LONG-TERM CHANGES IN ORGANIC CARBON CONTENT IN SEAGRASS BED IN HIROSHIMA BAY

Abstract

 The purpose of this study is to clarify long-term changes in organic carbon content in two seagrass beds in Hiroshima Bay, The distribution range of seagrass varied and competing seaweeds were distributed in Jigozen, however there was almost no change in the distribution range of seagrass in Kojiro. The total organic carbon content in the sediment was high in areas where seagrasses were distributed, suggesting that the distribution of competing seaweeds also had an influence. The amount of total organic carbon in seagrass did not differ between sites, and seasonal fluctuations were greater in the rhizomes and roots than in the leaves. Seasonal fluctuations in the persistent organic carbon content in Jigozen were small, however it increased from May to August 2021 in Kojiro, when seagrasses flourish. The organic carbon content in the sediment in seagrass beds in Hiroshima Bay was influenced by the distribution of seagrass and/or seaweeds.