Benthic Ecosystem Dynamics in Coastal Marine Systems

Coastal benthic ecosystems form the interface between land-derived and oceanic processes, underpinning nutrient cycling, organic matter mineralisation and habitat structure in shallow seas. The seabed communities of infauna, epifauna and microbial consortia regulate biogeochemical fluxes through bioturbation, bioirrigation and redox transformations, thereby influencing water quality, carbon storage and fisheries productivity. These dynamics are intimately linked to pelagic production: seasonal phytoplankton blooms, riverine inputs and sediment resuspension determine the quantity and quality of organic material reaching the seafloor, while benthic faunal composition and activity feed back on nutrient availability in the water column. Anthropogenic pressures—eutrophication, hypoxia, contaminant loading and climate-driven changes in temperature and circulation—alter functional diversity, community resilience and ecosystem services. Mechanistic models, field-based experiments and trait-based approaches are converging to reveal how deposit and suspension feeders differ in response times and biogeochemical impact, how redox gradients shape nutrient pathways and how shifts in organic matter quality control nitrogen cycling. Understanding these processes is essential for managing coastal filter functions, predicting ecosystem responses to environmental change and conserving benthic biodiversity on a global scale.

Research from Nature Portfolio

Recent studies have examined how hypoxia gradients alter the functional diversity and biomass of macrozoobenthic communities. Under reduced oxygen concentrations, taxa that persist exhibit limited bioturbation and bioirrigation, resulting in weakened benthic–pelagic coupling and diminished ecosystem functioning. Trait-based analyses indicate that species with dispersal-oriented traits and tolerance to short-term oxygen depletion serve as a reservoir for recovery once oxygenation returns. These findings highlight the critical thresholds at which oxygen stress disrupts sediment structure and nutrient recycling in coastal basins.

Benthic Ecosystem Dynamics in Coastal Marine Systems publication trend

The graph below shows the total number of articles in benthic ecosystem dynamics in coastal marine systems across all publications each year (not limited to Nature Index journals).

Technical terms

Benthic–pelagic coupling: Exchange of energy, organic matter and nutrients between the water column and seabed communities.

Bioturbation: Reworking of sediment by fauna that alters particle distribution, porosity and chemical gradients.

Hypoxia: Low oxygen conditions (often <2 mL L⁻¹) in bottom waters that constrain metabolic and bioturbation activities.

Functional diversity: Range and value of biological traits within a community that influence ecosystem processes.

Denitrification: Microbial conversion of nitrate into gaseous nitrogen forms, representing a major pathway of nitrogen removal from sediments.

References

1. Functional diversity of macrozoobenthos under adverse oxygen conditions in the southern Baltic Sea. Scientific Reports (2024).
2. Ecological ReGional Ocean Model with vertically resolved sediments (ERGOM SED 1.0): coupling benthic and pelagic biogeochemistry of the south-western Baltic Sea. Geoscientific Model Development (2019).
3. Seasonal Variability in Benthic–Pelagic Coupling: Quantifying Organic Matter Inputs to the Seafloor and Benthic Macrofauna Using a Multi-Marker Approach. Frontiers in Marine Science (2020).
4. Time Scales of Benthic Macrofaunal Response to Pelagic Production Differ Between Major Feeding Groups. Frontiers in Marine Science (2019).
5. Influence of settling organic matter quantity and quality on benthic nitrogen cycling. Limnology and Oceanography (2021).