The visitors at the Thiruvanmiyur beach in Chennai were in for a surprise last week. Known for its clean and picturesque beaches, the people of Chennai were given another reason to flock to the beaches. The newfound reason?  Over the past week, the waters at the beach have gained a blue, almost magical glow. 

Last week, as soon as the news of blue, sparkling waves hitting the shore went viral, so did the social media posts and videos. Bioluminescent waves along the shore were spotted on Sunday night by the visitors at the beach. 

After the initial fanfare regarding the Bioluminescent waves died down, the reason for its occurrence came to light. Caused by a phytoplankton type named Noctiluca scintillans, bioluminescence occurs when they convert their chemical energy into light energy on being washed ashore. As the waves hit the shore, the energy conversion takes place causing it to emit a blue glow on the face of the waves. The phenomenon is commonly also known as 'sea sparkle'.

While the phenomena has occurred before, its sightings have drastically increased recently. Bioluminescent tides were seen in the Maldives in the Indian Ocean last year and has been seen infrequently along coastal California in the Pacific Ocean. In India, the blue glow was also spotted at Eliot’s Beach at Besant Nagar. 

Old-time Chennaiites say the algae used to be a regular phenomenon earlier. “In the 2000s, it was quite common. They would be all over our shoes and pants during our night patrols at the beach. I once saw a crab that had eaten the algae, and it was glowing from inside,” said V Arun, coordinator for the Student Sea Turtle Conservation Network (SSTCN), an informal organisation that patrols an 8-km stretch of the beach at night to safely relocate nests of Olive Ridley turtles. “Since then, it seemed to have died down. However, this turtle nesting season (January - March) we saw a return of the algae,” he added.

The common folk were busy sharing videos and pictures of the beautiful ‘blue-coloured’ waves. However, the unique phenomena instilled curiosity amongst the researchers regarding the reason behind its occurrence.

Many of them are vary against the comeback of the “sea sparkle”. This is because the phenomena has in the past being linked to the warming of ocean currents due to climate change. With the sighting of it in Chennai, it is feared that it has been caused due to a change in the Marine ecosystem. Algae dominance in the ocean signals a death sentence for various other species, with algae dominant areas in the ocean even being nicknamed the “death zone”.

The trigger for the sudden algae boom is believed to be climate change and environmental degradation. Till now, the main causes are considered to be heavy rain, discharge of sewage into the sea and influx of pesticide-laden agricultural run-off into the ocean. This is further said to have an adverse impact on deep-sea fishing as well.

While “sea sparkle” certainly made for a beautiful sight, it also was a harsh reminder that the Earth is bleeding and that climate change is growing on us fast. What was once a once in a blue moon occurrence is not occurring far more frequently than it should be, and it’s a sign that we should do more to save the planet.