A tentacled squid stuck in a fishing net is a messy problem for fishermen worldwide. Unfortunately, for a loggerhead turtle or a diamond stingray, getting tangled up in a net usually means death.
But, new research seems to offers a potential solution to this problem.
An affixing LED light to fishing nets helps lower the catch of animals that aren’t targeted like squids and sharks, without influencing the quantity and quality of fish.
A LED-Powered Fishing Net Could Help Save Sharks & Turtles
According to Rebecca Lewison, a conservation ecologist from the San Diego State University (she wasn’t part of the research), this is a great study showing that there’s a decrease in the bycatch of several species that doesn’t have a long-term negative influence.
Plenty of coastal fishers use gillnets that hang in the water like chain-link fences. These nets can drift for hours and days and don’t discriminate against wanted and non-wanted species. Usually, the non-wanted species are tossed overboard with injuries that are usually fatal.
Bycatch is a significant contributor to the global extinction of species like sea turtles and dolphins and it also slows down the daily work of fishermen.
John Wang, marine ecologist from the National Oceanic and Atmospheric Administration, and his colleagues had made illuminated nets to resolve turtle bycatch.
Turtles are really good at seeing green light and in 2016, the researchers discovered that these lighted nets reduced the bycatch by a stunning 64 percent, although this may not be the case with other marine species.
The team collaborated with small-scale grouper and halibut fishermen off the coast of Baja California, Mexico due to the abundance of sea turtles and other marine animals there, according to Jesse Senko, a conservation ecologist from Arizona State University who’s also the head of the new study.
They released 28 such net pairs.
One net in each pair had LED lights and then they weighed and identified the critters snared overnight.
This showed a 63 percent of reduction in the bycatch and 51 percent fewer turtles and 81 percent fewer squid than in the other, nets without these lights.
Some Animals Avoid the Lights Better than Others
The researchers are still working on discovering why some of the animals are better at avoiding the lights than others are.
The elasmobranchs have sophisticated eyesight whereas the Humboldt squids have big eyeballs, so they may easily see the green lights, claim the researchers.
However, Wang notes that it’s a bit too simple to say that the targeted fish can’t see the lights as well as the others. Another benefit of the lighted net was that the fishermen also spent only half of the time hauling and disentangling their nets.
Still, Senko emphasizes that it’s a big drawback that the cost to put these lights on their fishing nets costs up to $140, something more than the fishermen are able to afford.
Currently, the research team is focused on testing solar-powered lights which are known to be longer-lasting than battery-powered ones.
They’re also trying to discover whether fewer lights per net can provide the same results.
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