Fish Guidance Systems

Shining a light on safety for turtles

A team of researchers including biologists from the University of Exeter have found that attaching green LED lights to fishing nets provides an effective means of reducing entanglements with sea turtles.

Their findings provide a simple and effective deterrent to the turtles and this can drastically reduce the number of sea turtle deaths by 64 percent, with the benefit of the lights not interfering with the fish catch yields.

The team which also includes researchers from NOAA have found that the lights are one of the few ways to effectively reduce turtle bycatch in nets. Explaining their findings in a news release, Dr Jeffrey Mangel said “this is very exciting because it is an example of something that can work in a small-scale fishery which for a number of reasons can be very difficult to work with”.

The biologists used 114 pairs of gillnets, attaching LEDs every ten metres on one net in each pair. The other net in the pair was left without lights as a control. The nets without the LEDs caught 125 sea turtles compared with to the illuminated nets which caught 62. This is the first occasion that lights have been used in a working fishery to mitigate the effects of bycatch.

Their research into the effective use of LEDs as a deterrent, reinforces the findings made by FGS during extensive trials conducted during the development of the high intensity light systems incorporated into many of the systems in the FGS range.

Dr Mangel went on to explain that “The turtle populations in the eastern pacific are amongst the world’s most vulnerable. We are hoping that bycatch, particularly in gillnets, will help with the management and eventual recovery of these populations”.