Question

Where does most of the primary production occur in an ocean ecosystem?

Answer 1

Primary producers are the photosynthetic organisms who trap the sunlight to be stored in organic substances. In open ocean, primary producers are floating phytoplanktons, mainly microscopic algae.

Explanation:

Submerged plants can thrive only near coasts where light penetrates the water. In open ocean, submerged plants can not thrive. As a result, gross primary productivity (GPP= g/sq m/yr) of open ocean is very less; but three-fourth of the earth is ocean and thus oceanic phytoplanktons trap a lot of sunlight.

From the following diagram, it could be concluded that most of the primary production takes place in pelagic zone.