A new study presented at the Ocean Sciences Meeting 2020 in San Diego has revealed that rising surface temperatures and acidic water could lead to the collapse of nearly all coral reefs by 2100. The researchers noted that restoration projects in these sites will face serious challenges.
Scientists are forecasting that 70 to 90 percent of coral reef habitats will vanish in the next 20 years as a direct result of climate change and pollution. Some organizations are trying to reign in this loss by relocating live laboratory-grown coral to dying reefs. These groups claim new, young coral species will bolster reef recovery and restore them to healthier conditions.
However, new research mapping shows that, while the reefs may flourish over the coming decades as a result of these endeavors, by 2100, few coral habitats will survive. The surface temperature of the ocean and the acidity will have such extreme effects that these restoration efforts won’t be able to adequately combat them.
“By 2100, it’s looking quite grim,” said Renee Setter, a biogeographer at the University of Hawaii at Manoa.
According to the Setter and her team, the findings reveal how destructive the effects of Earth’s warming climate are for marine life. Though pollution presents multiple threats to all sea creatures, the new research indicates coral is most vulnerable to changes in their environment.
Setter said that we need to continue our efforts in combating pollution, with ocean clean-ups being a prime concern. However, for the safety of our reefs, climate change is the prime concern. “At the end of the day, fighting climate change is really what we need to be advocating for in order to protect coral and avoid compounded stressors.”
Predicting the future of coral reefs
Warmer water causes coral to release symbiotic algae. This results in bleaching (when formerly brightly colored coral turns white). Bleached coral isn’t dead, but it’s at greater risk of dying, and these bleaching processes are becoming more prevalent thanks to climate change.
Setter and her colleagues identified suitable areas of the ocean for coral restoration efforts over the coming decades. In the new study, the researchers replicated ocean environment conditions such as sea surface temperature, water acidity, wave energy, pollution, and overfishing in sites where coral reefs currently exist. They also considered human population density and land cover use to estimate how much waste would be delivered into the surrounding waters.
The scientists found that, by as early as 2045, the areas where coral reefs can be found today won’t offer a healthy environment. By 2100, these regions will be inhospitable to sea life that comprises coral reefs.
While “most sites are out,” according to Setter, the limited sites that are feasible by 2100 include small portions of Baja California and the Red Sea. Both of these regions are sub-par for coral reefs because of their nearness to rivers.
According to the researchers, increasing temperatures and ocean acidification are mostly to blame for declining coral habitats, while the swelling human pollution is only a minor contributor to the future collapse of our planet’s reefs. However, to date, humans have already severely damaged reef habitats through such things as pollution, garbage, and sunscreen.