In Kochi, all roads currently lead to Kumbalangi. The postcard-pretty fishing village, approximately 15 kilometres from Ernakulam, has been hosting a natural neon party. The vast stretches of shrimp farms lined along with the backwaters have been shimmering in bioluminescence, a phenomenon that makes it glow in electric blue and fluorescent green sparkles in the night.

It is 11pm in Chellanam, another fishing village close to Kumbalangi, and it is teeming with people armed with long sticks and mobile phones. Some disturb the surface of the water with sticks, some splash about in the water and some even dive into it, leaving a trail of luminescent waves behind them, all the while capturing it on camera for their Instagram feeds.

Known as ‘kavaru’ in Malayalam, the phenomenon has been going on for the past few weeks making for a busy time for Kumbalangi and the surrounding regions with people coming in from across Kerala and outside, to witness the glowing waters. Ask for directions once you reach Kumbalangi and people instantly enquire: “Are you going to see the kavaru?”

Popularised by Instagrammers, the crowds have increased this year, say locals — some even put the unofficial number of visitors at five lakh. One of the biggest hits in Malayalam cinema, Kumbalangi Nights (2019), which featured the bioluminescent waters has also contributed to this sudden excitement.

However, for the locals, it is nothing unusual. “We have seen this all through our growing years. When we take the country boat out into the water at night during summers and cast the net, the water lights up from within, as if it has a hundred light bulbs inside. Remember that scene from Life of Pi ? It was very much like that,” says Jayaraj N M, who runs a small business and lives on Kareethara island which has only about nine houses.

“Usually, the bioluminescence vanishes with the first rain of the season. This year, we have not had summer showers, maybe that is why we still see this,” he adds.

Algal bloom

According to an official in the Central Marine Fisheries Research Institute (CMFRI), Kochi, the phenomenon is caused by dinoflagellate algae ( Gymnodinium sp.), which have luminescent properties. Any movement on the surface of the water — waves, a sudden surge, fish swimming, or a disturbance on the surface of the water can trigger the luminescence.

A combination of environmental factors leads to the multiplication of the algae in a particular area. Nutrient-rich water, favourable temperature and salinity causes the algae to multiply at a faster rate. changes in wind, and current patterns, level of nutrients or any other factors in the water can alter the multiplication of the algae.

Kumbalangi — one India’s first eco-tourism villages — has been successful in tapping its tourism potential for the welfare of the local community that is dependent on fishing and allied activities.

“We get a good crowd on weekends, but in this ‘kavaru’ season, the numbers have multiplied. The region has come under the spotlight with people coming in the evening to see the Chinese fishing nets being hauled up, and staying up till the wee hours to see the ‘kavaru’,” says Baiju Vijayan, one of the partners of OMKV Food Village, which serves seafood and other local delicacies in Kumbalangi.

The influx of ‘tourists’, however, is raising concerns among the shrimp farmers in Kumbalangi. In their enthusiasm to see the sparkle, people have been throwing stones, pieces of wood, which would affect the shrimp in their farms, say the local fish farmers.