The panel formed by the National Green Tribunal (NGT-South) to probe the cause of the sea turning red at Promenade Beach in Puducherry in October and November 2023 has attributed the phenomenon to plankton crash.
- As per a study, the majority of a particular unicellular species of phytoplankton — Noctiluca scintillans — in the sea were found ruptured, leading to the release of red pigment into the sea.
- The conditions were right for quick gathering of these planktons. This plankton, which turns a red color when in large numbers, experiences a crash, leading to the release of colored pigments from their cells.
- These pigments then stick to rocks and the sea floor, forming a biofilm-like layer and causing ‘red tides’.
- Supporting his findings, water samples showed the red color was not from man-made sources. Iron levels were high, which promotes plankton growth in the absence of enriched nutrients.
