On our nightly dog walk last night we were treated to a spectacular natural display, bioluminescence! The water was rough and when we first got to the beach the white caps appeared to be glowing. Our beach entrance has a lot of light pollution so we had to walk to a darker area to see what was really going on.
As we reached the dark stretches of beach the waves were definitely lit up and the sand was glowing green under our feet with every step. It was like being on a light up dance floor! We had so much fun running our feet through the sand and splashing the light up water with our hands. We’ve lived here for 10 years and have never seen a bioluminescence show of this caliber. That’s not to say that it hasn’t happened, we’ve just missed it. Our younger dog loves to chase the ghost crabs that come out at night and it was fun seeing his little footprints and digging spots light up. In some areas, even the crabs running across the sand caused the light up reaction. Needless to say, their usual 1 mile walk turned into 4.
It was extremely hard to capture this in a pic with just our iPhones but here’s our best attempt:
What causes bioluminescence?
There are a lot of bioluminescent creatures in the world. Lightning bugs on a summer night are one that everyone’s familiar with. Glow worms are another, but it’s much more prevalent in the ocean. The ocean is full of light up creatures big and small. One of my favorite things about night diving is turning off my flashlight and seeing the bioluminescence in the water. Bioluminescence also serves an important purpose to the creatures who possess it: defense against predators, as a warning to other creatures that they are not to be eaten, communication, camouflage and attraction. These apply to the big creatures though and that’s not what was lighting up our ocean and sand last night.
Last night’s light show was produced by noctiluca which is a type of dinoflagellate that lights up when disturbed. It makes sense then that we could only see it in the waves crashing and when we walked on or otherwise manipulated the sand and water. The name noctiluca literally means nightlight (nocti – night, luca – light) and their effects have been logged by boat captains for centuries. It was even mentioned in Jules Verne’s Twenty Thousand Leagues Under the Sea published in 1870.
Nature is amazing! I just hope we’ll be lucky enough to see it again tonight.
Enjoy your Sunday!
Warm thoughts to all!