Ocean

Lifeguards are flying purple flags to warn beach-goers of the organism that can cause uncomfortable stings and a rash.

Officials cleared up the gelatinous creatures with cleaning boats and even tractors.

About 70 percent of the world is covered by oceans.

Almost a third of coastlines around the world not covered in ice are sandy beaches.

Russia's submersible drone, known to Russia as Poseidon and to the U.S. as Kanyon, may change nuclear warfare as we know it.

How long can you hold your breath underwater? These people can hold theirs for up to 13 minutes.

The video "brilliantly shows the otherness of deep-sea life."

Scientists think the level of plastic is 16 times higher than previously thought.

"Boy, what an advance it would be to be able to see the world in a snapshot."

The mythical land first mentioned by Plato has stirred imaginations ever since.

This dynamic duo is another deadly threat to coral reefs. But people can do something about it.

Russia's Viktor Leonov has been spotted close to the American mainland for the second time in a year.

New York, San Francisco and Oakland are suing oil companies for causing 'catastrophic harm.'

It looks like a shark "that has undergone some kind of diabolical experiment."

But it can still be saved, scientists said.

New findings about the planet's distant past deepen mysteries of evolution.

The ocean can't seem to catch a break—or its breath.

Swimming in plain sight—the frilled giant Pacific octopus.

The pair of whirlpools was discovered spinning across the Tasman Sea.

Bright spots that could be a sign of recent water on the dwarf planet have piqued scientists' interest.

Scientists have a new way of tracking hundreds of new species.

Dozens of species in the reserve cannot be found anywhere else in the world.

It was in the deepest sea trench on earth.

Fluorescent dye could be the answer to finding the ocean's missing plastics.

Animals' natural habitats act as ecological air conditioning.

It's official: Plastic is utterly inescapable.

Scientists have finally figured out why a patch of water in the Pacific Ocean has remained stagnant for the past 1,000 years.

And someday soon, we're going to regret it.

Decades of climate research could be wrong, meaning we're in a much worse situation than previously thought.

"Keep it down out there!" they'd yell if they could.