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Summary
Set net fisheries in New Zealand pose a bycatch risk to protected seabirds, including penguin species whose coastal distributions overlap with fishing effort. Visual deterrents such as light-emitting diodes (LEDs) have shown potential to reduce bycatch in gillnet fisheries internationally, but their effects on seabirds in a New Zealand context, including the risk of attraction, remain uncertain.
This study tested the behavioural responses of little penguins (Eudyptula minor) to green LED lights in a non-fishing setting as a precursor to operational fishing trials. Trials were conducted in Oamaru Harbour, where penguins regularly transit between the marine environment and nesting sites. A grid fitted with commercially available green FishTek Marine NetLights was deployed across a known transit corridor, with trials alternating between illuminated and unilluminated conditions. Penguin movements and behaviour were recorded from shore during nocturnal transits.
Across nine trials conducted in October 2025, 168 observations of penguin movement in the vicinity of the experimental array were recorded; with 158 assumed to have occurred with the array and green LED lights being within the effective field of view of those penguins. Penguins swam through the grid on five occasions when no green LEDs were illuminated, whereas no penguins passed through the grid when LEDs were illuminated. Two observations involved penguins stopping briefly and altering their swimming direction when the grid was illuminated with green LEDs. No penguins were observed moving directly towards, circling, or interacting in any other way with the illuminated grid with green LED lights, i.e., there was no evidence of
attraction to the green LED lights. Results from this study have provided evidence to inform fisheries management decisions regarding the potential adoption of LED-based mitigation, while highlighting the need for species- and context-specific evaluation before broader implementation.
Publication information
Underwood, M.J., Jones, E.G. 2026. Preliminary results on the effect of Green LED lights on the behaviour of little penguins. Conservation Services Programme, Department of Conservation, Wellington, Aotearoa New Zealand. 17 p.