Marine ecologist Paul Sikkel discusses his passion for and work with coral reefs and the best ways to protect them.
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.
Reef historian Iain McCalman, in Sydney, and reef scientist Stephen Palumbi, in California, are monitoring reef degradation from opposite sides of the planet. They compared notes.
A tenfold increase in protected coral species was announced Wednesday, with 20 new corals added to the threatened species list.
When looking for a place to settle down, young corals and fish use chemical cues to sniff out bad neighborhoods littered with seaweed.
Journey across the province of Palawan, which pokes out to the West of the Philippine Islands like a long finger squashed between the South China Sea and Sulu Sea.
Scientists have unearthed evidence for the oldest animal-built reef in the world, which was built by an ancient filter feeder called Cloudina some 550 million years ago.
One of the world's great coral reef regions protected fish from the ravages of climate change for the past 3 million years.
The amazing diversity of sea anemone, stationary animals that typically live on the seafloor or coral reefs and are related to corals and jellyfish, comes to light in stunning images.
Google street view has added an image of whale sharks and an underwater museum to a set of undersea images of the planet.
Corals rely on the photosynthesis of algae for oxygen. To make sure algae get the light they need, coral tissue traps and redistributes sunlight.
In the clear waters off the coast of Peru, researchers have found a stunning new red coral species that was not previously described by scientists.
Winning photographs, illustration and video from the 2013 International Science & Engineering Visualization Challenge, including cosmic interactions, coral whirlpools and more.