Mumbai: For the second time this year, waves at Juhu beach were lit in ‘neon’ as curious onlookers gathered late on Thursday. The rare natural occurrence, in which the water turn a fluorescent blue, is known as ‘bioluminescence’ and is caused by dinoflagellete, a plankton found in coastal areas.
Dr. Anand Pendharkar, wildlife biologist and founder-director of environmental trust Sprouts, said when the plankton lash against each other, they emit light as a reaction to stress caused by water, which lights up the waves in neon blue. Dr. Parvish Pandya, assistant professor of Zoology and vice-principal, Bhavan’s College in Andheri, hotfooted it to the beach after a student, Nilesh Mane, called him a little after 9 p.m. on Wednesday. “This lovely phenomenon is a must-see for Mumbaikars,” he said. “”It can surface anywhere, and that’s the mystery.”
Zoology student Abir Jain, 21, experienced the neon waves first-hand in January. “One night, a friend from Juhu sent an image of the waves on WhatsApp and asked me what it was. At first, I thought she was playing a prank, but on visiting the beach, I came across this fascinating experience, romantic in its own way. The Juhu skyline and the waves were adding up to a mesmerising effect.”
This phenomenon is not common on the West coast, and was visible in January after a very long time, he said. “The National Geographic Traveller reported these images first, and shared it on Facebook.”
Mr. Jain collected samples for research, and it led him to a species called Noctiluca, commonly known as sea tinkle, a non-parasitic marine-dwelling species of dinoflagellate that shows bioluminiscence when disturbed. “This occurs when they get disturbed by a harder surface. They get heated up and agitated,” he said.
Nilesh Mane, 22, a city lad studying Ecology and Environment Conservation at n Pondicherry University, also witnessed the phenomenon in January. “This generally happens during the full moon and when there is a change in the water current. The micro-organisms get hit and come up. But in the end, they die, since they are very sensitive,” he said.