Community structure and seasonal variation of demersal nekton in the eastern waters of Laizhou Bay
In order to understand the community structure characteristics and seasonal changes of demersal nekton in the eastern sea area of Laizhou Bay,this paper based on the results of autumn and winter bottom trawling surveys carried out in the eastern waters of Laizhou Bay from 2020 to 2021,using species similarity index,relative importance index,cluster analysis,non-metric multidimensional scaling analysis(nMDS),niche width and overlap index,and food web topology network analysis,etc.,explored the community structure characteristics of bottom nekton in this water area and their seasonal trends.The results showed that 47 species and 40 species of bottom nekton were captured in autumn and winter respectively.The dominant species in autumn included 6 species:Cynoglossus joyeri,Oratosquilla oratoria and Chaeturichthys stigmatias,Trachysalambria curvirorostris,Loligo japonica,Portunus tritubercaulatus.The dominant species in winter included Chaeturichthys stigmatias,Callionymus beniteguri and Crangon hakodatei.The species composition of bottom nekton and the seasonal turnover of dominant species were more obvious.The grouping of the demersal nekton community was extremely significant based on the similarity of 49％(P＜0.01;Stress=0.12,0.13).According to the survey station,it could be divided into 2 groups in autumn and 3 groups in winter.The average niche breadth index in autumn and winter was 0.83 and 0.76,respectively,while the niche overlap index ranged from 0.11 to 0.94 and 0.13 to 0.93,respectively.The ecological niche space differentiation of bottom nekton was more obvious in autumn,but the relationship of resource competition was greater in winter.Comparing and analyzing the food web topological structure network and its related indexes,the food web structure of bottom nekton in autumn was more stable than that in winter,and the complexity was higher in autumn.Overall,the structural characteristics and stability of demersal nekton communities in the eastern sea area of Laizhou Bay showed obvious seasonal differences.
eastern waters of Laizhou Baydemersal nektoncommunity structureecological nichefood relations
万方数据
维普
