Application of the early diagenesis model to Ago Bay sediment, Japan: Comparison of the sediment characteristics between two observation sites

An early diagenesis model was developed and utilized to compare the material cycling characteristics of the sediment in aspects of the oxygen consumption, carbon, nitrogen, manganese, iron and sulfate at two measurement sites, Tategami and Takonobori, in Ago Bay, Japan.The model is a one dimensional vertical transport. The biogeochemical reactions in the model consist of primary and secondary reactions. The primary reaction describes the organic matter degradation, and the secondary reaction describes the reaction of reduced species produced by the primary reaction.In general, the model could reproduce most of the vertical concentration profiles of materials observed at those two measurement sites. The supplied particulate organic matter to the sediment surface is 14.69 mmol C/m2/day for both sites. The result shows that oxic respiration and sulfate reduction are dominant at Tategami, while sulfate reduction is dominant at Takonobori. We also found that sediment at Takonobori consumed less oxygen than at Tategami due to the release of dissolved organic matter from the sediment, which is transported mostly by irrigation process.