Why are sand dunes important?

23 Jun 2021
3 min read

Sand dunes will be an important line of defence against rising sea levels, so they need to be protected.

The very first World Sand Dune Day is taking place on 25th June this year, to highlight the importance of conserving these vital coastal habitats around the globe.

Sand dunes are a familiar sight at beaches and coastal areas, and they have a critical role to play in preserving the balance of our complex ecosystems. Here’s everything you need to know about sand dunes, why they are so important, and why we need to take action to protect them now.

What is a sand dune?

If climate change goes unchecked, we’ll see major coastal erosion and rising sea levels

Let’s start with the basics. A sand dune is an accumulation of sand formed by wind, waves and eroding sandstone – because of this their structure is constantly changing, shrinking and growing. After a big storm, for example, it’s not uncommon for the landscape to have changed dramatically.

Sandy coastline vulnerable to erosion

What are the benefits of sand dunes?

Sand dunes do a lot of work. They provide a future supply of sand to maintain beaches, protect our shorelines from coastal erosion and provide protection from coastal flooding. If climate change goes unchecked, we’ll see major coastal erosion and rising sea levels that could have devastating consequences for coastal communities – sand dunes will help to mitigate this.

Read more: Why are melting ice caps and rising sea levels a problem?

Sand dunes are also a vital habitat for a wealth of rare and specialised wildlife, including a range of wildflowers, birds and insects which require a bare sand habitat to survive. Without sand dunes to call home, this biodiversity is in trouble. Over the last 80 years, open sand has largely disappeared from sand dunes, replaced by dense grass and scrub. This change has been caused by factors such as the introduction of non-native plants, lower levels of grazing, climate change and air pollution. As the dunes have become more stable and overgrown, rare wildlife has declined.

What causes sand dune destruction?

The ever-changing nature of sand dunes means that they are often damaged by natural causes – by storms or through erosion, for example. However, the most significant and irreparable damage is caused by human activity, such as coastal development work or simply by walking across or playing on sand dunes, which disrupts their structure. Harry Potter fans might remember back in 2019 how Dobby’s ‘burial site’ on sand dunes in Pembrokeshire was moved because of the environmental impact the many visitors were having on the area.

What about artificial sand dunes?

If sand dunes are simply piles of sand, can’t we just rebuild them? Unfortunately not. Authorities and communities around the world have tried to build artificial dunes by simply bulldozing sand from the shore break to the back beach zone, but these are not proper sand dunes. They lack the ideal sediment layers and ability to obtain sand from where it is needed, and in the short term these artificial sand hills will be destroyed by the elements.

How can we protect sand dunes?

Quite simply, leave them alone! The best thing you can do is avoid walking, running or playing on sand dunes, and tell others to do the same. That’s the point of World Sand Dune Day – to raise awareness of this little-discussed subject. Spread the world on social media using the hashtag #WorldSandDuneDay – you could even include a picture of your favourite coastline.

The bottom line

Sand dunes don’t get a lot of attention among the wider climate crisis discussion but they’re going to be a vital means in mitigating some of its worst effects, so they need to be protected. Spread the important message of World Sand Dune Day so everyone knows to give them the respect they deserve.


The information in this article was correct at the time of writing and is provided for guidance only. Please see the full disclaimer in our terms and conditions.

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