Deep sea systems

Mesopelagic zone (200-1k m): Light is faint, not enough to support photosynthesis. Animals at this depth include octopus, squid and hatchet fish. Bathypelagic zone (1-4km): No light penetrates this deep, so it is extremely cold and completely dark. About 1% of all ocean species lives in this zone. Abyssopelagic zone (4-6km): Water temperatures border on freezing (pressure avoids ice formation). Very few creatures live this deep. Hadalpelagic zone (6-10km): Enormous pressure of around 1.1 tonnes per square centimetre.