A terrifying sight in ancient waters, the megalodon shark was once the most feared creature in the sea.

With nine brains, blue blood and a talent for camouflage, the octopus is one of the most fascinating creatures in the sea.

Viruses do more than just cause disease – they also influence ecosystems and the processes that shape the planet. Tracing their evolution could help researchers better understand how viruses work.

The ocean is naturally noisy. Here’s what all the buzz is about.

MPAs are a start - but more needs to be done to help protect much-loved species such as Atlantic puffins, bottlenose dolphins and orcas.

Among the dozens of endangered species, is a spiky snail named after The Clash lead singer, Joe Strummer.

The Blob, a long-lasting mass of warm water, sat off the Pacific coast of North America for years, bringing new species to formerly cold waters. What allows some to survive while others fade away?

When conditions are just right in some parts of the Indian Ocean, a type of bacteria will multiply and start to glow. Satellites are helping scientists study these milky seas for the first time.

Warm-blooded fish can swim 1.6 times faster than their cold-blooded relatives.

Scientists watched in real time as rising ocean heat transformed the sprawling reef. It was a harbinger for ecosystems everywhere as the planet warms.