LED fishing nets save turtles and dolphins

UNITED KINGDOM / PERU — Researchers at the University of Exeter and Peruvian NGO ProDelphinus have found that by putting LED lights on top of floating commercial fishing nets, the number of critically endangered species caught in them, can be reduced by 70 percent or more

The research published in the journal Biological Conservation looked at small-scale vessels departing from three Peruvian ports between 2015 and 2018. LEDs were placed every 30 feet along the float line of 864 illuminated gillnets.

Lead author Alessandra Bielli explained that gillnet fisheries often have high bycatch rates of threatened marine species such as sea turtles, whales, dolphins, and seabirds.

Saying, "Sensory cues – in this case, LED lights – are one way we might alert such species to the presence of fishing gear in the water."

Each gillnet was paired with an unlit gillnet to compare the results. Eighty-six percent of the turtles caught in the unlit nets were green turtles, however, loggerhead and olive ridley turtles were also found in the nets.

Among the small cetaceans captured, 47 percent were long-beaked common dolphins, 26 percent were dusky dolphins and 24 percent were Burmeister's porpoises.

The findings also support previous research which suggested LED lights reduce bycatch of seabirds in gillnets by about 85 percent.

Just as warning lights warn us of danger, the intelligent animals were able to see the illuminated nets, furthermore, the light modification made no change to the amount of commercial catch fisherman caught.

Researchers hope the cost-effective nets are promptly adopted by fishermen as more than one-third of the marine mammals and nearly one-third of sharks and fish are currently threatened with extinction due to the consequences of fishing and other human activity.

University of Exeter Professor Brendan Godley said, "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."