Projektergebnisse

Das seit 2016 vom Niedersächsischen Ministerium für Wissenschaft und Kultur geförderte, bis Ende des Jahres 2020 aktive Forschungsprojekt „Makroplastik in der südlichen Nordsee – Quellen, Verbreitungspfade und Vermeidungsstrategien“ umfasst ein interdisziplinäres Konsortium von Wissenschaftler*innen aus fünf Arbeitsgruppen der Universität Oldenburg. Es soll fundierte Erkenntnisse zur Belastung der Nordsee mit treibendem Meeresmüll, insbesondere Makroplastik, liefern und sowohl eine solide Wissensbasis über regionale Quellen, Verteilungswege, Einflussfaktoren und Ansammlungsgebiete schaffen, als auch ein tieferes Verständnis über den Umgang diverser Interessensgruppen mit der Müllproblematik generieren.

Nach vier Jahren Projektarbeit blicken wir zurück auf eine Vielzahl gewonnener Erkenntnisse: 10 bereits in internationalen Journals veröffentlichte, 3 weitere akzeptierte sowie mehrere sich in Begutachtung befindliche wissenschaftliche Artikel, verschiedenste Präsentationen, Berichte und Abstracts. Um dieses Wissen in transparenter, strukturierter Form weitergeben zu können haben wir folgende Übersicht über alle bisherigen Ergebnisse erstellt.

 

Ergebnisse des Gesamtprojekts

 

Zwischenbericht Makroplastik in der südlichen Nordsee - Quellen, Verbreitungspfade und Vermeidungsstrategien Kurzfassung 2017/18

Download Report (Deutsch Fassung)

Download Report (English Version)

Schöneich-Argent R, Freund H (2020) Was Holzdrifter über die Vermüllung von Mellum, Minsener Oog und Wangerooge verraten. Natur- und Umweltschutz 19(1):15-19. Download Full Issue

Schöneich-Argent R, Ricker M, Meyerjürgens J, Hahner F, Stephan K (2017) Projekt Makroplastik in der südlichen Nordsee - Ein Zwischenbericht. Natur- und Umweltschutz 16(1) 26-29 Download Full Issue

Schöneich-Argent R, Stephan K, Ricker M, Hahner F, Meyerjürgens J (2016) Plastik – Rohstoff, Wertstoff, Abfallprodukt und globales Problem. Wissenschaftler-Team der Carl von Ossietzky Universität Oldenburg erforscht die Wege des Plastikmülls in der Nordsee. Natur- und Umweltschutz 15(2) 64-67 Download Full Issue

 

Ergebnisse nach Projektschwerpunkten: Quellen, Verbreitungspfade und Vermeidungsstrategien

 

Quellen von Makroplastik in der Nordsee:

 

González-Fernández D, Hanke G, and the RiLON network (incl. Schöneich-Argent R) (2018) Floating Macro Litter in European Rivers - Top Items. Publications Office of the European Union, Luxembourg, JRC10817224, ISBN 978-92-79-96373-5. https://publications.jrc.ec.europa.eu/repository/handle/JRC108172

Abstract...

The JRC exploratory project RIMMEL provides information about litter, mainly plastic waste, entering the European Seas through river systems. RIMMEL has collected data on riverine floating macro litter inputs to the sea. Data acquisition was based on the Riverine Litter Observation Network (RiLON) activities, which collected data from rivers in the European marine basins over a period of one year (September 2016 – September 2017). Data was collected by visual observations and documented with the JRC Floating Litter Monitoring Application for mobile devices, allowing a harmonized reporting, compatible with the MSFD Master List of Categories for Litter Items. This report includes the Top Items lists of riverine floating macro litter, based on the total amount of litter items identified during RiLON activities and ranked by abundance. Top Items lists have been elaborated considering the whole database for the European Seas and further detailed for each individual European regional sea: Baltic Sea, Black Sea, Mediterranean Sea and North-East Atlantic. The North-East Atlantic and the Mediterranean Sea regions showed similar litter categories in their Top 20 Items. These two regions provided most of the available data, influencing the general Top Items list. In the Black Sea and Baltic Sea regions, where data availability was limited, the Top Items lists showed more differences among the different regions. Overall, the general Top Items list for the European Seas showed a predominance of plastic item categories (artificial polymer materials). As a whole, plastic items made up to 80.8% of all objects, with plastic and polystyrene fragments comprising 45% of the identified items in the database. Additionally, Single Use Plastics such as bottles, cover/packaging and bags were also ranked among the most frequently found floating litter. The similarities in the Top 10 and Top 20 items for the different regions, and the appearance of Single Use Plastics scoring high in the ranking, support the need for common actions against plastic pollution at EU level.

 

Schöneich-Argent R, Dau K, Freund H (2020) Wasting the North Sea? A field-based assessment of anthropogenic macrolitter loads and emission rates of three German tributaries. Environmental Pollution. 263 (2020) 114367. https://doi.org/10.1016/j.envpol.2020.114367 Download Full Paper

Abstract...

Research into the scope of litter pollution in freshwater systems has shown similar levels to the marine and coastal environment. Global model estimates of riverine emission rates of anthropogenic litter are largely based on microplastic studies as long-term and holistic observations of riverine macroplastics are still scarce. This study therefore aims to contribute a detailed assessment of macrolitter in the transitional waters of three major North Sea tributaries: Ems, Weser, and Elbe. Litter surveys were carried out in four river compartments: along the embankment, on the river surface, in the water column, and on the river bed. The data revealed spatio-temporal variability and distinct pollution levels for each compartment. Beaches had the highest debris diversity and were significantly more littered than vegetated sites and harbors. Stony embankments were least polluted. Benthic litter levels appeared substantial despite rapid burial of objects being likely due to high suspended sediment loads. Two extrapolation approaches were tested to scale daily and annual litter emission quantities of surface- and subsurface-floating litter. Using the mean (median) litter item mass from water column samples, total annual mass discharges were calculated: ∼0.9 (0.2) t y1 to ∼2.8 (0.5) t y1 emitted via the Ems, ∼1.3 (0.2) t y1 to ∼12.0 (1.9) t y1 through the Weser, and ∼14.7 (2.4) t y1 to ∼801 (128) t y1 carried into the North Sea by the Elbe. These rates deviate considerably from previous model estimates of plastic loads discharged by these three rivers. Future studies should therefore ground-truth model estimates with more river-specific and long-term field observations. Overall, the estimated plastic debris discharge quantities account for <1% of the total mass of mismanaged plastic waste per catchment.

Schöneich-Argent R, Dau K, Freund H (2020) Assessing litter loads and estimating macroplastic emission rates of three major North Sea tributaries – Ems, Weser, and Elbe – through holistic, field-based observations. Geophysical Research Abstracts, https://meetingorganizer.copernicus.org/EGU2020/EGU2020-5891.html, EGU General Assembly 2020 Download Presentation

 

Schoeneich-Argent R, Freund H, Hillmann F, Schaal P, Stephan K (2018) A wooden, scientific "message in a bottle" – German university team researches sources and dispersal of macroplastics through large-scale public participation experiment. Vortrag bei der 6th International Marine Debris Conference (6IMDC), San Diego, USA. URL (Book of Abstracts): http://internationalmarinedebrisconference.org/wp-content/uploads/2018/10/6IMDC_Book-of-Abstracts_2018.pdf

Abstract...

Regular beach cleanups provide insight into quantitative and qualitative changes of litter over time, and are a tool to raise public awareness. Yet there is agreement that it is necessary to combat plastic waste at its sources. Since mid-2016, an interdisciplinary project (Macroplastics Pollution in the Southern North Sea – Sources, Pathways and Abatement Strategies) from the Carl von Ossietzky University Oldenburg, Germany, has been researching the input and dispersal of macroplastics. Combining numerical models with monitoring, experimental field work, stakeholder analysis and citizen science, it aims to identify the origins of plastic pollution along the German North Sea coastline, the major tributaries Ems, Weser and Elbe, and in the German Bight. The goal is to provide governmental and non-governmental organisations with solid data and improved knowledge of the sources, pathways and accumulation areas of marine debris in order to devise acceptable and effective abatement strategies. A core component of this project is the release of wooden drifters – 9,000 to 10,000 per season – over a 2-year period at selected locations which are likely plastic litter source points (Fig. 1). Each drifter is branded with an individual ID and a message in German and English, inviting every finder to report ID, date and location via the project website (Fig. 2). Almost 50 % of the >24,000 drifters released so far have been registered from places in Germany, the Netherlands, Denmark and Norway. These data are used to validate and improve drift models, identify litter hotspots, and infer the possible sources of beached litter due to the known release points of the wooden drifters (back-tracking). Here we present initial, GIS-based results of report patterns and experiences from this unique, large-scale public participation experiment.

 

 

Verbreitungspfade und Ansammlungsgebiete:

 

Aden C, Stephan K (2017) Web-based Citizen Involvement in Research into Pathways and Hotspots of Marine Litter in the Southern North Sea. GI_Forum 2017, Issue 2 Page: 60 - 77. doi:10.1553/giscience2017_02_s60 Download Full Paper

Abstract...

This paper demonstrates a way in which citizens can be effectively involved in data collection to generate new knowledge about pathways and hotspots of marine litter abundance in the North Sea region of Germany. This should help to tackle the problem within an interdisciplinary research approach. We use a combination of in-situ experiments involving the release of degradable wooden drifters into the North Sea and a web-based survey provided by the Geospatial Content Management System (GeoCMS) ‘HotSpot’ to report drifter sightings. The focus lies on the techniques used to provide the web-based report tool as well as on the methods used to ensure data quality and inform participants via web mapping tools. We present an overview of the first results, which are also available in the project’s web portal, to increase public awareness of the global litter problem, in particular macroplastics in the oceans and along the North Sea coast.

Gutow L, Ricker M, Holstein JM, Dannheim J, Stanev EV, Wolff J-O (2018) Distribution and trajectories of floating and benthic marine macrolitter in the south-eastern North Sea. Marine Pollution Bulletin 131 763-772, doi: 10.1016/j.marpolbul.2018.05.003 https://www.sciencedirect.com/science/article/abs/pii/S0025326X18303102

Abstract...

In coastal waters the identification of sources, trajectories and deposition sites of marine litter is often hampered by the complex oceanography of shallow shelf seas. We conducted a multi-annual survey on litter at the sea surface and on the seafloor in the south-eastern North Sea. Bottom trawling was identified as a major source of marine litter. Oceanographic modelling revealed that the distribution of floating litter in the North Sea is largely determined by the site of origin of floating objects whereas the trajectories are strongly influenced by wind drag. Methods adopted from species distribution modelling indicated that resuspension of benthic litter and near-bottom transport processes strongly influence the distribution of litter on the seafloor. Major sink regions for floating marine litter were identified at the west coast of Denmark and in the Skagerrak. Our results may support the development of strategies to reduce the pollution of the North Sea.

Hahner F, Meyerjürgens J, Ricker M (2019) Lagrangesche Modellierung und Beobachtungen in der Nordsee. Poster. Abschlusssymposium Download Poster

Meyerjürgens J, Badewien TH, Garaba SP, Wolff J-O and Zielinski O (2019) A State-of-the-Art Compact Surface Drifter Reveals Pathways of Floating Marine Litter in the German Bight. Front. Mar. Sci. 6:58. doi: 10.3389/fmars.2019.00058  Download Full Paper

Abstract...

Lagrangian observations are important for the understanding of complex transport patterns of floatingmacroscopic litter items at the ocean surface. Satellite-tracked drifters and numerical models are an important source of information relevant to transport processes as well as distribution patterns of floating marine litter (FML) on a regional to global scale. Sub-mesoscale processes in coastal and estuarine systems have an enormous impact on pathways and accumulation zones of FML and are yet to be fully understood. Here we present a state-of-the-art, low-cost and robust design of a satellite-tracked drifter applicable in studying complex pathways and sub-mesoscale dynamics of floating litter in tidally influenced coastal and estuarine systems. It is compact, lightweight <5 kg, capable of refloating, easily recovered and modified. The drifter motion resolves currents of the ocean surface layer (top 0.5m layer) taking into account wind induced motions. We further showcase findings from seven of our custom-made drifters deployed from RV Heincke and RV Senckenberg in the German Bight during spring and autumn 2017. Drifter velocities were computed from high resolved drifter position data and compared to local wind field observations. It was noted that the net transport of the drifters in areas far away from the coast was dominated by wind-driven surface currents, 1% of the wind speed, whereas the transport pattern in coastal areas was mainly overshadowed by local small-scale processes like tidal jet currents, interactions with a complex shoreline and fronts generated by riverine freshwater plumes.

Ricker M, Stanev EV (2020) Circulation of the European Northwest Shelf: a Lagrangian perspective. Ocean Science 16(3), 637-655 doi.org/10.5194/os-16-637-2020. Download Full Paper

Abstract...

The dynamics of the European northwest shelf (ENWS), the surrounding deep ocean, and the continental slope between them are analysed in a framework of numerical simulations using Lagrangian methods. Several sensitivity experiments are carried out in which (1) the tides are switched off, (2) the wind forcing is low-pass filtered, and (3) the wind forcing is switched off. To measure accumulation of neutrally buoyant particles, a quantity named the “normalised cumulative particle density (NCPD)” is introduced. Yearly averages of monthly results in the deep ocean show no permanent particle accumulation areas at the surface. On the shelf, elongated accumulation patterns persist in yearly averages, often occurring along the thermohaline fronts. In contrast, monthly accumulation patterns are highly variable in both regimes. Tides substantially affect the particle dynamics on the shelf and thus the positions of fronts. The contribution of wind variability to particle accumulation in specific regions is comparable to that of tides. The role of vertical velocities in the dynamics of Lagrangian particles is quantified for both the eddy-dominated deep ocean and for the shallow shelf. In the latter area, winds normal to coasts result in upwelling and downwelling, illustrating the importance of vertical dynamics in shelf seas. Clear patterns characterising the accumulation of Lagrangian particles are associated with the vertical circulations.

Ricker M (2018) Particle transport model sensitivity on wave-induced processes in the coupled model system. COMOD Download Poster

Ricker M, Stanev EV, Badewien TH, Freund H, Meyerjürgens J, Wolff J-O, Zielinski O (2019) Drifter observations and Lagrangian tracking of the 2018 easterly wind event in the North Sea. Copernicus Marine Service Ocean State Report, Issue 4. Journal of Operational Oceanography, submitted February 2020, accepted

Schöneich-Argent R, Hillmann F, Cordes D, Wansing RAD, Merder J, Freund JA, Freund H (2019) Wind, waves, tides, and human error? – Influences on litter abundance and composition on German North Sea coastlines: An exploratory analysis. Marine Pollution Bulletin. 146 (2019) 155–172. https://doi.org/10.1016/j.marpolbul.2019.05.062 https://www.sciencedirect.com/science/article/abs/pii/S0025326X19304308

Abstract...

Being globally and locally prevalent, beach litter has been monitored at 29 sites along the German North Sea coastline. This study offers an exploratory analysis of data from 1991 to 2016. Schleswig-Holstein exhibited lower mean litter pollution levels than Lower Saxony, possibly because the locations in Lower Saxony are situated along the main coastal current, whereas the North Frisian Islands act as a barrier for the mainland sites in Schleswig-Holstein. Locations close to the Elbe estuary had significantly larger amounts of debris, likely receiving litter from marine and riverine sources. No clear overall pattern in litter abundance or composition could be detected. Significant quantitative similarities between debris types were inconsistent. The effect of wind, tides, and exposure appeared to be marginal. Recurring data inconsistencies, gaps, and outliers were partly attributed to human error. This could be reduced through hypothesis-driven monitoring with a simpler litter classification and continuous data checking.

Download Poster

Schönung M, Lettmann K, Fiesinger A, Wüllner T, Hahner F, Suckow J, Schöneich-Argent RI, Meyerjürgens J, Tietjen B, Badewien T, Zielinski O, Aden C, Schaal P, Mose I, Stanev E, Freund H and Wolff J-O (2019) Modellierung des Transportes von oberflächennahem Makroplastik in der Weser und Bestimmung seines Eintrages in die Deutsche Bucht. Poster. Abschlusssypmosium Download Poster

Stanev E, Badewien T, Freund H, Grayek S, Hahner F, Meyerjürgens J, Ricker M, Schöneich-Argent R, Wolff J-O, Zielinski O (2019) Extreme westward surface drift in the North Sea: Public reports of stranded drifters and Lagrangian tracking. Continental Shelf Research, 177, 24-32, doi:10.1016/j.csr.2019.03.003

Abstract...

Observations using two kinds of drifters were carried out in the southern North Sea aiming to study the propagation pathways of marine litter. One drifter, which was driven by the upper layer currents, was equipped with Global Positioning System. Further 1600 wooden drifters, mostly driven by wind and Stokes drift, were released offshore in German waters. The detailed reports of stranded wooden drifters from members of the public, the majority of which are likely to be non-scientists, provided a valuable contribution to the drifter experiment demonstrating the usefulness of citizen science. In 2018, an extreme wind event reversed the circulation of North Sea for more than a month which resulted in a large number of wooden drifters being washed ashore on the British coast. Lagrangian numerical experiments, calibrated using data from the drifter observations, helped explain the anomalous transport and the reversal of the circulation at the sea surface and in deeper layers. The plausibility of similar events during past decades has also been estimated using data from atmospheric analyses. Events as strong as the one observed in 2018 occurred only four times in the last 40 years.

Download Full Paper

Download EGU Abstract

Download EGU Presentation

Download Poster

Stanev EV, Ricker M (2019) The Fate of Marine Litter in Semi-Enclosed Seas: A Case Study of the Black Sea. Frontiers in Marine Science, 6:660. doi: 10.3389/fmars.2019.00660 Download Full Paper

Abstract...

The accumulation patterns of floating marine litter (FML) in the Black Sea and the stranding locations on coasts are studied by performing dedicated Lagrangian simulations using freely available ocean current and Stokes drift data from operational models. The low FML concentrations in the eastern and northern areas and the high concentrations along the western and southern coasts are due to the dominant northerlies and resulting Ekman and Stokes drift. No pronounced FML accumulation zones resembling the Great Pacific Garbage Patch are observed at time scales from months to a year. The ratio of circulation intensity (measured by the sea level slope) to the rate of the temporal variability of sea level determines whether FML will compact. This ratio is low in the Black Sea, which is prohibitive for FML accumulation. It is demonstrated that the strong temporal variability of the velocity field (ageostrophic motion) acts as a mixing mechanism that opposes another ageostrophic constituent of the velocity field (spatial variability in sea level slope, or frontogenesis), the latter promoting the accumulation of particles. The conclusion is that not all ageostrophic ocean processes lead to clustering. The short characteristic stranding time of 20 days in this small and almost enclosed basin explains the large variability in the total amount of FML and the low FML concentration in the open ocean. The predominant stranding areas are determined by the cyclonic general circulation. The simulated distribution of stranded objects is supported by available coastal and near-coastal observations. It is shown that the areas that were the most at risk extend from the Kerch Strait to the western coast.

Stanev EV, Ricker M (2020) Interactions between barotropic tides and mesoscale processes in deep-ocean and shelf regions. Ocean Dynamics, 70, 713-728, doi: 10.1007/s10236-020-01348-6 Download Full Paper

Abstract...

The interactions between barotropic tides and mesoscale processes were studied using the results of a numerical model in which tidal forcing was turned on and off. The research area covered part of the East Atlantic Ocean, a steep continental slope, and the European Northwest Shelf. Tides affected the baroclinic fields at much smaller spatial scales than the barotropic tidal scales. Changes in the horizontal patterns of the M2 and M4 tidal constituents provided information about the two-way interactions between barotropic tides and mesoscale processes. The interaction between the atmosphere and ocean measured by the work done by wind was also affected by the barotropic tidal forcing. Tidal forcing intensified the transient processes and resulted in a substantial transformation of the wave number spectra in the transition areas from the deep ocean to the shelf. Tides flattened the sea-surface height spectra down to ~ k−2.5 power law, thus reflecting the large contribution of the processes in the high-frequency range compared to quasi-geostrophic motion. The spectra along sections parallel or normal to the continental slope differ from each other, which indicates that mesoscale turbulence was not isotropic. An analysis of the vorticity spectra showed that the flattening was mostly due to internal tides. Compared with the deep ocean, no substantial scale selectivity was observed on the shelf area. Particle tracking showed that the lengths of the Lagrangian trajectories increased by approximately 40% if the barotropic tidal forcing was activated, which contributed to changed mixing properties. The ratio between the horizontal and vertical scales of motion varied regionally depending on whether barotropic tidal forcing was included. The overall conclusion is that the barotropic tides affect substantially the diapycnal mixing.

Staneva J, Ricker M, Krüger O, Breivik O, Stanev E, Schrum C (2017) Particle transport model sensitivity on wave-induced processes. Geophysical Research Abstracts, 19, EGU2017-2968. EGU General Assembly 2017, https://meetingorganizer.copernicus.org/EGU2017/EGU2017-2968.pdf

Abstract...

Different effects of wind waves on the hydrodynamics in the North Sea are investigated using a coupled wave (WAM) and circulation (NEMO) model system. The terms accounting for the wave-current interaction are: the Stokes-Coriolis force, the sea-state dependent momentum and energy flux. The role of the different Stokes drift parameterizations is investigated using a particle-drift model. Those particles can be considered as simple representations of either oil fractions, or fish larvae. In the ocean circulation models the momentum flux from the atmosphere, which is related to the wind speed, is passed directly to the ocean and this is controlled by the drag coefficient. However, in the real ocean, the waves play also the role of a reservoir for momentum and energy because different amounts of the momentum flux from the atmosphere is taken up by the waves. In the coupled model system the momentum transferred into the ocean model is estimated as the fraction of the total flux that goes directly to the currents plus the momentum lost from wave dissipation. Additionally, we demonstrate that the wave-induced Stokes-Coriolis force leads to a deflection of the current. During the extreme events the Stokes velocity is comparable in magnitude to the current velocity. The resulting wave induced drift is crucial for the transport of particles in the upper ocean. The performed sensitivity analyses demonstrate that the model skill depends on the chosen processes. The results are validated using surface drifters, ADCP, HF radar data and other in-situ measurements in different regions of the North Sea with a focus on the coastal areas. The using of a coupled model system reveals that the newly introduced wave effects are important for the drift-model performance, especially during extremes. Those effects cannot be neglected by search and rescue, oil-spill, transport of biological material, or larva drift modelling.

Download EGU Presentation

Wüllner T, Lettmann K, Meyerjürgens J, Hahner F (2019) BLEX: Beaching Litter EXperiment. Poster. Abschlusssymposium Download Poster

 

Vermeidungsstrategien:

 

Barrelet J, Schöneich-Argent RI (2020) Dokumentation Stakeholder-Workshop: „Makroplastik Nordsee – Verminderungs- und Vermeidungsstrategien". Carl von Ossietzky Universität Oldenburg Download Full Report

Barrelet J (2019) Evaluation und Priorisierung von Maßnahmen zur Verminderung und Vermeidung von Plastikeinträgen in die Nordsee Poster. Abschlusssymposium Download Poster

Martin MC, Binder FI, Schöneich-Argent R (2019) Einflussfaktoren der Müllverteilung und -zusammensetzung an zwei regionalen Touristenzielen: Wilhelmshaven und Dangast Poster. Abschlusssymposium Download Poster

Der Müllkoffer

Das interaktive Lehrangebot „Müllkoffer“ widmet sich der Aufklärung von Kindern und Jugendlichen über die Plastikproblematik im Meer, um einen nachhaltigen Umgang mit dieser Thematik zu fördern. Es umfasst Informations-, Aufgaben- und Lösungsmaterial sowie Anregungen zu Experimenten, Spielen und Exkursionen. Das Material entstand in Zusammenarbeit mit dem „Lernlabor Wattenmeer“ (Biologiedidaktik der Universität Oldenburg) und mit finanzieller Unterstützung der Barthel Stiftung. Die insgesamt sieben „Müllkoffer“-Exemplare können von Schüler*innen, Lehrer*innen, Umweltpädagog*innen und Naturschutzorganisationen kostenfrei bei den beteiligten Projektpartnern ausgeliehen werden. Weitere Informationen unter:

https://uol.de/icbm/arbeitsgruppen/muellkoffer

Müllkoffer