Annual Investigation And Analysis On The Composition And Water Quality Of Plankton Community In Mangrove Sea Area Of Puqian,Wenchang City

This study conducted an annual survey on the composition and water quality of the plankton community in the mangrove area of Puqianwan,Wenchang,Hainan Province from 2018 to 2019.By investigating the results of plankton and water quality at eight stations,and calculating the index of plankton community structure and eutrophication of water quality,the ecological structure and water pollution in Puqianwan mangrove area were analyzed in all directions.A total of 131 phytoplankton species(genus)were identified in the two-year survey,of which 85 species(genus)were diatom phylum,accounting for 64.89% of Prida;25species(genus),accounting for 19.08%;9 species,accounting for 6.87%;6 species,accounting for 4.58%;4 species and two species,accounting for 3.05% and 1.53%,respectively.Of the 131 species(genus)of floating plants,30 species(genus)of 3 phyla of red tide were found,accounting for 22.90% of the total number of phytoplankton species,17 species(genus)of diatom phylum and total diatom phylum 20.00% of species,accounting for 12.98% of of the total number of phytoplankton species,the main species are midrib,sea chain algae,Japanese stellate algae,danish,etc.A total of 12 species(genus)of red-tidal algae were found in the phylum,accounting for 48.00% of the total species of phylum,accounting for 9.16% of the total species of phytoplankton,the main species are marine polychaetesimaeophyta,lima,phaeophyta,phaeophyta,phaeophyta,phaeophyta,16.7% of red-tidaeophyta.76%;3 species(genus)of toxic algae,all of which are phylum,or 12.00% of the total species of Phaeophyta,accounting for 2.30% of the total number of phytoplankton species,respectively,with tail fin algae,the original algae of Lima and the algae of Okapi.A total of 44 species(genus)of 7 species of zooplankton,including copepods,annelids,larvae,rotifers,molluscs,protozoa and capsule,were identified in two years.Among them,copepods contained the most significant number of species,20 species(genus),accounting for 45.45% of the total species of zooplankton,followed by protozoa,eight species(genus),accounting for 18.18% of the total species of zooplankton,followed by larvae,seven species(genus),accounting for the total species of zooplankton,accounting for 15.9% of the total species identified by 3.Among the water quality survey indexes of mangrove area in Puqian Bay are salinity,temperature,ph?DO?COD?DIN?DIP? nonionic ammonia,etc.The annual temperature range of mangrove area in Puqian Bay is between 21? and 33?,low in spring and winter,high in summer and autumn,salinity range between 25‰ and 31‰;and 6-8 in ph.DO concentrations at site 4,winter 2019,except in some cases The mg/L,does not meet the three types of seawater quality standards,and the DIP concentration in the winter of 2018 exceeds the three types of seawater quality standards,with a maximum concentration of 0.133 mg/L;According to the analysis of eutrophication index,the nutritional level of each station in the investigated sea area is poor nutrition grade,and the water quality is stable and functional.The investigation and analysis of plankton community structure and water quality indicate that the Haven Bridge under construction has not had a significant impact on the mangrove ecosystem in Puiqian Bay.However,a large number of red tide algae and toxic algae still need to be focused on to prevent harmful phenomena such as red tide.