6:15 PM - 7:30 PM
[HQR23-P09] The growth process of Oyster reefs and Diatom assemblage in Tokyo bay - focus on a genus Amphora of diatoms
Keywords:Tokyo Bay, Oyster reefs, Diatom, Macro-benthos,, Ecosystem
In this study, the ecosystems of the oyster reefs are composed of C. gigas, sea anemone, ragworms, seaweeds, seagrasses and diatoms. In particular, we investigate living oyster reefs and diatoms. Oyster feed on diatoms playing a role in the base of food chain. Our field survey checks size of reefs, habitation density in reefs and organisms around the reefs, in comparison with various environmental indicators by the monitoring post of the Bay.
In general only macro-benthos and fishes are treated in the ecosystems of coastal areas, though seaweeds and seagrasses are important to comprehend the ecosystem. Gastropods in tidal zone eat mollusks, seaweeds and seagrasses. In fact, in Sanbanze, sea lettuces (Ulva sp., a kind of seaweeds), grows conspicuously along with seagrasses. A genus Amphora, one of the dominant diatoms in the reefs, is living in brackish to marine water, settling on algae or plants and is useful as an important marker of seaweeds and seagrasses in Sanbanze.