Storm-Surge Induced Water Level Changes in the Odra River Mouth Area (Southern Baltic Coast)

The Odra River mouth area is a region of the Southern Baltic coastal zone especially prone to the influence of storm surges. In the present study, the height and extent of the Baltic storm surges, and temporal offsets of the respective maximum water level occurrences in the Odra River mouth area were explored using cross-correlation, cluster analysis and principal component analysis. The analyses were based on hourly water level readings retrieved from water gauging stations located along the lower Odra reaches and at the coasts of the Szczecin Lagoon and the Pomeranian Bay during storm surge years 2008/2009–2019/2020. The analysis of mutual relationships between water levels during storm surges indicated that the extent of marine influence on the lower Odra River and within the Szczecin Lagoon was variable during the studied surge events, and dependent on meteorological conditions (the strongest during the sustained occurrence of wind blowing from the northern sector), discharge from the Odra River catchment (the strongest at low discharge), ice conditions on the lower Odra (suppressing the storm surge propagation upstream), and general sea level in the Pomeranian Bay (stronger at high sea levels). The strongest correlation between sea levels at Świnoujście and water levels in the Szczecin Lagoon and the lower Odra was found at a 6–7 h offset. The extent of storm surges usually reached 100 km up the lower Odra channels, less frequently reaching 130 km away from the sea.

Spatial and seasonal variation in dissolved silica benthic fluxes in the shallow zones of the southern Baltic Sea

<p>Dissolved silica (DSi) is an important macronutrient in the marine environment, necessary for growth of many aquatic organisms. Yet, DSi marine cycle is still not fully recognized, especially in dynamic, coastal zones. Although DSi is mainly transported to the sea by rivers, benthic fluxes of DSi, which originate from dissolution of the siliceous remains in the sediments, can also represent an important source of bioavailable silicon in the ocean. Benthic DSi fluxes are mainly powered by diffusion, but their rates are strongly shaped by the benthic fauna. Still, the role of benthos in these processes is not fully recognized. The main goal of this study was to investigate how various environmental factors and benthic fauna may shape the coastal cycle of Si in coastal environments during different seasons.</p><p>Our study was conducted in the shallow coastal ecosystems of the southern Baltic Sea characterized by contrasting environmental conditions: shallow, brackish and enclosed Szczecin Lagoon (Oder river estuary), dynamic open waters near Łeba with relatively low anthropogenic influence, enclosed Puck Bay and Vistula prodelta. We investigated both shore ecosystems (app. 0.5 m depth) and deeper areas (from 6 up to 60 m depth). DSi concentrations in the bottom waters and environmental characteristics (T, S, O<sub>2</sub>, sediment organic matter) were investigated at 6 stations, during three seasons (winter, spring and autumn) in years 2019-2020 with s/y Oceania (IOPAN) and directly from the shore. Additionally, samples from shore stations were collected during summer. DSi benthic fluxes were determined at each station by performing <em>ex situ</em> incubations of sediment cores (n = 4-5) with natural benthic assemblages. The benthic organisms in studied cores were collected, identified, counted, and weighed.</p><p>The lowest fluxes were measured at sandy stations while highest return fluxes were observed at muddy sites. High variability in DSi benthic fluxes along studied localities was observed, ranging from -1.11 mmol d<sup>-1</sup>m<sup>-2</sup> in summer at shore station in the Puck Bay and up to 6.79 mmol d<sup>-1</sup>m<sup>-2</sup> in Szczecin Lagoon in autumn. We used  Gaussian Generalized Linear Models (GLMs) to estimate the role of environmental conditions, benthic fauna characteristics  and interactions among them in the variability of DSi benthic flux across studied localities. The most important predictors for the fluxes were all pair-wise interactions of temperature, total organic carbon, the C/N molar ratio, and the density of benthic macrofauna. Both interaction terms that included C/N ratio, a measure of organic matter quality (i.e. low C/N ratio indicates higher quality), were associated with increased DSi uptake by the sediment. Further, the interaction term between T and benthic marcofauna density was also linked to negative benthic fluxes of DSi. In contrast, the interaction of T and TOC caused a strong increase in DSi return fluxes.</p>

Detection of white sturgeon iridovirus (WSIV) in wild sturgeons (Actinopterygii: Acipenseriformes: Acipenseridae) in Poland

IntroductionWhite sturgeon iridovirus (WSIV) disease is caused by a virus of the eponymous family and is mostly triggered by stressful environmental conditions, i.e. high rearing density, excessive handling, or temporary loss of water. The aim of this study was to develop the most effective diagnostic method for quick and efficient confirmation or exclusion of the presence of WSIV.Material and MethodsA total of 42 samples (spleen, gills, intestine, skin, kidney, and brain) were collected from eight sturgeon (Acipenser gueldenstaedtii and A. oxyrinchus) aged ≤5+ farmed or caught between 2010 and 2014 in open waters (Dąbie Lake and Szczecin Lagoon). They were tested for WSIV presence using conventional PCR, qPCR, and in situ hybridisation (ISH).ResultsIn gross examination, all fish appeared to be healthy. Neither species showed clinical signs typical of WSIV infection. In the majority of cases, fragments of iridoviral DNA were found using molecular methods in the kidneys, and also in the liver, gills, and skin. The detection rate using ISH was 47.37% and most commonly the brain and kidney tissues were positive. The most efficient of the methods used was real-time PCR, with 100% effectiveness in detection of WSIV DNA.ConclusionThe study demonstrates the capabilities for WSIV diagnosis available to sturgeon farmers and water administrators, indicating useful methods of adequate sensitivity as well as organs to sample in order to achieve the highest probability of viral detection.

Detection of koi herpesvirus (KHV) and carp oedema virus (CEV) in invasive round goby, Neogobius melanostomus Pallas, 1814, from Poland and Germany

IntroductionThe aim of the study was to determine the transmission potential of carp edema virus (CEV) and koi herpesvirus (KHV) introduced to Europe by the invasive round goby (Neogobius melanostomus).Material and MethodsA total of 70 round goby specimens were collected from the Szczecin Lagoon, Poland, and locations in Germany in the third and fourth quarters of 2018. The fish were analysed to detect KHV and CEV by PCR.ResultsSix fish specimens were positive for the presence of KHV, while none of the gobies examined showed the presence of CEV.ConclusionThe CEV genome was detected in the goby specimens from Germany and from Poland. Considering the high pace of the spread of the round goby and its effectiveness in acquisition of new ecological niches, it should be kept out during refilling of carp ponds. Further studies should focus on experimental cohabitation of CEV-infected round gobies and specific-pathogen-free (SPF) carp to investigate the potential for active virus transfer.

Mineralogy and Geochemistry of Fluvial-Lacustrine Pisolith Micronodules from the Roztoka Odrzańska, Odra River, NW Poland

Small-sized ferruginous micronodules or pisolith nodules, frequently occurring in inland freshwater systems in moderate climate zones, are important indicators of groundwater level changes and early diagenetic processes, especially within the Pleistocene post-glacial sedimentary systems, including swamps, peatbogs, rivers, or lakes. Compared to the other geochemical environments, pisolith nodules are usually dominated by iron hydroxides and oxides. In most cases, described micronodules indicate high phosphatization, significant contribution of allogenic detrital components, and low manganese content. The major aim of the article is to present textural, geochemical, and mineralogical variability of pisolith nodules recovered from the Roztoka Odrzańska, Odra river mouth area, NW Poland. We describe genetical relations between different types of pisoliths and try to interpret the possible formation phenomena. Analyzed loose ferruginous micronodules were separated from the lacustrine silty-clayey sapropel muds and gyttja, later analyzed using optical microscopy, SEM-energy dispersive x-ray (EDX), and XRD methods. As a reference material, we use archival iron bog ores and geochemical data of different types of nodules. Additionally, we describe previously unknown siderite-rich nodules found in neighboring sites of the Dąbie Lake and the Szczecin Lagoon.

Possibilities of safe yield increase in the Wydrzany well field (Uznam Island, Poland) by surface water from a drainage system

In parallel with intensified development of the Polish part of Uznam Island, there is an increase in the demand for drinking water in this area. This island ranks among areas with low water resources, which at the present time are allocated. In order to create the prospect of increased groundwater resources, a concept has been developed that allows for the recovery of part of the freshwater from drainage systems which discharge into the waters of Szczecin Lagoon or the River Świna. The present article discusses the secondary use of water from drainage systems for supply of the Wydrzany resource area. The notion of using water from the White Bridge pumping station was considered the most promising. The catchment area of the polder is 880 ha, 280 ha of which are located on Polish territory. The White Bridge pumping station transfers water from the polder, which it leads to the Peat Channel which, in turn, drains water gravitationally into Szczecin Lagoon. Here, results of simulations aimed at the use of drainage water to improve upon groundwater resources in the “Wydrzany” intake are discussed. On the basis of these simulations of artificial water supply to the intake, an increase of available resources by up to 50 per cent may be expected.

Diversification of Social Capital of Sailing Community and Development of Tourist Services of the Szczecin Lagoon

The aim of the present paper is to show the impact of the diversity of social capital of the international sailing environment on the development of tourist services around the Szczecin Lagoon and Dąbie Lake. The target group are Polish and German participants in nautical tourism in the cross-border research area. Materials for the article were collected during field studies conducted in 2009–2012. The questionnaire method was mainly used to obtain information. The paper uses elements of social capital for the purpose of creating the image of the place and promotional activities of the region. The sources of capital were: motivations for sailing, additional leisure time activities, form of sailing activity, individual choice of a place of rest as well as the most frequently chosen domestic and international destinations, as well as personal data like gender, age and nationality of respondents. Understanding capital as a resource allowed it to be used for the development of the research area. The analysis of the research results allowed to specify one characteristic which was positively evaluated by two groups of respondents and these are landscape conditions of the Szczecin Lagoon. Contact with nature turned out to be the most important motivation for sailing. On the other hand, the heterogeneity of the Polish and German sailing environment is clear in the context of age, sailing qualifications, property status, which determines the direction of cruises undertaken and other activities accompanying sailing. All the above-mentioned elements of social capital bring benefits for the research area, observed in the economic and social dimension. Based on them, promotional and infrastructural changes were proposed for the needs of the tourist services sector, including, among others, nature, cultural or qualified tourism.