Monitoring organic enrichment of coastal sediment
Organic enrichment of coastal sediment is of interest to coastal managers worldwide. It results from excess supply of organic carbon to coastal waters from both natural and anthropogenic sources such as, terrestrial runoff, eutrophication, and aquaculture. A large fraction of this carbon is mineralised by sulfate reduction, a bacterially mediated reaction that leads to the production of hydrogen sulfide (H2S). This is the culprit for the ‘rotten egg’ smell you encounter when digging up estuarine sediments. H2S readily reacts with sedimentary iron compounds to form iron sulfides that contribute to the distinct black colouration of organic-rich sediment.