Presence of plastic pollution on seabird islands: identifying hotspots for flesh-footed shearwaters

Lamb, S^1a., Ray, S^1b., Burgin, D^1c., Bell, E^1d.

¹96B Middle Renwick Rd, Springlands, Blenheim, 7201

^asimon@wmil.co.nz, ^bSamantha@wmil.co.nz, ^cdan@wmil.co.nz, ^dbiz@wmil.co.nz

Through their ingestion of plastics whilst foraging, seabirds act as vectors of plastic transmission from the marine environment to their terrestrial breeding grounds. Previous work almost a decade ago showed that the seabird colonies on Ohinau Island off the Coromandel Peninsula was a hot spot for plastic pollution within New Zealand. Here, we report on the incidental plastics found at, or near to, burrows while undertaking routine population monitoring of toanui/flesh-footed shearwaters (Ardenna carneipes) on Ohinau and Lady Alice Island (within the Hen and Chicken Island chain, Northland) during the 2021/22 breeding season. Additionally, we report on the lack of plastic debris found whilst undertaking a flesh-footed shearwater population census on Titi Island within the Marlborough Sounds during the 2021/22 breeding season. We show that the seabird colonies on Ohinau Island continue to be a hotspot for plastics, whereas only a handful of plastics were recovered from Lady Alice Island. The Titi Island seabird colonies thus far appear to be untouched by plastic pollution. We discuss possible reasons underlying these island differences and discuss the importance of monitoring plastics across seabird colonies in New Zealand.