The mystery behind the bright, florescent green water in the Venice Canal has been solved.
The neon stretch of liquid appeared near the Rialto Bridge in the famed Grand Canal on Sunday morning, puzzling onlookers and baffling city officials.
The Regional Agency for the Environment in Venice said the water-color-change was caused by fluorescein, a non-toxic chemical used to identify leaks during underwater construction. The ecologically harmless chemical was originally developed by NASA.
The Italian agency believes the amount of the chemical points to it being a deliberate act, though it was not immediately clear who was responsible and the exact quantity of the substance is unknown. There has been speculation it was a stunt by environmental activists.
Earlier this month, the Italian environmental group Ultima Generazione dumped black liquid into the Trevi Fountain in Rome as part of a protest against fossil fuels. The group denied any involvement in the Venice incident.
Tests are expected to continue as the investigation unfolds in Venice.
The canal changed color because of fluorescein once before. In 1968, Argentinian artist Nicolás García Uriburu dyed the waters of the canal with the chemical during the Venice Biennale — the city’s annual cultural festival — to raise awareness of ecological issues. The dye gradually disappeared during low tide.