Annual plastic ingestion and isotopic niche patterns of two sympatric gull species at Newfoundland, Canada. (December 2021)

• Record Type: Journal Article
• Authors: Jardine, Alexander M.; Provencher, Jennifer F.; Pratte, Isabeau; Holland, Erika R.; Baak, Julia E.; Robertson, Gregory J.; Mallory, Mark L.
• Is Part Of: Marine pollution bulletin. Volume 173:Part A(2021)
• Publication Date: 2021-12
• Subjects: Larus marinus -- Larus smithsoniansus -- Debris -- Litter -- Ingestion; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2021.112991
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Ingestion of plastic pollution by pelagic seabirds is well-documented globally, but increasingly, researchers are investigating plastic ingestion in generalist predators and scavengers like gulls. We studied the gut contents of two sympatric gull species, American herring gulls ( Larus smithsoniansus ) and great black-backed gulls ( L. marinus ), collected year-round as part of "kill-to-scare" measures at the regional sanitary landfill in St. John's, Newfoundland and Labrador, Canada, to compare ingested anthropogenic debris, trophic position and diet breadth through the year. Although great black-backed gulls fed at a higher trophic level, frequency of occurrence of plastic ingestion was similar to American herring gulls, and varied little through the year. Diet breadth (isotopic niche size) was similar between species, but American herring gulls fed at a lower trophic level during winter, perhaps indicating a change in their reliance on anthropogenic food subsidies throughout their annual cycle. Highlights: Sampled plastic in 2 species of gulls year-round in eastern Canada Approximately 50% of each species contained plastic debris. Debris ingestion was unrelated to trophic level as assessed by stable isotopes. Gulls could prove useful as biomonitors of coastal anthropogenic debris.