Study On The Community Structure Characteristics Of Fishery Resources,Zooplankton And Phytoplankton In Huanghua Port

To understand the variation characteristics of fishery resources,zooplankton and phytoplankton community structure in Huanghua port,two annual cruises of fishery resources and ecological environment investigation were carried out in 2014 and 2018.The relative importance index(IRI),Margalef index(d),Shannon-Winner index(H'),Pielou index(J'),cluster analysis,Abundance biomass comparison curve(ABC curve)and redundancy analysis(RDA)were used to evaluate density index of resources,species composition,dominance and community structure of marine life.The results showed :(1)the number of fishery resources in Huanghua port in 2014(49 species)was slightly higher than that in 2018(46 species),and the dominant species of fishery resources showed miniaturization and low-value.From the perspective of temperature adaptability,the fishery resources in 2014 and 2018 were mainly warm and warm-water species,and from habitat,the continental shelf shallow water bottom and the continental shelf shallow water upper were the main ones.(2)It was found in the two annual surveys that the spatial and temporal distribution of fishery resources in of Huanghua port was uneven and there were seasonal-differences.According to ABC curve,the community structure of fishery resources in 2018 was more stable than in2014.The change of biomass of crustaceans and gobiidae was the main reason for the difference of community structure.According to the cluster analysis of community structure,the similarity of community structure composition of fishery resources in2014 and 2018 was more than 40%,which indicated that the community structure characteristics of fishery resources in two years had good stability.Seasonal change may be one of the main reasons affecting the change of fishery resource community structure in Huanghua port.(3)In 2014,82 species of phytoplankton in 32 genera of 3phyla were collected in Huanghua port,among which the most species were detected in summer with 50 species of 25 genera of 2 phyla,followed by 40 species of 14 genera of 2 phyla in autumn,34 species of 18 genera of 1 phyla in winter,and 24 species of 14 genera of 3 phyla in spring.The phytoplankton are mainly Bacillariophyta,while the Pyrrophyta and Cyanophyta are relatively few.The seasonal variation trend of phytoplankton abundance was the highest in summer,followed by autumn,lower in winter and spring;Phytoplankton community of four cruises displayed low community diversity and evenness index;Autumn's dominant specie was only Rhizosolenia alata,while many phytoplanktons coexisted in spring,summer and winter,the succession of dominant species was obvious in different seasons.Through RDA analysis,it was found that in winter the main factors influencing the spatio-temporal variation of dominant species of phytoplankton were dissolved oxygen,temperature and phosphate,spring was the temperature and salinity,summer to salinity,dissolved oxygen and salinity,temperature and dissolved oxygen in autumn as the main influence factors.(4)In 2014,a total of 8 categories and 64 species of zooplankton were identified in Huanghua port,and the seasonal distribution trend of species was spring(7 categories and 41 species)> summer(8 categories and35 species)> autumn(7 categories and 23 species)> winter(4 categories and 12species),and Coelenterata and larva were dominant.The zooplankton community structure has obvious seasonal succession phenomenon,the autumn' dominant species was only Noctiluca miliaris,and a variety of zooplankton coexist in other seasons,but the species diversity in autumn was the lowest.Cluster analysis showed that zooplankton community structure in Huanghua port in 2014 could be divided into large groups in winter,spring,summer and autumn at 35% similarity level,and the community seasonal difference was significant.RDA analysis showed that different zooplankton responses to different environmental factors were the main causes of community seasonal differences,in which temperature,salinity and nutrien played important roles.Through the comprehensive investigation of fishery resources and phytoplankton in the Huanghua port,this research was expected to provide basic data for the development and management of marine engineering in Huanghua port and scientific support for the ecological restoration of Bohai Bay in the future.