Solar lights could save sea turtles from deadly fishing nets

Turtles are not only threatened by pollution or global warming – fishing nets pose a significant threat as well. They don’t only catch fish; they ensnare sea turtles, sharks, and other species that were never intended to be caught.

People have attempted to use lights to prevent this. Research says that when lights are mounted on nets, they make the nets visible to turtles, which then swim away.

But there’s a catch: the lights operate on batteries that do not last long, are expensive to replace, and do pose an environmental pollution hazard.

Additionally, the lights are large and do cause tangles on the nets, making life more difficult for fishers.

Solar lights for fishing

Instead of giving up on the idea, a group of researchers worked with gillnet fishers in Mexico to create something smarter: solar-powered LED lights that work like buoys.

The lights flash on and off to save energy and can keep going for more than five days without sunlight. And they attach directly to the float line of the nets, just like regular buoys – nothing fancy or frustrating.

In real-world tests in the Gulf of California, these solar-powered lights cut turtle bycatch by 63% compared to regular nets. And here’s the best part: they didn’t hurt the catch of targeted fish like yellowtail. In fact, the catch was slightly better, though not by much.

“The results were pretty exciting,” said Jesse Senko, an assistant professor in the ASU School of Ocean Futures who led the study.

“It’s a win-win in the sense that you’re getting a light that lasts significantly longer, and it also seems to reduce bycatch just as effectively as lights that require replaceable batteries.”

Studying solar lights and sea turtles

Sea turtles are more than just ocean icons. They’ve been around for over 100 million years and play unique roles in marine ecosystems that no other animals do.

Even though some species are slowly making a comeback, their overall numbers are still a small fraction of what they once were.

“Sea turtles are important for maintaining healthy oceans, which are needed to sustain resilient fisheries,” Senko said.

That’s one of the reasons why the ASU lab is putting energy into working directly with fishers. Instead of pushing complicated gear from the top down, they’re building solutions together.

One current project is happening off the coast of North Carolina, where the same lab is helping fishers reduce bycatch in pound nets- large traps anchored to the seafloor.

They’re comparing catch data from days with and without solar-powered lights, while also watching sea turtle behavior with underwater cameras.

Fishing with solar lights

The idea for the solar light buoys didn’t come from a lab. It came from two brothers, coastal fishers in Mexico: Juan Pablo and Felipe Cuevas Amador. They’re co-authors of the new study.

“They took us into account and gave us the freedom to give our opinions and make modifications,” said Juan Pablo. “For us, it’s important that it be done in collaboration because with what they know and what we know, we can do quite interesting things.”

This kind of partnership is a big part of what made the project work.

“That’s the meaningful innovation,” said Senko. “Because their ideas went into it, they’re more likely to want to use it and to share that information with their friends and their community and with neighboring communities.”

Production of solar lights for fishing

When the tests were over, the brothers asked if they could keep the lights. They said it made fishing easier since they didn’t have to spend so much time untangling turtles.

Now, they’ve kept using them – and as far as the research team knows, they’re the only fishers in the world using solar-powered lighted nets.

“When I heard that, I knew we were onto something,” Senko said.

The team is now working with a company called Fishtek Marine to start producing these solar-powered lights for sale. They hope they’ll be available within two to three years.

There’s also hope that government programs or conservation groups could help fishers pay for them, making it easier for more people to try the technology.

Keeping sea turtles out of nets

The team isn’t stopping yet. They’re now digging deeper into why the flashing light works – and how to make it even more effective.

The researchers are watching how turtles respond underwater, trying to figure out what works best to keep them away from nets.

“A 63% reduction in sea turtle bycatch is a magnificent starting point. However, there’s no reason why that can’t be improved, right?” said Senko. “My goal is how do we get that 63% reduction to a 95% reduction.”

It’s not just about protecting turtles. It’s about creating a future where both sea life and fishing communities can survive – and even thrive – together.

Funding for the research came from Schmidt Marine Technology Partners, the Disney Conservation Fund, and the National Philanthropic Trust.

The full study was published in the journal Conservation Letters.

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