A study led by researchers of the University of Exeter and Peruvian conservation organization ProDelphius proved that placing LED lights on fishing nets can reduce the chances of sea turtles and dolphins being caught by accident. The research result was published in the journal Biological Conservation, titled "An illuminating idea to reduce bycatch in the Peruvian small-scale gillnet fishery."
The research group have conducted experiment by attaching LED lights on fishing nets with small-scale vessels departing from three ports in Peru between 2015 and 2018. They found out that LED lights along the top of floating gillnets cut accidental "bycatch" of sea turtles by more than 70%, and that of small cetaceans (including dolphins and porpoises) by more than 66% but the amount of targeted fishes was not affected.
The lead author Alessandra Bielli said noted that gillnet fisheries often have high bycatch rates of threatened marine species such as sea turtles, whales, dolphins and seabirds but there was few solutions developed to solve the issue.
"Sensory cues - in this case LED lights - are one way we might alert such species to the presence of fishing gear in the water," said Bielli. 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 PhD graduate Dr Jeffrey Mangel, of Peruvian NGO ProDelphinus.
The team’s new findings support its previous research which suggested LED lights reduce bycatch of seabirds in gillnets by about 85%.
"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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