Environmental challenges in Polish agriculture covering a main area of the Baltic Sea Basin

Poland largely encompases the estuary of the Vistula and Odra rivers, which drain into the Baltic Sea. Only a very small area of the south-east part of the country is within the Black Sea Basin. Poland contributes significantly to the pollution of the Baltic Sea, with biogenic nutrients and organic substances. Poland includes more than half the coastal inhabitants of the Baltic Sea, and they use 40% of the arable land situated there. The contribution to the pollution of this sea with nitrogen, phosphorus and organic substances is approximately 30, 40 and 22%, respectively. The main sources of nutrients are untreated sewage and the runoff and leakage of fertilizers from agricultural land. The natural conditions in Poland are poorer than in Western Europe due to the prevalence of light soils and a short growing period with frequent droughts. After correcting the synthetic index for soil and climate, it was estimated that for each inhabitant of Poland there are 0.3 ha of farmland, which is comparable to that of Western Europe. For the maintenance of the population, intensive agricultural production must be accompanied by environmental protection regulations. Polish agriculture is not only a polluter but also a recipient of pollution, especially the deposits of sulphur and heavy metals emitted by industry and municipal areas. The estimated annual emission of sulphur dioxide is about 4 million t, which equals an average deposit of about 90 kg of sulphur per hectare of farmland. The pedological processes and acid deposits cause more than 60% of agricultural land in Poland to be acidic. The contamination of soils with heavy metals in general is lower than in Western Europe, but in some areas (e.g. Upper Silesia) it exceeds the safe limits.     

The science and management of the North Sea and the Baltic Sea: natural history, present threats and future challenges

The review provides an overview of the features of the North Sea and the Baltic Sea in their European geographical and socio-political context. To reach sustainability in the wider sense the common society has to meet the 7 tenets - that management actions have to be environmentally sustainable, economically viable, technologically feasible, socially desirable (or at least tolerable), legally permissible, administratively achievable and politically expedient. Each of these are explained and discussed using examples from the two seas including pollution control, physical resource exploitation (such as aggregates, habitat loss, renewable energy and oil and gas), and biological resources exploitation (fisheries and aquaculture). This paper discusses the similarities between the areas in terms of their management regimes, population in the catchment, history of anthropogenic changes, derivation of objectives against a wealth of information and understanding, and the history of management and control. In contrast, the differences between the areas centre on their differing hydrographic regimes, including residence and flushing times, biological features, nature of the pollutants discharged, dominant types of fishing and type of control indicated by a predominant Eastern Bloc for the Baltic as opposed to European Union control in the North Sea. The review ends with an assessment of future challenges and examples of the way in which environmental problems have been addressed in the two areas. In particular, it sets the features against a background of management designed to achieve the Ecosystem Approach within the prevailing European marine management framework.     

The mixed-bed glacial landform imprint of the North Sea Lobe in the western North Sea

During the last glacial cycle an intriguing feature of the British-Irish Ice Sheet was the North Sea Lobe (NSL); fed from the Firth of Forth and which flowed south and parallel to the English east coast. The controls on the formation and behaviour of the NSL have long been debated, but in the southern North Sea recent work suggests the NSL formed a dynamic, oscillating terrestrial margin operating over a deforming bed. Further north, however, little is known of the behaviour of the NSL or under what conditions it operated. This paper analyses new acoustic, sedimentary and geomorphic data in order to evaluate the glacial landsystem imprint and deglacial history of the NSL offshore from NE England. Subglacial tills (AF2/3) form a discontinuous mosaic interspersed with bedrock outcrops across the seafloor, with the partial excavation and advection of subglacial sediment during both advance and retreat producing mega-scale glacial lineations and grounding zone wedges. The resultant ‘mixed-bed’ glacial landsystem is the product of a dynamic switch from a terrestrial piedmont-lobe margin with a net surplus of sediment to a partially erosive, quasi-stable, marine-terminating, ice stream lobe as the NSL withdrew northwards. Glaciomarine sediments (AF4) drape the underlying subglacial mixed-bed imprint and point to a switch to tidewater conditions between 19.9 and 16.5 ka cal BP as the North Sea became inundated. The dominant controls on NSL recession during this period were changing ice flux through the Firth of Forth ice stream onset zone and water depths at the grounding line; the development of the mixed-bed landsystem being a response to grounding line instability. © 2018 John Wiley & Sons, Ltd.     

Bottom irregularities in the North Sea

Summary A pressure transducer fixed to a sledge was towed over the bottom of the sea. Pressure variations corresponding to bottom displacement variations were recorded along different profiles in the area west of Sylt. From the time series obtained power spectra of bottom irregularities were computed as a function of wavenumberk or wavelength . Total rms bottom displacement in the wavelength band 50 to 500 m ranges from 3 cm to 36 cm depending on the location of the profile. Presumedly this is due to different types of sediment. Therefore the area cannot be considered as uniform or isotropic concerning the spatial and directional distribution of bottom irregularities. The approximation of spectra byE(k)k– yields -values between 0.4 and 2.9.

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Bodenunebenheiten in der Nordsee

Zusammenfassung Mit Hilfe einer Druckdose, die von einem Schiff aus über den Meeresboden gezogen wurde, konnten auf ausgewählten Profilen westlich von Sylt Bodenunebenheiten registriert werden. Aus den gewonnenen Zeitserien wurden SpektrenE(k) für die Wellenzahlenk bzw. für die Wellenlänge berechnet. Hieraus lassen sich die Amplituden der Bodenunebenheiten im Wellenlängenbereich von 20 bis 500 m bestimmen. Die effektive Bodenwelligkeit im Bereich von 50 bis 500 m liegt je nach Profil zwischen 3 cm und 36 cm. Die Ursache dafür ist möglicherweise in der unterschiedlichen Sedimentzusammensetzung zu suchen. Eine Isotropie des Bodenspektrums im Meßgebiet ist nicht vorhanden. Die Annäherung der Spektren durchE(k)k– ergibt -Werte zwischen 0,4 und 2,9.

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Irrégularités du fond en Mer du Nord

Résumé Un manomètre enregistreur fixé à un traîneau a été remorqué sur le fond de la mer. Les variations de pression correspondant aux variations du fond ont été enregistrées le long de différents profils dans la zone Ouest de Sylt. A partir de la série de mesures obtenues, on a calculé le spectre de puissance des irrégularités du fond en fonction du nombre d'ondek ou de la longueur d'onde . Globalement, les variations du fond dans la bande de longueurs d'onde de 50 à 500 m varient de 3 à 36 cm en moyenne quadratique selon la situation du profil. On présume que cela est dû aux différents types de sédiments. Aussi, la zone ne peut pas être considérée comme uniforme ou isotrope en ce qui concerne la distribution dans l'espace et en direction des irrégularités du fond. L'approximation de spectres parE(k)k– donne des valeurs de comprises entre 0,4 et 2,9.

     

Plankton prognoses in the North Sea

Ocean Dynamics - Our understanding of the marine ecosystem is expressed in our ability to predict ecological processes. Several approaches are compared to make such predictions on plankton...     

Trace metals in the North Sea

The distribution of zinc, manganese, nickel, copper and cadmium in water and biological material has been measured in the southern North Sea and Straits of Dover, and off the north-east coast of England. These investigations provide baseline values against which future pollution changes can be measured.     

Trace metals in the northern North Sea

Cadmium, lead and copper have been determined in the dissolved and particulate phase for surface waters of the northern North Sea. Dissolved cadmium and copper show concentration gradients associated with salinity fronts which mark the boundary between coastal and ocean waters; lead does not. The particulate phase is shown to represent only a small fraction of the total metal concentration. Processes likely to be responsible for the observed distribution are discussed.     

Gas-induced erosion features in the North Sea

Pockmarks are prominent features on the seafloor at two main regions of the North Sea, the South Fladen area and the Norwegian Trench. The pockmarks vary in size from 5 m across to about 150 m and in depth from 1 m to about 20 m. Some of the features consist of several very small ‘unit-pockmarks’. These are probably gas-induced erosion features and found only in soft, finegrained, marine and glaciomarine sediments. They are probably caused by shallow- or deep-seated gas (or fluid) release through the seabed, whereby the finest particles are thrown into suspension and redistributed by nearbottom currents. On the North Sea Plateau a small pockmarked area has recently been found. A close relationship exists here between mobile gas in the upper sediments, faulting in the soft sediments and the morphology of the seabed. Other morphological features in the North Sea such as ‘coast parallel depressions’ and ‘elongated depressions’ or terraces are also interpreted here as gas-induced erosion products. This applies, yet again, to the ‘mottled seabed’ features, which appear as patches of high reflectivity on side scan sonar records from the North Sea Plateau; they correspond to shallow seabed depressions on the deep towed boomer records. Judging from reported observations from several shallow seas world wide volatile transport through the seabed is probably quite common and several morphological features are undoubtably induced by this process. Several erosion features of similar origin are probably common, also, in deep ocean basins.     

Extreme storm surge modelling in the North Sea

This study shows that storm surge model performance in the North Sea is mostly unaffected by the application of temporal variations of surface drag due to changes in sea state provided the choice of a suitable constant Charnock parameter in the sea-state-independent case. Including essential meteorological features on smaller scales and minimising interpolation errors by increasing forcing data resolution are shown to be more important for the improvement of model performance particularly at the high tail of the probability distribution. This is found in a modelling study using WAQUA/DCSMv5 by evaluating the influence of a realistic air-sea momentum transfer parameterization and comparing it to the influence of changes in the spatial and temporal resolution of the applied forcing fields in an effort to support the improvement of impact and climate analysis studies. Particular attention is given to the representation of extreme water levels over the past decades based on the example of the Netherlands. For this, WAQUA/DCSMv5 is forced with ERA-Interim reanalysis data. Model results are obtained from a set of different forcing fields, which either (i) include a wave-state-dependent Charnock parameter or (ii) apply a constant Charnock parameter (α _{C h} =?0.032) tuned for young sea states in the North Sea, but differ in their spatial and/or temporal resolution. Increasing forcing field resolution from roughly 79 to 12 km through dynamically downscaling can reduce the modelled low bias, depending on coastal station, by up to 0.25 m for the modelled extreme water levels with a 1-year return period and between 0.1 m and 0.5 m for extreme surge heights.