Why is the water of Venice's Grand Canal green?

It is an unusual and "coloured" Venice that tourists and Venetians found themselves facing on Sunday May 28th, when the waters of the Grand Canal appeared to be an intense fluorescent green.

The alarm went off shortly after 8.30 in the morning. Experts and authorities mobilized immediately, the to figure out what was going and if somebody was up pulling a prank of some kind.

Photo: Twitter @arpaveneto

It all started as a small fluorescent spot near the Rialto Bridge which, according to the news reported by the Italian media outlet Corriere della Sera, did not take long to increase to even more significant dimensions, until green water had invaded the Grand Canal, the major waterway in Venice.

At first, there were various hypotheses on the table, including those said it could be a protest of sorts by environmental groups. Nevertheless...

Various environmental groups, including 'Ultima Generazione', and Extinction Rebellion, have denied being responsible for this action, issuing statements and press releases about it to various news agencies, including LaPresse.

When environmental groups commit such actions as they did on May 21 in Rome, by pouring coal into the waters of the Trevi Fountain (pictured), they are quick to own up to it.

Since it does not appear to be a stunt or protest, a fact which is also mentioned in the analysis by IlSole24ore, therefore leads to discarding an environmental protest of sorts as the origin of this phenomenon. Make it necessary for authorities to look elsewhere for the reason behind Venice's green water, which has so far been decidedly unclear.

What, according to the first findings, would seem clear, however, could be the type of liquid used: a tracer, "that is, a liquid that is introduced in all those circumstances where there is a loss of water to understand the path followed",  explained the State Police in a press release.

Samples were taken from the waters of Venice which are still being analyzed and which will confirm (or deny) the first assumptions about the nature of the substance that gave rise to the phenomenon.

According to the first opinions released, it would seem that it could be a substance called fluorescein, a chemical compound with multiple areas of use, thanks, in fact, to its peculiar fluorescent color (in this case green).

In the photo, the redemption of the Gemini IV spacecraft in 1965, facilitated by the release of a green trail.

The words of Maurizio Vesco of ARPA (Regional Agency for Environmental Protection) to Repubblica, however, underline an interesting fact: in the most common operations, those of prospecting with fluorescein of underground watercourses or discharges, only a spoonful of fluorescein is usually used.

Photo: Benjah-bmm27, Public domain, via Wikimedia Commons

According to Maurizio Vesco, to dye an area of 500 meters green as happened in Venice "a kilo would have been used".

In the meantime, the investigations of the local police continue, who would be reviewing the local video camera footage to exclude or confirm the hypothesis of the accident and, if necessary, trace the perpetrator of the act.

Photo: Facebook Luca Zaia, President of the Veneto Region

However, the experts and the authorities have provided an answer to the first and perhaps most important question on the table: that of health.

With an official statement, both the State Police and the municipal and regional authorities confirmed that there is no danger to humans or animals, calling for the public to remain calm.

Photo: Instagram @zaiaufficiale

After all, a similar thing had already happened in 1968 when an Argentine artist Nicolás García Uriburo, during the Venice Biennale, created a stir by dyeing the city's waters green, as a protest against pollution.

In any case, whatever the cause of this action that has colored Venice, be it an accident, a hoax or a deliberate action, we are sure of one thing: these will be more photos to add to the annals of a city which, over the centuries, it has truly seen everything. Even twice.