First evidence of anthropogenic debris in nests of the Kelp Gull (Larus dominicanus) from a small semi-desert Argentinean coastal ecosystem

Highlights: • Anthropogenic litter was detected in nests of breeding Kelp Gulls. • Plastic and paper formed the majority of marine debris. • Flexible fragmented plastics greatly outnumbered hard fragmented plastics. • Plastics >10 cm in length and white/clear color coded debris prevailed. Here, we present the first findings of anthropogenic debris (AD) used as nest material by the Kelp Gull (Larus dominicanus) on a small semi-desert coastal ecosystem in northern Argentine Patagonia. Anthropogenic debris was found in ca. 40% of the 259 active nests, with an average of 2.80 ± 2.60 items per nest (n = 126) with >1 item recorded in >50% of surveyed nests containing debris. The average weight of AD per nest was 4.58 ± 12.74 g; the heaviest debris item weighed 82.58 g. Fragmented plastics were more abundant than unbroken items. Plastic followed by paper dominated the fraction of AD, with flexible plastic items dominating at both sites (nests: 97%, adjacent beach: 82%). Mega-sized plastics (>10 cm in length) and white/clear debris prevailed at both gull nests and the adjacent beach; fisheries and recreational activities were identified as the main sources of AD.