Bacterial Diversity in Submarine Groundwater along the Coasts of the Yellow Sea.

Qi Ye,Jinzhou Du,Jianan Liu,Jing Zhang

doi:10.3389/fmicb.2015.01519

Abstract

Submarine groundwater (SGD) is one of the most significant pathways for the exchange of groundwater and/or source of nutrients, metals and carbon to the ocean, subsequently cause deleterious impacts on the coastal ecosystems. Microorganisms have been recognized as the important participators in the biogeochemical processes in the SGD. In this study, by utilizing 16S rRNA-based Illumina Miseq sequencing technology, we investigated bacterial diversity and distribution in both fresh well water and brackish recirculated porewater along the coasts in the Yellow Sea. The results showed that Actinobacteria and Betaproteobacteria, especially Comamonas spp. and Limnohabitans spp. were dominated in fresh well samples. Distinct patterns of bacterial communities were found among the porewater samples due to different locations, for examples, Cyanbacteria was the most abundant in the porewater samples far from the algal bloomed areas. The analysis of correlation between representative bacterial taxonomic groups and the contexture environmental parameters showed that fresh well water and brackish porewater might provide different nutrients to the coastal waters. Potential key bacterial groups such as Comamonas spp. may be excellent candidates for the bioremediation of the natural pollutants in the SGD. Our comprehensive understanding of bacterial diversity in the SGD along the coasts of the Yellow Sea will create a basis for designing the effective clean-up approach in-situ, and provide valuable information for the coastal management.

Highlights

Submarine groundwater discharge (SGD) includes both fresh meteoric groundwater to the ocean by terrestrially-driven directly and recirculated seawater by permeable sediment (Garcia-Solsona et al, 2010)
By using 16S rRNA gene-based Miseq Illumina sequencing approach, we focused on the bacterial compositions in both fresh well water and recirculated brackish porewater along the coast of the Yellow Sea
After filtrating, Ra isotopes in the water were extracted using a MnO2-impregnated acrylic fiber column (20 g), the column with Mn-fiber was immediately placed in the Radium Delayed Coincidence Counter (RaDeCC) to measure the short-lived isotope 223Ra and 224Ra in the field (Moore and Arnold, 1996)

Summary

Introduction

Submarine groundwater discharge (SGD) includes both fresh meteoric groundwater to the ocean by terrestrially-driven directly and recirculated seawater by permeable sediment (Garcia-Solsona et al, 2010). More and more works showed that SGD is one of the most important pathways for the exchange of groundwater and/or source of dissolved compounds (e.g., nutrients, metals, carbon) to the ocean, which may cause negative impacts on the coastal ecosystems (Burnett et al, 2006; Moore, 2010). SGD has been determined as a main nutrient source to the Yellow Sea, which is one of the Bacterial Diversity in the Submarine Groundwater largest continental shelves in the world (Kim et al, 2005; Waska and Kim, 2011). Recent studies focused on the bacterial communities in the surrounding sea water during macroalgal blooms of Ulva prolifera in the Yellow Sea (Burke et al, 2011; Liu et al, 2011; Zhang et al, 2014). For our knowledge, up to now, there are few reports on the bacterial compositions in SGD along the coast of the Yellow Sea

Methods

Results

Discussion

Conclusion