抄録
Seasonal changes of attaching diatom flora were observed by means of the slide glasses immersed at intervals of about one month during the period from August 1978 to to August 1979 at 7 stations in Shonai Estuary, the Bay of Hamana-ko, Shizuoka Prefecture. At the same time, the measurements of water temperature, chlorinity, DO, chlorophyll-a and COD were made.
Shonai Estuary was found to be divided into four areas; one was mainly influenced by river water (Type I), another weakly by river water (Type II), another by coastal sea water (Type IV) and another was the middle area between Type II and IV (Type III).
The species compositions of attaching diatoms on slide glasses changed gradually from Type I to Type IV, and in each area several dominant species were observed which represent the environmental conditions of it. The combination of dominant species in each area was as follows; Nitzschia sp.-A-Navicula sp.-C, D-Fragiralia sp.-B in Type I, Nitzschia sp.-A-Nitzschia closterium-Navicula sp.-C, D in Type II, Nitzschia sp.-A-Nitzschia closterium-Navicula sp.-A, D in Type III and Navicula sp.-A-Nitzschia sp.-B-Cocconeis scutellum in Type IV.
