Learn about deep water corals and the coral gardens they slowly build in the dark

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....

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

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

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 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.

View a collection of glass sculptures of corals threatened by fishing and deep-sea mining

In "Depicting Dark Waters," British sculptural model maker Alice Baker depicts European cold-water corals, which make up 65% of all known coral species, to raise awareness of deep-sea ecosystems threatened by commercial and industrial activities. The project involved a collaboration with marine biologists from the Netherlands and Sweden.

The origin of the symbiotic relationship between corals and the algae that feed them

An analysis of fossilized reefs from northern Africa and Germany suggests that shallow water corals and photosynthetic algae formed a mutualistic partnership between 419 and 359 million years ago. The discovery was made by analyzing nitrogen-isotope ratios in the fossils, which differ depending on whether algae are present, due to various chemical processes.

Overview: All about coral reefs

Coral reefs aren’t just vibrant underwater landscapes; they are also some of the most biologically diverse ecosystems on Earth. The National Oceanic and Atmospheric Administration (NOAA) offers a comprehensive guide that explores coral reefs in...

Watch a time-lapse of hard coral growth, which forms coral reefs

Over several weeks in an aquarium, these staghorn coral polyps grew and produced new polyps as they deposited calcium carbonate, which forms the basis of coral reefs. At the 0:28 mark, you can see coral growth healing a damaged branch.

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.

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.

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

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

Read about coral reef restoration efforts, from coral IVF and cryopreservation

Researchers have collected coral eggs and sperm from healthy reefs, grown baby corals in lab pools, and released them to help repopulate damaged or lost reefs. Devices such as Coralclip® help attach these corals to existing structures, promoting growth without the use of chemical bonding agents. Corals near extinction can be frozen using liquid nitrogen for future restoration efforts.

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.

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.

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 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.

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.

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.

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

Fossils form in environments where dead organisms can be rapidly buried

Such landscapes enable corpses to be encased by terrain before significant decay occurs. They are most commonly found in river deltas and sinking coastal regions, where sediments accumulate over time until geological forces expose the areas to erosion, revealing embedded fossils.

The deep-sea fangtooth has the largest teeth of any marine species relative to body size

From transparent fish to the heaviest worms on the planet, these seven creepy creatures lurk in the deep sea. Learn all about them and the unique traits that help them survive and hunt.

Learn how to build your own vivarium

Creating a self-contained habitat for plants and microscopic animals requires a careful balance of organisms that maintain a cycle of water, nutrients, and other chemicals throughout. Bottlenecks in these cycles are mitigated through careful construction, such as incorporating a drainage layer to effectively manage water.

Meet siphonophores, breathtaking jellyfish-like organisms

Siphonophores are colonial jelly-like creatures made up of specialized segments that work together as one. They're fairly unknown despite being a significant sea predator. Sink into their strange beauty with this video.

Distinguishing the three types of mineral deposits collected via deep-sea mining

The greatest interest is in polymetallic nodules—structures formed from metals in seawater collecting around a core of shell, bone, or rock. Cobalt-rich ferromanganese crusts cover underwater mountain ranges and form over millions of years of metal deposition. Polymetallic sulfide deposits accumulate when seawater seeps into volcanic rocks.

Deep-sea trenches form when one tectonic plate subducts another underwater

Oceanic plates sink when colliding with less dense continental plates, bending the seafloor into steep depressions that can be almost 11 kilometers deep. Many of Earth’s strongest earthquakes occur at these plate boundaries, often featuring volcanic activity.

The ocean's ability to store carbon long-term is being hindered by marine heatwaves

More than 4,000 robotic floats with biogeochemical data sensors, including oxygen, pH, nitrate, suspended particles, chlorophyll, temperature, and conductivity, have been deployed as part of the Global Ocean Biogeochemical Array. They have identified changes to ecosystem structure affecting the ocean's ability to transport carbon from surface waters into the deep.

Massive blooms of microscopic plankton called dinoflagellates produce the neon blue light seen in glowing tides.

Scientists discover what looks like an underwater road

Crew aboard the Exploration Vessel Nautilus discvered a “yellow brick road” that looks it leads to Atlantis. Climage change may affect future ocean studies.

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

Learn about the construction of the undersea fiber optic cables carrying internet data

Over 750,000 miles of fiber-optic cables run along the seafloor, serving as a freeway for the Internet's data. Despite subsea cable projects costing hundreds of millions of dollars, depending on the length of the cable, it remains the fastest and most cost-effective way to send information.

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.

Planarian flatworms are small, aquatic worms with exceptional regenerative capabilities. When cut, the worms can regenerate multiple bodies in a matter of weeks.

What can be found underneath the Saharan sands?

Watch this 19-minute video to learn more about what can be found under the Sahara Desert, which spans almost all of northern Africa and is one of the largest deserts in the world. Deep under the Sahara desert sands lies evidence of life that once...

Waves off the coast of Nazaré, Portugal, can reach over 100 feet and are caused by the area's deep underwater canyon geography

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.

Most of the observable universe's volume consists of voids and supervoids—enormous regions of space with little to no galaxies, stars, or light.

In 1963, a basement renovation in Turkey revealed a passageway to a hidden, multilevel underground city that once housed as many as 20,000 people

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.

Larger animals like giraffes, elephants, and blue whales have developed a unique defense against cancer, a phenomenon known as Peto's Paradox

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.

Crows are believed to have intelligence on par with a seven-year-old child and demonstrate complex behaviors, from problem-solving with tools to recognizing human faces.

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.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

The Dracula character, now seen as the vampire archetype, was inspired by a seafood-induced nightmare its creator experienced.

Hedge funds, the private investment firms that trade a wide swath of financial assets, make money by imposing steep fees on investors and from the fund's investment performance.

Electrical grids worldwide must double their power delivery capacity by 2050 to meet surging demand from AI and electric vehicles.

Children are now three times more likely to say they want to be a YouTuber when they grow up than an astronaut, with some even attending 'YouTube camps' that teach kids how to create content for the platform.

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.