There might be a way to prevent sea turtles from getting caught and dying in fishing nets. Researchers have found that illuminating nets with green lights dramatically reduces the number of sea turtle deaths.
Many species of sea turtles use the coastal waters of Peru as foraging grounds. These species include green, olive ridley and hawksbill, loggerhead and leatherback sea turtles. However, Peru's gillnet fleet is one of the largest components in the nations' small-scale fleet. This means that many turtles can become captured and die as bycatch unintentionally. In fact, thousands of turtles per year suffer this fate.
In this latest study, though, the researchers wanted to see if light helped reduce the number of turtles captured. They used 114 pairs of nets each about 500 meters in length. The researchers placed light-emitting diodes (LEDs) every 10 meters along the length of the gillnet floatline. The researchers also used control nets that weren't illuminated.
So what happened? The researchers found that while the control nets caught 125 green turtles, the illuminated nets caught only 62. In addition, the target catch, which was guitarfish, was unaffected by the illumination. This, in particular, is good news for turtles in the future.
"This is very exciting because it is an example of something that can work in small-scale fishery which for a number of reasons can be very difficult to work with," said Jeffrey Mangel, one of the lead authors of the new paper that details the findings. "The turtle populations in the eastern Pacific are among the world's most vulnerable and we are hoping that by reducing bycatch, particularly in gillnets, will help with the management and eventual recovery of these populations."
The findings could be huge when it comes to helping endangered sea turtles. By lowering the amount of bycatch in nets, it could be possible to create more sustainable fisheries.
"Bycatch is a complex, global issue that threatens the sustainability and resilience of our fishing communities, economies and ocean ecosystems," said Eileen Sobeck, assistant NOAA administrator for fisheries. "Funding research like this is key to NOAA's efforts to reduce bycatch. Through this work, we can better protect our natural resources."
The findings are published in the March 2016 journal Marine Ecology Progress Series.
