BazTech - Yadda

1

Open-loop scrubbers and restricted waterways: A aase study investigation of travemünde port and increased sulphur emissions immediately after the scrubbers are turned off

Altarriba E., Rahiala S., Tanhuanpää T.

TransNav : International Journal on Marine Navigation and Safety of Sea Transportation

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2023

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Vol. 17 No. 2

465--471

EN

Open-loop sulphur scrubbers must be switched off, and the fuel must be changed to low-sulphur fuel before entering German inland waters. Immediately after the scrubbers are turned off, warm exhaust gases cause the residue left in the scrubber to vaporise, leading to the increased sulphur content of the exhaust gas. The momentary increase in sulphur emissions immediately after the open-loop scrubbers are turned off has received little attention in research. This paper presents the onboard measurement results of exhaust gases and examines the effects of sulphur compounds released into the air. In this case, the observed sulphur emission peak is problematic due to the geographical location. The ship sails to the river port, passing the coastal town of Travemünde, where the exhaust gases are released. Due to this, the emissions are more harmful when compared to emissions generated in the open seas.

2

Using the Coastal Clean Index to assess the impact of anthropogenic pressure on sandy beaches in Ustka, Poland

Bigus Katarzyna, Jarosiewicz Anna

Studia Quaternaria

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2023

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Vol. 40, Nr 2

67--76

EN

The article summarizes results of the studies of the Coastal Clean Index (CCI) on selected Polish beaches. In 2022, an attempt was made to estimate the amount of litter on the beach in Ustka. Debris on the beach was collected during a peak season in July and August. An attempt was also made to estimate the daily increase in garbage on the beach. The main part of the research was based on the quality and quantity of litter in beach sediments to the east and west of Ustka. Litter was divided according to a type of material, use, size and origin. The collected material was dominated by a plastic waste. The largest amount of marine litter was collected on the beach, on the eastern side of the Słupia River.

3

Preliminary approach to modelling eutrophication - anthropopressure impact on sea water quality

Bogalecka Magdalena

Safety and Reliability of Systems and Processes

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2023

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Summer Safety and Reliability Seminar 2023

19--31

EN

The chapter is devoted to the problem of eutrophication. Methods and parameters for its assessment are described. Furthermore, the eutrophication of the Baltic Sea is discussed in detailed. Finally, the semi-Markov model of the eutrophication process is proposed, and its characteristics are determined.

4

Kartografia 4D w strefie brzegowej południowego Bałtyku : zadanie państwowej służby geologicznej

Uścinowicz Grzegorz

Przegląd Geologiczny

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2023

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Vol. 71, nr 3

138--144

EN

The research task Geological integrated coastal zone mapping concerns the recognition and visualization of the geological structure of the Polish coastal zone, enriched with the modelling of erosion-accumulation processes, including prediction of changes in the position of the shoreline and identification of geohazards. It has been running since 2012 and implements multi-instrumental research methods. To date, a total length of about 155 km of the Polish coastal zone has been studied in an area of about 621 km 2 . The main results of the work are presented in the form of maps (e.g., lithogenetic, hydrogeological, geohazard), models (e.g., morpho-geological, hydrodynamic, predictive) and specialized analyses (e.g., morphodynamical, slope stability). In general, the work carried out is done for a utilitarian purpose, i.e. aimed at the practical use of environmental information. According to the standards of the Polish Geological Survey, most of the geological data acquired can be geoprocessed.

5

Potencjał południowego Bałtyku jako miejsca lokalizacji elektrowni falowych

Jakusik Ewa, Sapiega Patryk

Przegląd Budowlany

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2023

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R. 94, nr 11-12

96--101

PL

Wyczerpywanie się surowców nieodnawialnych oraz ich możliwy negatywny wpływ na środowisko i klimat skłania do wyszukiwania alternatywnych metod wytwarzania energii elektrycznej. W pracy przedstawiono analizę możliwości pozyskiwania energii z falowania w południowej części Morza Bałtyckiego w oparciu o reanalizę i pomiary falowania, zlokalizowanymi w dwóch różnych strefach głębokościowych. Maksymalna możliwa energia do wygenerowania mieści się w przedziale 5,7-7,2 kW/m grzbietu fali. Na podstawie danych pomiarowych falowania oraz danych producenta elektrowni pływakowej oszacowano, iż 71-88 km modułów pływakowych mogłoby zaopatrzyć w energię elektryczną aglomerację trójmiejską, a średnia wartość wytworzonej energii plasowałaby się w przedziale 100-169 kW. Przeprowadzona analiza wskazuje na przeciętny potencjał Bałtyku Południowego, związany z krótkookresowymi, wysokimi stanami hydrodynamicznymi morza.

EN

Depletion of non-renewable resources keep us for searching of new alternative methods of generating electricity. There were possibilities in the paper that two of the undulations that are consistent with the experience of the Baltic Sea based on reanalysis and wave measurements, operating based on different depth zones. The maximum power this system can generate is within 5,7-7,2 kW per meter of a wave rigde. Based on the waving mesurments and manufactures data of this kind wave plant, the length 71-88 km of modules could be supply Tri-city agglomeration consumption. Average power of installation would be range 100-169 kW. The conducted analysis access to the average potential of the South Baltic Sea, research with short-term, fast hydrodynamic states of the sea.

6

Variations of temperature, salinity and oxygen of the Baltic Sea for the period 1950 to 2020

Stockmayer Vera, Lehmann Andreas

Oceanologia

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2023

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Vol. 65 (3)

466--483

EN

Variations of temperature, salinity and oxygen of the Baltic Sea on interannual to decadal timescales were studied for the period from 1950 to 2020. Both observational data and the output of a numerical circulation model of the Baltic Sea were analyzed. In addition, we investigated the influence of atmospheric parameters and river runoff on the observed hydrographic variations. Variability of sea surface temperature (SST) closely follows that of air temperature in the Baltic on all timescales examined. Interannual variations of SST are significantly correlated with the North Atlantic Oscillation in most parts of the sea in winter. The entire water column of the Baltic Sea has warmed over the period 1950 to 2020. The trend is strongest in the surface layer, which has warmed by 0.3–0.4°C decade−1, noticeably stronger since the mid-1980s. In the remaining water column, characterized by permanent salinity stratification in the Baltic Sea, warming trends are slightly weaker. A decadal variability is striking in surface salinity, which is highly correlated with river runoff into the Baltic Sea. Long-term trends over the period 1950–2020 show a noticeable freshening of the upper layer in the whole Baltic Sea and a significant salinity increase below the halocline in some regions. A decadal variability was also identified in the deep layer of the Baltic Sea. This can be associated with variations in saltwater import from the North Sea, which in turn are influenced by river runoff: fewer strong saltwater inflows were observed in periods of enhanced river runoff. Furthermore, our results suggest that changes in wind speed have an impact on water exchange with the North Sea. Interannual variations of surface oxygen are strongly anti-correlated with those of SST. Likewise, the positive SST trends are accompanied by a decrease in surface oxygen. In greater depths of the Baltic Sea, oxygen decrease is stronger, which is partly related to the observed increase of the vertical salinity gradient.

7

Seasonal variation in size structure and production of autotrophic plankton community in eutrophied, low-light environment: A focus on Mesodinium rubrum

Labucis Atis, Labuce Astra, Jurgensone Iveta, Barda Ieva, Andersone Ingrida, Ikauniece Anda

Oceanologia

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2023

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Vol. 65 (2)

398--409

EN

Temporal variations in the primary production of the size-fractionated autotrophic plankton community were studied in coastal-estuarine waters of the eutrophic Gulf of Riga, Baltic Sea. The community was net-autotrophic during spring and summer and net-heterotrophic during autumn. The results of the present study clearly demonstrate strong covariation between net primary production (NPP) and <56 µm fractionated community biomass, particularly small-sized (16–33 µm) Mesodinium rubrum, implying that the majority of NPP stems from the lower end of the size spectrum. A pronounced size distribution shift was observed within the M. rubrum population. Large-sized (length ≥34 µm) M. rubrum was the most abundant in the first half of the productive season (until week 24), whereas small-sized M. rubrum dominated during the stratified period.

8

Rapid sea-level rise during the first phase of the Littorina transgression in the western Baltic Sea

Stattegger Karl, Leszczyńska Karolina

Oceanologia

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2023

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Vol. 65 (1)

202--210

EN

Glacio-isostatic adjustment (GIA) corrected limiting non-marine and marine sea-level data from the western Baltic Sea indicate a rapid relative sea-level (RSL) rise of 18 m for the first phase of the Littorina transgression using a linear age-elevation model. This accelerated RSL rise occurred in the time period 8.57 to 8.0 ka before present (BP) with an RSL rise rate of 31.5 mm/year. RSL rose from 28 m to 10 m below the mean relative sea level (bmrsl) during the time period of less than 600 years. The first phase of Littorina transgression documents the last big meltwater pulse (MWP), which has been reported also from various other regions in the world as a consequence of the final decay of the Laurentide ice sheet and additional meltwater sources from Antarctica.

9

Projections of wind climate and wave energy resources in Lithuanian territorial waters of the Baltic Sea in the 21st century

Jakimavičius Darius, Akstinas Vytautas

Oceanologia

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2023

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Vol. 65 (4)

534--547

EN

Wave energy is still insufficiently explored and exploited as a future energy source. Climate change is an additional force that affects energy potential changes. Therefore, this study aims to evaluate the wave energy under climate change and to project it for the near (2025–2044) and far (2081–2100) future by applying the wave energy flux (WEF) approach and statistical relations between wind speeds and wave heights. The study was concentrated on the Baltic Sea nearshore at the Lithuanian territorial water. The analysis of existing relations between wind speeds and wave heights was found based on historical observations of the reference period (1995–2014), and the projections of WEF were created using the downscaled output of best-fit global climate models (GCMs) according to four scenarios of Shared Socioeconomic Pathways (SSP). The results indicated strong relations between wind speed and wave height, especially for the west-origin winds. Depending on the selected scenarios, the projected WEF may increase up to 10% (SSP5-8.5) and 11% (SSP1-2.6) in the near and far future respectively. The absence of large differences between the periods may be caused by the rough resolution of grid cells of GCMs. The comparison with the results based on regional climate models output could be a future perspective in order to reach a better representation of regional forces and to introduce more clarity to the obtained results. The results of this study may be advantageous for the primary planning of renewable energy sources (RES) development, especially in the face of climate change.

10

Perceptions of an endangered Baltic Sea

von Storch Hans

Oceanologia

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2023

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Vol. 65 (1)

44--49

EN

In a series of ad-hoc surveys at different academic institutions in the Baltic Sea region, students and young scholars were asked about their views about the environmental issues of the Baltic Sea, and who would be responsible for the management of the Baltic Sea. Overfishing, climate change and waste were considered the most significant issues, while tourism and constructions (of bridges, etc.) were less often recognized as severe. The responsibility for the management of the Baltic Sea was mostly attributed to the European Union or to the respective national governments. Since climate is one of these issues, one question has dealt with the main task of climate science. It turns out that the most frequent assertion was not the genuine scientific task of generating knowledge about the dynamics of the system. Instead, the task of solving the problem and, equally often, supporting climate activism was favored. The results are not representative – neither for the separate surveys, nor for the selection of the sites of surveying. However, when taken all surveys together, the emergence of consistent perceptions may be considered evidence for a general attitude among students and young scholars in the Baltic regions. However, differences between groups – in terms of nationality, seniority and discipline - may be related to sampling randomness.

11

Natural and anthropogenic influences on the development of mud depocenters in the southwestern Baltic Sea

Porz Lucas, Zhang Wenyan, Schrum Corinna

Oceanologia

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2023

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Vol. 65 (1)

182--193

EN

The morphological evolution of two mud depocenters in the southwestern Baltic Sea is investigated by comparison of numerical model results to geological and oceanographic data. The pathways of dense currents during episodic dense-water inflows from the North Sea are shown to correspond to current pathways inferred from contouritic depositional geometries in the flow-confining channels within the study area. A favorable comparison of model results to published current speed observations shows that the mesoscale dynamics of individual inflow events are reproduced by the model, indicating that external forcing and basin geometry rather than internal dynamics control the mesoscale dynamics of inflow events. The bottom current directions during inflows show high stability in the flow-confining channels and explain the contouritic depositional geometries. Asymmetric depositional features in the channels are qualitatively reproduced in the model. Bottom currents are less stable in areas without contouritic features, possibly resulting in an overall diffusive effect on sediment distribution in those areas. In a simulation of resuspension by bottom-contacting fishing gear, inter-basin sediment transport is increased by 4–30%, depending on the area, compared to the case of natural hydrodynamic resuspension. The model predicts an increased winnowing of the finest sediment fraction due to bottom trawling, leading to an overall coarsening-to-fining trend in the direction of net sediment transport. The results show that rather than hemi-pelagic background sedimentation, episodic events with high bottom current velocities as well as bottom-trawling induced resuspension are responsible for the present-day and future morphological configuration of the mud depocenters in the southwestern Baltic Sea.

12

Model estimates of microplastic potential contamination pattern of the eastern Gulf of Finland in 2018

Martyanov Stanislav D., Isaev Alexey, Ryabchenko Vladimir A.

Oceanologia

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2023

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Vol. 65 (1)

86--99

EN

The work is focused on the assessment of microplastics transport and distribution in the eastern part of the Gulf of Finland by means of numerical modeling. In the present study only the riverine sources of microplastics are taken into account. The presented model also accounts for possible sink of suspended microplastic particles into sediments due to simple parameterization of biogeochemical processes such as biofouling and ingestion by zooplankton. Two basic scenarios with different initial fall velocities of suspended microplastic particles, 0.2 m/day and 1.2 m/day, are discussed. The distribution of microplastics coming with the riverine waters of the Neva, Luga, and Narva rivers has been investigated, based on a numerical hydrodynamical hindcast of the year 2018. Model simulations show that the transport of suspended microplastics occurs along the northern coast of the considered area more intensively compared to the southern coast, especially in the easternmost shallow part of the gulf. The results are in a good agreement with other studies focused on the microplastic pollution of the Neva Bay, and with available observational data. The presented results and developed model can be useful tools aimed to assess the intensity and mechanisms of microplastic pollution of the eastern Gulf of Finland. The results can be used in the selection of areas for future environmental monitoring of microplastics pollution of the eastern part of the Gulf of Finland.

13

Intermediate plumes of low oxygen in the southeastern Baltic Sea

Golenko Maria, Paka Vadim, Zhurbas Victor, Korzh Andrey, Kondrashov Alexey

Oceanologia

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2023

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Vol. 65 (1)

100--116

EN

Closely spaced CTDO profiling on the pathway of saltwater flow in the southeastern Baltic Sea in August and December 2019 revealed low oxygen intermediate layers-plumes with dissolved oxygen concentration (DOC) less than 2 mg/l under the upper boundary of permanent halocline. At the same time, DOC in the underlying layers was higher and reached 5.0–5.3 mg/l. In order to test the hypotheses about the origin of the intermediate hypoxic plumes, numerical hydrodynamic modelling was performed for time intervals including the measurement periods. The model was validated against bottom current velocity instrumental measurements by a TCM (Tilt Current Meter) moored on the track of the CTDO profiling. Numerical experiments with Lagrangian particles of neutral buoyancy coupled with the operational circulation model showed that sub-halocline hypoxic intermediate layers in the southern part of the Eastern Gotland Basin and in the Gdańsk Basin could be formed as a result of intrusion into the underlying bottom layer of denser, moderately oxygenated water from the Słupsk Furrow, which replaced the old anoxic and hypoxic water of Gotland and Gdańsk origin. It is assumed that cyclonic eddy activity above the saltwater flow along sloping bottom caused fragmentation of the hypoxic intermediate layer into separate plumes. The hypoxic intermediate layers in the Słupsk Furrow, in accordance with the results of monitoring measurements and modelling the motion of particles of neutral buoyancy, could be formed in the Bornholm Basin and moved eastward over the Słupsk Sill.

14

Bursztyn z Polski – żywiczny skarb i kopalina przyszłości – przegląd wiedzy o zasobach surowca

Młynarczykowska Anna

Inżynieria Mineralna

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2023

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no. 1

313--319

PL

Artykuł stanowi omówienie zmieniającego się znaczenia kulturowo-gospodarczego bursztynu bałtyckiego oraz opracowanie ilościowej oceny wykazów zasobów złóż bursztynonośnych za lata 2012–2023 w oparciu rozpoznanie geologiczne i opracowania naukowe. Autorka przedstawia wybrane aktualne aspekty formalno-prawne w odniesieniu do złoża strategicznego jakim stać się bursztyn.

EN

The article is a discussion of the changing cultural and economic importance of Baltic amber and the development of a quantitative assessment of amber-bearing deposits for the years 2012–2023 based on geological exploration and scientific studies. The author presents selected current formal and legal aspects in relation to the strategic deposit of amber.

15

Energetyczny wiatr od morza

Kowalczyk Artur

Energia i Recykling : gospodarka obiegu zamkniętego

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2023

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nr 5

PL

Morska energetyka wiatrowa (MEW) może być wkrótce jednym z ważniejszych elementów niezależności energetycznej Polski oraz istotną częścią miksu OZE. Sprzyjające warunki do rozwoju tego segmentu energii na Bałtyku, które wykorzystuje Ministerstwo Klimatu i Środowiska, pozwolą prawdopodobnie na zbudowanie pierwszych farm wiatrowych już na przełomie 2024 i 2025 roku. Według wielu analityków, morska energetyka wiatrowa należy do najszybciej rozwijających się technologii energetycznych na świecie. W 2021 roku,wg Międzynarodowej Agencji Energii Odnawialnej, na całym globie powstały instalacje o mocy niemal 257 GW, co zwiększa udział w miksie energetycznym o 9%.

16

Estimating the Size of a Crater after an Underwater Explosion

Kiciński Radosław

Advances in Science and Technology. Research Journal

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2023

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Vol. 17, no 5

187--194

EN

There have been terrorist attacks in the Baltic region that used explosives to destroy underwater infrastructure, including the Nord Stream 1 and 2 gas pipelines. Data from the Danish National Seismic Network indicate that two explosions occurred on 26 Sept 2022, causing gas leaks from pipelines. While examining the data from 26 Sept, two disturbing events were observed in the Baltic Sea, which caused tremors of magnitude 2.3 and 2.1 on the Richter scale. Both events had high wave energy, indicating an explosion, not an earthquake. Based on the above data, it was decided to analyze the potential effects of underwater explosions in the area of the Nord Stream gas pipelines. From the point of view of ecology, the volume of material torn up from the bottom is essential. For this purpose, empirical formulas for explosions on land were used, and then the crater's size was estimated per the physics of the underwater explosion phenomenon. Calculations indicate that the explosion of 750 kg of TNT will raise about 20 m3 of the bottom volume into the water column. Because of the explosion, a gas bubble will form directly at the bottom, and it will suck the sand and the impurities contained in it and particles of dead organisms, bringing them to the surface and dispersing them in the water column. These attacks pose a severe environmental and safety risk as gas leaks from pipelines can cause harmful effects on marine ecosystems and people. It also violates international law and international agreements, including the United Nations Convention on the Law of the Sea and the Convention on the Protection of the Marine Environment in the Baltic Sea Region.

17

Biodiversity of the benthic diatom flora in the coastal zone of the Gulf of Gdańsk: a case study of the Gdynia–Sopot transect

Hetko Dominika, Witak Małgorzata, Oliwa Sandra

Oceanological and Hydrobiological Studies

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2022

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Vol. 51, No. 2

224-238

EN

The objective of this study is to determine microhabitat preferences of benthic species occurring in epilithic (living on stones), epipsammic (growing on sand), epipelic (growing on mud) and epiphytic (living on seagrass) assemblages of the shallows of the Gulf of Gdańsk (southern Baltic Sea). The study material was collected from 19 sites along the Gdynia-Sopot coastal zone, including the Port of Gdynia. Most of the identified diatom taxa were observed in two or three microhabitats. However, diatom species living in only one type of microhabitat and those occurring in all analyzed microhabitats were also recorded. Autecological preferences of the identified diatoms indicate organic pollution of the coastal zone of Gdynia and Sopot. However, a higher frequency of α-mesosaprobionts and polysaprobionts indicates an increase in organic pollution in the Port of Gdynia and Marina Sopot, which is associated with intense port activity and large tourist traffic.

18

Validation of measurements of pine pollen grain concentrations in Baltic Sea waters

Pawlik Magdalena M., Ficek Dariusz

Oceanologia

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2022

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No. 64 (2)

233--243

EN

Each spring, pine pollen coats considerable expanses of Baltic Sea surface waters. Measurements have shown that there are areas where its concentrations in this surface layer are so high that they are the dominant constituent of the suspended particulate matter (SPM) (Pawlik and Ficek, 2016). It then determines to a large extent the optical properties of the water surface, inter alia by modifying the sea colour. To date, however, the concentration of this constituent in the marine environment has rarely been studied, and its presence is not accounted for in the satellite algorithms used to define the composition and properties of sea water. This may well be the source of substantial errors in the remote sensing of the optical properties of the water and the measurement of concentrations of the optically important constituents it contains (chlorophyll a, TSM, CDOM). Measuring the concentration of pollen suspensions in Baltic Sea water, which often contains prodigious amounts of other SPM, is a daunting experimental challenge. Firstly, we characterized the pollen from pine trees growing near the southern shores of the Baltic Sea (northern Poland) using a microscope and two instruments routinely used in oceanography for measuring SPM size distributions: the LISST-100X and the Coulter counter. The measurements and analyses showed that a correct interpretation of the LISST-100X and Coulter measurements, is sufficient to count the number of pollen grains in distilled water alone. Furthermore, our laboratory analysis of the particle size distribution spectra enabled the fraction due only to pine pollen grains to be separated from the overall SPM. We then tested our method of analysing the SPM composition, which showed that the LISST-100x instrument is both a useful and an effective means for the in situ detection of the pine pollen that one sees in spring in Baltic waters.

19

Striped texture of submesoscale fields in the northeastern Baltic Proper : Results of very high-resolution modelling for summer season

Zhurbas Victor, Väli Germo, Kuzmina Natalia

Oceanologia

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2022

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No. 64 (1)

1--21

EN

Very high-resolution modelling of the northeastern Baltic Proper shows that preferentially elongated along the flow, submesoscale inhomogeneities of hydrodynamic fields or stripes of the order of 10–20 km in length and 1 km in width, are typical for summer season both in surface mixed layer and for interior layers which are not directly exposed to atmospheric forcing. In surface layer, the presence of stripes is supported by the remote sensing imagery and their vertical extension is comparable with the mixed layer depth (approx. 5–8 m). In the interior layers, the vertical extension of stripes is considerably larger (approx. 10–50 m) and their slopes exceed the isopycnal slope. Four competitive mechanisms of formation of the mesoscale striped texture are considered: stirring of large-scale inhomogeneities by the eddy field, the classic, inviscid adiabatic fluid symmetric instability, the McIntyre instability, and the strain-induced frontogenesis. Based on the instability criteria and the growth rates and geometry of the disturbances, the classic symmetric instability and the strain-induced frontogenesis are probably responsible for the formation of submesoscale striped texture in the surface layer, while in the interior layers, the strain-induced frontogenesis and hypothetically the McIntyre instability can be essential. Stirring of large-scale inhomogeneities by the eddy field could be responsible for formation of striped texture in a passive tracer concentration and in temperature and salinity in the presence of thermohaline gradients on isopycnic surfaces (thermoclinicity), but it does not imply formation of stripes in dynamically active tracers, such as vertical vorticity, horizontal gradients of buoyancy, etc.

20

Plastic contamination of sandy beaches along the southern Baltic – a one season field survey results

Mazurkiewicz Mikołaj, Martinez Paula Sancho, Konwent Weronika, Deja Kajetan, Kotwicki Lech, Węsławski Jan Marcin

Oceanologia

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2022

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No. 64 (4)

764--780

EN

The subject of this study was microplastics (>32 µm), large micro-/macroplastics (>2 mm) and plastic litter (visible by naked eye) contamination on sandy beaches and in coastal waters along the Polish coast of the Baltic Sea. Microplastics were studied with particular attention, with simultaneous observations in the water and across the beach. Other data was intended to serve as a background and as possible sources of microplastics. Most of the microplastics found were fibers <1 mm long, with blue fibers dominating, followed by transparent, red and green ones, both in sand and water samples. The concentration of microplastics on the beach sand ranged from 118 to 1382 pieces kg−1, while in coastal waters from 0.61 to 2.76 pieces dm−3. As for large micro-/macroplastics and plastic litter, there was no dominant litter along the coast. The amount of large micro-/macroplastics ranged from 2 to 124 pieces m−2 (or from 0.13 to 44.30 g m−2). Regarding plastic litter, on average between 0.03 and 6.15 litter debris m−2 were found (or from 0.007 to 4.600 g m−2). The study confirms that plastic pollution of the Polish coastal zone is a significant problem comparable with both the rest of the Baltic Sea and other seas and oceans. Similar color-based composition of microplastics among all studied sites suggests that they may have a common source, while the contamination of large micro-/macroplastics and plastic litter (both amount of particles and their composition) along the Polish coast is highly site-specific and may be influenced by various local factors.