Microbial Community Based Habitat Diagnosis Method Of Coastal Zone

Environmental pollution of coastal area sound an alarm to human health as well as economic development. The diagnosis of coastal habitats could be a guidance of making pollution control strategies and warning management approaches. However, as the species of pollutants increased, their influences have been increasingly complex, which made the physicochemical indexes become limited in diagnosing the habitat as the only standard. In order to reveal the pollutants interactive effects on biological population, community and ecosystem, this study give a research on the comprehensive effects of pollutant in Shenzhen Bay Coastal area, and evaluate the health risk of human being.The main techniques of this study are high-throughput sequencing and fluorescence microscopy. By exploring temporal and spatial distribution of the microbial community structure, diversity and biomass, and the environmental factors, this study have obtained several results:(1) The physical and chemical indexes in Shenzhen Bay change along with east-west direction. Dissolved oxygen increase from inner bay to outer bay, while biomass, chlorophyll and DIN and TP decrease from inner bay to outer bay.(2) Effects of seasonal change is much larger than the changes in position and depth on the microbial community structure in Shenzhen Bay Coastal Zone. The RDA analysis shows that the most significant environmental factor on the microbial community structure is temperature. Effects of ammonia nitrogen and nitrate nitrogen on microbial community structure is the most significant index in nutrient. Biomass and nitrate nitrogen, ammonia nitrogen are significantly correlated at the 0.05 level, and total phosphorus is also a significant correlation in the 0.1 level.(3) Heavy rains in May has two main effects on microbial community of water environment in Shenzhen Bay: First, the diversity of microbial communities increased significantly in the beginning of heavy rains, however, declined into a average level after the rainstorm. Second, after heavy rain, the proportion of Cyanobacteria and Actinomycetes in community structure increased obviously.(4) The total average proportion of pathogenic bacteria in Shenzhen Bay water environment was 2.59 ‰. The main pathogenic bacteria are Aeromonas, Enterococcus, Mycobacterium, Pseudomonas aeruginosa, Staphylococcus saprophyticus and Yersinia. The proportion of pathogenic bacteria in different seasons showed a regulation that winter > autumn > spring > summer; where the proportion in off-shore is much higher than the proportion in the central line; the proportion in mid-bay is higher than the proportion in inner-bay and out-bay; the proportion in sufface water environment is similar to the proportion in bottom watter environment. Fecal pollution indicative microorganisms based source analysis shows the input of tipical city wastewater and tipical polluted river are not the main factor of pathogenic bacteria in Shenzhen Bay.(5) The main functional gene of Anatoxin, Nodularin, Brevetoxin, Saxitoxin, Cylindrospermopsin are not detected in Shenzhen Bay water environment. Mcy B gene of Microcystin are detected in Spring in Shenzhen Bay Coastal zone.