Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea

T Yokokawa,Gj Herndl,E Sintes,D De Corte

doi:10.3354/ame01393

Abstract

AME Aquatic Microbial Ecology Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsSpecials AME 59:185-195 (2010) - DOI: https://doi.org/10.3354/ame01393 Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea Taichi Yokokawa1,*, Daniele De Corte1,2, Eva Sintes3, Gerhard J. Herndl1,3 1Department of Biological Oceanography, Royal Netherlands Institute for Sea Research (NIOZ), PO Box 59, 1790 AB, Den Burg, The Netherlands 2Center for Ecological and Evolutionary Studies, University of Groningen, PO Box 14, 9750 AA Haren, The Netherlands 3University of Vienna, Department of Marine Biology, Faculty Center of Ecology, Althanstrasse 14, 1090 Vienna, Austria *Email: taichi.yokokawa@nioz.nl ABSTRACT: To determine the variation of bacterial activity and community composition between and within specific water masses, samples were collected throughout the water column at 5 stations in the eastern Mediterranean Sea corresponding to the regions of the northern Aegean, mid-Aegean, western Cretan, Ionian and southern Aegean Seas. Prokaryotic abundance below 100 m declined with depth at all the stations, while decreasing trends with depth in prokaryotic heterotrophic activity were present only at 2 out of the 5 stations. Bacterial community composition (BCC), determined using both automated rRNA intergenic spacer analysis and terminal-restriction-fragment length polymorphism, was also related to depth although the number of operational taxonomic units was remarkably constant throughout the water column. Overall, the maximums in similarity values of the BCC between water sample pairs decreased with increasing temperature–salinity (T–S) distance of the water samples probably due to distinct biogeochemical characteristics of water masses. However, considerable dissimilarity in the BCC between samples with identical T–S values, and hence within the same water mass, was also observed, possibly reflecting heterogeneity in the organic matter field or in biotic control within a given water body. Thus, we conclude that the richness of bacterial communities is remarkably constant with depth down to bathypelagic waters. The similarity of bacterial communities in water parcels with identical temperature and salinity can range from highly similar to very dissimilar, reflecting variability in substrate supply despite the physical uniformity of water parcels. KEY WORDS: Bacteria · Community composition · Patchiness · Spatial scale · Eastern Mediterranean Sea Full text in pdf format PreviousNextCite this article as: Yokokawa T, De Corte D, Sintes E, Herndl GJ (2010) Spatial patterns of bacterial abundance, activity and community composition in relation to water masses in the eastern Mediterranean Sea. Aquat Microb Ecol 59:185-195. https://doi.org/10.3354/ame01393 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in AME Vol. 59, No. 2. Online publication date: April 08, 2010 Print ISSN: 0948-3055; Online ISSN: 1616-1564 Copyright © 2010 Inter-Research.

Highlights

Prokaryotes play a major role in marine biogeochemical fluxes (Williams 2000)
To determine the variation of bacterial activity and community composition between and within specific water masses, samples were collected throughout the water column at 5 stations in the eastern Mediterranean Sea corresponding to the regions of the northern Aegean, mid-Aegean, western Cretan, Ionian and southern Aegean Seas
Bacterial community composition (BCC), determined using both automated rRNA intergenic spacer analysis and terminal-restriction-fragment length polymorphism, was related to depth the number of operational taxonomic units was remarkably constant throughout the water column

Summary

Introduction

Prokaryotes play a major role in marine biogeochemical fluxes (Williams 2000). The relation between microbially mediated biogeochemical transformation rates and the prokaryotic community composition is a central research topic in microbial ecology, linked to the function–stability debate (Miki et al 2008, Fuhrman 2009, Yokokawa & Nagata 2010). The distribution patterns of prokaryotic abundance and activity throughout the water column of the open ocean have been determined extensively in the Atlantic (Herndl et al 2005, Reinthaler et al 2006), in the North Pacific (Nagata et al 2000), in the Arabian Sea (Hansell & Ducklow 2003) and in the north-western Mediterranean Sea (Tanaka & Rassoulzadegan 2004, Winter et al 2009). Time-Series Study and the Hawaii Ocean Time-Series, microbial activity and community dynamics have been related. From these data, the notion emerged that the prokaryotic community composition of the open oceanic water column is highly stratified (Giovannoni et al 1996, DeLong et al 2006). The SAR 202 cluster dominates in waters below 2000 m depth, comprising up to 40% of the bacterial community in the North Atlantic (Varela et al 2008)

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