Revealed: The reason Venice’s famous canals turned bright green

Visitors to Venice’s famous canal network were in for a surprise this weekend when part of the water turned bright green.

Photos of a section of the canal near the Rialto Bridge were shared on social media after a fluorescent green stretch patch appeared in the Grand Canal in the Italian city on Sunday.

The alarming site prompted police to launch an investigation into whether a chemical had been planted in the water by climate activists.

Now, environmental officers have confirmed the discolouration was caused by a spillage of the chemical fluorescein.

Photos show how a portion of the canal near an embankment lined with bustling restaurants turned a shocking green colour and the local fire service also shared footage as a number of gondoliers passed through the discoloured water.

But experts have since confirmed that fluorescein isn’t toxic and explained that it is commonly used in underwater construction projects to identify leaks.

However, the high concentration of the substance found in the Venice canals suggests it probably wasn’t an accident, CNN reported.

Tests are now being carried out to help identify exactly how much of the substance was in the water, with results expected later this week.

It comes after a number of recent incidents across Italy in which environmental groups have targetted landmarks and monuments with colours and dyes.

Activists recently used charcoal to turn the water of the famous Trevi Fountain in Rome black as a mark of protest against the use of fossil fuels.

Unlike in previous incidents, no activist groups have come forward yet to claim responsibility for the green canals in Venice.

Fluorescein is also used in medicine, specifically in eye drops, to help identify lesions, according to the National Institute for Health and Care Excellence (NICE).