Context

Researchers have discovered way to measure the quantity of chlorophyll-a in the Bay of Bengal, a dominant pigment found in phytoplankton cell and present in a few areas of the ocean, in real-time. 

About

What are Phytoplanktons?

• Phytoplanktons are tiny microscopic plants found in the ocean. They are important ecological indicators that regulate life in ocean.
• They have chlorophyll to capture sunlight, and use photosynthesis to turn it into chemical energy. They consume carbon dioxide and release oxygen.
• All phytoplankton photosynthesise, but some get additional energy by consuming other organisms.
• Like terrestrial plants, the eco-friendly phytoplankton is largely dependent on light, temperature and nutrients.

Key-findings of the Study

• The findings were published in journal Environmental Science and Pollution Research.
• The study was based on in-situ and satellite data spanning over the last 16 years.
• They observed significant increase of chlorophyll-a concentration during pre-southwest monsoon seasons.
• The other parameters studied were total suspended matter (TSM) and coloured dissolved organic matter (CDOM), which are optically active substances in water.
• There were two peaks of chlorophyll-a —
  • the primary peak occurred during the pre-southwest monsoon due to the recurrent phytoplankton bloom in the coastal water
  • the secondary peak occurred during the end of the southwest monsoon, spreading to far offshore areas.

Major controlling factors for the abundance and distribution of phytoplankton

• Salinity and nutrients: The study area experienced maximum spatial variability during pre-southwest monsoon with salinity and nutrients — the major controlling factors for the abundance and distribution of phytoplankton.
• Physical forces: Apart from phytoplankton bloom contributing to this increase of chlorophyll-a in nearshore waters, the study found physical forces such as upwelling, wind-induced vertical mixing, convective overturn and local circulation pattern influenced the peaks by supplying dissolved chemical input.

How Phytoplanktons are ‘beneficial’ for the environment?

• Phytoplanktons contribute to more than half of the oxygen that we breathe.
• That apart, they influence our climate by absorbing human-induced carbon dioxide, a heat-trapping greenhouse gas.
• They also serve as the foundation of the aquatic food web.