The vast majority of continental shelf sediments are comprised of sands, which, unlike muds, are permeable in nature. The interaction between sediment topography (in the form of small ripples) and bottom water movement therefore causes advective flow of porewater within the sediment, supplying and removing electron donors and acceptors at velocities orders of magnitude higher than diffusion. This enhanced porewater supply leads to intense biogeochemical cycling and activity in permeable sediments, which act as a biocatalytic filter, removing anthropogenic pollutants such as nitrate from the coastal zone and reducing it to inert dinitrogen gas. The coastal sand filter is therefore increasingly recognized for its vital role in reducing eutrophication and remineralizing organic matter.
- Nitrogen cycling in sandy sediments; from beaches to the shelf break
- Nitrogen cycling eukaryotes in permeable sediments
- The influence of dynamic redox conditions on nitrogen cycling communities
- N-cycling pathways, oxygen dynamics and the fate of DOM at sites of groundwater seepage and within the seawater recirculation zone on beaches