カンキョウ ノ ヘンセン ト ユウコウチュウ : ユウコウチュウ ニヨル ニンゲン カツドウ ガ オヨボシタ キスイコ ノ カンキョウ ヒョウカ

During the last 30 years, there have been significant human activities in brackish lakes and coastal areas in Japan. Natural environments have been changed by these human activities, which include many artificial constructions such as coastal embankments and sluice gates, dredging of bottom sediment, and discharging of nutrients into brackish and coastal waters. As a national project of Japan in the 1970s, a large-scale land reclamation was planned and partly carried out in Nakaumi Lake. This project is now not working because of increasing requests that natural environment must be protected. Several artificial constructions were thus left incomplete, Which should have led to a primary factor that changed the environment of both the water qualities and living organisms from the 1970s through the 1990s. Foraminifera are significantly useful to reconstruct these environmental changes caused by human activities. Foraminifera have a large standing crop in brackish and coastal areas, and they are very sensitive to the changes of waters. Moreover, the remains of foraminifera are preserved as fossils, which make possible the time series analysis of environments. This paper reviews foraminiferal evidence responsed to the human activities in Nakaumi and Shinjiko Lakes