title: Comparative analysis of time series of marine litter surveyed on beaches and the seafloor in the southeastern North Sea.
abstract: The comparative analysis of marine litter in different marine compartments has rarely been attempted. In this study, long-term time series of marine litter abundance on the seafloor and on the coast, both from the southeastern North Sea, were analyzed for temporal trends and correlations. On four beach sections of 100 m length, mean abundances of total beach litter collected four times a year from 2002 to 2008 varied between 105 and 435 items. Mean densities of total inorganic litter on the seafloor amounted to 10.6 ± 9.7 kg km(-2) in the offshore region (2001-2010) and 13.7 ± 12.6 kg km(-2) in the Wadden Sea (1998-2007), respectively. In the offshore region, there was no significant long-term trend, while in the Wadden Sea, densities of marine litter declined significantly. Correlations between time series were weak, indicating different sources and transport processes responsible for compositions of beach litter and litter on the seafloor. Decreases in inputs from fisheries and substantial export due to resuspension are discussed as reasons for the decrease in litter on the seafloor in the Wadden Sea.
authors.affiliation: AquaEcology GmbH & Co. KG, Marie-Curie-Strasse 1, 26129 Oldenburg, Germany. Electronic address: mschulz@uos.de.
authors.forename: Marcus
authors.initials: M
authors.lastname: Schulz
authors.affiliation: Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany. Electronic address: r.krone@datadiving.de.
authors.forename: Roland
authors.initials: R
authors.lastname: Krone
authors.affiliation: Datadiving GmbH & Co. KG, Övelgönner Str. 25, 20257 Hamburg, Germany. Electronic address: g.dederer@datadiving.de.
authors.forename: Gabriele
authors.initials: G
authors.lastname: Dederer
authors.affiliation: Alfred-Wegener-Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany. Electronic address: Kai.Waetjen@awi.de.
authors.forename: Kai
authors.initials: K
authors.lastname: Wätjen
authors.affiliation: Institute of Environmental Systems Research (USF), University of Osnabrueck, Barbarastrasse 12, 49076 Osnabrueck, Germany. Electronic address: mmatthie@uos.de.
authors.forename: Michael
authors.initials: M
authors.lastname: Matthies
mesh_terms: D001493:Bathing Beaches / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000032:analysis*; D009659:North Sea; D013223:Statistics as Topic; D013995:Time; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants
keywords: Beach litter; Correlation analysis; Kriging; Seafloor litter; Time series; Transport process