Oceanographers divide the ocean into different vertical and horizontal zones based on physical and biological conditions. The pelagic zone consists of the water column of the open ocean , and can be divided into further regions categorized by light abundance and by depth. The photic zone includes the oceans from the surface to a depth of 200m ; it is the region where photosynthesis can occur and is, therefore, the most biodiverse. Photosynthesis by plants and microscopic algae (free floating phytoplankton) allows them to URLanic matter from chemical precursors including water and carbon dioxide. It is this upper sunlit ocean that creates the food supply that ultimately sustains most of the ocean ecosystem  . Light only penetrates to a  few hundred meters depth , so the remaining ocean below this is cold and dark. The continental shelf around the edge of the oceans is shallower (a few hundred meters or less) and this region is most impacted by human activity.
Oceanographers divide the ocean into different vertical and horizontal zones based on physical and biological conditions. The pelagic zone consists of the water column from surface to ocean floor throughout the open ocean . The water column is further categorized in other zones depending on light abundance and depth. The photic zone includes the water column from the surface to a depth of 200m , where photosynthesis can occur . This makes the photic zone the most biodiverse. Photosynthesis by plants and microscopic algae (free floating phytoplankton) allows them to URLanic matter from chemical precursors including water and carbon dioxide. This upper sunlit zone of the ocean ultimately sustains most of the ocean ecosystem since that is the origin of the food supply necessary to all life forms . Light only penetrates to a depth of a few hundred meters , so the remaining ocean below is cold and dark. The continental shelf where the ocean touches land is more shallow (a few hundred meters or less) and experiences more impact from human activity.
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from surface to ocean floor throughout
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meaning-changed clarity clarity
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, and can be divided into further regions categorized by
. The water column is further categorized in other zones depending on
coherence
clarity coherence coherence
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by
fluency
fluency fluency clarity
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oceans
water column
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clarity style clarity
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; it is the region
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and is, therefore, the
. This makes the photic zone the
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clarity coherence clarity
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It is this upper sunlit ocean that creates the food supply that
This upper sunlit zone of the ocean
clarity
clarity style clarity
A
since that is the origin of the food supply necessary to all life forms
meaning-changed
meaning-changed meaning-changed clarity
A
depth of a
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D
depth
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this
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around the edge of the oceans is shallower
where the ocean touches land is more shallow
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this region is most impacted by
experiences more impact from
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