There’s a wholly different and mesmerising world, hidden in plain sight, at night, underwater. There are things that glow in the dark. It's called fluorescent diving and it all happens with the flick of a switch.

That’s what we learnt in February this year when Mike Markovina of Moving Sushi introduced the Two Oceans Aquarium to Jacques Vieira, founder of the Fluorescent Shark Project South Africa [link goes to Facebook]. Their request was simple: could they come to the Aquarium after dark to find out what does, or doesn’t, fluoresce underwater? Our response was immediate: Please do!

Linda Markovina is a photojournalist and the other half of Moving Sushi, which is a team dedicated to all things ocean related … from filmmaking, journalism and photography to ground-breaking expeditions, fisheries science and ocean conservation. In this post, she writes about the fluo diving experience.

Jacques Vieira and a small team made up of Moving Sushi and other ocean advocates, including Ross Frylinck of the Sea-Change Project, came to the Two Oceans Aquarium one night in February to investigate and discover more about fluorescing animals. Once all the tourists and visitors had left for the day, the Aquarium turned off the lights. There in the dark, when the blue lights were shone on the different shark and fish species, something spectacular happened. Things were fluorescing that had not before been understood to even be capable of such actions. Penguins fluoresced, and so did crabs, horsefish, seahorses and the small puffadder and dark shysharks darting between the kelp.

What also became apparent is how little we know about this amazing fluorescing function. Sharks that we assumed must fluoresce, did absolutely nothing under the blue light, while other species, like some turtles, only fluoresced on certain parts of their bodies … And other turtle species didn’t fluoresce at all. This is the challenge that the Fluorescent Shark Project South Africa now faces - there simply is not enough information out there. But therein lies the sheer wonderment of doing something new. Since there is so little information out there, the discoveries are potentially endless.