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: 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