Hydrodynamics-seagrass interactions

Hydrodynamics-seagrass interactions

“Seagrass ecosystems are shaped by tightly coupled biological and physical processes that determine their persistence, recovery, and response to environmental change”

This Research Theme focuses on the physical-biological coupling between seagrass canopies and hydrodynamic processes. It quantifies the thresholds and feedbacks through which waves, currents, and sediments constrain seagrass persistence, resilience, or collapse.

Seagrass meadows develop in dynamic coastal environments shaped by waves, currents, and sediment transport. Hydrodynamic forcing controls not only where seagrasses can persist, but also how they function as ecosystem engineers, modifying flow, stabilising sediments, influencing biogeochemistry, and shaping coastal geomorphology.

My research combines field observations, controlled flume experiments, and experimental hydrodynamics to quantify how waves and currents constrain seagrass performance, and how seagrasses in turn reshape their physical environment through stabilising or destabilising feedbacks. The result is a physics-based foundation for predicting vulnerability under changing wave climates and increasing physical disturbance.

Core findings

Seagrass meadows function as biophysical feedback systems with quantifiable hydrodynamic thresholds. My research, conducted in collaboration with colleagues and students, shows that seagrass canopies attenuate waves, reduce bed shear stress, and stabilise sediments with roots, thereby engineering a local physical environment that promotes their own persistence. However, this self-facilitation operates only up to a critical level of hydrodynamic forcing. Beyond that threshold, feedbacks can reverse, sediment instability increases, and rapid meadow collapse becomes more likely.

By identifying these thresholds and feedbacks, this work provides a predictive, physics-based framework for assessing ecosystem resilience, guiding restoration design, and evaluating vulnerability to climate-driven increases in wave energy and storm intensity.

Wave-seagrass interactions

Wave energy is often the dominant physical constraint on seagrass distribution in shallow coastal systems. This work examines how waves propagate through vegetated canopies, how wave energy is dissipated, and how wave-induced motion affects plant stability, survival, and ecosystem functioning. These studies establish the upper physical limits of seagrass persistence and quantify the role of seagrass meadows in wave attenuation and coastal protection.

Key publications:

These wave-driven processes directly constrain seed retention, seedling stability, and restoration success, and therefore also feature prominently in the Seagrass restoration and Seagrass seeds Themes.

Flow, sediment dynamics, and resuspension

Currents and wave-driven flows interact with seagrass canopies to regulate sediment stability, particle retention, organic matter exchange, and erosion. These processes influence water clarity, nutrient cycling, and the stability of blue carbon stocks. This work quantifies how hydrodynamic forcing controls resuspension, bed-load transport, and the mobilisation or loss of organic carbon and nutrients from seagrass sediments.

Key publications:

These mechanisms demonstrate both blue carbon stability and restoration failure under high exposure, linking directly to applied outcomes discussed in the Seagrass restoration Research Theme.

Canopy structure, blade motion, and boundary-layer processes

Seagrass blades move with waves and currents, altering turbulence, mixing, and momentum exchange within the canopy. These fine-scale processes help explain emergent ecosystem functions and organismal responses to habitat complexity. This work explores how canopy structure affects boundary-layer development, turbulence generation, and the hydrodynamic environment experienced by fauna, linking physical structure to ecological performance and energetic costs.

Key publications:

Experimental hydrodynamics and flume studies

Controlled experiments are essential for isolating hydrodynamic mechanisms that are challenging to resolve in the field. A major component of this Theme is the development and application of experimental tools, including wave mesocosms and hydraulic flumes, to reproduce realistic forcing under controlled conditions and link hydrodynamic drivers to biological and sediment responses.

Key publications:

For applied synthesis and outcomes, see the Seagrass restoration Theme

Hydrodynamic resilience, erosion, and tipping points

Hydrodynamic forcing can push seagrass systems across thresholds through erosion, sediment mobility, and destabilisation of the seabed. This work links wave exposure and sediment response to resilience under climate change, including the risk of non-linear responses and tipping points in ecosystem functions such as carbon storage.

Key publications:

People, collaboration, and use

This research has been carried out in close collaboration with PhD students, postdoctoral researchers, technicians, and international partners. Training early-career scientists in field measurements, experimental hydrodynamics, and process-based thinking has been a central component of this work.

→ Link to Seagrass Ecology Lab

→ Link to People

How to use this Theme

  • Researchers: Explore physical-biological coupling and hydrodynamic thresholds.
  • Practitioners: Identify physical constraints relevant to restoration and management.
  • Students: Use this page as an entry point into ecohydrodynamics of vegetated coastal systems.

Linked publications, reports, and blogs provide direct access to detailed methods, figures, and data.

Further reading