Environmental Influences on Marine Bacterial Diversity and Activity

Bayindirli, Cansu (2016) Environmental Influences on Marine Bacterial Diversity and Activity. Doctoral thesis, University of East Anglia.

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In order to facilitate the conservation of biological diversity, a comprehensive knowledge of the microbial ecology of an ecosystem is required. As the vast majority of microbes are not readily culturable, it is necessary to use molecular tools to investigate their diversity and function in the marine ecosystem. Although it provides a vast quantity of data, the information obtained by molecular tools alone is not sufficient to understand the drivers behind the changes in bacterial communities.
This study aims to characterize changes in the diversity and activity of the heterotrophic bacterial community in relation to a changing environment, in time and space. Two different sampling strategies were used in order to achieve this goal; an annual time series study at a coastal station (station L4, Western English Channel Observatory (WECO)) and a Lagrangian study following an upwelling plume on its track to off shore (2nd filament, Surface Ocean-Lower Atmosphere Study (SOLAS) - Impact of coastal upwelling on the air-sea exchange of climatically important gases (ICON) cruise).
Surface water samples were collected from the time series station L4 of the Western Channel Observatory (50º15'N, 04º13'W; www.westernchannelobservatory.org) every week between 6th April 2009 and 26th April 2010. The respiration rate of the heterotrophic community was determined using Winkler titration to measure the dissolved oxygen content of the < 0.8 μm size-fraction of the seawater. This dataset sits within the larger framework of the Western English Channel bacterial diversity
time series (2003-2009) and the seasonal metagenomic and metatranscriptomic studies associated with this site.
The second approach was to investigate the bacterial diversity and activity in a dynamic environment, such as an upwelling region. The upwelling region off the coast of Mauritania is one of the most productive areas of the world ocean, yet little is known of the temporal and spatial variability in prokaryotic community structure and metabolic activity there, and crucially how this contributes to global elemental cycles.
During a Natural Environmental Research Council (NERC) SOLAS-funded Lagrangian study, we determined bacterial community structure and production together with total community respiration and production. This part of the study describes the temporal changes in bacterial community structure and its activity, in relation to the complex upwelling environmental conditions (mixing, chlorophyll, dissolved organic and inorganic nutrients). Turbulence and dissolved organic carbon appear to play an important role.

Item Type: Thesis (Doctoral)
Faculty \ School: Faculty of Science > School of Environmental Sciences
Depositing User: Stacey Armes
Date Deposited: 28 Jun 2016 15:57
Last Modified: 28 Jun 2016 15:57
URI: https://ueaeprints.uea.ac.uk/id/eprint/59617

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