title: Distribution and abundance of surface water microlitter in the Baltic Sea: A comparison of two sampling methods.
abstract: Two methods for marine microlitter sampling were compared in the Gulf of Finland, northern Baltic Sea: manta trawl (333μm) and a submersible pump (300 or 100μm). Concentrations of microlitter (microplastics, combustion particles, non-synthetic fibres) in the samples collected with both methods and filter sizes remained <10particlesm(-3). The pump with 100μm filter gave higher microlitter concentrations compared to manta trawl or pump with 300μm filter. Manta sampling covers larger areas, but is potentially subjected to contamination during sample processing and does not give precise volumetric values. Using a submerged pump allows method controls, use of different filter sizes and gives exact volumetric measures. Both devices need relatively calm weather for operation. The choice of the method in general depends on the aim of the study. For monitoring environmentally relevant size fractions of microlitter the use of 100μm or smaller mesh size is recommended for the Baltic Sea.
authors.affiliation: Finnish Environment Institute, Marine Research Centre, P.O. Box 140, 00251 Helsinki, Finland.
authors.forename: Outi
authors.initials: O
authors.lastname: Setälä
authors.affiliation: IVL Swedish Environmental Research Institute, Kristineberg 566, SE451 78 Fiskebäckskil, Sweden.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Magnusson
authors.affiliation: Finnish Environment Institute, Marine Research Centre, P.O. Box 140, 00251 Helsinki, Finland.
authors.forename: Maiju
authors.initials: M
authors.lastname: Lehtiniemi
authors.affiliation: IVL Swedish Environmental Research Institute, Kristineberg 566, SE451 78 Fiskebäckskil, Sweden.
authors.forename: Fredrik
authors.initials: F
authors.lastname: Norén
mesh_terms: D004784:Environmental Monitoring / Q000379:methods*; D005387:Finland; D009659:North Sea; D012623:Seawater; D014866:Waste Products; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014866:Waste Products; D014874:Water Pollutants, Chemical
keywords: Gulf of Finland; Litter; Manta trawl; Microplastics; Monitoring; Pump; Surface area