8. Ocean Zonation
The ocean can be divided into many zones. The ocean bottom is the
(1)benthic zone and the water itself (of the water column) is the (2)
pelagic zone. The (3)neritic zone is that part of pelagic zone that
extends from the high tide line to an ocean bottom less than 600
feet deep. Water deeper than 600 feet is called the (4)oceanic zone,
which itself is divided on the basis of water depth into the
(5)epipelagic, (6)mesopelagic, and (7)bathypelagic zones.
These zones roughly correspond to three other zones divided on the
basis of the amount of sunlight they receive. In the (8)euphotic
zone, enough light penetrates to support photosynthesis. Below
that lies the (9)disphotic zone, where very small amounts of light
penetrate. 90% of the space in the ocean lies in the (10)aphotic
zone, which entirely devoid on light.