The National Centre for Coastal Research (NCCR) has attributed the harmful algal bloom, resulting in a reddish tinge on the northern side of the Promenade Beach in Puducherry on October 17, 2023, to anthropogenic influences.
- Harmful algal blooms (HABs), occur when colonies of algae — simple plants that live in the sea and freshwater — grow out of control and produce toxic or harmful effects on people, fish, shellfish, marine mammals and birds.
- The human illnesses caused by HABs, though rare, can be debilitating or even fatal.
- The anthropogenic influences includes sewage mixing into the sea, besides the reversal of ocean currents and an increased concentration of nutrients in the coastal waters.
- There has been a reversal of currents from the north to the south, and it mixed with the sewage from the north.
- This resulted in a high concentration of nutrients in the coastal waters, which is possibly the cause behind this phenomenon.
- Algae grows with the increased presence of nutrients in the coastal waters.
