The present study tested LED lights in paired trials of a commercial gillnet fishery targeting Atlantic cod (Gadus morhua) in Iceland, due to previous studies that suggest attaching LED lights to gillnets to reduce seabird bycatch. The LED-equipped sets actually caught significantly more seabirds (mainly northern gannets and northern fulmars), and slightly (but statistically insignificant) reduced fish catch. While the use of LED lights on gillnets may reduce bycatch of some species, some bird species appear to be attracted to the lights.
Seabird bycatch in gillnets is a worldwide problem with few if any available mitiga-
tion tools. LED lights attached to the gillnets have been suggested as a potential solution, and a
study in Peru showed promising results where bycatch of diving seabirds was reduced by adding
LED lights to bottom set gillnets. In this study the potential bycatch reduction of LED lights was
tested in a set gillnet fishery that targets Atlantic cod Gadus morhua in Iceland. A variety of sea-
birds such as common guillemots, cormorants, eiders, northern gannets, northern fulmars, and
gulls have been observed as bycatch in that fishery. In a paired trial, nets with and without LEDs
were fished off a commercial gillnetter in western Iceland. The LED-equipped net sets caught sig-
nificantly more seabirds while a slight but statistically insignificant reduction in fish catches was
also observed. The seabirds caught in the LED-equipped nets were mainly northern gannets and
northern fulmars, plunge- and surface-feeding birds, which seemed to be attracted to the lights
while hauling and setting the nets. Caution should be taken when implementing the use of LED
lights on gillnets or trawls as while they might reduce bycatch of some taxa of diving seabirds or
sea turtles, it is possible that some bird species or groups of bird species are attracted to the lights,
in particular during hauling and setting of the nets.