Seagrass Restoration for a Healthier Planet

 Coastal erosion is accelerating worldwide due to climate change and human activity, threatening homes, habitats, and coastal communities. Seagrass meadows play a vital protective role by stabilising sediment, reducing erosion, slowing wave energy, capturing carbon, and improving water quality. With global seagrass in steep decline, large‑scale restoration efforts, such as those led by Swansea University, UK, are essential to protect coastlines and support planetary health.

                                                   Image by Dr David Buss created using OpenAI

The impact of coastal erosion

Given that nearly 70% of the Earth’s surface is covered by the sea, coastal erosion (the weathering and loss of coastal land, beaches,marshes, rocks, or cliffs caused by waves and tides) has become a serious problem in many parts of the world. Coastal erosion can lead to the loss of homes, natural habitats, infrastructure, and community livelihoods, resulting in huge economic costs and, tragically, sometimes loss of life.

Having been born in an area with a long coastline and now living on an island, I am well aware of its impact. I have witnessed beaches shrink over time and coastal communities become fragmented.

Climate change and human activities play a crucial role in accelerating coastal erosion. Sea levels are rising due to warming oceans and melting ice sheets. Even small increases in temperature can reshape coastlines. Scientists are now recognising that seagrasses could play an important role in preventing erosion.

Seagrass and its impact

Seagrasses are the only flowering plants that grow in marine environments. Several species exist, many with long, narrow leaves resembling land grasses. Their underground roots spread across the seabed, forming extensive underwater meadows that provide habitat for diverse marine wildlife and, during low tide, non‑marine species such as birds. Seagrasses are among the most widespread marine ecosystems on Earth, covering around 300,000 km² of seabed across 159 countries.

Research indicates that seagrass can act as a critical natural defence against coastal erosion. Their root mats trap and anchor sediment, reducing shoreline erosion by up to 70%. Seagrass meadows also slow wave energy, effectively acting as a buffer during storms.

In addition, seagrasses capture carbon from the atmosphere, reportedly up to 35 times faster than tropical rainforests, and absorb pollutants, improving water quality. Overall, they play a vital role in maintaining planetary health. In recognition of this, the United Nations has designated 1March as World Seagrass Day.

Decline of Seagrass

Despite their importance, global seagrass coverage is declining due to human activities such as rampant coastal development, pollution, climate change, dredging, and damage from boat propellers. The UK has lost approximately 90% of its seagrass meadows, with half of that loss occurring in the last 30 years. Seagrasses in the USA are also experiencing extraordinary decline, with losses of over 90% recorded in Florida’s Big Bend.

Seagrass restoration in the UK

Reversing this decline requires active conservation: protecting remaining meadows and restoring those that have been lost. One notable initiative is led by researchers at Swansea University, under Dr Richard Unsworth. They are developing methods to restore seagrass meadows at scale.

With the planting of 2‑hectare meadows, the team is undertaking one of the UK’s largest seagrass restoration projects. They are now involved in restoration efforts in North Wales, the Solent, and the Firth of Forth in Scotland. Working with research partners, they are developing scalable restoration techniques that could help reverse the decline of this endangered ecosystem on which the health of our planet depends.

 

References: 

The UK's biggest seagrass restoration project - Swansea University

Extensive and Continuing Loss of Seagrasses in Florida's Big Bend (USA) - PubMed