Laser technology for seabird bycatch prevention in commercial fisheries

Fernandez-Juricic E (2023) Laser technology for seabird bycatch prevention in commercial fisheries. In: ACAP - 11th Meeting of the Seabird Bycatch Working Group. SBWG11 Doc 11, Edinburgh, UK

To determine if lasers cause eye injury in birds, we performed two different experiments in which the birds were exposed to a wide range of laser energies. In the first we exposed one eye of each starling to a laser and used the other eye as a control to take into consideration potential variation within individuals. In the second, a laser exposed group of individual house sparrows (and a control group of individuals). Results suggest that lasers of an energy output similar to the ones used in fisheries can cause injures in two species across a range of laser powers and exposure times. Some of the eye injuries can translate into a blurred visual perception and dark spots in the visual field, which could negatively affect the ability of individuals to engage in behaviours that require high visual discrimination (e.g., food finding). We also conducted a behavioural study to assess the consequences of laser exposure at the level of foraging behaviour under controlled conditions (an enclosure with a food patch that animals were trained to feed on millet seeds hidden in a substrate of plastic beads). Results imply that laser exposure does lead to changes in foraging behaviour strategies that are the result possibly blurred vision and dark spots in the visual field. To explore to what extent our results apply to marine birds, we compared two indices of eye shape for our study animals to 12 marine bird species. We concluded that if marine species (considered in this study) were to be exposed to lasers, it would be likely that similar results would be obtained to those with House Sparrows and European Starlings in terms of eye injury. However, we also caution that no definitive conclusion can be reached without empirically testing lasers on marine birds.