2021年4月和8月枸杞岛贻贝养殖区现场调查数据,开展了大型底栖动物群落结构、季节差异及主要驱动因子的系统解析。调查共鉴定大型底栖动物172种,隶属14纲40目84科,物种季节更替率为83.14%。丰度等级分布(Rank abundance)曲线表明,夏季物种更丰富,但均匀度相对较低。春、夏季大型底栖动物Shannon-Wiener多样性介于1.61～2.95之间,季节间差异显著。Simpson指数与盐度、沉积物中值粒径(D50)存在显著正相关关系;生物量与沉积物中值粒径、总有机碳(TOC)存在显著负相关关系;物种数、Chao1指数、生物量、丰富度均与TOC显著负相关。聚类分析将春季分为四个组别,夏季分为三个组别,NMDS分析表明,春季分组物种分离不显著,夏季分组物种分离显著,相似性分析(ANOSIM)印证了这种差异。应用相似百分比(SIMPER)分析表明,季节平均相异率为87.57%,分歧种为丝异须虫(Heteromastus filiformis)。CCA分析表明,溶解氧、TOC和硝酸盐是驱动贻贝养殖区大型底栖动...

STUDY ON THE COMMUNITY STRUCTURE OF MACROBENTHOS IN THE MUSSEL BREEDING AREA OF GOUQI ISLAND

The species composition and community structure of macrobenthos indirectly reflect the benthic ecological status of the mussel farm. Based on the investigation data of macrobenthos in the mussel farm near Gouqi Island, Zhejiang, the East China Sea, in April and August 2021, the seasonal differences, community structure, and main driving factors of macrobenthos were studied. A total of 172 species of benthos were identified, belonging to 14 classes, 40 orders, and 84 families. The seasonal replacement rate of species was 83.14%. It was shown in the Rank abundance curves that the species were more abundant in summer and the evenness was relatively low. The value of Shannon Wiener''s index of macrobenthos in spring and summer ranged from 1.61 to 2.95, with significant seasonal differences. Simpson index was positively correlated with salinity and particle size significantly; the Chao1 index was positively correlated with water temperature significantly, and negatively correlated with organic carbon significantly. Benthic assembles were divided into four groups in spring and three groups in summer using cluster analysis. It was shown in the NMDS (non-metric multidimensional scaling) analysis that there was no significant difference between grouped species in spring except in summer, which was confirmed by similarity analysis (ANOSIM). According to SIMPER (similarity percentage) analysis, the average difference rate of macrobenthos between spring and summer was 87.57%, and the different species were Heteromastus filiformis. It was shown in the CCA analysis that dissolved oxygen, TOC, and nitrate had an important effect on the community of macrobenthos in the mussel culture area, of which dissolved oxygen and TOC were the main factors in spring and nitrate in summer. On the whole, the ecology status of macrobenthos under the mussel farm maintained a high species diversity level. However, eutrophication in summer needs to be concerned.