Oceans cover more than 70% of Earth's surface and contain an estimated 80% of all life on the planet, much of it still unexplored.
Oceans are divided into zones based on depth and light penetration. The sunlit zone supports most marine plant life, while deeper zones are home to bioluminescent creatures.
Though they cover less than 1% of the ocean floor, coral reefs support roughly 25% of all marine species.
The blue whale, the largest animal ever known to have existed, can grow up to 30 meters long and weigh nearly 200 tons.
Scientists estimate that more than 80% of the ocean remains unexplored, hosting unusual creatures such as anglerfish and giant squid.