Around the world, shorelines have been reshaped by human hands. But researcher Dhritiraj Sengupta has been watching and says that, in some cases, artificial developments are threatening coastal resilience.
Sengupta, a visiting researcher at the University of Southampton, recently wrote at The Conversation about his ongoing work, warning that artificial coastal developments -- such as luxury islands, sea walls, and dredged peninsulas -- are eroding the planet's natural shoreline defenses.
These designed coastlines, he says -- from the palm-shaped islands of Dubai to the grid-like expansions in Lagos -- are disrupting sediment flow, destroying wetlands, and leaving nearby communities more vulnerable to storms and rising seas.
Engineering these areas to expand coastlines is often described, perhaps confusingly, as "land reclamation," but Sengupta calls it a "double blow." First, heat-trapping gases are released during construction, including through any cement production involved. Then, there's the resulting loss of ecosystems that store carbon and shield people and habitats from floods.
"Such misplaced 'neatness' can have far-reaching consequences," Sengupta wrote. "Reclamation destroys mangroves, muddy tidal flats, and seagrass meadows -- ecosystems which act both as valuable stores of atmospheric carbon and fish nurseries."
Artificial coastlines may look orderly from above, but they can create chaos below the surface.
Dredging stirs up sediment, clouding the water and smothering coral reefs. Straightened edges and jetties interrupt natural water flow, which can cause beach erosion and dangerous flooding in coastal towns.
The loss of mangroves and tidal flats also strips away a natural line of defense against storm surges and sea-level rise. And as temperatures increase -- driven by the burning of fossil fuels and the heat-trapping pollution this creates -- more intense storms are striking these weakened coasts.
Without urgent limits on new reclamation projects, Sengupta has warned, vulnerable fishing communities could lose their land, safety, and livelihoods.
Sengupta calls for a global moratorium on new coastal reclamation and for prioritizing restoration efforts, including rehabilitating mangroves, protecting tidal creeks, and removing artificial "hard edges" where possible.
Using mapping tools may be one of the most effective ways to drive change. By combining satellite imagery with biodiversity and hydrodynamic data, researchers can inform policy and pinpoint which coastlines need protection -- and which developments are doing the most harm. It's an area in which Sengupta is working as an Earth observation research engineer at the private tech group GMV.
Communities and governments are also embracing nature-based defenses, such as wetland restoration and "living shorelines" that absorb wave energy using materials including plants, sand, rock, and oyster shells.
Protecting coastlines doesn't just save beaches -- it safeguards homes, fisheries, and local economies. Restoring natural buffers can help ensure that the world's living margins continue to sustain both people and the planet.
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