Catchment News

Understanding Seagrass in Ireland

Seagrass: The Hidden Life Beneath Our Shores

Seagrass meadows are among Ireland’s most important coastal habitats, supporting biodiversity and helping to capture and store carbon. Despite their ecological importance, these remarkable underwater ecosystems often go unnoticed beneath the surface of our bays, estuaries, and coastal waters.

A recent video, Seagrass: The Hidden Life Beneath Our Shores, explores the vital role seagrass plays in Ireland’s marine environment and highlights efforts to better understand, monitor and restore these valuable habitats.

What is seagrass?

Although many of us refer to the plants growing in the sea as “seaweed”, most of these organisms are actually algae. Seagrasses are unique because they are the only flowering marine plants found in our coastal waters. Like land plants, they have roots, leaves and flowers and are specially adapted to life in saltwater.

Ireland is home to both intertidal and subtidal seagrass species. Intertidal seagrasses can be exposed at low tide in sheltered estuaries and bays, while subtidal seagrasses remain underwater throughout most of the tidal cycle.

Why is seagrass important?

Seagrass meadows are recognised as important habitats for biodiversity, providing shelter, feeding grounds and nursery areas for a wide variety of marine species, including fish, shellfish, and waterbirds.

However, seagrass habitats are also sensitive to human activities and environmental pressures. Factors such as nutrient enrichment, physical disturbance, coastal development, and other pressures can negatively affect their condition and extent.

Monitoring seagrass in Ireland

Because seagrass responds to changes in water quality and environmental conditions, it can provide valuable information on the health of coastal ecosystems.

As part of Ireland’s national monitoring programmes, intertidal seagrass is used as a biological quality element under the Water Framework Directive (WFD). Monitoring the distribution, extent and condition of seagrass beds helps scientists assess ecological status and track changes over time.

Looking to the future

Historically, seagrass meadows were far more widespread across Europe than they are today. Significant losses have occurred over many decades, driven by declining water quality and other human pressures.

In recent years, interest in seagrass conservation has grown because of the many benefits these habitats provide, particularly their ability to capture and store carbon. As a result, seagrass restoration is now being investigated across Europe and beyond as a way of helping to recover lost habitats and strengthen ecosystem resilience.

Recognising their ecological importance, seagrass habitats have also been identified as a key focus within wider European nature restoration efforts.

Read More

Citizen Science-  Seagrass | Coastwatch Europe

Research on seagrass restoration:  Demo Site 2 – Seagrass Meadows – Climarest

EPA funded research:  RESET – UCD School of Civil Engineering

EPA monitoring:  EPA-Marine-Monitoring—Seagrass-Factsheet.pdf

Seagrass as a protected habitat:  Zostera Beds | OSPAR Commission