Fig. 2

a Relative abundance of methanogens at genus level based on mcrA sequencing. Methanolobus dominated in all original sediment down to 19 cm (D1–D4) and DMS-amended sediment except for sample H2D7 where methane production was minimal. b The mcrA gene copy numbers in original and DMS-amended sediment incubations as determined by qPCR. All reactions were set up in triplicate and the average abundance and standard error are shown. c PCoA plot of the mcrA sequences based on Bray–Curtis dissimilarity metrics. Ellipses indicate 95% confidence intervals according to treatment data. Colour indicates treatment (red untreated; green DMS-amended). Shapes indicate sampling site. D1 0–1 cm; D2 1–2 cm; D3 2–5 cm; D4 9–12 cm; D5 19–22 cm; D6 39–43 cm; D7 60–65 cm