Microbial Biomass, Rates of DNA Synthesis and Estimated Carbon Production in Kaneohe Bay, Hawaii

Estimates were made of microbial biomass and production in the water column and unconsolidated sediments in a transect across the barrier reef of Kaneohe Bay, Oahu, Hawaii over a 5-week period. Cell-associated parameters measured were chlorophyll a (chl a) and adenosine-5′-triphosphate (ATP), Microbial production was estimated from rates of DNA synthesis. The total biomass of microorganisms in the water column and coral sands ranged from 11.5 to 99.8 μg C liter^–1 and 281 to 941 μg C cm^–3, respectively. Total microbial community production (extrapolated from measurements of DNA synthesis) ranged from 3.3 to 17.4 μg C liter^–1 h^–1 in the water column, and from 11.3 to 58.2 μg C g^–1 (dry wt) h^–1 in the sediments. Total depth integrated microbial production in the sediments exceeded that in the overlying water by a factor of 100 when expressed on an areal basis. Our estimates for microbial carbon production in coral reef rubble are equivalent to, or exceed previous estimates for, the total coral reef ecosystem.