Abstract
In deep drinking water reservoir ecosystems, the dynamics and interactions of community compositions of phytoplankton and eukaryotes during the mixing periods are still unclear. Here, morphological characteristics combined with high-throughput DNA sequencing (HTS) were used to investigate the variations of phytoplankton and the eukaryotic community in a large canyon-shaped, stratified reservoir located at the Heihe River in Shaanxi Province for three months. The results showed that Bacillariophyta and Chlorophyta were the dominant taxa of the phytoplankton community, accounting for more than 97% of total phytoplankton abundance, which mainly consisted of Melosira sp., Cyclotella sp., and Chlorella sp., respectively. Illumina Miseq sequencing suggested that the biodiversity of eukaryotes increased over time and that species distribution was more even. Arthropoda (6.63% to 79.19%), Ochrophyta (5.60% to 35.16%), Ciliophora (1.81% to 10.93%) and Cryptomonadales (0.25% to 11.48%) were the keystone taxa in common, contributing over 50% of the total eukaryotic community. Cryptomycota as a unique fungus was observed to possess significant synchronization with algal density, reaching a maximum of 10.70% in December (when the algal density distinctly decreased) and suggesting that it might affect the growth of algae through parasitism. Co-occurrence network patterns revealed the complicated and diverse interactions between eukaryotes and phytoplankton, suggesting that eukaryotes respond to variations in dynamic structure of the phytoplankton community, although there might be antagonistic or mutualistic interactions between them. Redundancy analysis (RDA) results showed that environmental variables collectively explained a 96.7% variance of phytoplankton and 96.3% variance of eukaryotic microorganisms, indicating that the temporal variations of phytoplankton and eukaryotic microorganisms were significantly affected by environmental conditions. This study shows that potential interactions exist between phytoplankton and eukaryotic microorganism communities, andcould improve our understanding of the ecological roles of phytoplankton and eukaryotic microorganisms in changing aquatic ecosystems. However, long-term investigations are necessary in order to obtain comprehensive understandings of their complicated associations.
Highlights
Reservoirs have many important ecosystem functions such as being a major source of drinking water for local inhabitants and providing agriculture irrigation, flood control, and power generation [1,2]
Vertical profiles of water quality are influenced by physical thermal stratification [2,3], and the drivers of algal blooms in oligotrophic drinking water reservoir shave been investigated in the past few decades
Our results indicate that water quality parameters varied a lot with the changing environment, which significantly altered the community structure of phytoplankton and eukaryotes in Jinpen reservoir
Summary
Reservoirs have many important ecosystem functions such as being a major source of drinking water for local inhabitants and providing agriculture irrigation, flood control, and power generation [1,2]. Eutrophications, and especially the formation of algal blooms, have become increasingly severe in reservoirs, and have caused periodic-rising-water quality deterioration [5,6,7]. Adequate management is essential and of utmost importance in reservoirs. A reservoir is an ideal ecological-ecosystem model to explore the physical, chemical, and biological characteristics of aquatic environments [3]. Vertical profiles of water quality are influenced by physical thermal stratification [2,3], and the drivers (e.g., temperature, light, nutrients) of algal blooms in oligotrophic drinking water reservoir shave been investigated in the past few decades. Fewer studies have focused on the dynamics of phytoplankton and eukaryotes during mixing periods of drinking water reservoirs
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Environmental Research and Public Health
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
