Sediment samples were taken from the mudflat of Ledbetter embayment at the mouth of the stream, at summer pool when it was submerged and at winter pool when it was exposed. DNA was extracted and molecular techniques were applied to avoid problems associated with bacterial culture. Amplified Ribosomal DNA Restriction Analysis (ARDRA) found 96 different fingerprints in 350 clones containing amplified sediment 16S rDNA. There were 54 different patterns in the 180 clones examined from summer samples and 55 in the 170 clones examined from winter samples. Only 13 ARDRA patterns were found in both winter and summer. These were among the most abundant organisms found and were found frequently in both summer and winter. Sequence analysis of clones with different ARDRA patterns showed that the α and β Proteobacteria were the most abundant bacteria in these samples and were abundant in both winter and summer. The α Proteobacteria, however, were the most abundant group in winter and the β Proteobacteria were the most abundant group in the summer. Data suggest that there was seasonal turnover in the bacterial community and that the organisms that can thrive under, or at least tolerate, the differences in water level, temperature, nutrient, and oxygen availability are the most abundant species in the community throughout the year.