Benthic Zone - Organisation of the Marine Ecosystem

The benthic zone is divisible into sub zones horizontally. These are depicted in a cross section portion of the marine habitat, adjacent to a continent.

The shape of the benthic zone is roughly the form of an inverted hat. The upper most portion is called the,

• Supra littoral zone, comprising the beach down to the edge of the ocean.
• Littoral zone which represents the area between the upper and lower tide levels and is, therefore, also known as intertidal zone. Littoral zone is the shore of the ocean.
• Sub littoral or continental shelf which extends from the littoral zone to the beginning of the continental slope. The continental shelf is the underwater extension of the continent and extends to a depth of 125 to 200 metres.
• Continental slope. The continental slope after some distance forming the
• Continental rise which may be geologically active. This region has canyons and trenches which are subject to underwater eruptions and avalanches. The region of the continental slope and rise together comprise the bathyal zone. The bathyal zone which is 200 metres deep descends rapidly to a depth of 3,000 or 4,000 m. From this the bottom drops for further several thousand metres and levels, off around 6,000 m to form the broad flat
• Abyssal plains where temperature is never above 4°C.