Illuminated drift gillnets could help reduce bycatch

WASHINGTON, D.C.—Installing LED lights onto a drift gillnet could be one way to reduce bycatch of sea turtles and other protected species, according to a National Oceanic and Atmospheric Administration (NOAA) Fisheries report.

Illuminating nets with LED lights could help increase its visibility to protected species and, accordingly, reduce bycatch of gillnet fisheries. Fishers and NOAA scientists are testing the illuminated nets.

“Studies comparing ‘control’ or traditional nets with illuminated nets show that nets made more visible with simple LED lights can reduce bycatch of sea turtles without reducing target catch,” NOAA staff stated in a report. “Studies in Mexico show green sea turtle bycatch is reduced between 40-60 percent with no changes in target catch. Studies in Peru show green sea turtle bycatch is reduced between 65-80 percent with no changes in target catch.

“Studies in Indonesia show green, olive ridley and hawksbill sea turtle bycatch is reduced by 60 percent with increases of target catch and catch value,” the NOAA report continued.

Lighting up drift gillnets would be beneficial to several species that otherwise become victims of bycatch, such as seabirds, sharks, rays, skates, sawfish, dolphins, porpoises, whales and sea turtles.

NOAA scientists are also researching whether the use of sound could help prevent certain species from becoming entangled with a drift gillnet.

“Scientists are also investigating the effectiveness of sound as a deterrent. They have equipped nets with audio devices that emit an acoustic signal to alert turtles to the net and deter them,” NOAA staff stated in its recently published report. “The next step is to combine the two existing approaches—lights and sound—into one gillnet experiment, to see if this combination can reduce bycatch even more.”

New bycatch reduction techniques are being studied in Pakistan, Gabon, Turkey, Ecuador and the Adriatic Sea (Italy, Slovenia and Croatia).

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