Artificial light can be used to deter unwanted non-target catch (bycatch) from fishing gear, which is
thought to be achieved by repelling bycatch, or highlighting escape routes on nets. To select for
responses in bycatch species, light should 1) cause the bycatch species to avoid capture, and 2) not
invoke the same reaction in ...
Artificial light can be used to deter unwanted non-target catch (bycatch) from fishing gear, which is
thought to be achieved by repelling bycatch, or highlighting escape routes on nets. To select for
responses in bycatch species, light should 1) cause the bycatch species to avoid capture, and 2) not
invoke the same reaction in target species. One way to maximise the chance of a bycatch species
responding to light is to ensure the light colour used is more visible to bycatch species. Some studies
have considered the visual sensitivity of certain species to address this. In particular, the wavebands
of light that a species is sensitive to. However, using this measurement alone is incomplete as it does
not consider other factors that affect visibility, such as the ambient light spectrum, and wavelength-dependant light attenuation in different water types and depths. To account for these variables, and
to more accurately predict how both target and bycatch species view light colours in a fishing context,
we used a model of the vision of commercially relevant species in fisheries across the world. From
this, we show whether a light colour is more visible to a bycatch species compared to a target species
in a particular depth and water type, and how modelling can be used to make informed assessments
of the selection of relevant light colours in fishing. We also discuss limitations of using vision models
alone, and the need for corresponding behaviour and/or fishing trials with lights.