Authorities in Italy have officially narrowed down their investigation into why the canals in Italy turned green over the weekend.
The bright, emerald hue was first spotted on Sunday morning by the Rialto bridge before it began to spread, the Regional Agency for the Environment in Venice (ARPAV) said.
After environmental authorities conducted tests on the water they discovered its color was the result of Fluorescein, a non-toxic substance first invented by NASA, and most often used to test waterways. But it’s unclear to authorities how, or why, the tracer ended up in one of the world’s most famous waterway systems.
The ARPAV has argued that due to the amount released, it was unlikely an accident. But whether the green canals were the result of a political act remains unknown.
The green rivers resemblec artist Nicolas Garcia Uriburu’s work, “Coloration of the Grand Canal, Venice,” in which the land artist dyed the Venice canals green during the Venice Biennale in June 1968. Uriburu also used Fluorescein in his work that hoped to raise viewers’ ecological consciousness.
No ecological rights groups have claimed responsibility for Venice’s green canals this weekend, and Uriburu was not tied to the incident as he died in 2016.
On May 21, a group of environmental protestors dyed the Trevi Fountain in Rome black as an attempt to draw attention to fossil fuels' effect on the environment.
Further tests on the water will be performed later this week as local police continue to investigate how, and why, the canals turned green.