Buoys with looming eyes deter seaducks and could potentially reduce seabird bycatch in gillnets
Rouxel, Yann et al. (2021), Buoys with looming eyes deter seaducks and could potentially reduce seabird bycatch in gillnets, Dryad, Dataset, https://doi.org/10.5061/dryad.12jm63xxh
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 ~20-30% within a 50m 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.