Of all the ecosystems in our seas and oceans, coral reefs are the most valuable and diverse. But why are they such an important part of marine conservation? And what threats do they face both now and in the future?
In this guide, we’re shining a light on the beauty and significance of coral reefs, exploring what they are and why they’re so important to the biodiversity of our underwater world. We’ll also look at the biggest threats they face in oceans around the world, and the charities and organisations doing their part to safeguard them.
What Are Coral Reefs?
Coral reefs are living organisms that provide an important ecosystem for a variety of marine life. Made up of millions of individual animals called ‘polyps’, corals grow very slowly into impressive three-dimensional structures, creating a living home for fish, molluscs, sponges, sea urchins, and other colourful wonders of the deep.
Because coral reefs never move and are fixed to the seafloor, many people mistake them for plants. They are, in fact, classed as ‘sessile’ animals, a trait they share with similar marine organisms like anemones and sponges.
The term ‘sessile’ is used when an animal has no means of self-movement. This might seem like a disadvantage, but in the case of coral polyps and other sessile animals, it allows them to catch food and take in nutrients without expending a lot of energy.
Biologists estimate there to be over 6,000 species of coral. And while they’re most commonly associated with shallow tropical waters – like those of the Great Barrier Reef – coral is found in many different habitats, including the dark, cold depths of the open ocean.
Of all the coral in our oceans, Acropora is the most prevalent variety. Commonly known as staghorn coral, it’s been around for over 1.8 million years, helping to support marine life through some of the world’s most instrumental climate change events.
Why Are Coral Reefs Important?
Coral reefs contribute much to underwater ecosystems, beyond providing a home for marine life. And given the threat these organisms now face, it’s more important than ever to recognise the role they play in our natural world.
Here, we take a look at why coral reefs are so vital to our marine ecosystems.
Home to a Huge Variety of Life
It’s easy to underestimate the number of species which rely on coral reefs. Any one reef, anywhere on Earth, supports thousands of animals – providing a source of food, protection, and a place to safely incubate eggs.
The Great Barrier Reef alone is made up of over 400 coral species, its sweeping mass housing over 1,500 species of fish, six out of seven of the world’s sea turtles, and over 4,000 varieties of molluscs. Indeed, coral reefs are among the most biologically-diverse ecosystems anywhere on the planet, and biologists continue to make exciting new discoveries every day.
Global Value
From a monetary standpoint, coral reefs are believed to attract a global value of over £6 trillion a year. That’s three times higher than the UK GDP.
What accounts for this huge sum of wealth? Tourism is by far the biggest contributing factor, with millions of people every year travelling to tropical climates for the opportunity to scuba dive on the reef bed. Fishing is, of course, another industry which coral reefs help support, while coastal projects protected by underwater reefs also feel the benefit of these incredible natural features.
Natural Coastal Defence
As touched on above, one of the little-known attributes of coral reefs is their ability to reduce wave energy, providing an effective natural defence for vulnerable coastal communities around the world. This is particularly apparent in less-developed countries, where the impact of natural disasters like tsunamis is lessened by precious reef systems.
Coral reefs which sit in shallow waters close to coastlines dramatically reduce wave energy by as much as 97%. Without them, coastal communities and natural land environments like mangrove forests would face significantly increasingly flooding, as well as a less stable marine environment.
Medical Value
Did you know that coral reefs have directly contributed to some of the most commonplace treatments in 21st-century medicine? For decades, scientists have experimented with extracts sourced from coral reefs, which have been successfully used in the development of treatments for heart disease, arthritis, asthma, and cancer.
Given the volume of species which belong to coral reef systems, it’s small wonder these unique marine ecosystems have played such a pivotal role in the development of modern medicines. And, as the world continues to grapple with an ever-evolving list of viruses and diseases, these irreplaceable natural resources could prove more vital than ever.
What Are the Biggest Threats Coral Reefs Face?
Sadly, coral reefs are in sharp and consistent decline, with recent studies suggesting that over 50% of the world’s coral has already been destroyed. But what is contributing to the destruction of these valuable ecosystems?
Here, we take a look at the biggest threats that coral reefs face.
Bleaching
Bleaching is the main cause of coral destruction around the world. It sounds like it would have something to do with chemicals, but it’s actually a side effect of climate change and increasing sea temperatures.
As water warms, algae, coral’s main source of food, moves off, essentially starving the polyps which make up the reef. While coral reefs can regenerate in the wake of bleaching, the rising threat of global warming means that bleaching now contributes to an uncontrollable amount of coral destruction each year.
Other Major Threats
Coral reefs face all kinds of external pressures which threaten their health and growth, including:
- Overfishing
- Acidification – caused by things like plastic pollution
- Pollution
- Damage from boats
- Declining water quality
- Coral harvesting
Although the future looks bleak for major coral systems like the Great Barrier Reef, international efforts are being made to protect them and raise awareness of their importance. For further information on the ongoing action to protect coral reefs around the world, we’d recommend the following charities and organisations:
- Coral Reef Alliance
- Save the Reef
- The Reef-World Foundation
- The Ocean Conservancy
- Coral Restoration Foundation
At Blue Planet Aquarium, we aim to educate our visitors not only on the wonderful creatures in our exhibits, but in the value and beauty of our natural world and precious marine ecosystems. To find out more or to buy tickets online, visit the homepage