Transient Changes in Bacterioplankton Communities Induced by the Submarine Volcanic Eruption of El Hierro (Canary Islands)

Abstract

The submarine volcanic eruption occurring near El Hierro (Canary Islands) in October 2011 provided a unique opportunity to determine the effects of such events on the microbial populations of the surrounding waters. The birth of a new underwater volcano produced a large plume of vent material detectable from space that led to abrupt changes in the physical-chemical properties of the water column. We combined flow cytometry and 454-pyrosequencing of 16S rRNA gene amplicons (V1–V3 regions for Bacteria and V3–V5 for Archaea) to monitor the area around the volcano through the eruptive and post-eruptive phases (November 2011 to April 2012). Flow cytometric analyses revealed higher abundance and relative activity (expressed as a percentage of high-nucleic acid content cells) of heterotrophic prokaryotes during the eruptive process as compared to post-eruptive stages. Changes observed in populations detectable by flow cytometry were more evident at depths closer to the volcano (~70–200 m), coinciding also with oxygen depletion. Alpha-diversity analyses revealed that species richness (Chao1 index) decreased during the eruptive phase; however, no dramatic changes in community composition were observed. The most abundant taxa during the eruptive phase were similar to those in the post-eruptive stages and to those typically prevalent in oceanic bacterioplankton communities (i.e. the alphaproteobacterial SAR11 group, the Flavobacteriia class of the Bacteroidetes and certain groups of Gammaproteobacteria). Yet, although at low abundance, we also detected the presence of taxa not typically found in bacterioplankton communities such as the Epsilonproteobacteria and members of the candidate division ZB3, particularly during the eruptive stage. These groups are often associated with deep-sea hydrothermal vents or sulfur-rich springs. Both cytometric and sequence analyses showed that once the eruption ceased, evidences of the volcano-induced changes were no longer observed.

Fronts at the Surface Ocean Can Shape Distinct Regions of Microbial Activity and Community Assemblages Down to the Bathypelagic Zone: The Azores Front as a Case Study

“…Although, we did not collect samples for microscopic observations, we believe that the high side scatter in these HNA and LNA prokaryotes are due to their association with particles. Similar cytograms of prokaryotic assemblages with HSC were recently observed associated with the discharge of vent material in stations close to a shallow submarine volcano in the Canary Islands (Ferrera et al, 2015).…”

Electrochemical performance and microbial community profiles in microbial fuel cells in relation to electron transfer mechanisms

“…Primers 28F (5′- GAGTTTGATCNTGGCTCAG-3′) and 519R (5′- GTNTTACNGCGGCKGCTG-3′) generated amplicons spanning the V1 to V3 regions of the bacterial 16S rRNA gene, and primers 341F (5′-GYGCASCAGKCGMGAAW-3′) and 958R (5′-GGACTACVSGGGTATCTAAT-3′) were used to amplify archaeal fragments spanning the V3 to V5 regions. The generated pyrosequencing data were processed using the QIIME (Quantitative Insights Into Microbial Ecology) pipeline as described in Ferrera et al [ 21 ]. Briefly, a sequence filtration step was performed before denoising sequences to reduce the impact of pyrosequencing errors.…”

The Emissions of the Tagoro Submarine Volcano (Canary Islands, Atlantic Ocean): Effects on the Physical and Chemical Properties of the Seawater

“…However, heterotrophic prokaryotes increased with depth [2]. With respect to the bacterioplankton, there was an important change and groups often associated with deep-sea hydrothermal vents or sulfurrich springs were observed [31]. The increase in temperature and acidification, the decrease in oxygen and the precipitation of chemical compounds resulted in a reduction of the epipelagic stocks and a disruption of the nocturnal ascent of mesopelagic organisms [32].…”