EyeRIS is a specialized camera system designed for capturing 3D video of ocean animals. We’ve been using it for years now, and it is currently integrated with the remotely operated vehicle (ROV) Doc Ricketts for this expedition.

Yesterday, we wanted to use EyeRIS to capture the flow around corals. We needed to observe bright particles of plankton and marine snow swirling around the coral, but we ran into a big problem: too much light in the wrong place. EyeRIS uses an array of six lights. We were illuminating the coral and its background, but couldn’t see the particles. The diffuse way we were illuminating the scene was limiting the science we could do, and our approach just wasn’t cutting it.

We needed more light exactly in the right place. An anglerfish creates light in the ocean exactly where it needs it, hanging its glowing lure so that other animals are attracted to it. We took inspiration from the anglerfish to get light exactly where we want it. 

We came up with a plan in the evening after we wrapped up our first ROV dive to the seafloor, using components we already had on the ship. We took the original light array arms off the sides and combined them into an extra-long boom with two lights at the end. A hydraulic system we had already used to adjust the original light array was co-opted to adjust the angle of the boom. Rubber strips used as a shroud on both lights allow us to focus the light onto the particles in the water we want to look at, rather than illuminating other things outside of it. 

Today, we dove with the Anglerfish on EyeRIS, and we’re very pleased with the results! Often, with these impromptu engineering exercises, we expect them to fail quickly, but still give us important information to keep iterating on the design. But lo and behold, this time I actually thought it went just as close to perfect as it could have. We were very worried about the sway in the boom and the mechanical rigidity. It’s floppy like an anglerfish’s lure, and it worked out perfectly for what we wanted to do. 

The Anglerfish puts one of our lab’s core philosophies into practice: animals are some of the best engineers on Earth, evolving novel solutions to engineering problems. Expeditions like ours are revealing the engineering secrets of deep-sea animals, opening the doors to remarkable new technologies in the future.