Diving deep in the Red Sea, researchers discover a dim, blue world.
Corals are tiny animals that live in large communities made up of individual polyps that secrete a calcium carbonate substance that hardens and builds up to form the reef structure over time. There are different types of corals, such as brain corals and fan corals, that form different types of structures. The coral polyps live symbiotically with algae that provides them with their food. Disease, temperature extremes and pollution can cause corals to expel the algae, leaving only the white calcium carbonate skeleton behind, an event called coral bleaching. Coral bleaching is a worry with global warming heating up the oceans and carbon dioxide causing the oceans to acidify. Coral reefs are important ecosystems because they support larger communities of fish, mollusks, crustaceans and other sea creatures.
A blob of a coral has been caught violently pulsating, with tentacles wriggling every which way, as it ejects its algal residents in a time-lapse video of the phenomenon called bleaching.
Scientists are glimpsing how microscopic marine creatures move through their underwater environment and interact with each other in the ocean.
Thanks to an underwater microscope and computer interface that can be operated by a diver, researchers are glimpsing activity of coral polyps up close and in unprecedented detail.
A massive reef system lurking in the mouth of the Amazon River hides a hidden menagerie of strange and wonderful underwater creatures.
Australia's Great Barrier Reef corals are in trouble, with the northern part of the reef experiencing "the worst mass bleaching event in its history."
For only the third time on record, coral bleaching is occurring across the globe and climate change is to blame.
Aquarium enthusiasts and people who work in aquarium stores should be aware that some types of coral produce dangerous toxins.
Deep in the Red Sea, beyond the reach of most scuba divers, coral reefs are putting on a glowing, colorful show, scientists have discovered.
New evidence reveals that the ancient coral tombs of Leluh in Micronesia could be up to 700 years old — much older than previously thought.
Marine ecologist Paul Sikkel discusses his passion for and work with coral reefs and the best ways to protect them.