VICTORIA — A prank is probably responsible for turning water in the Goldstream River fluorescent green late Wednesday afternoon.

Horrified nature-lovers watched as water flowing past the Goldstream Park picnic area mysteriously changed colour.

While onlookers worried about the effect on fish and wildlife, water samples were collected by the Langford Fire Department and handed to teams from the provincial Environment Ministry.

“Ministry staff believe the cause of the colouring is a water-tracing dye used in the testing of sanitary water systems,” said Environment Ministry spokesman Dan Gilmore Wednesday evening.

Two samples will be reviewed Thursday and the ministry considers the incidents to be vandalism, he said.

If the green colouring is confirmed to be water-testing dye, it is not known to be harmful to fish and wildlife.

Fluorescein is a synthetic organic compound available as a dark orange/red powder soluble in water and alcohol. It is widely used as a fluorescent ...