How Blue Planet II filmed the gorgeous light show with rays and luminous plankton

BBC Natural History Unit producer Jonathan Smith reveals how the Blue Planet II team captured this nocturnal sequence on camera.

We were in the Sea of Cortez off the California Baja peninsular to film bioluminescent plankton, and the mobula rays helped produce a scene that was really quite magical.

Basically, at night you get a layer of plankton at the surface and if something brushes against them they glow. One explanation is that what they’re doing is lighting up predators. The rays are feeding on shrimps in the plankton; suddenly a ray that you can’t see at all because it’s pitch black becomes like an angel, glowing in some kind of ethereal light as these microscopic plankton spark and light it up.

You need total darkness, and cameras that operate like night vision goggles, to pick up the bioluminescent light. It’s a classic case of new technology opening up an opportunity that when we started making the series would only have been a pipe dream. We feel we’ve done something we never quite dreamed we’d be able to pull off.

Interview by Terry Payne