Abstract
In situ and on-board pulse-chase experiments were carried out on a sublittoral fine sand in the German Bight ( southern North Sea) to investigate the hypothesis that sandy sediments are highly active and have fast turnover rates. To test this hypothesis, we conducted a series of experiments where we investigated the pathway of settling particulate organic carbon through the benthic food web. The diatom Ditylum brightwellii was labelled with the stable carbon isotope 13 C and injected into incubation chambers. On-board incubations lasted 12, 30 and 132 h, while the in situ experiment was incubated for 32 h. The study revealed a stepwise short-term processing of a phytoplankton bloom settling on a sandy sediment. After the 12 h incubation, the largest fraction of recovered carbon was in the bacteria ( 62%), but after longer incubation times ( 30 and 32 h in situ) the macrofauna gained more importance ( 15 and 48%, respectively), until after 132 h the greatest fraction was mineralized to CO2 ( 44%). Our findings show the rapid impact of the benthic sand community on a settling phytoplankton bloom and the great importance of bacteria in the first steps of algal carbon processing.
Original language | English |
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Pages (from-to) | 120-129 |
Number of pages | 10 |
Journal | Marine Biology Research |
Volume | 2 |
Issue number | 2 |
DOIs | |
Publication status | Published - Apr 2006 |
Keywords
- C-13 labelling experiment
- bacteria
- macrofauna
- mineralization
- sandy sediment
- MICROBIAL COMMUNITY STRUCTURE
- IN-SITU HYBRIDIZATION
- NORTH-SEA SEDIMENTS
- MARINE-SEDIMENTS
- FATTY-ACIDS
- PHOSPHOLIPID ANALYSIS
- RAPID RESPONSE
- GERMAN BIGHT
- CARBON
- DEGRADATION