The paper presents the results of toxicity determinations carried out on sediment samples collected in the vicinity of the wreck of the German s/s Stuttgart (the southern part of the Gulf of Gdańsk, off the Polish coast) in relation to the determination of polycyclic aromatic hydrocarbons (PAHs). The toxicity of surface and core sediment samples was assessed using two biotest organisms-the bioluminescent bacteria Vibrio fischeri and the ostracod Heterocypris incongruens. PAH levels in these samples were determined by GC-MS. The surface sediments collected at W2 (ca. 34 m north of the shipwreck) and W4 (ca. 415 m north-east of the wreck) as well as the core sediments collected at WR3 (ca. 400 m north-east of the wreck) were the most heavily polluted with substances toxic to the biotest organisms. The chronic and acute toxicities in the case of most of the surface sediment samples studied are correlated. This may suggest that not only hydrophobic chemicals (like PAHs from fuel residues) but also more polar chemicals (resulting from the conversion of aromatic hydrocarbons) are responsible for the toxicity levels found. There is a clear dependence between the levels of chronic toxicity and PAH concentrations in the core sediment samples. In addition, a simultaneous decrease in the PAH content and chronic toxicity was noted in all the core sediment samples at depths below 80 cm.
The 3D CEMBS (3D Coupled Ecosystem Model of the Baltic Sea) is a coupled ecosystem model of the Baltic Sea. In operational mode it computes 48-h forecasts of the hydrodynamic and biochemical parameters describing the Baltic Sea state. The Cressman assimilation scheme was implemented as part of the system in order to improve overall model accuracy. The system uses satellite-measured sea surface temperature from the MODIS Aqua spectroradiometer for the assimilation process. The satellite measured SST is obtained from a predefined server, which is part of the Satellite Monitoring of the Baltic Sea Environment project (SatBałtyk).To validate the model results and the impact of assimilation on the model's accuracy, two separate test runs were performed using historical data covering the years 2011 and 2012. Independent computations were performed for the model with and without satellite SST assimilation, respectively referred to in this paper as 3D CEMBS_A and 3D CEMBS. The results of the computations were then compared with satellite and in situ measured data to validate the model and the assimilation scheme's implementation.The objective of this paper is to describe the implementation of the satellite SST data assimilation algorithm and to present the results of the preliminary validation of the models with observations.
The aim of this study is to determine the state and changes of the Vistula Canal (Wisła Przekop) external delta relief, in the period of [2009][2010][2011][2012][2013][2014], and in relation to the assessment of the conditions of free runoff of the Vistula River waters. This is an important element for assessing the effectiveness of flood prevention in the area of Żuławy. The basis of the study are detailed bathymetry monitoring and morphometric measurements of the external delta with the supply channel. Modern equipment was used (mainly RTK and DGPS specialist navigation systems and multibeam echosounder), providing the obtainment of a digital model of the seabed surface, with decimeter accuracy of location points. In subsequent years, a series of bathymetric maps for the scale of 1:10 000 was made, as well as relief maps and maps of differential changes of the relief. The observed significant changes in the nature of the relief (with relatively small changes in the contours of the delta), indicate their important role in shaping the conditions of free runoff Vistula waters.Streszczenie: Celem pracy jest określenie stanu i zmian rzeźby stożka ujściowego Wisły Przekop, w okresie lat 2009-2014, w relacji do oceny warunków swobodnego spływu wód Wisły. Stanowi to istotny element dla oceny skuteczności zapobiegania powodziom w rejonie Żuław. Podstawę badań stanowią szczegółowe, monitoringowe pomiary batymetrii i morfometrii stożka wraz z kanałem doprowadzającym. Stosowano nowoczesną aparaturę (głównie DGPS RTK i specjalistyczne systemy nawigacyjne oraz echosondę wielowiązkową) zapewniającą uzyskanie cyfrowego modelu powierzchni dna, z decymetrową dokładnością położenia punktów. W kolejnych latach wykonano serię map batymetrycznych dla skali 1:10 000, map rzeźby i map różnicowych zmian rzeźby. Stwierdzone znaczne zmiany charakteru rzeźby (przy względnie niewielkim zmianach konturów stożka), wskazują na ich istotna rolę w kształtowaniu warunków swobodnego spływu wód Wisły.
Weather is a crucial factor and the most unpredictable of all the factors determining success or failure of any offshore activity, such as investments in seabottom grid connectors (gas, energy or communication), oil & gas drilling facilities development as well as erection of offshore wind farms. Weather conditions cannot be foreseen accurately over a time horizon longer than a few days, and so arranging a realistic work schedule for such an enterprise poses a great challenge. This paper identifies and analyzes the greatest risks associated with weather conditions at sea. The importance and impact of weather on the project implementation were assessed and mitigating measures were proposed. As part of the work, a review of scientific literature was conducted, while the core conclusions were reached using the information-gathering techniques and a documentation review of the offshore projects implemented in cooperation with the Maritime Institute. The authors based their analysis on experience from survey campaigns conducted in the Baltic Sea in the areas of the investments planned for implementation. The analysis of risks associated with weather conditions is based on the statistical weather data obtained using the WAM4 model.The research reveals that it is impossible to create an accurate survey schedule for long-term offshore projects, however, using statistics for each individual hydrodynamic parameter can, to some extent, facilitate the creation of survey schedules for maritime projects.
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