Assay of phosphatase activity and ATP biomass in tideland sediments and classification of the intertidal area using chemical values

Detailed studies of the phosphatase activity in the tidelands were examined including the localization of the phosphatase activities and the spatial distributions of the activity in the tidelands around Hiroshima Bay, the Aki-Bingo Open Sea and Isahaya Bay of Kyushu on the western side of Japan. The results indicate that the phosphatase activity of the sediment fraction accounts for 98% of the tideland activity. Furthermore, we classified 19 tidelands into four groups by a cluster analysis using two parameters: phosphatase activities and ATP (adenosine 5'-triphosphate) biomass. The first group is a member of the tidelands located in areas remote from the cities. They have a low phosphatase activity and low ATP biomass and the seawater in the tideland is very clean. The second is a group with a low phosphatase activity and high ATP biomass. In the tidelands belonging to this group, large numbers of benthos and shellfish can be observed. The third group has a high phosphatase activity and a relatively low ATP biomass. The estuary tidelands located near Hiroshima City belong to the third group. The last one is tidelands with a high phosphatase activity and high ATP biomass. In this group, the ratio of the phosphatase activity to ATP biomass is relatively low. In the summer, we observed deterioration in the water quality and accumulation of sludge on the sea bottom in the tideland of the last group. Moreover, we employed a multiple regression analysis and proposed an equation to obtain the group number of the cluster analysis using the assayed values of the phosphatase activity and the ATP biomass. (C) 2003 Elsevier Science Ltd. All rights reserved.