Mariana Trench contains 'extraordinary' levels of toxic pollution

What's under the sea will take your breath away

Lost continent discovered under the African island of Mauritius

Should we stop eating shellfish?

Obama's national monuments are a big deal

Watch the first video of the rare ruby sea dragon

Visit Antarctica's colorful underwater world

2016 was the Arctic's warmest year on record 'by far'

Unknown 'ghost octopus' found 2.6 miles deep

Bizarre Mariana Trench 'alien call' identified

Killer whales vs. shark: Drone footage shows rare attack

The Earth's mountains, rocks and water bodies are ancient. Do you know how old they are?