A team of American and Indian scientists say climate change is the likely reason for the curious, glow-in-the-dark waves washing up on Mumbai’s beaches in recent years.

A year-long study by scientists at the Indian National Center for Ocean Information Services (INCOIS) and the National Oceanic and Atmospheric Administration recently found that global warming may be fueling the growth of a bioluminescent marine plankton called Noctiluca scintillans that is harmful to the fish population. Fish are dying in large numbers in the northern Arabian Sea.

“Less dense water comes to the surface because of the warming of oceans, encouraging these intense blooms, which has an adverse impact on fisheries. Currently, the western coast, Persian Gulf, and Oman are largely affected, but if it keeps on increasing, it will have drastic effects on fisheries along the Indian coast.  That could be alarming,” S.C. Shenoi, director of INCOIS, told the newspaper Mint.

Other scientists have linked the appearance of the neon-blue waves to the dumping of fertilizers and waste along India’s western coast, which caused the death of fish and other wildlife.

Blooms of Noctiluca scintillans, commonly known as “sea sparkle,” form patches that appear to glow at night. The phenomenon has been observed in recent years along Mumbai’s busy Juhu Beach, but the neon-blue patches have also been seen along beaches in China last year and in Hong Kong in 2015.

“Unfortunately, these beautiful patches indicate zones of decline because fish cannot thrive and sometimes die because of these blooms,” the study said. The organism is harmful to fish because it competes with them for food and chokes their supply. It also excretes large amounts of ammonia, which can be deadly for fish.