Abstract
Hakata Bay is an enclosing costal sea, whose hinterland is a large urban settlement with the population of about 1.4 millions. Construction of an artificial island has been carrying out at the inner part of the bay. The state of natural environments of Hakata Bay are main issues among the city government, citizen and scientists. The aim of this study is to investigate natural environmental characteristics of Hakata Bay by using data of various observation for water and sediment quality, benthos, marine planktons, and so forth. The multivariate statistical analysis and the proposed the environmental evaluation method are applied for studying natural environmental qualities of Hakata Bay and to verify validity of the proposed evaluation method. It is found that some of the water quality elements like T-P and SS have been constantly improving, although the physical environment is deteriorating due to construction of the artificial island. The proposed evaluation method clearly indicates this trend.
