The methane cycle in tidal flats

Methanogenesis in the subsurface of a sandy intertidal sediment


Methane concentrations in the water column in the back barrier tidal flat of the island of Spiekeroog were found to be twenty times higher than in the open ocean. However, sources and sinks of methane in tidal flats are rarely investigated so far. As high methane concentrations are not exclusively introduced by fresh water input, it is assumed that the major source is microbial methane production within the sediments. Methane can be produced under anoxic conditions by different groups of methanogenic archaea from acetate, hydrogen and carbon dioxide or methylated compounds. Most of these microorganisms compete for the available substrates with sulfate reducing bacteria. Previous molecularbiological surveys of an adjacent tidal flat from the same area indicated a succession of different physiological groups of methanogenic archaea along the depth profile (Wilms et al. 2007). While metyhlotrophic methanogenes were found within the entire sediment column, putitative hydrogenotrophic methanogenes were only detected in sediment layers where sulfate was depleted


Project partners
  • Kerstin Bischof (MPI Bremen)
  • Rudi Amann (MPI Bremen)

Related publications

Wilms R, Sass H, Köpke B, Cypionka H, Engelen B (2007) Methane and sulfate profiles within the subsurface of a tidal flat are reflected by the distribution of sulfate-reducing bacteria and methanogenic archaea. FEMS Microbiol Ecol 59:611–621

Wilms R, Sass H, Köpke B, Köster J, Cypionka H, Engelen B (2006) Specific bacterial, archaeal, and eukaryotic communities in tidal-flat sediment along a vertical profile of several meters. Appl Environ Microbiol 72:2756-2764

Köpke B, Wilms R, Engelen B, Cypionka H, Sass H (2005) Microbial diversity in coastal subsurface sediments - a cultivation approach using various electron acceptors and substrate gradients. Appl Environ Microbiol 71:7819-7830