Artificial reefs promote coastal carbon stabilization potential through hydrological condition and microbial pathways

Area of Science:

• Marine Ecology
• Geochemistry
• Microbial Ecology

Background:

• Artificial reefs (ARs) influence hydrodynamics and benthic microbial processes.
• The connection between ARs, hydrodynamics, microbial functions, and coastal carbon stabilization is not fully understood.

Purpose of the Study:

• To investigate how artificial reefs impact coastal carbon stabilization.
• To link hydrodynamic changes and microbial functions to sediment organic carbon content.

Main Methods:

• Hydrodynamic modeling, sediment geochemistry, fluorescence spectroscopy, and metagenomics were employed.
• Experiments were conducted across different AR habitats in the northern Yellow Sea.
• A 42-day dark incubation assessed microbial reworking of dissolved organic matter.

Main Results:

• Complex ARs increased upwelling and turbulence, leading to finer sediments and higher total organic carbon (TOC).
• Hydrodynamics, microbial genes, and environmental factors explained variations in TOC and humic-like fluorescence.
• Microbial activity enriched humic-like dissolved organic matter (DOM) and increased genes for aromatic compound transformation and nitrogen redox pathways.

Conclusions:

• ARs modulate hydrodynamics, which, coupled with nitrogen-redox microbial functions, enhances carbon stabilization.
• Findings support a framework where ARs promote carbon storage through altered water flow and microbial processes.
• Humic-like DOM enrichment and benthic carbon storage are key indicators of AR-driven carbon stabilization.