Abstract
We analyzed a change of the species composition of phytoplanktons with the variation of the nutriment concentration by using existing survey data in Hakata Bay.
As a result, the removal of phosphorus by advanced sewage treatment was decreased T-P concentration and contributed to restraint of the primary production in the bay. In addition, the cause of the prolongation of the red tide occurrence days of dinoflagellates in summer was not clear, but we understood that diatoms were hard to multiply by the decrease of phosphorus in winter season. Furthermore, it was became clear that Akashiwo sanguinea, which was a kind of dinoflagellates, was easy to multiply because A. sanguinea was hard to influence action to control an increase by the decrease of diatoms and the number of the red tide occurrence days of dinoflagellates increased.
Essentially, We want to study the adequacy of the volume of primary production that various creature habitation space can secure, and the nutriment supply in the future.
