Coral Reefs: Biodiversity, Threats, and Conservation


Post by Kathleen

May 22, 2024

The underwater world is as fascinating as it is vast. You can spend years diving and with each dive, you discover something new, surprising, and unique. It’s a living universe where you’ll not only find rich marine fauna but also unique organisms like coral reefs. These structures are not only of immense beauty but also play a crucial role in the conservation of oceans and the species that inhabit them.

In this article, we will share details about coral reefs and provide some key points to help preserve them against the numerous threats they face.

What Are Coral Reefs?

Coral reefs are underwater structures formed by the accumulation of calcareous skeletons secreted by hard corals, known as hermatypic corals, and other marine organisms such as calcareous algae and sponges. To visualise it more clearly, coral reefs are like underwater cities built by tiny animals called corals.


These are extremely diverse and productive ecosystems that host a wide variety of marine life, including fish, crustaceans, molluscs, sea turtles, and a broad range of other species.

How Are They Formed?

Coral reefs form when small animals called corals build hard rock structures on the sea floor. These corals, which belong to the same group as jellyfish and sea anemones and may appear plant-like at first glance, live in warm, shallow waters where there is plenty of sunlight.


Corals, which live in colonies, have soft bodies but secrete a hard, calcareous substance that accumulates over time. As more and more corals grow and join together, they create large structures known as coral reefs.

Impact on the Marine Ecosystem

Why are coral reefs so important? Here are some key points that make these rocky formations one of the greatest allies for marine ecosystem conservation.

  1. Coral reefs are among the most diverse ecosystems on the planet, hosting an incredible variety of marine life. They provide vital habitats for numerous species, including tropical fish, molluscs, crustaceans, sea turtles, and more.
  2. Many marine species depend on coral reefs for food and shelter. Corals provide feeding habitats for fish and other organisms, and also act as refuges from predators.
  3. Coral reefs help protect coastlines from erosion caused by waves and storms. They act as natural barriers that dissipate wave energy, thus reducing the impact of tides and currents on the coast.
  4. Coral reefs play a crucial role in the ocean’s nutrient cycle by absorbing nutrients from the surrounding water and converting them into biomass. This contributes to the overall health of the marine ecosystem and helps maintain ocean productivity.

Biodiversity of Coral Reefs

Who lives in coral reefs? As mentioned earlier, the biodiversity of these ecosystems is immense. They are true sources of life, places where everything converges, true underwater metropolises. As the name suggests, their main inhabitants are corals, those plant-like marine animals, which can be hard or soft, and are responsible for the reef’s construction.


However, they share the structure with many other neighbours, such as invertebrates, including sponges, crustaceans, molluscs, or echinoderms, various algae and plants, sea turtles, and, of course, fish.

In fact, coral reefs are home to an incredible variety of fish, ranging from small reef fish to large predators like sharks and barracudas. Reef fish are often very colourful and adapted to living in the intricate reef habitats.

Problems Facing Coral Reefs

Today, coral reefs face numerous problems, many of which are significantly influenced by human activities:

  • The increase in ocean temperatures due to climate change causes coral bleaching, a stress response that can lead to coral death if it persists for prolonged periods.
  • Pollution from nutrients, agricultural chemicals, plastic waste, and other contaminants can severely damage coral reefs by promoting algae growth that competes with corals for space and resources.
  • Destructive fishing practices, such as blast fishing and trawling, can destroy coral reefs and deplete fish stocks, leading to ecosystem collapse.
  • Unsustainable tourism, including uncontrolled diving, boat anchoring, and the collection of corals and marine species, can cause significant damage to coral reefs and the marine life that depends on them.
  • Unplanned coastal development and the destruction of natural coastal habitats, such as mangroves and seagrasses, can increase sedimentation and nutrient runoff to coral reefs, making them more vulnerable to environmental impacts.
  • Ocean acidification due to increased carbon dioxide emissions can also negatively affect coral reefs by reducing the ability of corals to build their calcium carbonate skeletons.

Importance of Coral Reef Conservation

It is necessary to protect all forms of natural life, but in the case of coral reefs, this necessity is even greater given their key role in numerous aspects. First and foremost, as a habitat for thousands of marine flora and fauna species, but also for the ocean’s food sustainability.

Additionally, coral reefs act as natural barriers that protect coastlines from erosion caused by waves and storms. They help stabilise beaches and reduce the impact of tides and currents on coastal communities, protecting infrastructure and properties.


Their role in climate regulation should not be overlooked, as they absorb carbon dioxide from the atmosphere and act as carbon sinks. They help mitigate climate change by reducing CO2 levels in the ocean and contribute to global climate stability.

Where to See Coral Reefs? Popular Diving Destinations!

Now, let’s discover where you can marvel at the majesty of coral reefs! Fortunately, there are still many areas where you can dive among thriving reefs. Here are some recommendations:

  • Great Barrier Reef, Australia: It is the largest coral reef system in the world and offers an incredible variety of diving sites. Cairns and Port Douglas are excellent starting points for exploring the Great Barrier Reef.
  • Maldives: This island country in the Indian Ocean is famous for its clear waters, colourful coral reefs, and great marine biodiversity. The North Male and Ari Atolls are some of the most popular diving spots.
  • Indonesia: There are many places in this vast archipelago to enjoy corals, such as Raja Ampat, known for having the world’s greatest marine biodiversity, or Nusa Penida, with its beautiful live corals. Plus, you can dive with DPM Diving!
  • Belize: Belize’s coral reefs are part of the second largest barrier reef in the world. Ambergris Caye and Caye Caulker are excellent places to dive and explore these reefs.
  • Fiji Islands: These South Pacific islands are known for their impressive coral reefs and clear waters. Taveuni and Beqa Lagoon are popular destinations for diving and discovering Fiji’s rich marine life.
  • Thailand: Koh Phi Phi and Koh Tao are popular diving destinations in Thailand. The coral reefs here are impressive and home to a wide variety of tropical fish and other marine creatures. Visit our schools located on these islands!

Now it’s your turn, where have you seen the best coral reefs? We look forward to your recommendations! At DPM Diving, we are especially committed to the conservation of these ecosystems through responsible diver training and participation in local conservation initiatives.


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