Direct counts of bacteria in the sediments of a North Carolina salt marsh

The number of bacteria in sediments of a North Carolina salt marsh was determined by direct counts with epifluorescent illumination and acridine orange stain. Cell number decreased from 8.36–10.90×10⁹ cells/cm³ of sediment at the surface to 2.19–2.58×10⁹ cells/cm³ of sediment at a depth of 20 cm. No significant difference was found among four stations located on a transect which crossed the marsh and spanned subtidal to intertidal sediments.