How a robot fish “as silent as a spy” could help advance ocean science and protect “the lifeblood of Earth”

July 7, 2023

The mysteries of the ocean abound. And now, a group of student researchers is trying out a new way to gain better and more accurate information — with a robot fish.

The robot, named Belle, was created by students at the university ETH Zürich. They designed the fish so that it can swim underwater to film and collect samples without disturbing the natural environment.

“The idea was that we want to capture the ecosystems the way they actually behave,” student researcher Leon Guggenheim told Reuters. “… That’s why we then developed the fish that behaves like a fish and is also accepted by other marine creatures as a fish.”

That requires two things that the students say they accomplished: Making it move like a fish and being silent.

“We want to really go in there and be as silent as a spy,” assistant professor of robotics Robert Katzschmann said, “and just literally coming in and being a spy on the marine life.”

And it takes a full-body experience to make it happen.

The “head” of the roughly 3-foot-long robot fish is what contains the electronics and camera, Guggenheim said, and is “the only proper waterproof part” of the device. The “belly” of the fish is where the battery and motors lie, as well as the filter and pumps that allow the robot to capture environmental DNA.

Environmental DNA capture is a “more sophisticated option” in gathering biodiversity information underwater, Guggenheim said. It entails using a filter to catch fine particulars, including larvae and algae, that researchers then use to extract DNA and see what creatures are in a certain area.

The final part of the robot fish, the fin, is made of silicone and contains two cavities that are filled and emptied with water through internal pumps that help the nearly 22-pound robot move.

And much like a real fish, this one must also be found and caught when it’s time to reel it in to go home. Guggenheim explained that the device can’t connect to radio frequencies, so when it swims to the surface after about two hours of data-gathering, it emits a GPS signal that tells researchers where to pick it up. At that point, the filter needs to be emptied and the batteries need to be replaced.

The team hopes that their device will make ocean exploration safer for the living things that reside within.

“Oceans are severely under pressure from overfishing, from pollution, from climate change, and we know fairly little about them,” Guggenheim said. “…It covers 70% of our oceans, so it’s very hard to get accurate, good amounts of accurate data on the biodiversity in these ecosystems.”

Katzschmann said that current research typically relies on unmanned vehicles that can be “definitely very disturbing” to ecosystems and aren’t made for delicate environments.

“Those areas are particularly vulnerable to propeller-based systems that would just sort of shred through the corals or go and scare the fish away,” he said. “So that’s not our goal, right?”

Ocean exploration and research continue to be a vital priority worldwide. According to the National Ocean Service, “the ocean is the lifeblood of Earth” and covers about 70% of its surface. It helps regulate weather, climate, temperature and life for all — including humans.

But more than 80% of the ocean remains untapped, and marine biodiversity – which these researchers are hoping to be able to better study – is “critical” in helping life on Earth thrive, according to the U.N.

“Evidence continues to emerge demonstrating the essential role of marine biodiversity in underpinning a healthy planet and social well-being,” the U.N. said in 2017.

And the students’ new device embodies the goals of the U.N.’s historic High Seas Treaty. Passed just weeks ago, the treaty puts a more concerted effort into marine conservation and protecting marine environments.

“The high seas are among the last truly wild places on Earth,” Monica Medina, the Assistant Secretary of the U.S. Bureau of Oceans and International Environmental and Scientific Affairs, previously told CBS News’ U.N. correspondent Pamela Falk. “…The ocean is more fragile than most people understand. It is also more essential.”