Study reveals LED lights on commercial fishing nets can save turtles, dolphins

A new research study by the University of Exeter and Peruvian conservation organisation ProDelphinus revealed that placing LED lights on fishing nets may reduce the chances of dolphins and sea turtles getting caught by accident.

LED lights along the top of floating gillnets cut accidental "bycatch" of sea turtles by more than 70 percent, and that of small cetaceans (including dolphins and porpoises) by more than 66 percent.

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The study looked at small fishing vessels operating from three Peruvian ports in a period between 2015 and 2018 and found the lights did not reduce the amount of fish caught from 'target species' but drastically reduced 'accidental bycatch' rates for dolphins and sea turtles. The results of the study were published in the journal Biological Conservation.

"Gillnet fisheries often have high bycatch rates of threatened marine species such as sea turtles, whales, dolphins, and seabirds," said lead author Alessandra Bielli, who carried out analyses as part of her master’s research at the Centre for Ecology and Conservation at Exeter's Penryn Campus in Cornwall.

He further added that commercial fishing can lead to a sharp decline in the populations of these non-target species. However, few solutions to reduce gillnet bycatches have been developed so far. Sensory cues -- in this case LED lights -- are one way non-target species may be alerted against the presence of fishing gear in the water.

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Bycatch of sea turtles

The researchers placed lights every 10m along the float line of 864 gillnets, pairing each with an unlit net to compare the results.

"The dramatic reduction in bycatch of sea turtles and cetaceans in illuminated nets shows how this simple, relatively low-cost technique could help these species and allow fishers to fish more sustainably. Given the success we have had, we hope other fisheries with bycatch problems will also try illuminating their fishing nets," said Exeter Ph.D. graduate Dr. Jeffrey Mangel, of Peruvian NGO ProDelphinus.

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The study found that most of the turtle caught were green turtles -- comprising of 86%, along with loggerhead and olive ridley turtles. Among the small cetaceans captured, 47% were long-beaked common dolphins, 26% were dusky dolphins and 24% were Burmeister's porpoises.

"This work has further shown the usefulness of lights on nets to save wildlife. We now need lights that are ever more robust and affordable," said Professor Brendan Godley, of the University of Exeter.

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(With ANI Inputs)