Distribution Of Benthic Foraminifera Population In The Intertidal Zone Of Zhoushan And Its Ecological Response To Marine Environmental Factors

The ocean has long been the most stable ecosystem on the earth.Human activities have caused deterioration of the marine ecological environment.Major environmental problems such as marine pollution and ocean acidification have become increasingly prominent.In this paper,the use of regional modern benthic foraminifera and environmental parameters of the study as the basis for the use of benthic foraminiferes(mainly Ammonia beccarii,Elphidiella kiangsuensis and Cribrononion vitreum)as an indicator for microbiological experiments,select the main marine trace Heavy metals(Cu,Cr,Zn,etc.),nutrient salts(N,P)of major biogenic elements,and seawater C(CO2,characterized by seawater p H)were used as research indicators to explore the impact of benthic foraminifera on marine heavy metal pollution,marine Changes in biogenic elements and ecological response to ocean acidification.In this study,foraminiferal sediment samples were collected from January 2016 to November 2017 for a total of 23 months.More than 69 samples and 32321 foraminifera individuals were collected,picked and analyzed.Statistics show that the main living species are Ammonia beccarii vars.,Elphidium,Cribrononion,Trochaminia,etc.The average abundance of the foraminiferal organisms is 529/10cm3,and the overall average abundance is 891/10cm3.The abundance is high in spring and summer and low in autumn and winter.The dominant species of foraminifera in the region are Ammonia beccarii,Elphidiella kiangsuensis and Cribrononion vitreum,which can be used as the preferred sensitive species in ecological research.In the study area,the species distribution of foraminifera is not obvious,and the species of the foraminifera distributed in each part of the intertidal zone are similar and only change in quantity.The experimental results of heavy metal stress indicated that different heavy metal pollutants had different stress effects on the foraminifera Ammonia beccarii vars.The high concentration of Cu,Zn lead to more pronounced distortion and stronger stress;There's sensitivity difference in stress factors,the sensitivity to Pb and Cr is relatively low,the ecological response is slow,the sensitivity to Zn and Cu is strong,and the ecological response is fast;Ecological response to different concentrations of heavy metal solution sensitivity,the higher the concentration,the stronger the sensitivity,the more obvious the distortion,the greater the ecological response.According to the results of nutrient monitoring experiment,Nitzschia closterium grows rapidly with the increase of nutrient salts,and foraminifera will grow rapidly due to rich food,but with the continuous growth of algae and consumption of oxygen,under anoxic conditions,Foraminifera stopped growing and died.Among them,Elphidiella grew well and was a species that was more resistant to hypoxia.The results of acidification experiments showed that with the decrease of p H value and the increase of cultivation time,the dissolution of various foraminifera shells was aggravated,and thin and transparent shells and atrioventricular exfoliation appeared.When the p H value was 7.4,the foraminiferal dissolution rate reached the highest value;the shell thickness had a great influence on the dissolution rate,and the shell morphology also had a certain influence on the dissolution rate;the p H value of 7.80 can be defined as the threshold for significant dissolution of foraminifera.Cribrononion vitreum can be used as an index species for ocean acidification in the study area.