Coral Reefs Face More Challenges
Coral reefs, already under existential threat from rising water temperatures, face further risks as projected sea level rises will outpace the speed they are able to grow, new research suggests.
Current growth rates in the tropical western Atlantic and Indian Ocean have so far kept up with modern global sea level rises – 6cm during the 19th Century and 19cm during the 20th century. But projections for sea level rises by the end of the 21st Century will outpace coral growth, the study says.
Reef growth is already severely hampered by combinations of coral disease, deteriorating water quality and fishing pressure, along with severe impacts from “coral bleaching” caused by climate change.
Even under modest climate change prediction scenarios, only about 3 per cent of Indian Ocean reefs will be able to track local sea-level rise projections without sustained ecological recovery, whilst under continued high emission scenarios, most reefs will experience water depth increases in excess of half a metre.
Reefs serve as natural breakwaters that reduce flooding by dampening waves and breaking them early.