Bacterial growth and tidal variation in bacterial abundance in the Great Sippewissett Salt Marsh

Publisher Website
Google Scholar
Abstract
Bacterial abundance was measured monthly during 2 consecutive tidal cycles in the main channel of the Great Sippewissett Salt Marsh. It was consistently highest in low tide waters and lowest in water flooding the marsh from Buzzards Bay. Absolute tidal variation in bacterial abundance was lower in winter than in summer. Relative variation (logarithm of bacterial abundance vs. time) was approximately the same throughout the year. Most of the tidal variation in bacterial abundance was apparently due to conservative mixing, but that the bacteria-rich water sampled at low tide was the result of bacterial growth. In Aug., bacterial growth rates were estimated from changes in bacterial abundance in water samples in which the particles were diluted 10-fold. Bacteria appear to grow fast enough to account for the difference in bacterial abundance between low and high tide. In spite of the large difference in bacterial abundance in low vs. high tide samples, there was no significant net export of bacteria from Great Sippewissett into Buzzard Bay during the year. The estimates of bacterial growth rates and biomass were also used to calculate the contribution of bacteria to the C cycle of the marsh. Bacterial production was small compared to net primary production in the marsh and did not appear to contribute significantly (< 10%) to the C required by the large mussel population in Great Sippewissett.