title: Microscopic anthropogenic litter in terrestrial birds from Shanghai, China: Not only plastics but also natural fibers.
abstract: The level of contamination by microscopic anthropogenic litter (0.5-5mm) in terrestrial ecosystems is not well understood. After chemical digestion in 10% KOH, microscopic anthropogenic litter from the gastrointestinal tracts of 17 terrestrial birds was identified and categorized under a stereomicroscope based on its physical properties and melting tests. In total, 364 items from 16 birds were identified as microscopic anthropogenic litter, ranging in size from 0.5 to 8.5mm. No relationship between plastic load and body condition was found. Natural fibers, plastic fibers and fragmented plastics represented, respectively, 37.4% (136 items), 54.9% (200 items) and 7.7% (28 items) of total litter items. Small sample sizes limited our ability to draw strong conclusions about the metabolism of natural fibers, but the decline in the proportion of natural fibers from the esophagus to stomach to intestine suggested that they may be digestible. Particles smaller than 5mm represented more than 90% of the total number of pollutant items. Particles with colors in the mid-tones and fibrous shapes were overwhelmingly common particles. The results reflect pollution by microscopic anthropogenic litter in the terrestrial ecosystem of the study area. Microscopic natural fibers, which may disperse and adsorb chemical pollutants differently from microplastic and may pose an even greater risk, are in urgent need of further research.
authors.affiliation: State Key Laboratory of Estuarine and Costal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Shiye
authors.initials: S
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Estuarine and Costal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Estuarine and Costal Research, East China Normal University, 3663 North Zhongshan Road, Shanghai 200062, China. Electronic address: TOKEILEE@gmail.com.
authors.forename: Daoji
authors.initials: D
authors.lastname: Li
mesh_terms: D000818:Animals; D001717:Birds; D002681:China; D004784:Environmental Monitoring; D010969:Plastics / Q000032:analysis; D014866:Waste Products / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D010969:Plastics; D014866:Waste Products; D014874:Water Pollutants, Chemical
keywords: Anthropogenic litter; Birds; Microplastic; Natural fiber; Terrestrial ecosystem