Distinct Seasonal Patterns of Bacterioplankton Abundance and Dominance of Phyla α-Proteobacteria and Cyanobacteria in Qinhuangdao Coastal Waters Off the Bohai Sea

Abstract

Qinhuangdao coastal waters in northern China are heavily impacted by anthropogenic and natural activities, and we anticipate a direct influence of the impact on the bacterioplankton abundance and diversity inhabiting the adjacent coastal areas. To ascertain the anthropogenic influences, we first evaluated the seasonal abundance patterns and diversity of bacterioplankton in the coastal areas with varied levels of natural and anthropogenic activities and then analyzed the environmental factors which influenced the abundance patterns. Results indicated distinct patterns in bacterioplankton abundance across the warm and cold seasons in all stations. Total bacterial abundance in the stations ranged from 8.67 × 10 4 to 2.08 × 10 6 cells/mL and had significant (p < 0.01) positive correlation with total phosphorus (TP), which indicated TP as the key monitoring parameter for anthropogenic impact on nutrients cycling. Proteobacteria and Cyanobacteria were the most abundant phyla in the Qinhuangdao coastal waters. Redundancy analysis revealed significant (p < 0.01) influence of temperature, dissolved oxygen and chlorophyll a on the spatiotemporal abundance pattern of α-Proteobacteria and Cyanobacteria groups. Among the 19 identified bacterioplankton subgroups, α-Proteobacteria (phylum Proteobacteria) was the dominant one followed by Family II (phylum Cyanobacteria), representing 19.1-55.2% and 2.3-54.2% of total sequences, respectively. An inverse relationship (r = −0.82) was observed between the two dominant subgroups, α-Proteobacteria and Family II. A wide range of inverse Simpson index (10.2 to 105) revealed spatial heterogeneity of bacterioplankton diversity likely resulting from the varied anthropogenic and natural influences. Overall, our results suggested that seasonal variations impose substantial influence on shaping bacterioplankton abundance patterns. In addition, the predominance of only a few cosmopolitan species in the Qinhuangdao coastal wasters was probably an indication of their competitive advantage over other bacterioplankton groups in the degradation of anthropogenic inputs. The results provided an evidence of Bacterioplankton Abundance and Diversity Patterns their ecological significance in coastal waters impacted by seasonal inputs of the natural and anthropogenic matter. In conclusion, the findings anticipate future development of effective indicators of coastal health monitoring and subsequent management strategies to control the anthropogenic inputs in the Qinhuangdao coastal waters.

Bacterioplankton community variation in Bohai Bay (China) is explained by joint effects of environmental and spatial factors

“…The OTU richness and Shannon index were significantly negatively correlated with AN. However, in other studies of similar environments, higher richness was often observed in coastal rather than offshore areas (He et al, ; Richa et al, ; Shan et al, ). Nevertheless, in Guanabara Bay lower richness was observed in the more polluted inner bay water (Vieira et al, ), and in the coastal region of Zhejiang area, a negative correlation between AN and bacterial alpha diversity was also detected, although it was not significant (Wang et al, ).…”

“…Bacterioplankton has long been recognized as a key player in food web dynamics and biogeochemical cycling in the global ocean (Fuhrman, 2009). The structure and abundance of bacterioplankton involved in the marine microbial cycle (Farooq & Francesca, 2007) are canonical indicators of ecosystem status and the extent of anthropogenic impact on coastal waters (He et al, 2017;Zhang, Wang, et al, 2014). Several studies found that the distribution of bacterioplankton communities in coastal zones depends on both environmental and spatial processes, and most of the studies revealed that the microbial taxa exhibit distinct biogeographical distribution patterns in the ocean, which are correlated with varying environmental parameters (Delong & Karl, 2005;Seo, Kang, Yang, & Cho, 2017;Wang et al, 2015;Zhang, Zhao, Dai, Jiao, & Herndl, 2014).…”

Archaeal community variation in the Qinhuangdao coastal aquaculture zone revealed by high-throughput sequencing

“…Salinity and temperature are parameters that naturally vary, while nutrient concentrations and DO levels can indicate the extent of anthropogenic activities and their influence [8]. Environmental conditions can determine community composition within specific habitats, and understanding associations between taxa and environmental conditions can elucidate the exact response of individual taxa to environmental changes.…”

“…Consequently, 16S rRNA gene high-throughput sequencing has been used to investigate the distribution of Archaea among various environments [19–21]. Investigations of microbial diversity in the Qinhuangdao coastal ecosystem have mainly focused on evaluating bacterial communities in waters and intertidal sediments [7,8,10]. In contrast, nothing is known of the archaeal community composition and diversity in Qinhuangdao coastal aquaculture environments.…”

Flow Cytometry for Rapid Enumeration and Biomass Quantification of Thraustochytrids in Coastal Seawaters

“…Environmental parameters were analyzed following the methods described in our previous study ( 10 ).…”