This story was originally published on Yale Environment 360. It is part of the Climate Desk collaboration.
Christian Voolstra, an ecological genomicist in Saudi Arabia, began his work in 2009 on corals. One of the greatest benefits to his job was the opportunity to scuba dive on beautiful reefs. The times have changed. Voolstra, who is now at the University of Konstanz, Germany, said that she was stunned when she returned in September. There is a lot rubble. The fish are missing. The colors are missing.
It's a sad, but familiar tale. The Global Coral Reef Monitoring Network published the first ever report aggregating global statistics on corals. It documented the state of reefs in 12,000 locations across 73 countries over the past 40 years. They report that the world has lost 14% of its corals between 2009 and 2018, which is approximately 11,700 km of coral.
Voolstra says that if this happened to Amazon, the Amazon would have been in the news overnight if it had gone white or black. No one notices because it is underwater.
Global warming is causing corals severe problems. Corals have to release their symbiotic algae, called zooxanthellae, in order to survive. While local pollution is still a concern for corals and an issue, global warming is becoming the dominant threat. The International Panel on Climate Change (IPCCC) reported in 2018 that global warming of 1.5 degrees Celsius would lead to global coral reefs declining by 70 to 90%. Current global temperature is 1.2 Celsius. If the world were 2 degrees Celsius warmer, it would lose 99 percent of its corals.
There are some signs of hope. Global Coral Reef Monitoring Network report reveals that corals can be regenerated if they are given about a decade to recover from the heat. The trend has been reversed in some spots, including the Coral Triangle in East Asia which is home to nearly a third global corals. Some corals may be adapting to warmer temperatures, according to some hints. Research is expanding on innovative ways to improve coral restoration. This includes selectively breeding super corals and spreading probiotics on stressed coral reefs.
Im hopeful, says Voolstra. He says that it will take a lot more time and effort to save all the reefs. It is impossible. It is important to save some reefs in order for them to survive the dark ages caused by climate change.
Hard coral has remained relatively stable on the reefs of the world since 1978, when data collection started for the Global Coral Reef Monitoring Networks. The first global mass bleaching occurred in 1998. This was a major change. The El Nio caused global warming to wipe out approximately 8 percent of corals, which is equivalent to 6,500 km2. David Souter, who is the coordinator of the Global Coral Reef Monitoring Network, and a researcher at Australia Institute of Marine Science, Townsville, said that all the drama began in 1998. We see real problems when the temperature rises for months. Corals can withstand short, sharp temperature changes.