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.

Chlorophyll Chlorophyll is a pigment or a chemical compound that absorbs and reflects specific wavelengths of light. Chlorophyll is found within cells in the thylakoid membrane of an organelle called the chloroplast. The primary pigment of photosynthesis is chlorophyll A. Chlorophyll A absorbs light from the orange-red and violet-blue areas of the electromagnetic spectrum. Chlorophyll A transfers energy to the reaction center and donates two excited electrons to the electron transport chain. Chlorophyll B is an accessory pigment because it is not necessary for photosynthesis to occur. All organisms that perform photosynthesis have chlorophyll A, but not all organisms contain chlorophyll B.

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.