We observed water quality at 16stations in Shimizu Port from 1986to 2005. The observation was carried out
4times a year,and the distributions of coliform bacteria and marine bacteria were discussed.Salinity,pH,DO,COD
and T-N have increased since 1998,whereas transparency,SS and T-P have decreased.These may be dependent on
the change in loading rate of these substances from the rivers and internal biological production in Shimizu Port.
Bacteria were also observed at the mouth of Tomoe River and Orido Bay. The number of coliform bacteria was
3.5×10 5CFU/100ml at the mouth of the Tomoe River.This probably implies that the Tomoe River is polluted with
bacteria,such as fecal coliform due to feces origin.The number of a general marine bacteria from the surface water
in the inner part of Orido Bay was 2.3〜2.6×10 5CFU/100ml.The dominant bacteria were Vibrio-Aerogenes.They
are often found in eutrophicated sea area. Cellulose decomposing bacteria were also found in the sediments.