Varying levels of microplastics in benthic sediments within a shallow coastal embayment. (30th September 2020)

• Record Type: Journal Article
• Authors: Pagter, Elena; Frias, João; Kavanagh, Fiona; Nash, Róisín
• Is Part Of: Estuarine, coastal and shelf science. Volume 243(2020)
• Publication Date: 2020-09-30
• Subjects: Subtidal sediments -- Plastic marine litter -- FTIR -- MSFD -- Pollution; Estuarine oceanography -- Periodicals; Coasts -- Periodicals; Estuarine biology -- Periodicals; Seashore biology -- Periodicals; Coasts; Estuarine biology; Estuarine oceanography; Seashore biology; Periodicals; 551.461805
• DOI: 10.1016/j.ecss.2020.106915
• Languages: English
• ISSNs: 0272-7714

Abstract

Abstract: Microplastics are pervasive items in the environment and it has been suggested that subtidal sediments are a potential sink and hotspot areas for these pollutants. Due to logistic limitations, this environmental compartment is not routinely sampled, which is evident in the limited number of studies conducted in subtidal zones, compared to intertidal zones and open waters. In order to fill part of the knowledge gap, this study aims to determine the abundance of microplastics in subtidal sediments in a shallow coastal embayment. Sediment samples were collected using the Reineck box corer from the RV Celtic Voyager . Microplastics were extracted by density separation using sodium tungstate dihydrate (Na2 WO4 ·2H2 O)). Subsequently, a subsample of fibres were confirmed as having a synthetic origin by μ-FTIR spectroscopic analysis. A relatively low abundance of microplastics was recorded, c . 73 MP/kg d.w. of sediment, with a variable range across and within stations e.g. 0.3–15.4/100 g d.w. All identified microplastics were secondary (i.e. fibres (99%), fragments (1%)), with the majority identified as polystyrene, polyester, and polyethylene terephthalate. The data in this study illustrates the need for replicates and monitoring marine sediments for microplastics. Highlights: Total of 693 microplastics recorded in 9.5 kg d.w. sediment, approximately 73 MPs/kg d.w. More than half of the microplastics recovered were in 8% of the sediments. Variability in count of microplastics ranged from 0 to 37 items per replicate. Microplastic fibres identified ranged 301 μm–4969 μm in length, 64% less than 2 mm.