Researchers at the University of Exeter and proDelphinus, a Peruvian conservation group, have found that installing LED lights on top of floating gillnets can significantly reduce the likelihood of accidentally capturing protected species. A study at three peruvian ports between 2015 and 2018 showed that lighting reduced sea turtle misbreeding by 70 percent and dolphins by 66 percent.
Since ancient times, gillnets have been the standard equipment of fishermen all over the world. The gillnets are designed primarily to catch fish, and are made of heavier vertical mesh plates that are suspended by vertical lines attached to buoys. When fish swim into the net, their gills are entangled or trapped when they try to swim backwards.
As an ancient technique, gillnets work very well – but the use of gillnets is strictly regulated by some national and international laws to prevent overfishing and the capture of conservation species. Fortunately, by adjusting the various elements of the network, they can be highly selective, but the problem persists.
A big problem is that gillnets can catch not only fish, but also seabirds, turtles and mince whales. According to the Exeter team, LED lights have been shown to be successful in reducing seabird catch by 85 per cent.
Alessandra Bielli, head of research at the Penryn Campus Ecology and Conservation Centre in Exeter, said: “Gilling fisheries often miscatch threatened marine species such as sea turtles, whales, dolphins and seabirds. In the populations of these non-target species, no solution has been developed to reduce gillnet catch estica. Sensory cues (in this case LED lights) are a way for us to alert such species to the presence of fishing gear in water. “
For testing, the researchers equipped the floating lines of 864 gillnets for every 10 meters with LED lights and compared them to nets that were not equipped with LED lights. The researchers found that the control net captured species such as green turtles, red turtles, long-horned common dolphins and ratfish dolphins, but the number of led nets was much lower.
Professor Brendan Godley, of the University of Exeter, said: “This work is further evidence that online lights can save wildlife. We now need more durable, cheaper lamps. “
The study was published in the journal Biological Conservation.