MEPS 202:289-295 (2000)  -  doi:10.3354/meps202289

ABSTRACT: We examined the ability of foraminifera in taking up freshly deposited algal carbon in intertidal estuarine sediments. Lyophylized ¹³C-labelled axenic Chlorella was added to intact sediment cores containing natural benthic biota. The response of the system as a whole was rapid; ~5% of the added carbon was respired to CO₂ within 6 h. Bacteria assimilated ~2 to 4% of the added carbon within 12 h. Among the foraminifera, the dominant foraminifer Ammonia exhibited rapid uptake and it is estimated that ~1 to 7% of the added carbon was ingested within 3 to 53 h. This rapid, substantial uptake by Ammonia and the significant contribution of foraminifera to meiobenthic abundance and biomass (37 and 47% respectively) suggest that foraminifera play an important role in the carbon cycle in these sediments.

KEY WORDS: Meiobenthos · Benthic foraminifera · Bacterial biomarkers · Algal carbon · Carbon cycle · CO₂ · ¹³C labelling