Phytoplanktons, the grasses of the sea, are single-celled organisms living in the southern ocean. They nourish and sustain the entire ocean’s food chin, being first link in the food chain of ocean. Using sun’s energy, they assimilate carbon and synthesize organic compounds.
The diminishing number of these organisms due to the depletion of ozone layers affects other organisms of the ocean, finally leading to the extinction of life on earth.