Whoever named the sea cucumber after a vegetable didn’t give it enough credit. Yes, sea cucumbers are soft, warty tubes that scoot eyelessly along the seafloor. But they aren’t helpless. Some secrete a poison that’s deadly to other animals. And some, when threatened, shoot sticky threads out of their anuses to tangle up predators.

Mud-dwelling organism that lives head down in a tusklike tube found alive for first time, although its existence had been known of for centuries

‘Last year was bad enough, this is a disaster,’ says one expert as Australia Research Council finds fresh damage across 8,000km.

So you've been stung by a jellyfish. The good news: there's no need to get your friend to pee on you. The bad news: all the other solutions you've heard of will probably only make it worse.

ENVIRONMENT -- I took a lot of grief and criticism in October from around the world, perhaps not totally undeserved, for promoting an obituary for the Great Barrier Reef. This week, the science journal Nature and The New York Times are suggesting the notion isn't...

There were startling colors here just a year ago, a dazzling array of life beneath the waves. Now this Maldivian reef is dead, killed by the stress of rising ocean temperatures. What's left is a haunting expanse of gray, a scene repeated in reefs across the globe in what has fast become a full-blown ecological catastrophe.

The film "Aliens of the Lembeh Strait" by Sascha Janson won Gold in the video category of the 2017 Our World Underwater International Imaging Competition.

There are plenty of mammals that have adapted to life in water, some more than others. That meant they also had to adapt the way they feed.

Last year, scientists declared a decades-old mystery solved - that bizarre monstrosity you see in the image above had for years defied classification, but two separate studies said they finally had solid evidence that it was in fact a vertebrate.

A large research synthesis, published in one of the world’s most influential scientific journals, has detected a decline in the amount of dissolved oxygen in oceans around the world — a long-predicted result of climate change that could have severe consequences for marine organisms if it continues.

Scientists have discovered “extraordinary” levels of toxic pollution in the most remote and inaccessible place on the planet – the 10km deep Mariana trench in the Pacific Ocean. Small crustaceans that live in the pitch-black waters of the trench, captured by a robotic submarine, were contaminated with 50 times more toxic chemicals than crabs that survive in heavily polluted rivers in China.

Nasty chemicals abound in what was thought an untouched environment.

Huge coral system reef where the Amazon River meets the Atlantic Ocean was discovered last year.

Two-year project aims to learn why carcasses have washed up on Argentina’s coast. By Robin McKie.

A female shark separated from her long-term mate has developed the ability to have babies on her own.

A scuba-diving philosopher explores invertebrate intelligence and consciousness.

Photo by David Doubilet.

New Zealand locals reportedly flocked to Muriwai Beach yesterday, to catch a glimpse of the so-called Muriwai Monster - a sprawling mass that looks exactly like something you’d drag up from the depths of the ocean.

Bioluminescent organisms have evolved dozens of times over the course of life’s history. Recent studies are narrowing in on the complicated biochemistry needed to illuminate the dark. By Steph Yin.

More than two-thirds of Australians think the condition of the Great Barrier Reef should be declared a “national emergency” and support much stronger measures to protect it than are now being considered. On Thursday the government released its report on the reef to Unesco, which was a condition of the reef being excluded from the UN body’s “world heritage in-danger” list. The government reported slow progress on the key issue of water quality and the failure of a major plank in the plan – slowing tree clearing in Queensland.