Why Coral Reefs Are Important

The Tiny Organisms Preserving the Richness of Marine Life and Protecting Life on Earth

Take a deep breath. Now take another. Every second breath we take, or 50% of the world’s oxygen, is produced by the ocean and the phytoplankton within it. An organism that covers less than 1% of the ocean’s floor is critical to this production. These small and mighty creatures are crucial for sustaining all life on Earth– and as you might have guessed from the title of this article, we’re talking about coral reefs. 

Coral polyps form the building blocks that support countless marine animals, protect our coastlines, and safeguard Earth's critical carbon sinks. They’re vital to our ocean's health, and our oceans sustain life on Earth. Anything that threatens coral reefs, threatens us as well. 

We’ve all heard that we need to save the reefs. But how many of us actually understand why? These ecosystems are incredibly vulnerable, with climate change already causing coral around the world to bleach. Without urgent action, they could vanish within our lifetime.

What exactly is coral?

Corals are marine invertebrates that form colonies of polyps, which are tiny animals related to sea anemones. Tiny polyps drift in the sea’s currents until they settle on rocky surfaces, beginning their transformation into living corals. By secreting calcium carbonate to create hard skeletons, polyps collectively build the intricate structures known as coral reefs. These reefs then become vibrant habitats, critical to life on Earth.

Why are corals bleaching? 

It’s important to understand why corals are dying in the first place. Coral reefs “bleach” when they expel symbiotic algae from their tissues, often due to warm ocean temperatures, pollution, disease, or other disruptions. These algae, called zooxanthellae, provide corals with their food source and their vibrant colors. Without them, corals become more vulnerable to disease, and can ultimately die off.

As global temperatures rise, coral reefs and the diverse species they support struggle to survive, posing threats to both ocean and human health. Coral ecosystems, while adaptable and resilient, are also fragile. They're highly susceptible to shifts in ocean temperature, which are exacerbated by climate change.

The carbon dioxide heating our atmosphere intensifies El Niño events by warming ocean temperatures. With rising greenhouse gases, future El Niño impacts could worsen, endangering coral reef health in an ongoing cycle of environmental stress. The ocean absorbs 90% of the heat in our atmosphere, acting as a major regulator of our climate. However, human activity is pushing the ocean to its limit, and warmer waters are damaging ocean health.

During the last major El Niño event from 2014 to 2017, warm waters affected 70% of global coral reef ecosystems. These warmer waters devastated iconic dive sites like Australia’s Great Barrier Reef, where hundreds of miles of coral were severely bleached. In 2024, another round of El Niño conditions threatens reefs from the Maldives to the Philippines.

So, why are coral reefs important? They are among Earth’s most critical ecosystems, absorbing carbon dioxide from the ocean—a vital role as human activities accelerate climate change. They support a diverse array of marine life, and their potential loss would disrupt oceanic balance. Let’s explore four more reasons why coral reefs matter.

1. Homes of Biodiversity

Coral reefs represent an epicenter of biodiversity. From tiny clownfish darting between the anemones to majestic sea turtles searching for a snack, these reefs harbor a staggering diversity of marine life.

Despite covering less than 1% of the ocean floor, coral reefs are home to 25% of all marine species on the planet.

Every creature plays a role in its ecosystem's survival. Marine biodiversity supports the fisheries that provide food security to millions of people living in coastal areas. It contributes to climate regulation through carbon sequestration. And, diverse marine ecosystems create and protect economic benefits that coastal communities rely on. Without biodiversity, the balance of life on Earth is threatened.

2. Protectors of Coastlines

Coral reefs are nature's first line of defense against storms and coastal erosion. Their complex structures act as natural barriers, reducing the impact of waves and storms on coastal cities and developments. In famous dive sites like the Maldives or Belize, where coral reefs fringe the coastlines, they protect beaches, prevent erosion, and even help mitigate the devastating effects of tsunamis.

If all coral disappeared tomorrow, coastlines would be hit with extreme storm surges and waves. Erosion would cause coastal damage and a loss of land. Local economies would suffer, and some may even lose their homes to flooding. These tiny polyps help protect us from rising sea levels, safeguarding the some 3 billion people that live within 200 kilometers of a coastline.

3. Engines of Economic Prosperity

Those same billions of people who live by the coast also depend on reefs for their livelihoods, whether through tourism, fisheries, or coastal protection services. Tourists flock to incredible reef destinations like Australia's Great Barrier Reef or the coral gardens of the Caribbean to witness firsthand the kaleidoscope of colors and life beneath the waves. Fishermen rely on reef ecosystems to sustain fisheries, providing food and income for communities.

The United Nations Food and Agricultural Organization reports that more than 3 billion people worldwide rely on fish and other seafood as a significant source of animal protein. As coral reefs bleach and marine biodiversity is threatened, both the economic prosperity and wellbeing of these communities are threatened.

4. Signals of Ocean Health

Coral reefs are known as the barometers of ocean health. Their decline can signal broader issues affecting the underwater world, like pollution, overfishing, and climate change. Coral bleaching is a stark reminder of the impact of rising sea temperatures, urging us to address and mitigate global warming caused by the greenhouse gases in our atmosphere.

By monitoring and protecting coral reefs, we can better understand and address the challenges facing our oceans, ensuring they remain full of life and resilient.

A Call to Action for Coral Reefs

As stewards of our blue planet, it’s our responsibility to cherish and safeguard the animals that provide us with great practical and ecological benefits. Whether we prefer to explore coral reefs firsthand, or simply to admire them from afar, it’s impossible to deny their invaluable contributions to our survival. Coral reefs are not just breathtaking to observe– they are essential components of Earth's intricate web of life, and some of our biggest allies in the fight against climate change.

The oceans, and the reefs within them, play an incredible role in sustaining all life on Earth. Yet, they also act as a source of inspiration and wonder across cultures and countries. Coral reefs, with their bright colors and harmonious life forms, symbolize the interconnectedness of all living things. They remind us of the limitless beauty and mysteries that grace our world. This reverence encourages us to take active steps to preserve corals, safeguard their habitats, and mitigate climate change, helping coral wonders endure for generations to come.