Coral reef in the future

Details: Category: CnyBlog

Whether you’re a diver or not, you probably already heard the words “coral bleaching” “heat waves” or “global warming”. What does that mean? And what are the perspectives? Let’s take a closer look together.

By Cindy

Cindy

Teaching Director

Cindy is our In House Padi Master Instructor she is always keen to share her views and philosophy as an Instructor with her students. Dedication, knowledge and professionalism are only a few of her qualities. She speaks French German Italian and English and is originaly from Switzerland Her knowledge and passion will guide you as you gain skills and experience with her. On her dark side she reveals her CCR Trimix skills and will take you to some amazing Technical dives.

In the last few decades, the world population increased non-stop, in fact it has doubled since the fifites. In 2024, human population was estimated to be about 8.2 billion people. This massive growth results in more consumption and of course more pollution. Another factor is industrializaion, with it being closely linked to pollution since industrial activities generate waste and harmful emissions. These activities, such as manufacturing, processing and raw material extraction result in contamination of air, water and soils.

What are the consequences of this increase of pollution on the oceans? And on coral reefs?

As humans, a change of 0.5°C or even 1°C in temperature might seem insignificant and barely noticeable. However, for the ocean and its delicate ecosystems, such a variation represents a major upheaval. Even a slight rise in temperature can disrupt the chemical balance of seawater, affecting its pH and oxygen levels. For example, corals are highly sensitive to these changes: increased temperatures and ocean acidification can lead to coral bleaching, weakening their skeletal structure and threatening entire marine habitats that depend on healthy coral reefs.

Indeed, corals are organisms that live in symbiosis with algae, called zooxanthellae, which function almost like their internal digestive system. These algae provide the corals with essential nutrients through photosynthesis, while the corals offer them protection and access to sunlight. However, when the temperature of the water rises, the algae become stressed and start producing toxic substances. In response, the corals expel the algae, leading to what we call coral bleaching. Without their symbiotic partners, corals lose their color and, more importantly, their main source of energy, making them extremely vulnerable and at risk of dying if stressful conditions persist. Different species have different reactions and some of them are more resilient, but unfortunately most of them are eventually affected and might not survive. This is primarily due to the impacts of climate change, mainly changing ocean temperatures, as well as other stressors like pollution and overfishing.

Lately, since February 2025, scientists and the diving community have observed a new wave of coral deterioration. Surveys and monitoring efforts have confirmed that coral bleaching is once again widespread. Unfortunately, this is no longer a localized issue: it has become a global phenomenon. Not only are the reefs of the Indian Ocean affected, but corals in the Pacific Ocean, the Atlantic Ocean, and even the Caribbean are also suffering. From the Great Barrier Reef in Australia to the coral gardens of the Maldives and the reefs off the coast of Florida, rising sea temperatures are pushing these fragile ecosystems to their limits. Indeed, global temperatures in the first quarter of 2025 were the second warmest on record, extending a remarkable run of exceptional warmth that began in July 2023.

Moreover, these effects and consequences are difficult to reverse. People do not realise that "oceans are the lungs of the planet". Oceans play a vital role in regulating the Earth's climate and producing oxygen through photosynthesis. They are responsible for a significant portion of the oxygen in the atmosphere, absorbing carbon dioxide, and buffering against the effects of climate change. Consequently, if scientific projections come true, namely that a very high percentage of coral reefs could disappear within the next 50 years, with some estimates suggesting a 90% loss by 2050, the whole planet Earth will be endangered.

Today, there is an urgent need to raise awareness and drive action — not just at a local level, but on a global scale. While individual efforts are important, isolated local actions alone will have only a limited impact. What we truly need is a united response from all nations around the world. However, without strong political will and international cooperation, the outlook remains bleak.

One of the greatest challenges in protecting the ocean is that so few people actually see its deterioration. As a result, many do not feel directly concerned or motivated to act. This is why, as divers and ocean lovers, it is our responsibility to be the voice of the underwater world and help raise public awareness about the urgent need to protect it.

A special thank you to Olly, who always helps us better understand the science behind the oceans and generously provided the images for this special article.

Ti Koraye, Mauritius, Indian Ocean,