Coastal growth squeezes beaches, threatening flood protection

Coastal beaches can look calm, but they are brimming with life and activity. Many of these sandy environments are at risk as they become trapped between rising seas and bustling human developments.

Scientists warn that these shorelines are losing their natural breathing room, and this leads to problems for people and wildlife. The new findings highlight how a lack of space along coasts threatens everything from habitat preservation to freshwater availability.

Narrow beaches mean less space for dunes to form, limiting the ecosystem services they provide. This reality was described by coastal ecologist Eva Lansu from the University of Groningen, who examined how close buildings tend to be to the sea worldwide.

Coastal squeeze leaves no space for dunes

On average, the first roads or buildings appear about 0.25 miles from the high tide line, which leaves little space for dunes to shift inland. Over time, waves and storms can wear down these sandy stretches, and there is nowhere for them to go.

“This coastal squeeze is not only a problem for biodiversity, it also affects our defense against flooding and our drinking water supply,” said Lansu.

The growing strain on coastal ecosystems has sparked urgent questions about how to protect these zones without hindering economic interests.

Why coastal biodiversity matters

Healthy dunes act as natural barriers that absorb storm impact, filter groundwater, and stabilize shorelines. They also support countless tiny organisms and plants that keep coastal systems in balance.

Beach plants, insects, and birds rely on these zones for food and shelter. These interactions benefit humans too, since coastal vegetation can help slow erosion, enhance tourism, and provide a natural line of defense.

Coastal squeeze in a growing population

Global population trends make the coastal squeeze worse. About one in three people live within 30 miles of a coast, with many moving closer for jobs, housing, and recreation.

As more people settle near the ocean, land use decisions often prioritize short-term development over long-term sustainability. This demand increases pressure on natural areas and limits the space needed for dunes to thrive.

How squeezed beaches harm plants

One study found that a biodiverse dune area in the Netherlands requires about 2.36 miles of width, yet actual dunes there often measure only around 0.62 miles. This shortfall puts plant diversity at just over half of its potential.

Many areas face pressure from roads, holiday resorts, and seawalls. These structures keep creeping closer, reducing the range for plants and animals that are sensitive to movement of sand.

Protecting water resources

People often forget that dunes are critical for drinking water supply. Groundwater flows through these sandy soils, where impurities can be filtered before reaching wells or reservoirs.

Frequent storms and rising tides can contaminate freshwater sources with saltwater. When dunes are compressed by nearby developments, they lose some of their capacity to protect these underground resources.

Innovative coastal management

Efforts in the Netherlands show that adding new sand to the shoreline can create space for embryonic dunes to form, boosting biodiversity and resilience. The Sand Motor project near the village of Monster, carried out in 2011, helped illustrate how innovative coastal management can work.

Some experts see these expansions as a better solution than erecting large barriers. They argue that a thriving coastal ecosystem is more adaptive to future changes than fixed walls or dams.

Eco-friendly solutions are more enduring

Other coastal regions have begun to explore greener strategies that respect natural sediment shifts and plant growth. These approaches balance economic activities like tourism with the long-term health of beaches.

Groups that manage these landscapes often involve local communities to maintain vegetation and reduce erosion. This cooperation can lead to solutions that are less expensive, less disruptive, and ultimately more enduring.

Preventing the coastal squeeze

Researchers highlight the need for long-term spatial planning that protects coastal zones from being walled in. Allowing dunes and wetlands to move naturally is seen as an investment in future sustainability.

Overbuilt shores could face more severe flooding and water shortages in the decades ahead. Early action can prevent irreversible damage and safeguard the natural areas that benefit everyone.

Balancing nature and economy

Regular monitoring of sandy shorelines helps decision-makers see how quickly changes occur. Scientists also encourage stronger policies that limit development near the water and protect these fragile habitats.

Success stories from around the world show that restoration efforts can bring back lost biodiversity. When done carefully, it becomes possible to keep both nature and local economies thriving.

Coastal lands do far more than enhance a postcard view. They stand at the crossroads between human progress and natural resilience, showing us that a balanced approach can keep shorelines alive and well.

The study is published in Groningen.

—–

Like what you read? Subscribe to our newsletter for engaging articles, exclusive content, and the latest updates. 

Check us out on EarthSnap, a free app brought to you by Eric Ralls and Earth.com.

—–