Abstract
Clams (Ruditapes philippinarum, Mactra veneriformis, Mercenaria mercenaria, Meretrix lusoria) were caged on the highly eutrophicated Oi tidal flat in Tokyo Bay, and their survival was monitored during warm seasons for two years. Environmental variables that could potentially control their survival (e.g. temperature, salinity, sediment characteristics, dissolved oxygen and sulfides) were also monitored. The clams died mainly during summer, but no clear relationships between mortality and the environmental variables monitored were detected for each clam species.
