Experience warp speed: kayak a bioluminescent bay

“It’s almost something out of Star Trek, it seems like you’re going at warp speed through the stars,” my father told me when I asked him to describe kayaking through a bioluminescent bay in St. Croix.

And he was right.

A windy and sometimes blinding drive down through the island during the sunset led us to Salt River Bay National Park in St. Croix, U.S. Virgin Islands. There my mother and I were led by tour guides out from the marina across the bay to a red mangrove lagoon right after the sun set in our clear-bottomed kayaks. During the winter in the Caribbean they experience ‘Christmas winds’ or as I like to call it, something that helps me sleep at night in the otherwise hot climate. Last night was no different from the usual weather pattern as we conquered the rough waters with the rest of our group out through the bay and to the lagoon.

Bioluminescence is made possible by dense concentrations of a certain species of dinoflagellates, or single celled organisms. There are 14 bays worldwide, and 11 of them are in the Caribbean and the Gulf of Mexico. Five of them are in Puerto Rico. What makes these bio bays special are the red mangroves that surround them. These plants provide vitamin B12 to the species that live in the bay and allow them to glow when agitated.

IMAGE CREDIT: TRIPADVISOR.COM

IMAGE CREDIT: TRIPADVISOR.COM

The dinoflagellate species in this bay is Pyrodinium bahamense var. bahamense – there are 81 species of bioluminescent dinoflagellates. It’s not certain why these organisms glow, but one hypothesis is called the burglar alarm. This might be more apparent with the comb jellyfish that also live in the bay. If you are lucky and come across one at night, your paddle will glow as bright as a glowstick, but just for a second. It’s thought that this can blind the jellfish’s attacker so they are able to get away. One of our tour guides was able to capture one in a container with water so we could gently glide our hand into the jar and pick it up carefully to see it glow up close and personally. The comb jelly was about the size of a softball in diameter, but much flatter. When I bounced it around it flashed with bright blue stripes through it’s clear body.

I experienced ‘warp speed’ for myself when we paddled through the lagoon fast and I looked down through the bottom of my kayak, seeing the organisms light up as they hit the boat and pass by me quickly. When I placed my hand in the water and splashed around it seemed like my fingers gave off sparks. The glow was there, but it was subtle.

The sky in St. Croix at night is similar to when you go camping and you are away from all the city lights – you are surrounded by darkness and can see the stars so clearly in the cloudless sky. The constellations were so clear – Orion, Seven Sisters, Taurus and the North Star I could all identify, though I wish I knew more by heart.

If all of the bioluminescent dinoflagellate glowed at exactly the same time I would imagine they’d look like stars glimmering from the water. 

(IMAGE CREDIT FOR DINOFLAGELLATES, FROM LEFT TO RIGHT: MICROBEWIKI.KENYON.EDU, WIKIPEDIA.ORG, UNIVERSITY OF SOUTH CAROLINA)