Summary
The authors tested the effectiveness of 'scarybird', a visual deterrent, to reduce seabird bycatch in bottom gillnet fisheries in Portugal. The scarybird is a raptor-shaped aerial device that is flown behind the stern of the boat up to ~7m above sea level. The scarybird successfully detered seabirds during fishing operations, especially within the closest 20m from the vessel, where there was a significant reduction in yellow-legged and lesser black-backed gull (Larus michahellis and L. fuscus, −56 %) and northern gannets (Morus bassanus, −72 %). Target catch was not affected, suggesting this mitigation measure could be an easily implementable device for any fishery gears where bird interactions occur close to the surface.