Ingestion of anthropogenic materials by yellow-legged gulls (Larus michahellis) in natural, urban, and landfill sites along Portugal in relation to diet composition

• Published in: Environmental science and pollution research international Vol. 28; no. 15; pp. 19046 - 19063
• Main Authors: Lopes, Catarina S., Paiva, Vitor H., Vaz, Patrícia T., Pais de Faria, Joana, Calado, Joana G., Pereira, Jorge M., Ramos, Jaime A.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2021; Springer Nature B.V
• Subjects: Animals; Anthropogenic factors; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Breeding seasons; Breeding sites; Charadriiformes; Debris; Detritus; Diet; Earth and Environmental Science; Eating; Ecosystem; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental science; Fisheries; Food; Food resources; Food sources; Foraging habitats; Ingestion; Landfill; Landfills; Laridae; Larus michahellis; Marine ecosystems; Pellets; Plastics; Portugal; Prey; Research Article; Seasonal variations; Species; Terrestrial ecosystems; Urban areas; Urbanization; Waste Disposal Facilities; Waste disposal sites; Waste management; Waste Water Technology; Water Management; Water Pollution Control; Portugal; Diet analysis; Gulls; Laridae; Regurgitations; Pellets; Plastic pollution; Debris ingestion
• ISSN: 0944-1344; 1614-7499; 1614-7499
• DOI: 10.1007/s11356-020-12161-5

Pollution is a global concern, increasing rapidly throughout marine and terrestrial ecosystems, and affecting many species. Urbanization enhances waste production, leading to the opening of landfills that constitute a spatially and temporally predictable food source for opportunistic species. Several species of gulls are known to exploit and breed in urban areas, taking advantage of accessible and diverse food resources. The exploitation of anthropogenic food subsidies at sea (e.g. fishery discards), urban sites, and landfills leads to debris ingestion by gulls with potential negative effects. Here we characterize anthropogenic debris ingested by yellow-legged gulls (
Larus michahellis
) along Portugal, by analysing the content of pellets collected in (1) natural and urban breeding locations, and in (2) urban and landfill resting sites, to assess seasonal patterns in the ingestion of anthropogenic debris. We also relate diet with the presence of anthropogenic debris. Debris materials were found in 28.8% of pellets from breeding locations (natural and urban) and in 89.7% of pellets from resting sites (urban and landfill). Gulls from the most urbanized breeding location exhibited higher levels of ingested materials during the entire breeding cycle, however, gulls from a natural breeding site also ingested high levels of debris during the pre-breeding season. At resting sites, small seasonal differences were detected in the number and mass of debris items ingested, which were both higher during spring and summer. Gulls that typically fed on pelagic fish had significantly less sheet and fragment plastics in their pellets. The presence of certain debris categories in gull pellets was positively related to the presence of some prey items, suggesting that gulls may accidentally ingest debris while foraging at multiple habitats. The quantity of anthropogenic materials ingested by gulls from urban locations and landfills indicates a need for improved waste management.