Ingestion of anthropogenic debris by migratory barnacle geese Branta leucopsis on a remote north-eastern Atlantic island

Although seabirds are frequently used as sentinel species for anthropogenic pollution, the extent and impacts of synthetic debris ingestion remains poorly studied for many water bird species. Here, we assess ingestion of synthetic particles (≥0.5 mm) by barnacle geese, Branta leucopsis, wintering on a remote island. Faecal samples were collected over a period of four wintering seasons. In total, 71 individual samples were assessed, with 79% of samples displaying at least one debris particle (maximum lengths 0.5–5 mm) from anthropogenic sources. The recovered synthetic debris were identified as micro-fibres (n = 166) and micro-fragments (n = 165). The number of synthetic particles detected per sample was generally low at 4.7 ± 0.9, 43 (mean ± SE, maximum): micro-fibres 2.3 ± 0.3, 10; micro-fragments 2.3 ± 0.8, 40. Particle numbers detected per gram of faecal sample differed amongst wintering seasons. Our results suggest that non-marine water birds can frequently ingest low quantities of synthetic particles in remote coastal habitats.