Overview: All about coral reefs

Why are coral reefs important?

Coral reefs are vital ecosystems that millions of people and countless species depend on. This two-minute video from London's Natural History Museum looks at the ecological and economic significance of coral reefs, including their biodiversity and...

Scientists explore innovative solutions to protect coral reefs

As coral reefs are under increasing stress due to climate change, pollution, and other factors, scientists are employing creative solutions to save these crucial marine ecosystems. This National Geographic article explores the various scientific...

The importance of coral reefs since their first appearance hundreds of millions of years ago

Formed from calcium carbonate skeletons deposited by hard corals, some estimates suggest these reefs provide habitats for over a million marine species. Spanning massive areas, coral reefs also serve as buffers against extreme weather, such as tropical storms.

Coral Bleaching

Coral reefs around the world, including the Great Barrier Reef, are undergoing a crisis known as coral bleaching—which threatens both their existence and the ecosystems they support. This comprehensive report from the Australian Museum explores...

An overview of the Coral Triangle, which contains about 76% of global coral species

Spanning the waters of Indonesia, Malaysia, Papua New Guinea, the Philippines, the Solomon Islands, and Timor-Leste, the region contains more than 600 coral species and over 2,200 of the world's coral reef fish species. It sustains 120 million people with food and other resources, as well as a $12B yearly tourism industry.

Discover the economic value of coral reefs, which benefit one billion people worldwide

The National Oceanographic and Atmospheric Administration estimates that US commercial and recreational fisheries valued at $200M depend on coral reefs, which provide up to $1.8B in flood protection by absorbing 97% of wave energy. Combined with the benefits from tourism, US coral reefs provide $3.4B in value annually.

Can coral live in cold water?

Dive deep beyond the sunlit coral reefs, and you'll discover a world of deep-sea corals. This article from the National Oceanic and Atmospheric Administration (NOAA) explores the ecosystems of deep-sea corals found way below the water's surface....

Learn how humans can protect coral reefs

When diving and snorkeling in environments containing reefs, avoid touching reefs, anchoring on them, or using sunscreen with active ingredients harmful to marine life. Properly recycling and disposing of trash in bins helps reduce microplastics and chemicals that can run off into wastewater and into the oceans.

View the three types of coral reefs, categorized by where they form

Fringing reefs—the most common type—are built from coral depositing calcium carbonate onto the seafloor closest to the shoreline. Barrier reefs grow further from and parallel to the shore, while atolls are the result of mid-ocean volcanoes or seamounts eroding away and leaving a lagoon surrounded by reefs.

Corals are themselves not coral reefs—the term refers to the tiny marine invertebrates that build the rigid reef.

How the environmental diversity of coral reefs provides potential medical treatments for humans

As immobile animals, corals and the organisms that live on them have evolved a suite of chemical compounds to prevent disease and ward off predators they cannot outrun. These include antibiotics, antivirals, and powerful toxins that target the nervous system and are studied for applications involving pain management and neurological treatments.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

Explore the history, structure, and species of Australia's Great Barrier Reef with this interactive journey narrated by Sir David Attenborough.

Explore coral reefs in Google's "street view"

Expanding its mission to map the world, Google Maps partnered with The Catlin Seaview Survey to introduce the first-ever underwater panoramas, making oceanic marvels like the Great Barrier Reef accessible to everyone. With Google Maps, the public...

View a media gallery of coral reefs from around the world

Developed by The Ocean Agency, the Ocean Image Bank launched in 2021 with the help of more than 200 ocean photographers, videographers, and science organizations to help engage the public and inspire support for oceans as part of the UN Decade of Ocean Science.

Coral reefs get their colors from zooxanthellae—microorganisms that line corals' digestive tracts and provide them with sugars in exchange for a home within this protective tissue.

The marine animals that rely on coral reefs for habitats, camouflage, and food

Parrotfish and surgeonfish feed on algae that grow on coral reefs to prevent overgrowth while serving as prey for larger fish across the food chain. Reefs also serve as structures for organisms like sea anemones, which provide shelter for clownfish, and homes for invertebrates such as crabs, lobsters, and shrimp, which help recycle nutrients.

The world's largest coral, as seen from space

The world’s largest individual coral colony—measuring over 100 feet wide and 100 feet long—was discovered in the Solomon Islands. This coral is so large it can be seen from space, and is estimated to be between 300 and 500 years old. The coral's size and health provide hope amidst a global coral bleaching crisis, wherein three-quarters of coral reefs have experienced significant bleaching in recent decades. See the photos from space and learn more here.

Explore the animals that populate the depths of the ocean, from fish and coral in the first few hundred feet, all the way down to the bottom of the Mariana Trench.

Artificial coral reefs have been 3D printed from nontoxic, biodegradable terracotta clay, which coral polyps have used as a foundation for rebuilding marine ecosystems.

What animals live in the ocean?

The oceans host an incredible diversity of fascinating species. Oceana's Marine Life Encyclopedia beautifully presents facts and photos of ocean animals from Atlantic Cod to Zebra Sharks.

Coral polyps reproduce via broadcast spawning, where entire reefs simultaneously release reproductive cells for about one hour, once a year.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

38 thought-provoking facts about the ocean

Coral produces its own sunscreen, tsunamis move at 500 miles per hour, one of the loudest sounds ever recorded came from an ice quake, and other interesting facts collected from sources such as National Geographic and NASA.

Underwater nighttime photos capture the ocean's diversity

Self-taught photographer Steven Kovacs explores Palm Beach's ocean after sunset, capturing tiny sea creatures in deep waters. Over eight years, he's dived into Florida's eastern coast, drifting from 0 to 100 feet, photographing rarely seen larval fish. Lacking formal marine biology training, Kovacs collaborates globally to identify species like cusk eels and the female blanket octopus, known for its revealing membrane. Check out his photos here.

Desert wildlife: diverse, threatened, and misunderstood

This article sheds light on the surprisingly diverse wildlife that thrive in deserts, while also highlighting the gaps in human understanding of these ecosystems. Deserts are home to one-quarter of terrestrial vertebrate species—three percent of...

Niagara’s bedrock holds 440-million-year-old coral fossils

The Lockport Dolomite that caps Niagara Falls is composed of fossilized coral reefs from a tropical sea that once covered the region 440 million years ago.

Explore landforms that exist across America's national parks

Landforms are not just scenic vistas; they are geological storytellers that shape ecosystems, climates, and our understanding of Earth's history. In this comprehensive look at landforms from the National Park Service, you will learn not only about different types of American landforms, but you will understand how these geological features are shaped by various forces, how they reveal an area's geological history, and how they influence climate and ecology.

Amazon rainforest facts, species, and threats

The World Wildlife Federation presents a brief overview of the Amazon rainforest, covering key facts like location, size, and importance. An overview of threats includes unsustainable resource extraction, climate change, and poorly planned construction projects.

A list of common questions and answers about hurricanes from NOAA

This FAQ answers many questions hurricane researchers at NOAA have received, sorted by category. The answers provide insights into hurricane classification and naming, forecasting their movement and growth, and tips for preparing ahead of landfall.

A fun, illustrated history of the Jurassic Coast

The 95-mile stretch of coastline along England's southern shores known as the Jurassic Coast is unique in the world due to its clear demonstration of 185 million years of geological history. Now, you can see the story of that formation told in a whimsical, absorbing video created by artist Tim Britton and his pen.

See how each of the more than two million known species relates to each other—and to common ancestors—in this zoomable tree of life.

Biosphere 2 is the largest Earth science experiment ever built

The vivarium—an enclosed system including animals and plants—is sealed from below with 454 metric tons of stainless steel liner and includes an ocean habitat with more than 700,000 gallons of seawater. B2 is visited by 100,000 people yearly, including more than 10,000 K-12 students.

Watch how deep-sea mining equipment collects and processes polymetallic nodules—metal-rich, potato-shaped rocks—from the ocean floor and creates environmentally damaging plumes of sediments.

All rainbows are 'raincircles' caused by water droplets separating white sunlight into a spectrum of colors, but Earth's surface blocks the bottom half of the circle from our line of sight.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

SpongeBob exemplifies Aristotle's philosophy for living well because he understands that happiness doesn't come from external factors like money, recognition, or power.

Scientists can determine Earth's past climate conditions by analyzing air trapped in microscopic bubbles within ice cores—columns of compressed snow layers that build up over hundreds of thousands of years.

The US Constitution is widely regarded as the longest-standing written national constitution still in force—see how it has influenced rights worldwide.

Explore fun facts from the USPS, including unique post office buildings, a stamp that traveled past Pluto, and more.

This poison ivy knowledge quiz—accompanied by photos of the plant's varied forms—may help you identify this common rash-inducing growth.

'Grand Canyon of the Yellowstone,' a work by American painter Thomas Moran, inspired Congress to establish Yellowstone National Park.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.

Louisiana's 'Cancer Alley' is infamous for having some of the highest industrial pollution, toxic air emissions, and cancer risks in the US.

Volcanoes 'die' when their supply of magma runs out, if they are shifted away from their underlying magma reservoir, or if they get clogged by collapsing or their magma cooling back into rock.

The first steps to rebuilding your credit score include getting to know exactly what's on your credit report and figuring out how far you are from the '700 club,' or 'good score' range.

Three Ebola species are responsible for most large outbreaks of the disease, yet the only approved Ebola vaccine is known to work against just one of them.