Hi Aspirant,

• The benthic zone is the layer closest to the bottom of the water body, while the pelagic zone belongs to the uppermost layers of the water body.
• The species living in the benthic area are coined as 'benthos,' and the organisms residing in the pelagic regions are referred to as pelagic organism.
• In terms of the open sea, the benthic zone is characterized by low temperatures, low dissolved oxygen levels, low/no light and high pressures. There is however a gradient in the pelagic zone from top to bottom.
• When we equate the diversity in these areas, the rich pelagic waters have higher diversity than the benthic zone with lower wealth.
• Photosynthesis does take place in the epipelagic zone, but the benthic zone does not get enough light.
• Pelagic food webs are dominated by photosynthesis, while benthic ecosystems are usually powered by detritus drifting from the upper layers.
• No photosynthetic organism can be found in the benthic region; it is inhabited by detritivores and scavengers. Photosynthetic species as well as active predators are dominant in the pelagic zone.
• Most of all creatures in the benthic zone are bottom-dwellers or sessile animals, while all creatures in the pelagic zone are free-living.

Thank you