Abstract
In order to conserve bay ecosystems, it is important to evaluate impacts of anthropogenic environmental alteration on bioligical communities. In this study, we tested whether assessment based on fatty acid composition analysis could differentiate between two local communities with different distances from a river mouth in Shizugawa Bay. As a result, significant differences in marker fatty acid composition were found between predatory fish and benthic consumers as well as between the two sampling locations. The food web near the river mouth depend relatively more on diatom-derived organic matter, while that of the offshore location depended more on green algae-derived organic matter. These retuslts support that the characteristics of local community and food web structures were evaluated by applying fatty acid composition analysis of consumer organisms. Our results also indicated that predatory fish concentrated EPA and DHA of prey thorugh their assimilation. Particularly to further apply fatty acid compositon analysis of predatory fish for the estimation of food web structures as a method of ecosystem assessment in bays, it is further necessary to quantitatively understand the patterns of fatty acid concentration along trophic levels.
