The Crumpling Reefs: Coral Bleaching is Changing the Ocean
Khushee Somaiya
International School of Tanganyika
Dar es Salaam, Tanzania
Who doesn't love stunning, colorful reefs? The same coral reefs we used to watch videos about in primary school regarding their decline, and thought nothing of. What if I told you that at this rate, the next generation will just be looking at plain whiteness, no color, and no life? The 2023-2025 coral bleaching event is an ongoing environmental disaster, the most extensive coral bleaching event recorded in history. It is affecting approximately 84% of Earth's coral reef ecosystems. The International Coral Reef Initiative (ICRI) announced this in April 2025 and stated that this bleaching event was the fourth globally documented bleaching event. It surpassed the previous 2014-2017 event, which impacted around two-thirds of the global coral reefs. Around 82 nations where coral reefs are found suffered enough thermal stress to undergo bleaching.
Also, if you don't already know what coral bleaching is, it is basically something that occurs when environmental stressors, like particularly ocean temperatures due to climate change, disrupt the symbiotic relationship between coral polyps and zooxanthellae, the algae that reside within them. This algae also provides the corals with essential nutrients through photosynthesis and is responsible for their vibrant coloration. When long thermal stress occurs, these algae release toxic compounds, which prompt the algae to expel them as a defensive measure. This expulsion reveals to us the white coral that you see in the images, which is the coral's white limestone skeleton, leaving the organism weakened and significantly more vulnerable to mortality.
