Grand Canal in Venice Mysteriously Turns Fluorescent Green

Authorities in Venice are investigating what caused water in the city’s famous Grand Canal to turn fluorescent green.

Venetians woke up on Sunday morning to this unusual sight, while speculation is rife as to what might have caused the water around the famous Rialto Bridge to change color.

The verdant blob grew slowly, according to multiple images posted on social media, which showed gondolas, water taxis and water bus boats skimming through the emerald substance.

🇮🇹 | El agua del Gran Canal de #Venecia se tiñe de verde y nadie sabe por qué.

Las autoridades locales han convocado una reunión urgente para investigar el origen y la causa de lo sucedido. pic.twitter.com/sKR44RfzS3

— ALERTAS RD 🇩🇴 Y EL 🗺️ (@Alertas_RD) May 28, 2023

Theories range from the release of dye to a protest by environmental activists.

City councilman Andrea Pegoraro immediately blamed environmental activists who have been attacking Italian cultural heritage sites in recent months.

The group Ultima Generazione, which poured charcoal into the Trevi Fountain in Rome last weekend, told CNN when asked if they were behind the green water, “It wasn’t us.”

Italian media reported that local police were examining CCTV to determine whether the release might have been a stunt to coincide with the Volgalonga regatta that took place at the weekend.

In an interview with Italian daily La Repubblica, Maurizio Vesco of the Regional Agency for Environmental Protection said that early analysis indicated that the green patch was likely caused by the release of fluorescein, a harmless dye commonly used to track the flow of water.

While this substance is not uncommon, Vesco said that the usual dosage was one spoonful of dye powder – yet the size of the patch suggested that at least 1kg had been dumped in the waters.

“I find it hard to believe that it was an incident… and that a kilo of fluorescein was casually released into the canal,” he told La Repubblica.

Many social media users said the images coming out of Venice were remindful of the 1968 stunt by Argentine artist Nicolás García Uriburu, who dyed the waters of the Grand Canal green in order to raise awareness of ecological issues.

Grand Canal is the major water-traffic corridor in Venice

The Grand Canal forms one of the major water-traffic corridors in Venice. One end of the canal leads into the lagoon near the Santa Lucia railway station and the other end leads into the basin at San Marco; in between, it makes a large reverse-S shape through the central districts (sestieri) of Venice.

It is 3.8 km (2.4 mi) long, and 30 to 90 m (98 to 295 ft) wide, with an average depth of 5 metres (16 feet).

The banks of the Grand Canal are lined with more than 170 buildings, most of which date from the 13th to the 18th century, and demonstrate the welfare and art created by the Republic of Venice.

The noble Venetian families faced huge expenses to show off their richness in suitable palazzos; this contest reveals the citizens’ pride and the deep bond with the lagoon.

Related: Venice Canals Dry Up as Italy Braces for Severe Drought