What’s that glowing in the ocean?

If you are visiting Holbox and you go to the beach at night, you’ll be surprised to witness the brightness of star-like bioluminescent phytoplankton scintillating like a starry sky that comes from the water. You won’t need any special equipment or goggles, though snorkelers can enjoy the blast of swimming in a pool of light. You just need your own eyes and some time to actually digest that this spectacular view is not a product of your imagination: it is just nature.

Phytoplankton, as well as other creatures such as sea-fireflies, can produce light through chemical reactions taking place within their bodies. This is known as bioluminescence. Certain types of chemicals when mixed together produce energy, which ‘excites’ other particles on vibration and generate light. This causes the amazing glow that looks like shining stars.

Bioluminescent dinoflagellates are a type of plankton that cast a bluish-green color. Bioluminescent dinoflagellate ecosystems are rare, mostly forming in warm-water lagoons with narrow openings to the open sea. Bioluminescent dinoflagellates gather in these lagoons or bays, and the narrow opening prevents them from escaping.

However, human beings are not the only ones attracted by plankton. The whale shark, also known as the Rhincodon typus, feeds mainly on it. This animal has a very large mouth and is a filter feeder, which means that it feeds by straining suspended matter and food particles from water. Whale sharks are found in tropical and warm oceans and live in the open sea.

Although it cannot be seen from the shore, the presence of bioluminescent phytoplankton indicates that it is possible a whale shark habitat. From mid-May to mid-September, Holbox island gets plenty of phytoplankton and hundreds of whale sharks.

So, when if you come to Holbox during the summer, don’t forget to pass by the beach at night to appreciate the uniqueness of bioluminescence. Probably you will have to get into the ocean and move the water to see it glow. You will not regret it. The jaw-dropping view will remind you of the beautiful things nature still has to offer.

(pictures of the phenomenom are very hard to take. the one in the cover is for illustrative purposes)