The preset condition of water pollution in Lake Biwa was investigated based on the attached diatom assemblages in 1988. In the investigation, samples were collected from 31 sites along the shore (22 sites in Northern basin,9 sites in Southern basin),12 sites on the traverse line of the lake (9 sites in Northern basin,3 sites in Southern basin).
Among dia tom taxa occurred in those samples,164 taxa belonging to 29 genera which identified were listed up and 231 photographs with 2000 magnification on 100 taxa were shown in 7 plates.
Ecological information on the water pollution of this lake will be reported in other paper.
