The open ocean, or pelagic zone, is divided into several layers, based on depth. The first layer is the epipelagic, which extends down to around 200m, which is also around the lowest depth that light can penetrate. This is the layer that people know most about, as it is relatively easy to explore with conventional diving equipment. In the epipelagic, the fish, sea mammals, and other sea life that most people are familiar with are found, even if they can be a little weird. Because it's so familiar, we're not going to talk anymore about this layer.

The other layers are where the really neat stuff is found!

To learn about some representative organisms in these other layers and the adaptations they need to survive there, click on the ocean layer you want to investigate.

The Bioluminescence Web Page

Deep Sea Beastiary

Sea and Sky: Monsters of the Deep

National Geographic's Deep Sea Critter Cam

Dive and Discover! Expeditions to the Sea Floor!

OceanLink's Questions and answers about the Deep Sea

  to marine biodiversity index