Coral islands under threat?
The spectre of rising sea-levels haunts the future of many islands worldwide. The threat would seem especially urgent for coral islands: low-lying lands formed by uplifted reefs or by reefs that accumulate sand and other detritus over time. It is widely believed that many of these could disappear entirely if sea levels rise by several metres from today’s levels. The entire country of the Maldives, comprised entirely of coral islands and atolls, would then be at risk. This led then-president Naseed to declare in 2009 that they would become the world’s first carbon-neutral country. The same year, he even chaired a headlinegrabbing underwater cabinet meeting. The world acclaimed Naseed’s foresight and leadership but even then the evidence that the islands are sinking was patchy. The problem is that coral islands naturally shift over time. They lie on a platform of calcium carbonate derived from dead coral – what’s left after fish and others have grazed on live corals, together with that killed by violent storms. Ground down over time, the resulting sediment can then be deposited onshore. A storm might bring fresh material to one stretch of coast while eroding elsewhere, causing the island to creep infinitesimally across the sea. Piecemeal measurements of beach erosion can therefore often seem to suggest sea-level encroachment, but need to be taken as part of a bigger picture. New Zealand coastal geomorphologist Paul Kench, of the University of Auckland’s School of Environment, has led a study of how reef islands in the Pacific and Indian Oceans respond to rising sea levels. His work suggests that more islands are growing than are shrinking. If he is right, it still poses a huge challenge to a country like the Maldives that has put almost all its bets on tourism by building more than 100 resorts, many on otherwise uninhabited islands. Even if they do not sink under the waves, large shifts in coastlines will mean widespread and expensive mitigation measures to protect their investments. The present government seems unfazed. Under President Abdulla Yameen, the country has taken a different tack, no longer talking of carbon neutrality and buying land to rehouse, and instead concentrating on making money while they can. Among the new projects approved are Emboodhoo Lagoon, a three-island resort with a marina and a Hard Rock hotel. The developers, Singha Estate, are as keen as any in the country to be clear that they will also be “supporting the Maldives’ ecological environment”. The question may be, how long will it continue to support them?