Diffusive Fluxes across Sediment–Water Interface in the Seto Inland Sea, Japan

Abstract

Spatial investigations of pore water nutrient concentrations and their theoretical fluxes were carried out in six different sediment types within a coastal environment (Shido Bay, the Seto Inland Sea, Japan fluxes increased with the C:N ratio of sedimentary organic matter. Differently, the highest Si(OH) 4 fluxes were related with the relative high pheo-pigments and biogenic silica (Bio-Si) contents in the surface sediment, which are affected by fecal matter from the oyster culture. As a result, organic matter availability was found to be an important factor in regulating spatial variability of NH 4 + and PO 4 3− fluxes, whereas significant contents of sedimentary pheo-pigments and Bio-Si characterise the sites where Si(OH) 4 is available.