Green ocean water off the coast of British Columbia is bringing back memories of the green swimming pool at Rio 2016, but a scientist says it鈥檚 a harmless phenomenon.
The ocean water between Metro Vancouver and Vancouver Island turned a light shade of green roughly at the start of August, but its tone has intensified over the past few days.
The green shading varies in size and at its largest, has even been spotted by NASA satellites overhead.
"I mean it's green for the whole length of Howe Sound today," said Tom Stackhouse, who works as a tour guide for Sewell's Marina in West Vancouver. "It almost sort of looks like it's Caribbean water, it looks a lot warmer than it would be."
Stackhouse says tourists have asked lots of questions about the water, and the colour produces a range of confused reactions.
But a local researcher says the cause is pretty simple.
Nicky Haigh of the University of Vancouver Island's Harmful Algae Monitoring Program says the colour is caused by tiny phytoplankton called coccolithophorids.
The coccolithophorids are a 100th of a millimetre in size, and the scales on their bodies reflect light, typically creating a chalky colour.
However, the creatures appear to be mixing with other sea life this summer, creating a bright green colour.
"This is an unusual bloom in the Strait of Georgia," she told CTV Vancouver, referring to the body of water between Vancouver Island and Vancouver. "We're not really sure why they're blooming in this area."
She says coccolithophorids are usually seen in June and July off the west coast of Vancouver Island, but not to this extent between the island and the mainland.
Haigh says the bloom -- which is a rapid increase in the population of algae -- could be linked to changing acidity in ocean water, which is linked to climate change, but can't give a definitive conclusion to the green colour.
The water that turned water a reddish brown colour last year, temporarily shutting down fisheries and tainting local seafood.
But this year's bloom is not harmful at all, at worst it may hinder people trying to enjoy a swim.
"It's not toxic, it may be a bit of a nuisance because it reduces visibility in the water and might reduce the light levels for things trying to grow in the water but it doesn't produce a toxin at all," she said.
Haigh says that the phenomenon could disappear once fall weather rolls in.
With a report from CTV Vancouver's Nafeesa Karim
