The deep ocean floor is covered with fine sediment known as ooze.

Steve Irwin died after being pierced by a stingray barb.

The Great Barrier Reef is home to thousands of marine species.

Octopuses can squeeze through tight spaces due to their soft bodies.

The Mariana Trench is so deep that Mount Everest could be placed inside it and still be covered by over a mile of water.

Blue whales are the largest animals known to have ever lived.

Many deep-sea fish have transparent or nearly invisible bodies.

Plankton form the base of many marine food chains.

Jellyfish have existed for hundreds of millions of years.