Bacterial production in marine sediments: will cell-specific measures agree with whole-system metabolism?

Abstract
Estimates for bacterial production in nearshore western Atlantic Ocean sediments were made using the frequency of dividing cell and thymidine uptake methods. The frequency of dividing cell (FDC) method resulted in estimates in the range of 5 to 50 g C m-2 d[day]-1. The thymidine uptake (THY) method resulted in estimates of 0.1 to 0.8 g C m-2 d-1. Metabolic measurements based on sediment O2 uptake show that the FDC estimates are unreasonably high, while THY estimates, which were corrected for DNA extraction and thymidine dilution, are reasonable with respect to O2 uptake data. Problems associated with these 2 bacterial production methods when used in sediments are discussed.