Enhanced benthic activity in sandy sublittoral sediments: Evidence from C-13 tracer experiments

S. I. Buhring*, S. Ehrenhauss, A. Kamp, L. Moodley, U. Witte

*Corresponding author for this work

Research output: Contribution to journalArticle

26 Citations (Scopus)

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 languageEnglish
Pages (from-to)120-129
Number of pages10
JournalMarine Biology Research
Volume2
Issue number2
DOIs
Publication statusPublished - 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

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