If global warming continues at the same rate, coral reef structures will shrink and weaken, reducing coastline protection from high waves.
The complex structure of the coral reef, with its countless branches and depressions, impedes the flow of water and serves as a natural and reliable barrier that protects the coastline from waves. However, continued coral bleaching and reef deaths threaten to leave the coast without this protection. This will lead to the fact that by the end of the century, in some areas of the ocean, the height of waves reaching the coast will double. Scientists write about this in an article published by the journal Science Advances.
Coral reefs - perhaps the richest and most complex ecosystems on the planet - are dying everywhere. Warming and increasing acidity in ocean water causes the algae to disappear, discoloring the bright colors of the corals and killing them. Scientists have long sounded the alarm, and to save the Great Barrier Reef, it is even proposed to carry out a massive "transplant" of more resistant polyps. Indeed, the consequences of coral death can be dire.
New aspects of this process were revealed by Daniel Harris and his colleagues. They note that the rugged, complex structure of the reef itself creates significant friction for the water flowing through it. This dissipates the vibrational energy and reduces the height of waves that reach land. Stressed corals do not form such complex and large reefs and do not form such a spectacular barrier from waves.
Scientists have modeled the consequences of their death on four areas of the ocean in French Polynesia, so far rich in corals and differing in typical wave energy. The work showed that not even death, but a simple decrease in the size and complexity of the reef structure leads to the fact that waves passing over it and through it will not decrease as noticeably as they do today. If warming continues as expected, the height of the waves reaching the shore in 2100 will be 2.4 times higher.
Sergey Vasiliev