The Response Of Macrofouling Assemblages To Heavy Metal Stress In Haikou Bay

Macrofouling assemblages are widely distributed in marine environments,and they have considerable merits in the fields of marine ecotoxicity and environmental monitoring,such as various types,sessile animals,clear boundaries,sensitive to environmental pollutants.In this study,the characteristics of response of macrofouling assemblages under heavy metal copper stress were studied by two experimental systems,the laboratory microcosm experiments and field experiments at Haikou Bay,in the South China Sea.The experiments were carried out in both dry and rainy seasons.The correlation between fouling assemblage response and ecological factors,including heavy metal copper,was systematically analyzed through multiple comparison.The main experimental results are as follows:(1)The attachment of macrofouling fauna in Haikou Bay can occurred throughout the year.Twenty species were found in the dry season.According to biomass,the dominant species were Bugula neritina,Bugula robusta,and Laeospira papillatus.While according to abundance,the dominant species were Lichenopora radiata,Membranipora savartii,and Sinoflustra annae;Eighteen species were found during the rainy season.The dominant species were Hydrooides elegans and Amphibalanus reticulates according to biomass, while Membranipora savartii,Sinoflustra annae,and Lichenopora radiate according to abundance.(2)In the microcosm experiment,under the copper stress,all biomass(wet weight)of species showed a decreased trend.The tolerance to copper stress of the macrofouling assemblages are positively related to their coverage and biomass.(3)In the microcosm experiment,the Cu contents varied with different species.Under the stress of copper,the contents of Cu in the dominant species showed an increased trend,and especially apparent in the early six days.While the Cu contents in the dominant species decreased with the increase of assemblage biomass.(4)Both Cluster and MDS analysis showed that the assemblage structure of macrofouling fauna changed under the stress of copper.The overall extent of changing negatively related to the increase of coverage rate.(5)BIO-ENV analysis showed that the copper was the main factor in affecting assemblage structure in microcosm experiments,and the assemblage structure was negatively correlated with the coverage.In the field exchange experiment,copper was detected as one of the main influential factors,and has a high correlation with the change of assemblage structure.The results provide valuable references for the monitoring of coastal copper using macrofouling assemblages.(6)The change trend of the macrofouling fauna assemblage structure in the microcosmic experiment is similar to that in the field experiment.This indicated that these two experimental systems showed a satisfactory correlation.