Ewan Garvey, one of Project Seagrass’ Interns for the 2025-26 academic year, explores how seagrass can provide protection for coastal communities. As the seasons transition from autumn into winter, storms often become a pressing concern for coastal communities. In recent years, the growing impacts of climate change have become increasingly
Ewan Garvey, one of Project Seagrass’ Interns for the 2025-26 academic year, explores how seagrass can provide protection for coastal communities. As the seasons transition from autumn into winter, storms often become a pressing concern for coastal communities. In recent years, the growing impacts of climate change have become increasingly clear: extreme weather events once considered “once-in-a-decade” now seem to strike far more frequently. In response, governments and communities are looking for protective solutions, investing heavily in sea defence systems, ranging from sandbags to seawalls. But what if nature has already developed a solution? Enter seagrass. Seagrass’s unique characteristics make it a powerful ally in protecting coastlines. Unlike concrete walls or other flood defence systems, seagrass meadows work with natural processes to reduce erosion and flooding, while also creating vital habitat for marine life. How Seagrass Protects Our Shores Root FixationMuch like how trees stabilise the soil in forests, seagrass root systems anchor sand and mud in place, reducing sediments from being washed away during storms. This helps to maintain the structure of beaches, providing more stable coastal habitats. Dissipation of Wave EnergyWhen waves pass over seagrass meadows, the blades create friction. This slows the water, disperses energy, and reduces the force that reaches the shoreline. This means water travels up the beach less and can lessen flooding events. Challenges Hard-engineered coastal defences such as rock armour can cost upwards of £1 million for just a 35-metre section. Seagrass restoration is also expensive, and to date has been largely funded through philanthropic and government funding mechanisms. Seagrass restoration is not without challenges; newly planted seeds are vulnerable to being washed away or buried by shifting sediment before they can properly establish. Seagrass also requires good water quality; too much pollution can prevent seedlings from developing. In many areas, improving river and coastal water quality must go hand in hand with restoration for projects to succeed. A Blended Solution Is seagrass the silver bullet for coastal protection? Not entirely. By blending natural and engineered approaches, we can create more sustainable, resilient coastlines—ones that not only protect us from storms but also support thriving marine ecosystems. Combining engineered solutions such as breakwaters or seawalls with seagrass meadows could reduce wave energy and sediment loss, which would lower the stress on the artificial defences. This could result in cheaper, smaller sea defence structures, reducing both environmental impact and cost. References and Extra Research “Seagrass as a nature-based solution for coastal protection” by Forrester, Leonardi, Cooper & Kumar (2024) Infantes et al. (2022) — Seagrass roots strongly reduce cliff erosion rates in sandy sediments Donatelli et al. (2018) — “Seagrass Impact on Sediment Exchange Between Tidal Flats and Salt Marsh, and The Sediment Budget of Shallow Bays” Bricheno, L. M., et al. “Climate change impacts on storms and waves relevant to the UK and Ireland.” MCCIP Science Review 2025 (2025).
