Scientists have noticed an increase in mysterious white water patches in the shallow waters off the Bahamas. The discoloration is caused by fine-grained calcium carbonate, but it is still unclear why it appears in the ocean.

To find out, researchers from the University of South Florida compiled a detailed review of events in Bahamas Shoal. To do so, they used NASA satellite observations from 2003 to 2020.

The team analyzed the images using machine learning. It uncovered a mysterious increase in color variations over the past decade, which peaked in 2015, as well as seasonal patterns in these fluctuations.

Scientists speculate that this data may indicate a link to sporadic microbial reproduction in the ocean or to currents pulling calcium carbonate particles to the surface.