Under threat of climate change, coral reefs work diligently to survive and thrive

By: Emily Engelbart
Art by: Gloria Lee

Coral reefs are one of the many wonders of our planet, and because of the disheartening truth of global warming, their future is uncertain. A sliver of hope remains: the rapid rate in which coral reefs can evolve. 

Although many people, including some scientists, refer to evolution as a long process spanning the course of thousands, or even millions, of years, this is not always the case. Different species evolve at different rates. 

Misha Matz is a professor at The University of Texas who studies ecological genomics of reef-building corals. His research centers around one question in particular: will coral reefs survive through climate change with the help of their adaptive qualities? Through employing particular mechanisms which involve the exchange of migrants between locations, coral reefs  help each other survive and evolve. 

Coral reefs have the ability to evolve rapidly and efficiently. Because of the CO2 emissions damaging our planet, it is essential that coral reefs adapt successfully; if they could not, they would be unable to survive in the rising temperatures of their habitat.

In Matz’ publication, “Estimating the Potential for Coral Adaptation to Global Warming across the Indo-West Pacific,” he uses a model based on real ocean currents to examine how corals are evolving in the Indo-West Pacific oceans, the most biodiverse ocean. The goal for his work is to demonstrate the efficiency of the migrant exchanges between coral reefs that allow for rapid evolution. 

Matz likens this process to a group of students exchanging notes, the coral reefs exchange migrants for their own benefit. When the need for adaptation arises due to climate change, the exchange occurs. Any species or biological system populating a location of great environmental variation will adapt to local conditions through the exchange of migrants.

Without evolution, everything would die rapidly. Matz said, the efficiency of evolution depends on the temperature of a given location. The coral reefs at the least risk of death from climate change are located in places with cool temperatures and therefore lots of immigrants. 

Immigration is promising for coral reefs because the migrants carry adaptive alleles, which are any one of at least two genes occurring alternately at a given site. The adaptive alleles are rescuing the local population from extinction by supplying the fuel necessary for natural selection. The coral reefs are helping each other by providing ways to live through the high temperatures. 

In hot places, the coral reefs aren’t receiving immigrants; instead, they are only sending immigrants. Because of this, they don’t have any outsiders to rely on, leaving them in a fatal state of isolation.

The future of coral reefs is uncertain. Scientists like Matz who study coral reefs are working diligently to foresee their battles. Matz believes the highly adaptive nature of coral reefs will allow them to persevere through climate change, but not forever. Because there is still hope, we have time to act. Therefore, we need to act aggressively on reducing carbon dioxide emissions if we want to continue appreciating the beauty of coral reefs.