Physical and anthropogenic drivers shaping the spatial distribution of microplastics in the marine sediments of Chilean fjords

• Published in: The Science of the total environment Vol. 814; p. 152506
• Main Authors: Jorquera, Alberto, Castillo, Cristóbal, Murillo, Vladimir, Araya, Juan, Pinochet, Javier, Narváez, Diego, Pantoja-Gutiérrez, Silvio, Urbina, Mauricio A.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 25-03-2022
• Subjects: Aquaculture; Coastal population; Environmental Monitoring; Estuaries; Geologic Sediments; Humans; Marine sediments; Microplastics; Physical and anthropogenic forcing; Plastic pollution; Plastics; Water Pollutants, Chemical - analysis; Marine sediments; Physical and anthropogenic forcing; Coastal population; Plastic pollution; Aquaculture
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2021.152506

Several studies have focused on the presence and distribution of microplastics within the water column of coastal waters, but the dynamics of these particles in sediments have received little attention. Here we examine the concentrations and characteristics of microplastics in sediment samples collected from 35 stations within the Inner Sea of Chiloé, Chilean Patagonia. Current velocity, grain size, intensity of salmon farming activities, and human population density were all evaluated as factors potentially explaining concentrations and distribution of microplastic particles within these sediments. Microplastics were detected in all samples, with the highest abundance represented by fibers (88%), fragments (10%) and films (2%). Across the sampled sites, microplastic concentrations averaged 72.2 ± 32.4 (SD) items per kg dw (dry weight) sediment, with the principal polymers identified as polyethylene terephthalate (PET), acrylic, polypropylene (PP) and polyurethane (PUR). Approximately 40% of the variability in distribution and abundance of microplastics was explained by current velocity combined with proximity and intensity of local salmon production activities.
Marine currents and aquaculture intensity explain abundance and dynamics of microplastics in marine sediments.
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•Microplastic particles were found in all sediment samples from the fjords examined.•Fibers were the most abundant type of particle detected.•Polyethylene terephthalate and acrylics were the most abundant polymers.•Aquaculture intensity, currents and sediment texture shaped particle distributions.