Can humans grow new islands in the world's lowest-lying country?

Across the globe, shorelines are under threat from rising sea levels and intensifying storms. Island states and coastal cities are taking action to defend themselves, from building seawalls to dredging sand from the seabed and pumping it onto beaches.

In the Maldives, a 900-kilometer-long chain of about 1,200 islands in the Indian Ocean, a collaboration between an academic institution and a local organization is exploring a natural solution to protect and potentially grow islands. The project involves using submersible structures to harness the ocean’s forces to make sand accumulate in strategic areas.

Field tests have been conducted in the Maldives since 2019, as erosion is a prevalent issue on almost every island. Various experiments have been carried out, including submerging rope structures to collect sand and using a material that transforms from textile to concrete when sprayed with water.

The collaboration uses data collected from wave and ocean current information, tide and weather data, computer simulations, and machine learning models to determine the ideal designs and orientations of the structures. The goal is to create a more sustainable and cost-effective method of protecting coastlines by utilizing the natural force of the ocean.

The Maldives, being the world’s lowest-lying country with an average elevation of just one meter above sea level, has previously relied on dredging and hard engineering solutions. However, these interventions are expensive, difficult to maintain, and detrimental to ecosystems.

The collaboration aims to find solutions that work with natural forces rather than against them. Through ongoing field experiments, they are learning how to use the simplest, most sustainable, and scalable techniques to accumulate sand. The findings can be leveraged to rebuild existing beaches and islands effectively.

The ultimate goal is to grow artificial islands. The most promising results so far came from the second field experiment, where biodegradable textile bladders were strategically placed to create a sand bar. Over four months, half a meter of sand accumulated, and the sand bank continues to expand.

Other countries are also exploring natural solutions, such as the Netherlands’ sand motor and New York’s oyster reefs. Incorporating nature into coastal defense strategies is gaining interest, although securing funding can be a challenge due to the preference for solid engineering structures.

In the Maldives, the government is supportive of the collaboration’s work, but financial support is yet to be provided. Ongoing tests supported by a grant aim to demonstrate the success of the project at scale. The results will be important for the wider recognition and adoption of natural coastal protection methods.