The Divisions of the Ocean Layers and Deep Sea

I. Ocean is Broken Into Different Layers A. Scientists separate the ocean into different layers to study it easier 1. Each layer has specific characteristics 2. Each layer has specific types of organisms

B. There are two major parts to the ocean 1. The Pelagic a. waters of the ocean b. pelagic means water 2. The Benthic a. the “floor” of the ocean b. benthic means substrate

II. The Layers of the ocean Layers of the pelagic water 1. Photic zone – surface to 200m a. part of the ocean that contains sunlight b. layer where most life exists c. primary production of entire ocean - photosynthesis

d. three layers of the photic zone 1. Intertidal zone – zone between high and low tide marks 2. Neritic zone – water over the continental shelf 3. Oceanic zone – includes all other “lighted” waters ***these are all pelagic layers***

2. Disphotic Zone a. zone where light shines, but no photosynthesis occurs b. “twilight zone” 3. Aphotic zone – 200m and down a. completely dark b. NO SUNLIGHT c. layers of the aphotic zone

1. Mesopelagic a. 200m - 1000m b. upper aphotic zone 2. Bathylpelagic a. 1000m – 4000m b. water over the bathyl region 3. Abyssalpelagic a. 4000m – 6000m b. water over the abyssal plains

4. Hadalpelagic a. 6000m – 11000m b. water over and in the trenches ***these are all pelagic layers***

B. Layers of the Benthic 1. Photic Zone Layers a. Littoral Zone 1) floor of the intertidal zone 2) the substrate between low and high tide area b. Sublittoral zone 1) floor of the neritic zone 2) continental shelf; 200m

2. Aphotic zone layers a. bathyl zone 1) floor of the bathylpelagic 2) the continental slope 3) 200m – 4000m b. abyssal zone 1) floor of the abyssalpelagic 2) abyssal plains 3) 4000m – 6000m

c. Hadal zone 1) floor of the hadalpelagic 2) the trenches 3) 6000m – 11000m ****there is a matching benthic zone for most pelagic zones****

Neritic Zone Oceanic zone Mesopelagic Sublittoral zone Intertidal Zone bathylpelagic Bathyl zone Continental slope Littoral Zone Abyssalpelagic Abyssal plains hadalpelagic Hadal zone

Pelagic zone Photic zone Aphotic Zone Benthic