Baltic Sea Catchment Research Articles

Pharmaceutical emissions on the example of the Baltic Sea catchment: comparing measurements with multi-tier predictive models

Currently, there is uncertainty about emissions of pharmaceuticals into larger closed ecosystems that are at risk such as the Baltic Sea. There is an increasing need for selecting the right strategies on advanced wastewater treatment. This study analysed 35 pharmaceuticals and iodinated X-ray contrast media in effluents from 82 Wastewater Treatment Plants (WWTPs) across Denmark, Estonia, Finland, Germany, Latvia, Lithuania, Poland and Sweden. Measured concentrations from Finland and Denmark were compared to predicted effluent concentrations using different levels of refinement. The concentrations predicted by the Total Residue Approach, as proposed by the European Medicines Agency, correlated with R2 of 0.18 and 0.031 to measured ones for Denmark and Finland, respectively and the predicted data were significantly higher than the measured ones. These correlations improved substantially to R2 of 0.72 and 0.74 after adjusting for estimated human excretion rates and further to R2 = 0.91 and 0.78 with the inclusion of removal rates in WWTPs. Temporal analysis of compound variations in a closely monitored WWTP showed minimal fluctuation over days and weeks for most compounds but revealed weekly shifts in iodinated X-ray contrast media due to emergency-only operations at X-ray clinics during weekends and an abrupt seasonal change for gabapentin. The findings underscore the limitations of current predictive models and findings (...) demonstrate how these methodologies can be refined by incorporating human pharmaceutical excretion/metabolization as well as removal in wastewater treatment plants to more accurately forecast pharmaceutical levels in aquatic environments.

Diversity of Sarcocystis parasites in southeastern Baltic Sea catchment ecosystems.

Currently, research on apicomplexan Sarcocystis parasites is mainly carried out by analyzing animal carcasses. However, environmental studies would not only allow faster detection of possible sources of infection but also avoid the use of animals for investigations. Therefore, in the current study, we aimed to identify tested Sarcocystis species in sediment collected from water bodies located in the southeastern Baltic countries. A total of 99 sediment samples were collected during the summer from different types of water bodies in Estonia, Latvia, Lithuania, and Poland. Species-specific nested PCR targeting cox1 gene was used for the detection of selected Sarcocystis species (S. cruzi, S. bovifelis, S. hirsuta, S. arieticanis, S. tenella, S. capracanis, S. miescheriana, and S. bertrami) infecting livestock. The results showed a statistically lower (p < 0.05) occurrence of Sarcocystis parasites in Estonia (50%) compared to three countries, where the detection rate of Sarcocystis spp. DNA was remarkably higher, ranging from 88 to 100%. Among Sarcocystis species tested, S. cruzi (83.8%) and S. arieticanis (55.6%) using cattle and sheep as their intermediate hosts were most commonly identified. The detection rates of some of the analyzed Sarcocystis species were significantly different in southeastern Baltic countries. It is discussed that the detection rates of certain Sarcocystis species depend not only on the number of animals per 1 km2 but also on various ecological factors and farming practices that differ in the amount of contact domestic animals have with predators and the potential for animals to become infected through natural water or food sources.

Thermal regimes of lakes in the southern and eastern part of the Baltic Sea catchment area during the period of climate change

The study covered eleven lakes located in northern Poland and Belarus, aiming to determine the degree and trends of surface water temperature changes for the years 1971–2020 and lake ice cover for the period of 1961–2020 under the influence of ongoing climate changes. The analysis focused on changes and trends in average monthly surface water temperatures (SWT), as well as changes in the onset and end, duration and maximum thickness of ice cover. The average annual surface water temperature increased in the lakes by an average of 0.044°C per year. The lake with the highest trend is Chervonoe, at with 0.066°C per year, while the lowest is 0.029°C per year in Lake Hańcza. The ice cover duration showed a decrease of 0.6 days per year, and there was a reduction in maximum ice thickness of 0.27 cm per year

Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part I: Case study on the watercourses in the Baltic Sea catchment area.

Microbial and chemical quality assessment of the small rivers entering the South Baltic. Part I: Case study on the watercourses in the Baltic Sea catchment area.

Diversity and Variability of the Course of Ice Phenomena on the Lakes Located in the Southern and Eastern Part of the Baltic Sea Catchment Area

The aim of the study is to determine the scale of differentiation and variability of ice phenomena on the lakes in the south-eastern part of the Baltic Sea catchment area. The analysis was performed based on data from the period 1961–2020 from 15 lakes located in Poland (10) and Belarus (5). The characteristics of ice phenomena were characterized, i.e., the length of their occurrence and ice cover, the thickness of ice cover and the number of breaks occurring in the ice cover in the given years were characterized. The analysis of the course of ice phenomena made it possible to distinguish three regions with an increasing length of ice phenomenon occurrence from west to east. The zones were the west of the Vistula, the east of it and the eastern part of the Belarusian Lake District. In the analyzed multi-year period, a shortening of the duration of ice phenomena and ice cover, a decrease in the maximum thickness of the ice and an increasing number of breaks in ice cover were observed. These data correlate with the upward trend in air temperature.

Regional variability of the mean and extreme characteristics of the present meteorological regime of the eastern part of the Baltic Sea catchment

The features of the regional heterogeneity of the modern meteorological regime are assessed, as a refinement of existing estimates of large-scale climate changes – for the eastern part of the Baltic Sea catchment on the example of the Leningrad Region and nearby territories of neighbouring subjects of the Russian Federation (northern part of the region), as well as the Zapadnaya Dvina catchment within the Republic of Belarus (southern part of the region). Significant differences in surface air temperature and snow water equivalent (hereinafter referred to as snow storage) were revealed for the winter period, with similar precipitation, more intense interannual and long-term changes in the southern part of the region. The common feature for the region is the presence of a significant correlation of the long-term January – March atmospheric circulation indices variability only with the variability of surface air temperature, as well as minor differences in the number of anomalous years with similar anomaly amplitudes. Surface air temperature has the greatest contribution to the long-term variability of snow storage everywhere, which is most pronounced in the south of the region. The turning points in the long-term variability of surface air temperature coincide in the north and south of the region, the turning points in the course of total precipitation do not coincide. The number of anomalies (exceeding the standard deviation) in the long-term series of characteristics in the northern and southern parts of the region differ little (9–12 cases in the positive and negative ranges of values) in the absence of coincidences and the similarity of the amplitude of the anomalies. The range of values of extreme threshold values (extreme percentiles) of surface air temperature in the north of the region is lower than the range of values in the south, the variability of small percentiles exceeds the variability of large ones; the rate of long-term increase in average temperatures is accompanied by a significant increase in small percentiles in the north and large percentiles in the south of the region. The values of extreme threshold values of precipitation and their standard deviation vary little across the territory; positive trends in maximums and negative trends in minimum thresholds are small, consistent with a slight increase in mean total precipitation. According to the spatial distribution of average values of snow storage, the values of their extremely small and large threshold values in the north of the region are higher than in the south; in the north of the region, the values of percentiles in the interval 1985–2002 stand out as the lowest.

Quantification of nitrogen and phosphorus inputs from farming activities into the water bodies in the Leningrad and Kaliningrad regions.

Agricultural intensification leads to higher diffuse environmental pollution. Successful pollution control requires the continuous monitoring of farming activities, reliable baseline data, and tested computational models for the quantitative assessment of diffuse loads. The study aimed to quantify the diffuse inputs of manure nitrogen (N) and phosphorus (P) to the marine environment from large livestock farms and to identify the lowering effect of the best available techniques of manure/organic fertiliser handling. The study area was the Leningrad and Kaliningrad regions, found in the Russian part of the Baltic Sea catchment area. The total diffuse load in 2017 was estimated by the Russian and Belarus methodologies based on the calculations of the livestock density and the total field application of nitrogen and phosphorus with organic fertilisers. In the Leningrad Region, it was 4571.53 t N year-1 and 280.01 t P year-1; in the Kaliningrad Region-6132.48 t N year-1 and 372.32 t P year-1. The introduction of relevant best available techniques and the supply of all farms with waterproof manure storages and pads could reduce the diffuse load on the catchment in the Leningrad region by 1078.07 t N year-1 and 55.5 t P year-1 and in the Kaliningrad Region-by 1060.43 t N year-1 and 40.5 t P year-1. Such a reduction would provide a marked contribution to fulfilling the nutrient input ceilings set for the Russian Federation under the Helsinki Commission (HELCOM) Baltic Sea Action Plan.

Micropollutants in urban wastewater: large-scale emission estimates and analysis of measured concentrations in the Baltic Sea catchment

Wastewater treatment plants (WWTPs) transmit many chemical contaminants to aquatic environments. Quantitative data on micropollutant emissions via WWTPs are needed for environmental risk assessments and evaluation of mitigation measures. This study compiled published data on substances analysed in effluents from WWTPs in the Baltic Sea region, assessed country related differences in the data sets and estimated micropollutant inputs to the Baltic Sea catchment. Concentration data were found for 1090 substances analysed at 650 WWTPs. Heterogeneity and low number of data points for most substances hindered adequate comparisons of country specific concentrations. Emission estimates were made for the 280 substances analysed in at least five WWTPs in years 2010 to 2019. For selected substances, mass loads were compared to previously published estimations. The study provides data useful for national and Baltic Sea-scale pressure analysis and risk assessments. However, it also highlights the need for broad scope monitoring of micropollutants in wastewater.

The long road to determine microplastic trends in a Baltic Sea catchment

The long road to determine microplastic trends in a Baltic Sea catchment The multidisciplinary MicroCatch_Balt project determines inland sources and sinks of microplastics and models the relevant fate processes on its pathways to the open Baltic Sea within the exemplary Warnow catchment area. It covers the most significant aspects of microplastic contamination in Northern Germany—from limnic to marine systems— providing expertise to support stakeholders in designing future monitoring or mitigation strategies.

The Lower Vistula and Its Ice Problems

Abstract In many countries of the northern hemisphere during winter period ice forms appear on various water bodies, which results in significant changes of physical, chemical and ecological conditions. These changes are different in rivers, channels, lakes or once-through reservoirs. On the terrain of Poland ice always caused considerable problems affecting intensive inland navigation and other river use. These problems appeared especially on the Vistula River, which in 17th and 18th century was one of the most navigable rivers in Europe. The Vistula is the largest Polish river, which flows from the south in the Carpathian Mountains to the Baltic Sea in the north. It is the second largest river, after Neva, of the Baltic Sea catchment. The length of the Vistula is 1047 km and its catchment amounts to 194 thousand km2. The predominant part of the Vistula river basin (87%) is now on Polish territory and the remaining (13%) catchment is in Belarus, Ukraine and Slovakia. The course of the Vistula can be divided into three distinctly different sections: upper, middle and lower. These river sections have appropriate catchments with their tributaries. There are hydraulic structures on the main river course and on its tributaries which serve navigation, hydroenergy, flood protection, water supply and recreation. All over the Vistula catchment there are frequent floods during spring and summer time resulting from excessive precipitation but in winter caused by ice phenomena. Numerous flow problems appear especially along the lower Vistula course because of ice phenomena and they result very often in severe flood problems. The Vistula has a very variable time and spatial discharge, because of existing climate conditions over its catchment. The aim of the paper is to present hydraulic and hydrologic characteristics of the Lower Vistula river with special emphasis on the management of this river section for navigation, hydroenergy, flood protection and water supply in view of ice phenomena appearing there. Information concerning changes of water characteristics due to various water temperatures are presented as well as on the formation of various forms of ice in flowing water. Numerous ice studies were carried out in Poland and especially on the Lower Vistula section as it was very ice prone and where many ice jams and ice-jam floods occurred. A special hydraulic situation existed at the mouth of the Vistula, which caused important floods in the 18th century and resulted in the construction of a special direct channel to the sea (Przekop Wisły) solving flood problems in this area. Information is presented on changes in open channel flow due to the appearance of ice cover and other ice forms. The paper includes ample information on the run, consequences and studies connected with a very important ice-jam-flood on the upper part of Włocławek reservoir in 1982.

Beaver under spotlight in the Baltic Sea Region

The Eurasian beaver (Castor fiber L.) populations are considered to have reached densities causing substantial damage to forestry, e.g., in the south eastern Baltic Sea countries. The project Water Management in Baltic Forests WAMBAF of the Interreg Baltic Sea Region started in March 2016 and lasted for three years. WAMBAF committed to water management in Baltic forests and aimed to reduce nutrient and mercury export from forestry to streams, other water bodies towards the Baltic Sea. Three main topics like riparian forests, drainage system and beaver population / dam management that strongly related to mentioned issues. Protection of the Baltic Sea catchment is based on the protection of inland waters because the Sea gains the main inflow of nutrients and toxic compounds from inland watersThe Eurasian beaver (Castor fiber L.) populations are considered to have reached densities causing substantial damage to forestry, e.g., in the south eastern Baltic Sea countries. The project Water Management in Baltic Forests WAMBAF of the Interreg Baltic Sea Region started in March 2016 and lasted for three years. WAMBAF committed to water management in Baltic forests and aimed to reduce nutrient and mercury export from forestry to streams, other water bodies towards the Baltic Sea. Three main topics like riparian forests, drainage system and beaver population / dam management that strongly related to mentioned issues. Protection of the Baltic Sea catchment is based on the protection of inland waters because the Sea gains the main inflow of nutrients and toxic compounds from inland waters

Comparing ecotoxicological and physicochemical indicators of municipal wastewater effluent and river water quality in a Baltic Sea catchment in Poland

While legal regulations require treated wastewater to be tested based only on its physicochemical parameters, surface water assessment also has to include biological indicators. However, neither approach provides a complete picture of water quality due to lack of ecotoxicological information. Therefore, the aim of the study was to perform an ecotoxicological evaluation of treated wastewater and river water in the catchment scale using a battery of biotests. In the period between June 2017 and July 2018, six sets of treated wastewater samples were taken from 17 municipal wastewater treatment plants (WWTPs) of different sizes (small: < 2,000 people equivalent - p.e.; medium size: 2,000–9,999 p.e.; large: 15,000–99,999 p.e.), as well as river water samples from seven sites along the 342 km Pilica River in central Poland. Physical and chemical analysis were performed of total nitrogen (TN), total phosphorus (TP), biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total suspended solids (TSS), as well as organic suspended matter (OSM), ion content (fluorides, nitrates, ammonium, potassium and sulphate), and pH, conductivity and redox potential (RP). Ecotoxicity assessment was performed using a battery of biotests comprising the producer Pseudokirchneriella subcapitata (chronic toxicity biotest), consumer Thamnocephalus platyurus (acute toxicity biotest) and decomposer Tetrahymena thermophila (chronic toxicity biotest). It was found that in small WWTPs, the recommended levels of TN, TP, BOD, COD and TSS were often exceeded. Also, the highest mean toxicity hazard in the ecotoxicological biotests was observed for samples from small WWTPs. No clear dependence was found between any of the studied physicochemical parameters of the water and the ecotoxicity of samples: however, a correlation was observed between growth inhibition of P. subcapitata and TN and NH4+ concentration (r = 0.43 and r = 0.48, respectively). Also, the mortality of T. platyurus was correlated with NH4+(r = 0.72), TN (r = 0.64), BOD (r = 0.52), TSS (r = 0.44) and OSM (r = 0.46). The most sensitive organism in the applied battery of biotests was the alga P. subcapitata (producer), with a 90% toxic response for WWTP samples and 100% for river samples. T. platyurus (consumer) demonstrated a 56% toxic response for WWTP samples and no toxicity (0%) for river samples. In turn, T. thermophila demonstrated a 25% toxic response for WWTP samples and 33% for river samples. The addition of an ecotoxicological evaluation (battery of biotests) to the physicochemical monitoring of treated wastewater and river water delivered new information about the biological impact on organisms related to their different sensitivity. Additionally, the small WWTPs turned out to be the highest source of hazard.

Itämeren aleneva suolapitoisuus muokkaa Suomen rannikon lajien levinneisyyttä

The physical and chemical properties of water are vital for aquatic organisms. Should changes in these conditions occur, responses would follow both in the distributions of species and ecosystem functioning. Water salinity is particularly critical because it induces osmotic stress and requires specific physiological adaptations from the living organisms. Current climate change models suggest increasing precipitation in the Baltic Sea catchment area and decreasing seawater salinity along the Finnish seacoast. In order to envisage potential consequences of decreasing salinity in the coastal ecosystems, we apply alternative Baltic Sea salinity scenarios based on climate change and species inventory data with GIS modelling to estimate possible changes in the distributions of four aquatic species within the next 50 years. The results suggest that marine species are to lose much of their current distribution areas: blue mussel may constrain its distribution into the Archipelago- and Bothnian Sea areas only, while eelgrass will likely disappear completely. In contrast, the studied freshwater species, brackish water sponge and the common water mosses, will strongly expand their distributions along the Finnish seacoast. Their currently isolated populations in the Gulf of Finland and the Gulf of Bothnia will expand their populations as far as the Archipelago Sea, which will thereby become a biogeographically interesting contact zone. As many of the studied organisms are keystone species, their changing distributions will induce cascade effects at the ecosystem level.

Digital methods for agro-monitoring and nutrient load management in the Russian part of the Baltic Sea catchment area

The article describes the basic requirements for an interactive programme designed for agro-monitoring and nutrient load management in the Russian part of the Baltic Sea catchment area within the borders of the Leningrad Region. The programme will monitor the farm generation of nutrients (nitrogen and phosphorus) in the organic fertilisers and create the logistical scheme of their application with due account for environmental and economic factors. The functional objectives of the interactive programme are to receive the relevant source information on the region, agricultural organisations, applied animal/poultry manure handling technologies, and manure storage types; to visualize all agricultural organizations on a digital map: location, name, specialisation, animal stock, available agricultural land; to calculate and display the current situation in agricultural enterprises: amount of organic fertiliser received, land sufficiency for all organic fertiliser application, and required volume of manure storages and composting pads; to calculate and display the forecast situation in agricultural organizations and to create the electronic passports of farms, districts and the whole Leningrad Region including the logistics of organic fertilisers distribution from supplier farms to consumer farms considering the nutrient load standards and the data on the nutrient load distribution within the boundaries of agricultural lands in the catchment area.

Variation in the Content of Different Forms of Mercury in River Catchments of the Southern Baltic Sea – Case Study

Abstract Mercury (Hg) is recognised as a global environmental pollutant. Despite numerous studies being conducted around the world, the transformation of mercury in natural environments is still not fully understood. In addition, increasing droughts and heavy rains are currently observed to contribute to changes in the circulation of Hg. The purpose of this study was to recognise the influence of extreme meteorological and hydrological conditions on the inflow of various forms of mercury to the coastal zone of the Bay of Puck. The studies were carried out at estuarial stations of four rivers belonging to the southern Baltic Sea catchment: Reda, Zagorska Struga, Gizdepka and Płutnica. The results showed that meteorological and hydrological parameters affect mercury speciation in river catchments, which translates into inflow of labile mercury to the southern Baltic Sea.

An Analytical Review of Different Approaches to Wastewater Discharge Standards with Particular Emphasis on Nutrients

Despite the implementation of strict legal standards concerning nutrient loads within wastewater discharges in all European Union (EU) Member States it was not possible to achieve good ecological and chemical water status by 2015 in all EU countries. The main reasons for this situation are the imperfections of the legislation tools regarding the standardization of wastewater quality and the methodology of determining the conditions for wastewater introduction into receivers. The study aims to review and analyze the currently existing in various countries legal regulations setting the standards for wastewater discharged into receivers, which were intended for surface water protection and eutrophication mitigation. Besides the EU effluent standards, the regional and national regulations in chosen EU Member States (e.g., Germany, Sweden, and Denmark) have been reviewed. Moreover, the Helsinki Commission recommendations for signatory countries within the Baltic Sea catchment and the approaches for wastewater quality standardization in non-EU countries (e.g., Russia, Belarus, Switzerland, China, USA, Canada, and Dubai) were assessed. The analysis of the reviewed legal regulations allowed to diversify the methodological approaches for setting effluent quality standards in different regions and countries and to assess the effectiveness of existing legal tools in the field of eutrophication mitigation with the consideration of the environmental and economic reasonability. The results suggest that the receiver-oriented policies used among others in Switzerland and China are the most reasonable in terms of eutrophication mitigation.

High Resolution Discharge Simulations Over Europe and the Baltic Sea Catchment

Regional coupled system models require a high-resolution discharge component to couple their atmosphere/land components to the ocean component and to adequately resolve smaller catchments and the day-to-day variability of discharge. As the currently coupled discharge models usually do not fulfill this requirement, we improved a well-established discharge model, the HD model, to be globally applicable at 5 Min. resolution to prepare high-resolution discharge simulations over Europe and the Baltic Sea catchment. Here, no river specific parameter adjustments were conducted so that the model is generally applicable for climate change studies and over ungauged catchments. For the validation of the 5 Min. HD (HD5) model, we drive it with prescribed fields of surface and subsurface runoff. As no large-scale observations of these variables exist, they need to be calculated by a land surface scheme or hydrology model using observed or re-analyzed meteorological data. In order to pay regard to uncertainties introduced by these calculations, three different methods and datasets were used to derive the required fields of surface and subsurface runoff for the forcing of the HD5 model. 10-years simulations (2000-2009) show that for many European rivers, where daily discharge observations were available for comparison, the HD5 model captures the main discharge peaks reasonably well. As direct anthropogenic impact on the discharge, such as by regulation or dams, is not regarded in the HD model, those effects generally cannot be simulated. Thus, discharges for many heavily regulated rivers in Scandinavia or for the rivers Volga and Don are not well represented by the model. The comparison of the simulated discharges obtained indicates that the HD5 model is suitable to evaluate the terrestrial hydrological cycle of climate models or land surface models, especially with regard to the separation of throughfall (rain or snow melt) into surface and subsurface runoff.

Mobility of mercury in soil and its transport into the sea.

Mercury (Hg) is deposited temporarily in soil and can be remobilised into rivers and seas. Given that rivers are a significant part of the mercury budget in the southern Baltic region (inland sea located in northern Europe) and meteorological changes (e.g. intense rain, drought) are observed more frequently, it is important to recognize the factors affecting the cycling of bioavailable Hg forms. The aim of this study was to identify the processes influencing the changes of labile and stabile mercury proportion in soil and the potential impact on the outflow of labile Hg into fluvial systems. For this purpose, soil samples, river sediments, and river water were collected from the Reda River (southern Baltic Sea catchment area) during the 2015 hydrologic year. The material was analysed for total and particulate mercury content and Hg forms, by a thermo-desorption method. The analysis showed that due to changes of meteorological and hydrological conditions Hg can enter rivers and then be introduced into the marine environment in various forms. On the one hand due to high precipitation events washing out of labile (i.e. bond with halogenides, MeHg, HgSO4), Hg forms into the river can be enhanced which affects increasing of availability of the most dangerous Hg form in the water systems. On the other hand the same event can cause the limitation of bioavailable mercury forms by a conversion of labile Hg into the most stable one (HgSO4 ➔ HgS) under anaerobic conditions.

Slurry Acidification as a Tool to Reduce Ammonia Emissions

Ammonia emissions are a worldwide major environmental concern. In 2017, ammonia emissions in the European part of Russia amounted to 80.9 thousand tons, of which up to 56.9 thousand tons came from agriculture. The main source of ammonia in this sector is the farm animal/poultry manure (slurry) utilisation technologies. Slurry acidification technology (SAT) is one of the methods to reduce ammonia emissions. ( Research purpose ) To assess the potential application of this technology in the Russian part of the Baltic Sea catchment area within the North-West Federal District of the Russian Federation. ( Materials and methods ) The area under study included Republic of Karelia, Kaliningrad, Leningrad, Novgorod and Pskov Regions. The authors considered the statistical data on the farm animal stock and the slurry output in the pilot area. The dynamic pattern of pig slurry pH was experimentally determined. The economic efficiency of slurry acidification technology was calculated for two functioning livestock complexes. ( Results and discussion ) According to statistical data, around 11.8 million tons of animal/poultry manure is produced in the pilot area annually, including around 7.4 million tons of slurry, which could potentially be acidified. Three SAT options – in-house, in-storage and in-field application – were considered for the Russian conditions. The main limiting factors for SAR application were identified. The SAT introduction costs and economic benefits were compared. ( Conclusions ) The prospects of SAT introduction in the pilot region were estimated. The need for the integrated research under the Russian conditions involving engineers, biologists, soil scientists, ecologists and other specialists, who could prove the feasibility and economic efficiency of the slurry acidification technology, was established.

Nitrate leaching losses from two Baltic Sea catchments under scenarios of changes in land use, land management and climate.

Pollution with excess nutrients deteriorate the water quality of the Baltic Sea. The effect of combined land use and climate scenarios on nitrate leaching and nitrogen (N) loads to surface waters from two Baltic Sea catchments (Norsminde in Denmark and Kocinka in Poland) was explored using different models; the NLES and Daisy models for nitrate leaching, and MIKE SHE or MODFLOW/MT3DMS for N transport. Three Shared Socioeconomic Pathways (SSP1, SSP2 and SSP5) defined change in land use and agricultural activities. The climate change scenarios covered 2041-2060 compared with 1991-2010 under RCP8.5, applying four different climate models. Increases in predicted N-load from climate change vary from 20 to 60% depending on climate model. SSPs moderate these N-load changes with small changes for SSP1 to large increases for SSP5, with greater increases for Norsminde than Kocinka due to land use differences. This stresses needs for new measures and governing schemes to meet sustainability targets.