Buoys with looming eyes deter seaducks and could potentially reduce seabird bycatch in gillnets

Abstract

Bycatch of seabirds in gillnet fisheries is a global conservation issue with an estimated 400 000 seabirds killed each year. To date, no underwater deterrents trialled have consistently reduced seabird bycatch across operational fisheries. Using a combination of insights from land-based strategies, seabirds' diving behaviours and their cognitive abilities, we developed a floating device exploring the effect of large eyespots and looming movement to prevent vulnerable seabirds from diving into gillnets. Here, we tested whether this novel above-water device called ‘Looming eyes buoy' (LEB) would consistently deter vulnerable seaducks from a focal area. We counted the number of birds present in areas with and without LEBs in a controlled experimental setting. We show that long-tailed duck Clangula hyemalis abundance declined by approximately 20–30% within a 50 m radius of the LEB and that the presence of LEBs was the most important variable explaining this decline. We found no evidence for a memory effect on long-tailed ducks but found some habituation to the LEB within the time frame of the project (62 days). While further research is needed, our preliminary trials indicate that above-water visual devices could potentially contribute to reduce seabird bycatch if appropriately deployed in coordination with other management measures.

Bycatch of Loons Assessed in Coastal Arctic Char Fisheries in the Canadian Arctic

“…Acoustic pulses have been used to deter marine mammals (Waples et al 2013) and may hold promise for seabirds in some situations (Melvin et al 1999;McGrew 2019). However, a recent study found that buoys with painted "googly" eyes deterred sea ducks from certain spaces (Rouxel et al 2021); this may be a practical means of deterrence of loons and sea ducks. Finally, shifting the timing of the fishery may hold promise for reducing loon and other seabird bycatch in Arctic gill-net fisheries.…”

“…However, a recent study found that buoys with painted “googly” eyes deterred sea ducks from certain spaces (Rouxel et al. 2021); this may be a practical means of deterrence of loons and sea ducks. Finally, shifting the timing of the fishery may hold promise for reducing loon and other seabird bycatch in Arctic gill‐net fisheries.…”

A systematic review of sensory deterrents for bycatch mitigation of marine megafauna

“…In the same area, Bielli et al (2020) reported an 84% reduction in seabird bycatch using green LEDs, although statistical significance was not reported. Looming eye buoys (rotating panels with eye spots, attached to a buoy) are a promising development in deterring seabirds, with significant reductions of long-tailed duck abundance within 50 m of the modified buoys compared to controls (Rouxel et al 2021).…”

“…In this study, habituation trials were confounded by the seasonal presence of migrating ducks, so further research was suggested to investigate the long-term deterrent capabilities of looming eye buoys (Rouxel et al 2021).…”

“…More technologies have been trialled with success for one taxonomic group rather than multiple, generally due to species-specific biology, such as electrosensory systems in elasmobranchs (Jordan et al 2013), echolocation in odontocetes (Trippel et al 2008), or visual cues above the water for seabirds (Rouxel et al 2021). Where multiple groups are caught, it may be appropriate to use multiple technologies in combination.…”