Physico-chemical data including methane concentrations, as well as methane oxidation rates, measured at time-series station Boknis Eck (Baltic Sea) from 2012-2014

Coastal seas may account for more than 75% of global oceanic methane emissions. There, methane is mainly produced microbially in anoxic sediments from where it can escape to the overlying water column. Aerobic methane oxidation (MOx) in the water column acts as a biological filter reducing the amount of methane that eventually evades to the atmosphere. The efficiency of the MOx filter is potentially controlled by the availability of dissolved methane and oxygen, as well as temperature, salinity, and hydrographic dynamics, and all of these factors undergo strong temporal fluctuations in coastal ecosystems. In order to elucidate the key environmental controls, specifically the effect of oxygen availability, on MOx in a seasonally stratified and hypoxic coastal marine setting, we conducted a 2-year time-series study with measurements of MOx and physico-chemical water column parameters in a coastal inlet in the southwestern Baltic Sea (Eckernförde Bay). We found that MOx rates generally increased toward the seafloor, but were not directly linked to methane concentrations. MOx exhibited a strong seasonal variability, with maximum rates (up to 11.6 nmol l-1 d-1) during summer stratification when oxygen concentrations were lowest and bottom-water temperatures were highest. Under these conditions, 70-95% of the sediment-released methane was oxidized, whereas only 40-60% were consumed during the mixed and oxygenated periods. Laboratory experiments with manipulated oxygen concentrations in the range of 0.2-220 µmol l-1 revealed a sub-micromolar oxygen-optimum for MOx at the study site. In contrast, the fraction of methane-carbon incorporation into the bacterial biomass (compared to the total amount of oxidised methane) was up to 38-fold higher at saturated oxygen concentrations, suggesting a different partitioning of catabolic and anabolic processes under oxygen-replete and oxygen-starved conditions, respectively. Our results underscore the importance of MOx in mitigating methane emission from coastal waters and indicate an organism-level adaptation of the water column methanotrophs to hypoxic conditions.

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Cite this as

Steinle, Lea, Maltby, Johanna, Treude, Tina, Kock, Annette, Bange, Hermann Werner, Niemann, Helge (2017). Dataset: Physico-chemical data including methane concentrations, as well as methane oxidation rates, measured at time-series station Boknis Eck (Baltic Sea) from 2012-2014. https://doi.org/10.1594/PANGAEA.871890

DOI retrieved: 2017

Additional Info

Field Value
Imported on November 30, 2024
Last update November 30, 2024
License CC-BY-NC-3.0
Source https://doi.org/10.1594/PANGAEA.871890
Author Steinle, Lea
Given Name Lea
Family Name Steinle
More Authors
Maltby, Johanna
Treude, Tina
Kock, Annette
Bange, Hermann Werner
Niemann, Helge
Source Creation 2017
Publication Year 2017
Resource Type text/tab-separated-values - filename: boknis-eck_ch4-2012-2014
Subject Areas
Name: Chemistry

Name: Ecology

Name: Lithosphere

Related Identifiers
Title: Effects of low oxygen concentrations on aerobic methane oxidation in seasonally hypoxic coastal waters
Identifier: https://doi.org/10.5194/bg-14-1631-2017
Type: DOI
Relation: IsSupplementTo
Year: 2017
Source: Biogeosciences
Authors: Steinle Lea , Maltby Johanna , Treude Tina , Kock Annette , Bange Hermann Werner , Engbersen Nadine , Zopfi Jakob , Lehmann Moritz F , Niemann Helge .