Question

Discuss the main reason for the low productivity of the ocean.

Answer 1

Productivity:

• Productivity is an attribute of the ecosystem and is defined as the amount of organic matter (biomass) produced by the plants per unit time.

Reason for ocean'slow productivity:

1. In aquatic ecosystems, the limiting factor for productivity is light as the producers depend on light which is scanty in deeper layers.
2. The amount of minerals in oceanic water is also low compared to soil in the terrestrial ecosystem.
3. The producers in the ocean ecosystem are mainly free floating phytoplankton, which are either very small or unicellular, compared to terrestrial system in which the producers are big multicellular plants having many chlorophyll containing cells.
4. Photosynthetic capacity is a measure of the maximum rate at which leaves are able to fix carbon during photosynthesis. It is typically measured as the amount of carbon dioxide that is fixed per metre squared per second. The photosynthetic capacity of the terrestrial plants is more compared to very low photosynthetic capacity of the producers of the oceanic ecosystem.
5. Therefore, despite occupying the 70% of the surface of the earth, the productivity of ocean is very low.