Ocean Zonation

Pelagic Zone

• Water Environment• Divided into the Neritic Zone and Oceanic Zone

Oceanic Zone

• Open ocean away from the direct influence of land

Neritic Zone

• Coastal zone or the sublittoral zone.

• Shallow water zone where light

penetrates to the bottom.

Benthic Zone

• Sea Floor Environment

Epipelagic

• A.K.A.:Photic, Euphotic or Sunlit Zone• Depth: approximately 200 meters deep• Depends on the turbidity of the water• General Characterisitics: Top of the ocean. Generally

receives lots of sunlight and relatively warmer temperatures. High D.O.

• Energy and Producers: the main source of energy is the sun. Phytoplankton and macroalgae are the main producers but there are a few marine plants as well.

• Organisms Adaptations: countershading- light on bottom and dark on the top.

Mesopelagic• A.K.A.: Disphotic or twilight zone.• Depth: 200- 1000 meters• General Characterisitics: receives some sunlight. Contains the

thermocline and is between 4-20 degrees Celsius. Pressure can be up to 1,470 psi. Less D.O. than the photic zone

• Energy and Producers: Not enough sunlight for photosynthesis. Relies on plant matter and algae that fall into the zone “marine snow”. Most animals are predators and prey on others in the zone.

• Organisms Adaptations: Large eyes, small, dark and thin. Bioluminescence is used to lure prey and for camouflage. Counterillumination: lit on bottom not lit on top. Large teeth and jaws.

Bathypelagic

• A.K.A.:Midnight or Aphotic Zone• Depth: 1,000- 4,000 meters• General Characterisitics: No sunlight. Temperatures

are nearly freezing. The pressure is extremely high• Energy and Producers: No photosynthesis.

Organisms rely heavily on organic matter that drift down from the photic zone. Most organisms are predators and scavengers.

• Organisms Adaptations: Colored red and black for camouflage.

Abyssopelagic

• A.K.A.: The Abyss, Midnight Zone (Greek- for no bottom)• Depth: 4,000 – 6,000 meters• General Characterisitics: No sunlight. Temperatures are

nearly freezing. The pressure is extremely high up to 11,000 psi

• Energy and Producers: No photosynthesis. Chemosynthesis can occur here (producing sugars from chemicals instead of sunlight). Most organisms are predators.

• Organisms Adaptations: Colored red and black for camouflage.

Hadalpelagic Zone

• A.K.A.: The Hadal Zone or Trenches (Greek- named after the god Hades)

• Depth: 6,000 to -10,000 (deepest is the Mariana Trench 10,911 meters)

• General Characterisitics: No sunlight. Temperatures are nearly freezing. The pressure is extremely high up to 16,000 psi

• Energy and Producers: No photosynthesis. Chemosythesis can occur here (producing sugars from chemicals instead of sunlight). Most organisms are predators.

• Organisms Adaptations: have to withstand extreme pressure. Dark or clear. Mostly invertebrates

Intertidal/Littoral Zone

• A.K.A.: • Width: From high tide to low tide• General Characterisitics: at times it is

submerged and others it is exposed. High D.O. and nutrients. Lots of Sunlight

• Energy and Producers: Photosynthesis, mainly algae and some plants

• Organisms Adaptations: remember from the tide notes.

Subtidal/Sublittoral/Neritic Zone

• A.K.A.: the coastal zone• Width: extends from the low tide mark to the shelf

break, the outer most edge of the continental shelf. (avg. 150 meters)

• General Characterisitics: Lots of sunlight and nutrients. High D.O.

• Energy and Producers: Photosynthesis. Phytoplankton and macroalgae (kelp).

• Organisms Adaptations: Epifauna: live on top of sediment and Infauna: burrow or dig in sediment