The bleaching of coral reefs
The bleaching of coral reefs is the process by which corals lose their vibrant colours and turn entirely white. The colour we see on corals is given by a specific and incredibly little algae called zooxanthellae. The relationship between the algae and coral is mutual so it is beneficial for them both. However, due to climate change and the rising temperatures in the ocean, corals get stressed out and expel zooxanthellae which leads to the colour fading away. Nevertheless, corals do not die when this tragic event happens, although they become under more stress and are exposed to mortality. They also become subjects to mortality due to fish which stop going there to find food.
Why does coral bleaching matter?
Coral bleaching is a major issue because once corals die, reefs are eventually not coming back. If just a few corals survive, they struggle to reproduce. Reef ecosystems are really important to people and wildlife so if corals deteriorate it’s a huge problem. This is due to the significant amount of tourists which pay to look at coral reefs so when they turn white and eventually die there’s also an impact on the economy (an economy already taking hits because of modern issues such as Covid-19).
According to the National Oceanic and Atmospheric association, between 2014 and 2017, around 75% of the world’s tropical reefs are suffering from heat-stress, which is enough to activate bleaching. 20% of reefs in the whole world died because of this event and only 5% are healthy and alive.
By Lavinia Amabile and Ginevra Tocci