According to a new study published in, rising global sea levels could actually be beneficial for the long-term future of coral reef islands like the Maldives Geophysical research letters,
Deep-lying coral reef islands are usually less than three meters above sea level and are therefore very vulnerable to sea-level rise associated with climate change. However, research has found new evidence that the Maldives – the lowest country in the world – was formed when the sea level was higher than it is today.
The evidence was discovered by researchers studying the formation of five islands in the southern Maldives. Using a core drilling technique they were able to reconstruct how and when the islands formed.
They found that large waves caused by distant storms off the coast of South Africa led to the formation of the islands about three to four thousand years ago. Known as high energy wave events, these large waves broke coral remnants off the reef and transported them to reef platforms, creating the foundation for the reef islands.
At that time, sea levels were up to 0.5 meters higher than today, giving the waves more energy. This means that higher sea levels and large wave events were crucial for the construction of the islands.
The researchers say that under climate change, projected sea level rise and the magnitude of large wave events could actually lead to the growth of reef islands, but only if the coral reef remains healthy to provide building material.
The research was Holly East from the Department of Geography and Environmental Sciences at Northumbria University, Newcastle. She explained, "Coral islands are believed to be very vulnerable to sea-level rise, which is a major concern of coral reef islands, where reef islands are the only habitable land.
"However, we have found evidence that the Maldive reef islands have actually formed at higher sea levels than we currently are, which makes us optimistic that climate change will lead to sea-level rise and an increase in high-energy wave events in Europe In fact, this could create the perfect conditions for the region to reactivate the processes that have built the reef islands in the first place, rather than drowning them. "
Dr East emphasized, however, that this would only be possible if healthy corals were available in the reef communities of the region.
"Since these islands are mostly coral, a healthy coral reef is essential to provide the materials for the island's construction," she said. "However, this can be problematic as corals are exposed to a range of threats from climate change, including rising sea surface temperatures and ocean acidity, and if the reef is unhealthy, we could end up with the perfect construction conditions, but not with the bricks."
Dr. East worked with academics from the University of Exeter (UK). Simon Fraser University (Canada); University of Auckland (New Zealand); Southern Institute of Technology (New Zealand) and the United Kingdom Natural Environment Research Council (NERC) for this study.
Dr East added, "It is also important to note that the large wave events required to build reef islands can destroy the island infrastructure and potentially affect the habitability of the reef islands in their present form Development of the infrastructure with the ability to withstand major wave events or to be adaptable. "
Their paper, initiation and development of coral reef islands under higher sea levels is now available in Geophysical research letters,
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of the EurekAlert press releases! by contributing institutions or for the use of information about the EurekAlert system.