Coastal Conundrum: How Salt Marshes Protect the Coast, But Not Where It Is Needed Most

One of the many ecosystem services that salt marshes offer is flood protection for the coast. Particularly in low-lying nations like the Netherlands, this is crucial.

Coast are protected by salt marshes

(Photo : MARCO BERTORELLO/AFP via Getty Images)

Over a three-year period, researchers from the University of Groningen, the Royal Netherlands Institute for Sea Research (NIOZ), and the local water authority have been observing wave run-up during storms, as per Phys.org.

Ecologist Beatriz Marin-Diaz kept a close check on the weather report throughout the hurricane season for three years.

The study region was located through the Wadden Sea, a shallow area with wetlands and a number of barrier islands between the northern Dutch coast and the Wadden Sea.

She has measured various aspects of the shoreline, including the vegetation growth, the width of the salt marshes, and the promotion of the mud flats.

In addition to tracking the location of flood markings on the dikes, wave loggers were used to gauge the impact of storms.

For the purpose of examining variations in salt marsh size, she examined charts going back around twenty years.

The findings demonstrate that salt marshes do, in fact, lessen wave run-up on dikes.

Also read: More Than 90% Of the World's Salt Marshes Are Likely To Be Submerged by the End of the Century

How do salt marshes form?

Estuaries, wherein a river meets the sea, are where marshes are typically found, as per The Saltmarsh app.

Estuaries are home to a variety of fauna. Waves and currents are not too powerful, salt marshes develop.

A salt marsh's foundations are mud or sand flats.

Mud and sand flats gradually become overrun by microscopic and obvious algae, which slows the movement of the sediment.

 A salt marsh forms whenever a mud/sand flat is sufficiently stable and nutrient-rich for saltmarsh plants to start growing.

Learn to conserve salt marshes

Maintaining salt marshes is crucial for community safety, marine ecological health, coastal economic growth, and shoreline preservation, as per Pew.

To create strategies that restore, safeguard, and enable these essential ecosystems to adapt to adjusting environmental conditions, communities may and should collaborate.

Do salt marshes is enough to prevent flood?

Since the height of the mud flat is quite low, Marin-Diaz claims, there are no salt marshes.

Her extensive research showed that salt marshes retreated mostly where the mudflats ahead of them began eroding, while marshes expanded where the nearby tidal flats were higher.

In consequence, those regions would require more protection because marshes are not growing there.

This leads us to the conclusion that while these natural protections are insufficient in some areas, we will still rely on hard technical solutions.

For the neighborhood water authority, this is a crucial finding.

Growing salt marsh in the coast

Human activities can aid in the formation of marshes in regions where they do not naturally occur.

One approach may be to construct sedimentation fields or to add sediment to encourage the establishment of new salt marshes, while there might be consequences to constructing new marshes as well.

Tidal flats, that are necessary for wading birds, would be sacrificed in the process.

Furthermore, despite human efforts, some places simply do not allow marshes to flourish. The dikes could then need to be strengthened.

Related article: Salt Marsh Erosion Driven By Regular Weather, Not Sporadic Violent Storms