The vast oceans of the world are majestic and beautiful in themselves, with thriving marine life. Add to that another exquisite element of underwater life- coral reefs, and the ocean becomes a living paradise! The coral reefs are one of the most exotic and stunning elements of the oceans. They are home to vast species of marine life and are the protector of coastlines.
What are Coral Reefs?
Coral reefs are a diverse ecosystem of the world and underwater in particular. The coral reefs are formed by coral polyps, tiny animals that shape the large colonies of attractive coral reefs we see.
The coral reefs are the ‘rainforests of the sea,’ as they are the habitat to diverse species of marine life. Fish primarily depends solely on the coral reefs, living amidst the flowing beauty. Additionally, coral reefs also act as their food source, shelter, and a place to reproduce and nurture their young safely. Around 25% of the total fish population of the oceans depends heavily on coral reefs. Apart from fishes, shallow coral reefs also support other types of marine life like invertebrate species, sea turtles, and marine mammals.
The orientation of coral reefs is generally upwards, facing the open sea. Its uppermost part is the fore reef that roots into deeper water and embeds into the seafloor. The reef has a shallow platform, the reef framework, and seagrasses and algal mats surround them.
Living Process of Coral Reefs
Coral reefs usually live along with algae in a process called symbiosis. In this process, both the marine organisms cooperate and co-exist. Algae’ Zooxanthellae’ reside inside the coral reefs, and the algae, in return, provide food for the reefs made from photosynthesis. The exquisite colors of the coral reefs also come from these Zooxanthellae algae. However, this symbiotic cooperation depends on the temperature of the ocean water. As the ocean water gets warmer, the Zooxanthellae algae emerge from the tissues of the coral. It makes the coral lose color and their food source. This process is called ‘coral bleaching.’ The process of coral bleaching, however, doesn’t always mean that the coral is dead and the reef gets to rejuvenate and revive the Zooxanthellae algae, but the process takes time and requires cooler water temperatures.
Types of Coral Reef
There are many varied types of coral reefs globally- some living in warm and tropical areas and others living in cold depths of the ocean. Scientists divided the coral reefs into four main categories. They are:
- Fringing reefs: These coral reefs grow closer to the coastline around the landmass and are separated from the shore by shallow lagoons. Fringing reefs are the most common reef type we see in the oceans.
- Barrier reefs: These reefs grow parallel to the coastline and are separated from the shore by deeper and wider lagoons. At its shallowest point, the reefs grow and emerge out into the surface as a barrier to the coastline. The Great Barrier Reef of Australia is the most extensive in the world.
- Atolls: These are coral reefs that create thriving lagoons and exist primarily in the middle of the ocean and form when islands surrounded by spreading fringing reefs sink into the sea, and the water level rises around the landscape.
- Patch reefs: These are tiny isolated reefs that emerge on the bottom of any island platform or a continental shelf and occur primarily between the fringing reefs and the barrier reefs and exist in extended sizes.
Threats to Coral Reefs
Coral reefs are the wonders of the aqua world. Unfortunately, these precious beauties are also severely threatened. The threats are both natural and manmade. Natural threats include diseases, predators, violent storms, and manmade threats, including aqua pollution, sedimentation, violent fishing practices, and climate change. The rising temperatures of the oceans also fuel the ocean acidification process and the withering and death of coral reefs. Also, manmade stress often stresses the coral, which eventually leads to coral bleaching and death. If not death, coral reefs often suffer from physical damage from the threats.
Coral reefs usually revive and recover from bleaching if the aqua conditions around them improve. However, this process takes a lot of time. Across the world, scientists are now trying to develop ways to revive and nurture the withering coral reefs of the world. They are testing new methods to help the coral reef ecosystems, like cultivating and growing coral reefs in nurseries and then transplanting them in the damaged areas.
Extraordinary Coral Reefs of the World
Great Barrier Reef in Australia
The Great Barrier Reef of Australia is perhaps the coral ecosystem that comes to everyone’s mind when they think of corals. This coral ecosystem is majestic (the most extensive coral system on Earth) and the most beautiful. The reef has more than 3,000 individual tiny coral reef systems filled with thriving marine life. It has over 400 types of corals co-existing together. The Great Barrier Reef exists near the coast of Queensland and spreads to form several islands with pristine beaches that attract thousands of tourists worldwide. It is a protected UNESCO World Heritage Site and lists in the Seven Natural Wonders of the World.
Sosomoso Strait in Fiji
Fiji is rightly known as the ‘coral capital of the world.’ Rightfully so, with the majority of the coral reef systems existing around its shores and the ocean. The Somosomo Straight exists between the Taveuni and Vanua Levu islands and has a sizeable thriving growth of soft corals.
New Caledonia Barrier Reef in New Caledonia
A Protected UNESCO World Heritage Site ‘The New Caledonia Barrier Reef’ is the second largest barrier reef on Earth. It is the finest creation of nature with sparkling blue waters that hue in its myriad shades. The reef system exists in the South Pacific Ocean near the northeast coast of Australia. The New Caledonia Barrier reef is home to varied marine species, with some of them yet to be classified. The rare green turtles and 1,000 fish species find their home in this great reef.
Red Sea Coral Reef in the Red Sea
The Red Sea Coral Reef is a world in itself! It exists in between two arid deserts- the Sahara and the Arabian deserts and spreads 1,200 miles long and dates back to more than 5,000 years old. It is home to around 300 coral species and 1,200 fish species. One of the distinctive characteristics of this coral reef system is that it is one of the most robust and most durable coral reefs and can withstand several extreme temperature fluctuations.
Rainbow Reef in Fiji
The Rainbow Reef system exists between the second and third largest Fiji islands of Vanua Levu and Taveuni. The reef gets its name from the kaleidoscope of myriad of vibrant colors that shine up from under the water and has both hard and soft corals- 230 species and around 1200 species of fish. Rainbow Reef of Fiji is one of the famous diving destinations in the world.
Tubbataha Reefs Natural Park
It is a national park and a protected UNESCO World Heritage Site. The Tubbataha Reefs Natural Park is an underwater world with beautiful hued corals and marine species. Located in the Philippines, it is a popular diving destination of the world and home to around 600 fish species, 360 varied fishes, 11 shark species, 13 dolphin species, and a lot of marine life. The system comprises two coral atoll reefs and has deeper lagoons and two coral islands.
Raja Ampat in Indonesia
The Raja Ampat coral reef system is a biodiversity hotspot and an underwater habitat of diverse marine life. There are 450 species of reef-growing and thriving corals and they stand out as the largest biodiversity coral ecosystems in the world. Scientists and marine campaigners are on the move to protect this rich biodiversity coral system as more and more coral reefs of the world slowly extinguish. The Raja Ampat exists in the Coral Triangle, comprising 75% of rich coral species and 1,427 fish species. It is also a diving hotspot for divers from across the world.
Palancar Reef in Mexico
A diver’s paradise, the Palancar Reef exists on the coast near the island Cozumel in Mexico. The coral reef system is a multicolored wonder with different hues (bright pinks, greens, oranges, and yellows) of marine flora and fauna species. Palancar Reef is itself a part of a larger reef ecosystem- the Mesoamerican reef system. The reef system is a house to exotic fish species like the butterfly, squirrel and parrotfish, seahorses, and sea fans.
Great Chagos Archipelago in the Indian Ocean
The Great Chagos Archipelago system exists in the Indian Ocean and spreads across 55 islands. It is the largest coral atoll existing in the world and the least polluted system. The system houses around half of the world’s coral population with endemic varieties like the Stenella chagius present here. Stenella chairs coral resembles the look of a brain. The great Chagos Archipelago is also a habitat for large fish populations and other marine species like turtles, dolphins, and whales.
Wakatobi Islands in Indonesia
The Wakatobi National Park exists in the Coral Triangle near the southeast portion of Sulawesi in Indonesia. Spreading across 1.39 million hectares, it has around 750 coral reefs and gives a spectacular sight with the turquoise-colored water flowing around it. The reef system is a UNESCO World Heritage Site and is a habitat for around 942 fish species.
Lord Howe Island in Australia
The Lord Howe Island is a marine national park and a UNESCO World Heritage Site located in the Pacific Ocean. It towers onto the water’s surface and under the water into the depths with vibrant-hued coral reefs. The Lord Howe Reef is a habitat for diverse marine species with more than 90 coral and 500 fish species.
Belize Barrier Reef in Belize
A UNESCO World Heritage Site, the Belize Barrier Reef Reserve System is the most significant barrier reef of the Northern Hemisphere. In addition to rich marine life and coral species, the system also has several coastal lagoons and rich mangrove forests. There are around 106 hard and soft coral species existing here and 500 fish species. However, this reef system is under threat, and around 40% of it is already damaged. Marine biologists are making constant efforts to save this precious coral reef system.
The distinctive feature of the Belize Barrier Reef is the Great Blue Hole, an enormous underwater sinkhole that depths down 124 m into an underwater cavern. The area attracts the most significant number of sharks like nurse sharks, hammerhead sharks, and blacktips. Also, divers from across the world visit the coral reef system and the blue hole to deep dive into the dark blue waters and explore its grandeur.
Apo Reef in the Philippines
It is spread across 13 miles long, and the Apo Reef system exists in the South China Sea on the Mindoro Strait. The second-longest coral reef system of Earth, it has exotic colored coral reefs and rich marine species like triggerfish and sea turtles thriving on the coral system. The coral lists on the current tentative list of UNESCO for a World Heritage Site status. Apo Reef has a designated National Park status and lists among the most protected coral species of the world.
Bonaire Reef in Dutch Caribbean
The Bonaire Reef of the Dutch Caribbean is famous as the ‘The Diver’s Paradise’ and consists of hard and soft corals in vibrant blue, green, yellow, purple, and exotic pinks. Thanks to the crystal clear water that surrounds it, the reef system is visible from the surface. It is a habitat for some rich marine species like angelfish, groupers, sea turtles, and seahorses.
The Grand Central Station and Chimneys in Fiji
The Grand Central Station and Chimneys coral system of Fiji is famous as the world’s ‘soft coral capital.’ It has two coral towers with soft corals flourishing in vibrant colors. The Grand Central Station is famous for varied marine life manta rays, marble rays, and hammerhead sharks. With 400 corals species, around 445 documented aqua plants, and more than 100 invertebrate species, it is one of the treasured coral reef systems of the world.
Coral reefs are undoubtedly the beautiful treasures of the aqua world. They stand as a robust foundation of underwater marine life and ecosystems and offer habitat and food to different marine species. Plan your next trip to these exotic marine ecosystems and feast your eyes on the stunning underwater treasures of Earth.