On the edge of twilight, the surface of the sea glows. Millions of tiny dots produce an eerie blue light, barely visible to humans. Each one is a single plankton shining with bioluminescence, and the dots’ light blurs together as the waters churn around them.

Tom Fecht captured this image in Brittany, France, looking down into the Atlantic Ocean under a bright moon. The luminescence of the plankton is dim, so his first attempts to catch it resulted in nothing but darkness. “I figured something must be going on which you couldn’t see with the naked eye, so I just blindly started opening the shutter every time a wave broke,” says Fecht. Finally, he captured the light from the plankton mixing with reflections of moonlight in a churning wave. He titled the image after the compounds, called luciferins, that generate this light.

While these plankton aren’t officially endangered – no plankton species is, in part due to the impossibility of tracking them individually – their future is highly uncertain. Warmer waters force them to migrate polewards and, in some places, die off, their access to nutrients blocked by changing ocean currents.

The word “luciferin” comes from the Latin for “light-bringer”, and Fecht hopes the plankton’s otherworldly glow also brings light to the plight they face. “If you want to engage in protecting nature, you first of all need an understanding of its beauty,” he says.

This image is part of the touring exhibition from the Prix Pictet award, on view at Fotografiska Shenzhen in China until 29 November.