Benthic carbon turnover in continental slope and deep sea sediments: importance of organic matter quality at different time scales

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Instantaneous benthic response to different organic matter quality: In situ experiments in the Benguela Upwelling System

The benthic community in continental slope and deep-sea sediments of the Benguela Upwelling System was supplied with 13C-labelled organic matter (OM) of two different qualities using a benthic chamber lander. Freeze-dried cultures of Skeletonema costatum served as ‘fresh’ OM. ‘Altered’ OM of the same material had been additionally dialysed to remove low-molecular weight compounds. In order to investigate the benthic response pattern, mineralization of labelled OM, uptake by macrofauna and incorporation into bacteria were followed over 18–36 h. Total oxygen uptake was not affected beyond natural variation by the OM addition. Mineralization dominated the 13C-labelled phytodetritus processing, constituting 71–95% of the total processed OM. Bacterial incorporation of phytodetrital carbon exceeded macrofaunal uptake at all stations. Stations situated in a major centre of OM deposition showed phytodetritus processing rates on average twice as high as outside the depocentre. Phytodetritus processing was 1.5, 2.5 and 4.3 times higher for fresh than for altered OM at 605, 1019 and 1335 m water depth, respectively. Our observations clearly indicate the importance of OM quality on mineralization rates

Parallel architectures and languages for advanced information processing A VLSI-directed approach

SIGLETIB Hannover: RO 7624(57) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman