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Re­search at the Haakon Mosby Mud Vol­cano

Novel meth­ane con­sum­ing mi­croor­gan­isms dis­covered at the Haakon Mosby Mud Vol­cano in the Arc­tic deep sea
 
Not lava, but muds and methane are emitted from the Arctic deep-water mud volcano Haakon Mosby. When reaching the atmosphere, methane is an aggressive greenhouse gas, 25-times more potent than carbon dioxide. Fortunately, some specialised microorganisms feed on methane and thereby reduce emissions of this greenhouse gas. For the first time, a German-French research team showed which methane consuming microorganisms thrive in the ice-cold Arctic deep-sea. In an article in the journal Nature, the scientists also describe which environmental parameters control their activity – with a surprising result: High flow velocities of mud volcano water in the seafloor reduce the efficiency of the natural gas filter by 60%.
In 1990, the Haakon Mosby mud vol­cano was dis­covered by an in­ter­na­tional re­search team on the con­tin­ental slope of the Bar­ents Sea. The sci­ent­ists chose its name in hon­our of the fam­ous Nor­we­gian ocean­o­grapher Haakon Mosby. The mud vol­cano has a size of a about 1 square kilo­meter and is loc­ated at a wa­ter depth of 1250 m. The centre emits muds, wa­ter and meth­ane that rise from a depth of about 2 km be­low the mud vol­cano. Helge Niemann and Tina Lösekann from the Max Planck Institute for Marine Microbiology in Bre­men, Ger­many in­vest­ig­ated in their PhD thesis which meth­an­o­trophic mi­croor­gan­isms could thrive in the -1°C cold Arc­tic deep-sea.

Haakon Mosby is a rather flat mud vol­cano rising only 10 m above the ocean floor. By visual in­spec­tion, the Ger­man and French re­search­ers dis­tin­guished three dis­tinct con­cent­ric ring-shaped zones: the centre, then a zone covered with sul­fur bac­teria and then the outer rim in­hab­ited by tube­worms.
Al­though these hab­it­ats dif­fer, meth­ane is the primary food source for most mi­croor­gan­isms thriv­ing in the ocean floor. At the sur­face of the centre, the sci­ent­ists dis­covered formerly un­known bac­teria that use oxy­gen to feed on meth­ane. In sed­i­ment lay­ers be­low the sul­fur bac­teria, Helge Niemann and Tina Lösekann found a new group of meth­ane-con­sum­ing ar­chaea that live in sym­bi­osis with bac­teria. This com­munity does not use oxy­gen but sulph­ate to ox­id­ize meth­ane. This pro­cess is called the an­aer­obic ox­id­a­tion of meth­ane (AOM) and is in­vest­ig­ated in the research project MUMM. To their sur­prise the sci­ent­ists dis­covered that the ma­jor­ity of meth­ane is con­sumed in the tube­worm hab­itat and not in the centre.
From the left to the right: (1) Most of the methane is emitted from the centre of the mud vulcano. (2) Beggiatoa in the middle zone. (3) Tubeworms living at the outside (Source: IFREMER). (4): The novel consortia of Archeae (green) and Bacteria (red) visualized by a special staining method called FISH (T. Lösekann, MPI Bremen).
Auf­steigende Gas­blasen.
(Quelle: IFRE­MER)
Tube worms
(Quelle: IFRE­MER)
Why methane escapes the microbial filter
With their meas­ure­ments, the sci­ent­ists were able to show that only 40% of the rising meth­ane is con­sumed by mi­croor­gan­isms. This is less than in most meth­ane-rich hab­it­ats. Un­til now, sci­ent­ists as­sumed that a higher fluxes of meth­ane lead to higher num­bers of meth­ane con­sum­ing mi­croor­gan­isms. At Haakon Mosby, very little meth­ane is con­sumed in the gassy centre of the mud vol­cano.

The mar­ine bio­lo­gist Helge Niemann ex­plains this phe­nomenon: “The meth­ane con­sum­ing mi­croor­gan­isms need oxy­gen or sulph­ate from the sea­wa­ter to ox­id­ize meth­ane. In the mud vol­cano wa­ter that flows up­wards through the ocean floor both com­pounds are miss­ing. Since the flow ve­lo­city of this wa­ter is so high, only very little oxy­gen and sulph­ate from the sea­wa­ter can pen­et­rate the ocean floor and there­fore the mi­croor­gan­isms in the centre and bac­teria mat zone just don’t get enough en­ergy.“


At the rim of the vol­cano, the situ­ation is very dif­fer­ent: Tube­worms grow about 60 cm deep into the sea­floor and act­ively pump sea­wa­ter into deeper lay­ers. Mi­croor­gan­isms liv­ing at the roots of the worms profit from this situ­ation. Here, Helge Niemann and Tina Lösekann found the highest con­sump­tion rates of meth­ane in­dic­at­ing an ef­fi­cient bio­lo­gical fil­ter against the po­ten­tial green­house gas meth­ane.


Helge Niemann and Tina Lösekann were sup­por­ted by a Ger­man-French re­search team who mapped the vol­cano with sonar and video sys­tems and ana­lysed geo­chem­ical pro­cesses. The util­isa­tion of the deep-wa­ter ro­bot Victor 6000 of the French re­search in­sti­tute IFREMER, Brest was cru­cial for the two highly suc­cess­ful ex­ped­i­tions to the mud vol­cano with the re­search ves­sels “L’Atalante” of IFRE­MER and “Polarstern” of the German Alfred Wegener Institute.
The deep-water vehicle VICTOR 6000 (Source IFREMER).
Future work
For the first time, de­tailed sur­veys of ele­ment fluxes and mi­cro­bial con­sump­tion were car­ried out at a deep-sea mud vol­cano in the frame­work of the GEOTECHNOLOGIEN pro­ject MUMM. It is now im­port­ant to ex­am­ine the ef­fi­ciency of bio­lo­gical fil­ters at other meth­ane seeps. This factor may be rel­ev­ant for the global cli­mate but is till now rather poorly known.

The Ger­man-French re­search team will there­fore con­tinue the in­vest­ig­a­tion of mud vol­ca­noes. The next ex­ped­i­tion with the Ger­man re­search ves­sel Met­eor and the ROV Quest of Marum in Bre­men tar­gets re­cently dis­covered meth­ane seeps in the east­ern Medi­ter­ranean. In ad­di­tion, fur­ther ex­ped­i­tions to the Haakon Mosby mud vol­cano are planned in the frame­work of the European re­search pro­ject HERMES.


Contact:
Dr. Helge Niemann
+49 421 2028 653
mo­bile phone +49 179 233 2572
hniemann@mpi-bre­men.de
Max Planck In­sti­tute for Mar­ine Mi­cro­bi­o­logy,28359 Bre­men, Ger­many

Dr. Tina Lösekann
001 (650) 493-5000 x63163 tloeseka@stan­ford.edu
Stan­ford Uni­versity School of Medi­cine, Palo Alto, CA 94304, USA

Prof. Dr. Antje Boetius
+49 421 2028 860
mo­bile phone +49 175 2475 301
aboe­t­ius@mpi-bre­men.de
Max Planck In­sti­tute for Mar­ine Mi­cro­bi­o­logy, 28359 Bre­men, Ger­many
and In­ter­na­tional Uni­versity Bre­men, 28759 Bre­men, Ger­many

Dr. Manfred Schlösser (press of­ficer)
+49 421 2028 704 mschloes@mpi-bre­men.de
and Heiko Löb­ner
+49 421 2028655 hloeb­ner@mpi-bre­men.de
Max Planck In­sti­tute for Mar­ine Mi­cro­bi­o­logy, 28359 Bre­men, Ger­many


Contributing Institutes
Max-Planck-Institut für marine Mikrobiologie, 28359 Bre­men, Ger­many

Alfred Wegener Institute for Polar and Marine Research, 27515 Bremer­haven, Ger­many
Dr. Mi­chael Klages; +0049 471 4831 1302; mk­lages@awi-bremer­haven.de

DFG Research Center Ocean Margins, University of Bremen, 28334 Bremen, Germany

Centre Ifremer de Brest, BP70, 29280 Plouzane, France
Dr. Jean Paul Foucher; +0033 2 98 22 42 69; jean.paul.foucher@ifremer.fr

UMR 7156 Université Louis-Pasteur/CNRS, Département Microorganismes, Génomes, Environnement, 67083 Strasbourg Cedex, France

International University Bremen, 28759 Bremen, Germany


Reference:
Helge Niemann, Tina Lösekann, Dirk de Beer, Marcus Elvert, Thierry Nadalig, Katrin Knittel, Rudolf Amann, Eberhard J. Sauter, Michael Schlüter, Michael Klages, Jean Paul Foucher, Antje Boetius. Novel microbial communities of the Haakon Mosby mud volcano and their role as a methane sink. Nature, October 2006.
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