Assessment Of Plankton Integrity In The Hanjiang River(Meizhou Section) And The Pearl River(Guangzhou Section)

In this study,plankton organisms,community structure,and species diversity index of 24 samples from Hanjiang(Meizhou section)and 22 samples from Pearl River(Guangzhou section)were investigated.Several candidate planktonic sensitivity indicators were tested and selected,the index of plankton organism integrity index system suitable for China's Hanjiang(Meizhou section)and Pearl River(Guangzhu section)regions based on the IBI(Index of Biotic Integrity)principle were established.To provide a certain amount of basic data for a thorough understanding of the health of the Hanjiang River and the Pearl River,thus providing a scientific basis for the governance,prevention,and control of water pollution.The specific findings are as follows:1.Hanjiang River(Meizhou Section)24 sampling sites were set up according to the river entry point and the middle and lower reaches of the point of entry into the reservoir.6 phyla and 120 phytoplankton species were identified in the wet season.Among them,11 species of Cyanophyta,51 species of Chlorophyta,23 species of Bacillariophyta,9 species of Euglenophyta,4 species of Pyrrophyta and 5 species of Cryptophyta.There are a total of 58 species(genus)of zooplankton,including 45 species of Rotifers and 9 species of Cladocera.6 phyla and 118 phytoplankton species in the dry season,including 10 species of Cyanophyta,57 species of Chlorophyta,36 species of Bacillariophyta,6 species of Euglenophyta,5 species of Pyrrophyta,and 4 species of Cryptophyta.36 species of zooplankton,including 25 species of Rotifers and 7 species of Cladocera,plankton diversity index and plankton abundance showed Spindle-shaped structures in the upper reaches of the reservoir,in the reservoir and downstream of the reservoir,and the diversity and abundance in the reservoir was the highest.Both upstream and downstream are reduced to varying degrees.2.In the Pearl River(Guangzhou section),22 sampling points were set up according to the main stream and part of the tributary of the Pearl River that was greatly affected by life.7 phyla and 89 phytoplankton species were identified,of which 9 were Cyanophyta and 49 were Chlorophyta,21 species of Bacillariophyta,5 species of Euglenophyta,2 species of Pyrrophyta,3 species of Cryptophyta,and 2 species of Chrysophyta.34 species(genus)of zooplankton,including 22 species of Rotifers and 9 species of Cladocera,exhibited Dumbbell-shaped structures along the plankton biodiversity index and plankton abundance in the upper,middle,and lower reaches.The lowest level,higher upstream and downstream.3.An assessment system for different water period integrity indexes for the Meizhou section of the Hanjiang River and the Guangzhou section of the Pearl River was obtained,and the integrity evaluation of 24 sampling points of the Meizhou section of the Hanjiang river was conducted.The results showed that 11 samples were evaluated moderate,5 samples were evaluated as high,4 samples were evaluated as good,and 4 samples were evaluated as poor.The evaluation of the integrity of the 24 samples in the dry period of the Meizhou section of the Hanjiang River showed that the 8 samples were evaluated as high,7 samples were good,5 samples were moderate,4 samples were poor,and the integrity showed moderate-highmoderation phenomenon,appeared in the upstream of the reservoir,in the reservoir and downstream of the reservoir.The integrity evaluation was performed on 22 samples from the Guangzhou section of the Pearl River.The results showed that 5 sections were moderately assessed,3 section integrity was poor,5 sections were good,9 sections were high,and integrity was from upstream to downstream.High-moderate-high phenomenon.4.The differences in plankton biointegrity indicators between Hanjiang(Meizhou section)and Zhujiang(Guangzhou section)within the same region(Guangdong Province)were compared.For Hanjiang with good water quality,algae is sensitive to changes in the environment.For the relatively poor water quality of the Pearl River,zooplankton is sensitive to changes in the environment,and the integrity index value is related to physical and chemical indicators and biological indicators.Analysis showed that both planktonic integrity in the dry season were significantly associated with dissolved oxygen and ammonia nitrogen,and high significant associated with phytoplankton diversity,zooplankton diversity,zooplankton richness,and total nitrogen,suggesting that the same water period had the same regional impact.The factors of planktonic integrity indicators have good applicability in different watersheds.For the indicators of planktonic integrity of the Hanjiang River(Meizhou section)in the same basin in different periods,the algae index has a larger proportion in the complete indicators of wet season,and the proportion of zooplankton in the dry season is higher than that in the wet season.The correlation analysis of index values with physical and chemical indicators and biological indicators showed that compared with the wet season,the dry season completeness index values were significantly correlated with the abundance of ammonia nitrogen and zooplankton in the dry season,and were significantly associated with zooplankton diversity and zooplankton richness.Also it shows that the wet season and dry season zooplankton indicators compared to the integrity of the relationship more closely.