In a recent study, the two of the most omnipresent species of reef-building corals were found able to survive and cope with climate change and the rise of temperature.
They were found to do it at least so long as the warming is under 2 degrees C, a target placed by the Paris Agreement.
The study was released in the Nature Scientific Reports and its lead author, Rowan McLachlan, a coral expert from Oregon State University says they’ve discovered hope.
There Was Not Much Hope Around Coral Reefs
Hope hasn’t been present a lot lately when it comes to coral reefs.
Unfortunately, due to the human-caused greenhouse emissions that often go through the roof, corals are faced with warmer water, higher marine heatwaves, and increasingly acidic waters. The list goes on and the stress they feel is further worsened by overfishing and pollution.
Currently, the world has gone warmer by 1.1 degrees C and this warming has led to mass fatalities among coral reefs. The largest reef system, the Great Barrier Reef, is in a crisis, according to a recent report by the UN.
This report included a warning by the IPCC that some of the coral reef ecosystems may be permanently damaged if the world becomes warmer by 1.5 degrees C.
A 2018 report by the IPCC also concluded that a 2 degrees C warming or more could result in the loss of 99 percent of the reef-building corals.
Essentially, this means that they would disappear if this happens.
However, this wasn’t what McLachlan and her colleagues noted when they subjected corals in Hawaii to a simulated 2 degrees C world for almost two years.
They discovered that there were two highly resilient species and two-thirds of these corals survived this increased temperature simulation, i.e. the finger and lobe corals.
They thought they would notice more mortality than they did, but they found that the corals were hanging on and surviving. It seems that within limits, certain corals are capable of adjusting to a world that’s warmer.
The Dangers of Coral Bleaching
The ocean absorbs some of the heat in the atmosphere. The heat waves strengthened by climate change cause corals to discharge the algae that nourish them. This is known as coral bleaching and it may destroy reefs.
And, oceans also absorb the surplus CO2 from the atmosphere and increase the acidity of seawater and this causes the skeletons of the corals to weaken.
Despite the hope that some coral species can survive in this century; unless the emissions are significantly reduced, they will eventually lose and die out.
The current policies to lower emissions have the planet on track to warm by around 2.7 degrees C by the end of this century, according to Climate Action Tracker. This is above the 2 degrees C that McLachlan and her team simulated.
According to coral reef ecologist at the University of Hawaii, Alan Friedlander, more marine protected areas are necessary to make sure these climate-resilient corals aren’t impeded by the local degradation and pollution.
Anyway, some conservationists emphasize the need for active restoration of corals, rather than just their protection from fishing and pollution.
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