Preface The expedition ARK XIX/3 with the German icebreaking RV ...

profiler). Bottom water samples have been obtained at various sites to investigate
methane oxidation in the water column, measured by injection of tritiated methane.
Tab B5.1-2: Sediment samples obtained by gravity corer. Sediment samples were split into
different layers for rate measurements, biomarker analysis, for total bacterial counts,
fluorescence in situ hybridization (FISH), as well as for microbial diversity analysis (every 25-
50 cm over the total length of the core). In most cores up to 50 cm of the surface appeared to
be lost. The recovered length was measured in the opened cores.
Device Station No Date
length [cm]
Sediment conditions,
community Lat N Long E
GC PS64/332 2-Jul-03 461 Centre, warm fluids 72° 0,28 14° 43,57
GC PS64/336 5-Jul-03 470
Pogonophora, small pieces
of GH at -410cm 72° 0,02 14° 43,57
GC PS64/339 5-Jul-03 465 Centre, archive 72° 0,13 14° 43,81
GC PS64/341 5-Jul-03 114
Pogonophora 10cm chunk of
GH at -114cm 72° 0,17 14° 43,85
GC PS64/371 11-Jul-03 488
Bacterial mat but first 0.5 to
1m lost 72° 0,20 14° 43,88
GC PS64/372 11-Jul-03 430 Centre NW with warm fluids 72° 0,26 14° 43,59
GC PS64/373 11-Jul-03 453 Centre middle 72° 0,21 14° 43,66
GC PS64/374 11-Jul-03 166
Bubble site with
Pogonophora in core 72° 0,38 14° 43,61
Water samples are taken with three types of water samplers: the rosette for 4-1200 m
above seafloor (CTD), the horizontal water sampler (BWS) as well as from the ROV
bottles (PEP) to investigate the methane emission from the sediments into the water
column (Tab. B5.1-3).
The major aim of this study was the investigation of microbial sulfate reduction (SRR)
and anaerobic methane oxidation (AOM) in methane enriched surface sediments of
the HMMV. For the measurement of methane concentrations in sediments, a sample
is mixed into a sodium hydroxide solution. After equilibration with the headspace of
the sample vial, a gas sample is removed with a gas tight syringe and injected into a
gas chromatograph with a flame ionisation detector. Sulfate and sulfide
concentrations in sediment pore-water fixed with zinc chloride will be determined
photometrically. For the tracer measurements both radioactive tracers 35 SO 4 and
14 CH 4 were injected into replicate core sub-samples (inner diameter 1 cm) which were
incubated anoxically at in situ temperature for 24 hrs. After incubation, the sediment
sub-cores (1-5, 7-11, 13-17 cm) were mixed with zinc acetate (20% w/w) or sodium
hydroxide (2.5% w/w), respectively, to stop the bacterial activity. These samples will
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