ECOSYSTEMS > OPEN SEA

As you continue your downward journey through the ocean waters, you reach an area of near total darkness called the Twilight Zone. Light can still penetrate into these deep waters, but it’s so weak as to be invisible to the human eye. In fact, the scientific name for this zone is the Disphotic Zone — “disphotic” meaning “poorly lit” in Greek. Here the ocean appears to be a dark blue to black void. It’s impossible to judge distances and sizes, or sometimes up from down. In fact, floating in the Twilight Zone may be as close as you can get to experiencing the vacuum of space without leaving the Earth’s atmosphere.

Where the Twilight Zone begins can change from place to place, depending on the murkiness of the water. In most cases, the zone will begin at about 600 feet (182.8 m), just at the edge of light’s ability to penetrate sea water. If the water’s filled with silt, plankton or other matter which limits light, then the zone can begin at depths as shallow as 50 feet (15 m). The zone can extend down as deep at 3,300 feet (1,000 m).

Features Related to the Twilight Zone:

Riddle of the Coelacanth: Once thought extinct, then considered a species which had escaped evolutionary change, the Coelacanth is both a fascinating and mysterious resident of the deep ocean.

Whales, Dolphins and Porpoises of Oregon: From the massive blue whale to the diminutive harbor porpoise, this identification guide contains beautiful illustrations of each species and is a great research tool for students, teachers or just anyone who loves whales, dolphins and porpoises.

Earth: The Ocean Planet: Seen from space, the Earth is clearly a world of water. In fact, life here simply wouldn't exist without this one huge, interconnected ocean.

Representative Species of the Twilight Zone:

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