Nature-inspired solution softens impacts of hard coastal structures

Seawalls and other unyielding structures meant to keep rising waters at bay and to protect against storm surges can cause other significant harm to the coast, often by disrupting natural processes and accelerating erosion. The gap between protection and preservation might be bridged with a softer, nature-inspired solution, according to an international research team.

In a study published on Oct. 7 in Ocean-Land-Atmosphere Research, the researchers detailed how artificial mangrove roots (AMRs) offer a viable, scalable solution for shoreline management. Inspired by the mangrove trees that grow in brackish or salty water, AMRs at two pilot sites in Thailand proved to enhance shoreline stability, dissipate wave energy and promote sediment retention, the team said.

“Coastal protection structures such as seawalls and revetments are designed to safeguard properties and infrastructure from waves and storm surges,” said corresponding author Butsawan Bidorn, assistant professor in the Department of Water Resources Engineering at Chulalongkorn University in Thailand. “However, these rigid barriers disrupt natural sediment transport and can intensify erosion in adjacent areas by reflecting wave energy seaward.”

Bidorn explained that, over time, this leads to beach narrowing, scouring — erosion caused by moving water — near the structure, and the loss of natural habitats needed to support biodiversity, recreation and tourism.

“These unintended impacts are becoming increasingly problematic under climate change, forcing coastal communities to protect one place at the expense of another,” Bidorn said. “To overcome these drawbacks, attention is shifting toward soft and adaptive solutions that can be installed rapidly, repositioned if needed, and designed to work with natural coastal processes.”

AMRs are one such solution, as they can mimic the wave-dissipating and sediment-trapping functions of natural mangrove root systems, Bidorn explained. The researchers installed AMRs at two different sites along coastlines in Thailand, each with different environmental conditions. Over a year, the researchers used remote sensing technology and site visits to evaluate the resiliency of the AMRs and the impact on the sites.

“We found AMRs can serve as an additional option for mitigating erosion in areas where hard structures have caused negative end effects. Rather than blocking waves completely, AMRs allow water to pass through and help reduce wave impact, which encourages sediment to remain along the shoreline,” Bidorn said, noting that the approach supports more natural beach behavior compared to rigid seawalls and revetments. “AMRs are adjustable, removable and scalable, which helps coastal managers respond to changing shoreline conditions without committing to permanent infrastructure.”

AMRs are not intended to replace existing coastal protection, Bidorn cautioned, but rather to complement hard structures and offer more flexibility for sustainable and community-supported coastal management.

Next, the researchers plan to improve the AMR design to better adapt to different coast conditions, as well as to continue studying how AMRs influence the areas where they are installed.

“Our broader goal is to provide coastal managers with more adaptable and environmentally compatible tools that can be combined with existing protection measures,” Bidorn said. “By offering a flexible and scalable option, AMRs can help communities respond to erosion pressures while maintaining the natural characteristics of the coastline. We aim for AMRs to support more resilient coastal management strategies, particularly in places where urgent or temporary protection is needed.”

Bidorn is also affiliated with the university’s Center of Excellence in Interdisciplinary Research for Sustainable Development.  

Other collaborators are Warit Charoenlerkthawin and Thanawatth Sattabongkot, Chulalongkorn University; Narakorn Srinil and Yan Naung Aye, Newcastle University in the United Kingdom; and Ni Nyoman Pujianiki, Udayana University in Indonesia.

Chulalongkorn University and the International Science Partnerships Fund of the UK Department for Science, Innovation and Technology in partnership with the British Council, supported this work.