Low cost LED lights can help king salmon escape commercial fishing trawl nets
A 2020 study by the Pacific States Marine Fisheries Commission and NOAA’s Northwest Fisheries Science Center showed that LEDs are very effective in directing king salmon to escape windows in trawl nets targeting Pacific hake, the largest groundfish fishery on the West Coast, which typically produces more than 500 million pounds a year.
In the study 86 percent of escaped salmon used the LED-framed openings without losing the targeted catch, showing that king salmon are much more likely to exit the nets where lights are placed.
“Our data and video observations indicate that at deeper, darker depths where trawl nets go, light from the LEDs are enhancing the salmon’s ability to perceive the escape areas and the areas outside the nets,” said Mark Lomeli, lead researcher at the Pacific commission.
Lomeli added that the lights have also proven effective at reducing bycatch of eulachon (Pacific smelt) and juvenile rockfish and flatfish in the shrimp trawl fishery off Oregon.
“We also think the LEDs could be used in other fisheries — for example, in the pollock midwater trawl fishery in Alaska — to reduce chinook salmon bycatch,” Lomeli added in a NOAA release about the project.
“Many fishermen are aware of this technology and use it if they think chinook bycatch will be an issue. It’s easy to use, relatively cheap, and widely available. You can easily clip the lights to the webbing of the net around the escape openings. With these research results in hand, the lights are on the shelf for them when they need them. We think these LEDs are low-hanging fruit for contributing to the recovery of this species and can also play an important role in the stability of this fishery,” Lomeli said.
This video shows king salmon quickly escaping a trawl net in the hake fishery.