Nav: Home

Rising sea levels may build, rather than destroy, coral reef islands

November 13, 2018

Rising global sea levels may actually be beneficial to the long-term future of coral reef islands, such as the Maldives, according to new research published in Geophysical Research Letters.

Low-lying coral reef islands are typically less than three metres above sea level, making them highly vulnerable to rising sea levels associated with climate change. However, research has found new evidence that the Maldives - the world's lowest country - formed when sea levels were higher than they are today.

The evidence was discovered by researchers who studied the formation of five islands in the southern Maldives. Using a coring 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 approximately three to four thousand years ago. These large waves - known as high-energy wave events - broke coral rubble off the reef and transported it onto reef platforms creating the foundations for the reef islands.

At the time, sea levels were up to 0.5 metres higher than they are today, which gave the waves more energy. This means that higher sea levels and large wave events were critical to the construction of the islands.

The researchers say that under climate change, projected increases in sea level 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 the building material.

The research was led by Dr Holly East of the Department of Geography and Environmental Sciences at Northumbria University, Newcastle. She explained: "Coral reef islands are typically believed to be highly vulnerable to rising sea levels. This is a major concern for coral reef island nations, in which reef islands provide the only habitable land.

"However, we have found evidence that the Maldivian rim reef islands actually formed under higher sea levels than we have at present. This gives us some optimism that if climate change causes rising sea levels and increases in the magnitude of high-energy wave events in the region, it may actually create the perfect conditions to reactivate the processes that built the reef islands in the first place, rather than drowning them."

However, Dr East stressed that this could only occur if healthy live coral was available in the region's reef communities.

"As these islands are mostly made from coral, a healthy coral reef is vital to provide the materials for island building," she said. "However, this could be problematic as corals face a range of threats under climate change, including increasing sea surface temperatures and ocean acidity. If the reef is unhealthy, we could end up with the perfect building conditions but not 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 UK's Natural Environment Research Council (NERC) on this study.

Dr East added: "It is also important to note that the large wave events required for reef island building may devastate island infrastructure, potentially compromising the habitability of reef islands in their current form. A challenge for reef island nations may therefore be to develop infrastructure with the capacity to withstand, or be adaptable to, large wave events."
-end-
Their paper, Coral Reef Island Initiation and Development Under Higher Than Present Sea Levels is now available in Geophysical Research Letters.

Northumbria University

Related Climate Change Articles:

Mapping the path of climate change
Predicting a major transition, such as climate change, is extremely difficult, but the probabilistic framework developed by the authors is the first step in identifying the path between a shift in two environmental states.
Small change for climate change: Time to increase research funding to save the world
A new study shows that there is a huge disproportion in the level of funding for social science research into the greatest challenge in combating global warming -- how to get individuals and societies to overcome ingrained human habits to make the changes necessary to mitigate climate change.
Sub-national 'climate clubs' could offer key to combating climate change
'Climate clubs' offering membership for sub-national states, in addition to just countries, could speed up progress towards a globally harmonized climate change policy, which in turn offers a way to achieve stronger climate policies in all countries.
Review of Chinese atmospheric science research over the past 70 years: Climate and climate change
Over the past 70 years since the foundation of the People's Republic of China, Chinese scientists have made great contributions to various fields in the research of atmospheric sciences, which attracted worldwide attention.
A CERN for climate change
In a Perspective article appearing in this week's Proceedings of the National Academy of Sciences, Tim Palmer (Oxford University), and Bjorn Stevens (Max Planck Society), critically reflect on the present state of Earth system modelling.
Fairy-wrens change breeding habits to cope with climate change
Warmer temperatures linked to climate change are having a big impact on the breeding habits of one of Australia's most recognisable bird species, according to researchers at The Australian National University (ANU).
Believing in climate change doesn't mean you are preparing for climate change, study finds
Notre Dame researchers found that although coastal homeowners may perceive a worsening of climate change-related hazards, these attitudes are largely unrelated to a homeowner's expectations of actual home damage.
Older forests resist change -- climate change, that is
Older forests in eastern North America are less vulnerable to climate change than younger forests, particularly for carbon storage, timber production, and biodiversity, new research finds.
Could climate change cause infertility?
A number of plant and animal species could find it increasingly difficult to reproduce if climate change worsens and global temperatures become more extreme -- a stark warning highlighted by new scientific research.
Predicting climate change
Thomas Crowther, ETH Zurich identifies long-disappeared forests available for restoration across the world.
More Climate Change News and Climate Change Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Reinvention
Change is hard, but it's also an opportunity to discover and reimagine what you thought you knew. From our economy, to music, to even ourselves–this hour TED speakers explore the power of reinvention. Guests include OK Go lead singer Damian Kulash Jr., former college gymnastics coach Valorie Kondos Field, Stockton Mayor Michael Tubbs, and entrepreneur Nick Hanauer.
Now Playing: Science for the People

#562 Superbug to Bedside
By now we're all good and scared about antibiotic resistance, one of the many things coming to get us all. But there's good news, sort of. News antibiotics are coming out! How do they get tested? What does that kind of a trial look like and how does it happen? Host Bethany Brookeshire talks with Matt McCarthy, author of "Superbugs: The Race to Stop an Epidemic", about the ins and outs of testing a new antibiotic in the hospital.
Now Playing: Radiolab

Dispatch 6: Strange Times
Covid has disrupted the most basic routines of our days and nights. But in the middle of a conversation about how to fight the virus, we find a place impervious to the stalled plans and frenetic demands of the outside world. It's a very different kind of front line, where urgent work means moving slow, and time is marked out in tiny pre-planned steps. Then, on a walk through the woods, we consider how the tempo of our lives affects our minds and discover how the beats of biology shape our bodies. This episode was produced with help from Molly Webster and Tracie Hunte. Support Radiolab today at Radiolab.org/donate.