Watermelon Snow Is Causing Mount St. Helens to Turn Pink, Experts Say

Posted

The snow on Mount St. Helens is turning pink and freaking climbers out, officials said.

Several mountain climbers have asked Gifford Pinchot National Forest officials why the snow on Mount St. Helens is turning pink. Hikers have also reported seeing the pinkish snow on Mount Rainier.

The color change isn’t something that spilled or blood splattered on the mountainside. It’s a tiny living thing.

“It’s called ‘watermelon’ snow, and it is due to a species of cold-loving green algae,” officials said Monday on Facebook. “Though it may look tasty- we don’t recommend eating it, as it could make you sick.”

Specifically, it can act as an unpleasant laxative, according to the Ocean Conservancy.

The snow algae, known scientifically as Chlamydormonas nivalis, is actually green under a microscope, according to Scientific American.



It appears red in the snow because the chemicals the algae produces to protect itself from harsh UV must be brightly colored. The pigment that absorbs the UV gives off an orange or red hue, the Scientific American reported.

“It lays dormant during winter months but during warmer summer months, the algae ‘activate’ their carotenoid as a protective barrier, or sunscreen, against the sun’s damaging UV radiation, and become red,” the Ocean Conservancy reported.

The snow’s color isn’t the only reason it’s called “watermelon snow.” The pink snow can give off a slightly sweet scent, according to Smithsonian Magazine. It can also stain a climber’s shoes.

Even though the watermelon snow may look cool, it could mean bad news for a glacier. Gifford Pinchot National Forest officials said the algae darkens the surface of a glacier and can ramp up the speed at which it melts.

“The addition of color to the translucent snow causes it to absorb more heat rather than reflect, which ultimately leads to faster melting rates,” the Ocean Conservancy reported. “This can be especially problematic in areas like the Arctic and Antarctic where algae are found in glaciers, contributing to critical issues like sea level rise.”