John's Nature Pictures

Watermelon Snow

In summer snow gets a red-pink 'watermelon' color. The color is even more pronounced just below the surface, as evidenced by footsteps in it. When you walk on enough of it your boots will gain that color. The strange phenomenon is caused by high concentrations ('blooms') of microscopic Snow Algae (Chamydomonas nivalis). This unicellular organism is a type of green algae, and contains a bright red carotenoid pigment to protect it's chlorophyll from the ultraviolet light which is stronger at high elevations. It's a cryophilic (cold-loving) fresh-water algae which thrives in freezing water. Supposedly, it even tastes like watermelon, though I haven't tried it.

Picture #383 -  copyright © 2006 by John Sherman


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