Prokaryote Communities at Active Chimney and In‐Situ Colonization Devices after a Magmatic Degassing Event (37°N MAR, EMSO‐Azores Deep‐Sea Observatory)
|Author(s)||Rommevaux Céline1, 2, Henri Pauline2, Degboe Jefferson3, Chavagnac Valérie3, Lesongeur Francoise4, Godfroy Anne4, Boulart Cedric3, 5, Destrigneville Christine3, Castillo Alain3|
|Affiliation(s)||1 : Aix Marseille Univ, Université de Toulon, CNRS, IRD, MIO UM 110 Marseille, France
2 : Institut de Physique du Globe de Paris ‐ Sorbonne Paris CitéUniversité Paris Diderot, CNRS UMR 7154 Paris ,France
3 : Géosciences Environnement Toulouse <sup>(</sup>GET), UMR 5563 (CNRS/UPS/IRD/CNES), Université de Toulouse, Observatoire Midi‐Pyrénées Toulouse ,France
4 : Univ Brest, CNRS, Ifremer, UMR 6197, Laboratoire de Microbiologie des Environnements Extrêmes Plouzané ,France
5 : Sorbonne Universités, UPMC Univ Paris 06, CNRS UMR 7144, Adaptation et Diversité en Milieu Marin, Équipe Chimie Marine, Station Biologique de Roscoff Roscoff ,France
|Source||Geochemistry Geophysics Geosystems (1525-2027) (American Geophysical Union (AGU)), 2019-06 , Vol. 20 , N. 6 , P. 3065-3089|
|Keyword(s)||Lucky Strike, magmatic degassing, microbial community structure, multidisciplinary study|
The mixing zone between high temperature hydrothermal fluids and seawater produces redox gradients, promoting the development of unique ecosystems based on chemotrophy. The structure of microbial communities depends on their environment, which can vary according to space and time. Hydrothermal circulation within the oceanic crust determines the chemical composition and flow of fluids, depending on underground events (earthquakes, volcanic episodes....), and impacts the development of microbial communities. This link between hydrothermal vent communities and deep geological events is the focus of the present study, the first of its kind for slow‐spreading ridge.
In this study, we present a unique set of multidisciplinary data collected from 2008 to 2011 on the Eiffel Tower hydrothermal site (Lucky Strike vent field, Mid‐Atlantic Ridge). We benefit from continuous geophysical monitoring (temperature, seismicity) of the site, annual sampling of hydrothermal fluids (hot and diffuse) for geochemistry analyses, sampling of hydrothermal chimneys and an in situ microbial colonization experiments over a year for microbial study.
The high CO2 content and concentrations of major elements (Cl, Ca, Si) and SO4 in the end‐member fluids collected in 2010, indicate that a magmatic degassing occurred between 2009 and 2010 under the Lucky Strike hydrothermal field. This is supported by the large temperature variations observed in March‐April 2010. These magmatic CO2 inputs seem to have affected microbial communities’ colonizing the high temperature chimney, as well as the basalts in the more diffuse and mixed zone, promoting the development of thermophilic/anaerobic Archaea and Bacteria (Archaeoglobales, Nautiliales, Nitratiruptoraceae).