Responses of spatial-temporal dynamics of bacterioplankton community to large-scale reservoir operation: a case study in the Three Gorges Reservoir, China

Abstract

Large rivers are commonly regulated by damming, yet the effects of such disruption on bacterioplankton community structures have not been adequately studied. The aim of this study was to explore the biogeographical patterns present under dam regulation and to uncover the major drivers structuring bacterioplankton communities. Bacterioplankton assemblages in the Three Gorges Reservoir (TGR) were analyzed using Illumina Miseq sequencing by comparing seven sites located within the TGR before and after impoundment. This approach revealed ecological and spatial-temporal variations in bacterioplankton community composition along the longitudinal axis. The community was dynamic and dominated by Proteobacteria and Actinobacteria phyla, encompassing 39.26% and 37.14% of all sequences, respectively, followed by Bacteroidetes (8.67%) and Cyanobacteria (3.90%). The Shannon-Wiener index of the bacterioplankton community in the flood season (August) was generally higher than that in the impoundment season (November). Principal Component Analysis of the bacterioplankton community compositions showed separation between different seasons and sampling sites. Results of the relationship between bacterioplankton community compositions and environmental variables highlighted that ecological processes of element cycling and large dam disturbances are of prime importance in driving the assemblages of riverine bacterioplankton communities.

Spatial and temporal dynamics of bacterioplankton community composition in a subtropical dammed karst river of southwestern China

“…Although the diversity and dynamics of microbes in karst springs (Farnleitner et al., ; Ohad et al., ; Savio et al., ), unsaturated and saturated karst aquifers (Cooper et al., ; Gray & Engel, ; Johnson et al., ; Lin et al., ; Menning et al., ), and water pools (Shabarova et al., ) as well as in groundwater‐surface water exchange systems (Li, Song, et al., ) have been discussed in the literature, much less attention has been paid to the structure of bacterioplankton communities in dammed karst rivers. In addition, previous studies on bacterioplankton communities in the canyon‐shaped and meso‐eutrophic Rimov Reservoir (Simek et al., ), the dammed Ebro River (Ruiz‐González, Proia, Ferrera, Gasol, & Sabater, ), and the rivers controlled by the Three Gorges Dam (Huang et al., ; Li, Lu, et al., ; Yan et al., ) did not include the seasonal variation or depth dynamics in bacterioplankton.…”

Dynamics of Bacterial Community Diversity and Structure in the Terminal Reservoir of the South-To-North Water Diversion Project in China

“…As complex artificial ecosystems, they may have artificial or natural cycles (depending on replenishments and withdrawals) as well as high spatial and temporal heterogeneity [1,2]. Such changes can have profound impacts on the compositions of prokaryotic communities and other organisms [3][4][5]. The composition of bacterioplankton communities in aquatic ecosystems can be highly diverse in response to both spatial-temporal environmental variations and anthropogenic activities, and changes in composition may influence drinking water quality and surrounding biodiversity.…”

Toxicity evaluation of Wanzhou watershed of Yangtze Three Gorges Reservoir in the flood season in Caenorhabditis elegans

“…In the soil or the sediment in the TGR region, inorganic compounds, such as herbicide, and heavy metals, such as Hg and Cd, have also been detected 62 – 64 . Moreover, in the fresh water in the TGR region, two dominated bacterioplankton communities, Proteobacteria (39.26%) and Actinobacteria phyla (37.14%), were detected 13 . Recently, the evidence has been raised that the microbial structure and function can be affected by the environmental changes from the Three Gorges Dam 65 , 66 .…”

“…We selected the flood season (September) to collect the water samples in order to assess the possible effects of some chemicals released from the sediment or surrounding mountains. We performed the acute exposure in this study, because we noticed the existence of certain amount of bacterial community in the water in Yangtze River in TGR region 12 , 13 . Meanwhile, all the exposures were performed in the liquid solutions for nematodes at 20 °C.…”

“…In freshwater ecosystems in TGR region, dissolved heavy metals, organic pollutants, surface-suspended particulate matter, and microplastic pollutant have been detected 5 , 7 , 9 – 11 . Bacterioplankton assemblage analysis in the TGR region further revealed the ecological and the spatial-temporal variations in bacterioplankton community composition 12 , 13 . Several reports have implied that the water fluctuation in TGR region may cause the disruptions on algal biomass, species composition, diversity, and richness 14 – 16 .…”