It was at first unknown what had caused the river to change colour so dramatically, but it soon emerged that it was the result of someone adding fluorescein to the water.
However, the culprits have still not been caught almost three weeks after the incident.
The colouring lasted several hours and no fish were harmed or coloured by the dye, which is commonly used as a tracer agent in water studies.
A study conducted at Environment Canada’s Pacific Environmental Science Centre in North Vancouver confirmed that the water was not toxic.
One hiker who saw the unusually-coloured water while walking by the river, Tyson Elder of Victoria, British Columbia, told The Sun: ‘We had been hiking all day so to see something so bright and unexpected was kind of unnerving, especially because it is a popular tourist destination.
‘In the winter the Bald Eagles mate and nest there so we were worried about what it would do to the animals. But luckily tests showed it was not toxic.
‘Everyone was shocked by what they saw, it was big news that day.
‘No one seemed to know what was going on. It was quite an interesting day.’
Mr Elder and his friends recorded the strange sight and uploaded the images to YouTube, where they have attracted over 500,000 hits.
Fluorescein was previously used to dye the Chicago River green on St Patrick’s Day, however, vegetable dye is now used.

Sorry, this entry is only available in Italiano.

Sorry, this entry is only available in Italiano.