Happening nearby: These plankton blooming in Edmonds glow in the dark


Walkers along the Edmonds waterfront have lately been noticing masses of brownish floating matter coming in to shore.

Don’t worry; it’s not garbage or sewage.  Rather it is a periodic population explosion of one the many living organisms that call Puget Sound home.

According to the Edmonds Beach Rangers, this is a bloom of Noctiluca scintillans, and these events are not uncommon on Edmonds beaches in the summer. A type of zooplankton (non-photosynthetic plankton) commonly known as Sparkle of the Sea, these single-celled organisms measure about a millimeter across. They love to feed on phytoplankton (photosynthetic plankton), and their voracious appetites don’t leave much for other organisms that depend on these as a food source.

Unlike the notorious red tide, Noctiluca won’t get you sick. But these blooms can make it a bit messy for swimmers and waders.

While Noctiluca do not produce toxins, they have been found to accumulate toxic levels of ammonia, which is then excreted into the surrounding waters.

Now for the fun part.  They glow in the dark!

Noctiluca are bioluminescent, and when the water around them is disturbed will glow with shimmering, ghostly blue cast. It’s not really bright, but according to the Beach Rangers is pretty easy to see if you’re there on a dark night. It’s this trait that gives Noctiluca its common name, Sparkle of the Sea.

Learn more about Noctiluca here.

There is also information on this YouTube video.

— By Larry Vogel


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