Descend into a cold, dark world filled with some of Earth's strangest life.
Below the sunlit surface lies an enormous environment where light becomes scarce and water pressure increases dramatically. Deep-sea organisms survive through special adaptations that help them find food, communicate, and reproduce under challenging conditions.
Explore what happens as sunlight disappears beneath the ocean surface.
Learn MoreLearn why water pressure becomes enormous in the deepest parts of the sea.
Learn MoreDiscover animals that create their own light through bioluminescence.
Learn MoreMeet anglerfish, giant isopods, squid, and other unusual animals.
Learn MoreSee how ecosystems can thrive around hot mineral-rich water on the seafloor.
Learn MoreVisit the narrow underwater valleys containing Earth's deepest ocean waters.
Learn MoreDiscover the vehicles and robots scientists use to study extreme depths.
Learn MoreSunlight weakens as it travels through seawater. Far below the surface, the ocean becomes completely dark except for light produced by animals or exploration equipment. Because plants need sunlight for photosynthesis, ordinary plant life cannot grow in the deepest ocean.
Water has weight, so the pressure increases as an animal or submarine travels deeper. At great depths, pressure can be hundreds of times stronger than at the ocean surface. Deep-sea animals have body structures and chemistry adapted to conditions that would be dangerous for most surface organisms.
Many deep-sea animals can produce light through chemical reactions in their bodies, a process called bioluminescence. They may use light to attract prey, hide their silhouette, communicate with others, or confuse predators. In the dark ocean, even a tiny flash can be important.
The deep sea contains animals with extraordinary adaptations. Anglerfish may use glowing lures to attract prey, while some deep-sea fish have very large mouths and expandable stomachs. Squid, jelly-like animals, crustaceans, sea cucumbers, and many other organisms also inhabit deep waters.
Hydrothermal vents form where seawater interacts with hot rock beneath the ocean floor. Instead of relying directly on sunlight, microorganisms near vents can obtain energy from chemicals in the water through chemosynthesis. These microorganisms support communities that may include tube worms, crabs, snails, and other animals.
Ocean trenches are long, narrow depressions in the seafloor, often created where one tectonic plate moves beneath another. The Mariana Trench contains the deepest known part of the world's ocean. Even these extreme places contain living organisms adapted to tremendous pressure.
Scientists explore the deep sea with crewed submersibles, remotely operated vehicles, autonomous robots, sonar, cameras, and sampling equipment. These tools allow researchers to observe animals and seafloor features without sending divers into dangerous conditions. Large areas of the deep ocean remain poorly explored.