Abstract
The growth of phyto and animal benthos in Fukuyama inner harbor is inhibited because of the discharge of untreated wastewater into the harbor. Field experiments and benthos observations are conducted to examine the restoration processes of ecosystem in the harbor. When gravel was used as the basement, the reduced level of the basement was evaded, leading to the growth of benthos at an early stage. And then, the growth of benthos that are more tolerant to organic-enriched sediment was confirmed. However, the ability (e.g., mineral dissolution, adsorption) of gravel in evading the reduced level was low. Therefore, alkaline materials, such as fly ash and slag, can be used instead of gravel for restoring the ecosystem in the harbor that seriously affected by untreated wastewater discharge.
