To clarify capability of small scale artificial tidal flat (SAT) in urban area, we focused on manila clam production and investigated some SATs in Tokyo Bay. Manila clam production rate on a main SAT was comparable or higher than natural tidal flat in Tokyo Bay. But, manila clam was damaged by hypoxia seriously in late summer to autumn in one SAT which was main research area. Another one SAT, manila clam wasn't damaged hypoxia, because of the shallow area was widely than main SAT. Further, benthic microalgae was main food source of Manila clam in all SATs, and manila clam populations related to benthic microalgae abundance. It suggested manila clam production was affected directly benthic microalgae production, and benthic microalgae production on SAT was changed by design or maintenance condition of each SAT.

No abstract

No abstract

Valuing coastal ecosystem service is important for disentangling the complex human society-ecosystem relationships and incorporating the value into public decision-making processes. We developed a new evaluation method to comprehensively and concisely quantify the current status and likely future of shallow coastal environments by an ocean health index (OHI) score. We evaluated the environmental condition of four intertidal flats located in Tokyo Bay using OHI. Our method can provide a tool to explicitly show the strengths and limitations of each coastal ecosystem functioning.