Speaker
Description
Marine sediments are hotspots of microbial activity and play a key role in cycling carbon, nitrogen and sulfur at the sea floor. In shallow coastal areas like the Belgian part of the North Sea, sediment characteristics can vary considerably over short distances, from muddy organic rich deposits to coarse permeable sands, creating very different conditions for microbial life. Yet we still know relatively little about how these differences in sediment type, compared to seasonal changes, shape both the taxonomic composition and functional potential of these communities.
In this study, we applied whole metagenomic sequencing to 16 sediment samples collected across four stations with contrasting sediment types in the Belgian North Sea over five seasonal campaigns. This approach allowed us to simultaneously characterize microbial community composition and assess functional gene profiles for nitrogen, carbon and sulfur cycling — going beyond what traditional marker gene approaches can offer.
Beta diversity analysis showed clear separation between stations across all three cycles, with sediment type explaining 58–69% of the variation while sampling month had no significant effect. At the process level, nitrification, denitrification and aerobic respiration were consistently higher at the coarse sandy station while muddy stations showed elevated nitrogen fixation, sulfate reduction and methanogenesis, patterns that matched well with the distinct taxonomic profiles observed at each station. This direct link between community composition and functional potential is something that 16S-based studies simply cannot provide.
These results suggest that sediment type matters a lot more than season for microbial functional diversity in Belgian coastal sediments. Given increasing pressures from bottom trawling and dredging in the Belgian North Sea .i.e. activities known to alter sediment characteristics and benthic communities,this study provides a robust foundation for understanding how physical disturbance may cascade through microbial communities to affect seafloor biogeochemical cycling.
| Status Group | Master Student |
|---|---|
| FOR TALKS: Poster Presentation Option | Yes, I’m willing to present as a poster. |