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Day 4 – Q 2. The highest concentration of marine life is found in which parts of the ocean? Why?

2. The highest concentration of marine life is found in which parts of the ocean? Why?

2.समुद्री जीवन की उच्चतम सांद्रता समुद्र के कुछ हिस्सों में पाई जाती है? क्यूं?


  • Write a short introduction of 1 or 2 lines
  • Body must include regions of high concentration of marine life with their respective reasons and one example for each region would make your answer complete (diagrams can be included)
  • An apt conclusion


Considering Vertical Distribution:

Surface layer:

  • Also called Photic zone or epipelagic zone which can be upto 100m depending on the latitude.


  • abundant amount of sunlight. The energy is used by phytoplanktons for photosynthesis. Since they are the food source of a large variety of life forms in ocean, living organisms thrive in this region.
  • energy surplus region
  • There is constant mixing of water in this region. Because of this, the temperature remains constant.

Considering Horizontal Distribution:

Continental Shelf


  • Optimum sunlight
  • shallow waters and gentle slope
  • high amount of nutrients coming from the land

Eg: Regions of coral reefs which in turn are home to many different species

Regions where contrasting ocean currents meet


  • high availability of nutrients
  • optimum temperature

Eg: Grand Banks of Newfoundland, The cold Labrador Current mixes with the warm waters of the Gulf Stream here. Best fishing grounds of the world

Regions of ocean water upwelling

Wind-driven motion of dense, cooler, and usually nutrient-rich water towards the ocean surface, replacing the warmer, usually nutrient-depleted surface water

Reasons: The nutrient-rich upwelled water stimulates the growth and reproduction of primary producers such as phytoplankton

Eg: Strong upwelling of California Current system


Climate change and pollution due to high human intervention in the oceans has been the reason for changing balance of ecosystem and biodiversity in the oceans.

Best Answer: Ivjyot Oberoi

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