A Study on the Sediment Quality of the Sea off Fukuyama, the Seto Inland Sea, Japan.

瀬戸内海福山沖海域底層の生物生息環境を評価するため、1998年9月16日、9測点において採泥し、底質について分折を行った。分析項目は、泥温、酸化還元電位、pH、含水率、強熱減量、酸揮発性硫化物量、底質酸素要求量、および間隙水中の硫化水素濃度の8項目である。さらに、底質直上水を採取し、溶存酸素濃度、硫化水素濃度およびアンモニア態窒素濃度について測定した。アンモニア態窒素濃度については、表層水についても測定した。その結果、この海域の底層水環境は生物にとって危機的ではないが、底質は一般に硫化物や有機物がやや高めであり、特に芦田川河口沖では底生生物の生息環境として良好とは言えないことが明らかとなった。A study was carried out on the sediment quality of the sea off Fukuyama, the Seto Inland Sea, Japan to evaluate the environmental conditions. Sediment temperature, oxidation-reduction potential, pH, water content, loss on ignition, acid-volatile sulfide concentration, and sediment oxygen demand were measured, along with the hydrogen sulfide concentration in the interstitial water of the sediment. Concentrations of dissolved oxygen, hydrogen sulfide and ammonia in overlying water of the sediment were measured. Ammonia concentration of the surface water was also determined. It revealed that the quality of overlying water of the area is not so deteriorated as to impart serious damage to benthic oraganisms. However, sediment of the area, in particular off the Ashida River, was rich in organic content and sulfide, and hence inhabitable by benthic organisms