Context-dependent consequences of Marenzelleria spp. (Spionidae:Polychaeta) invasion for nutrient cycling in the Northern Baltic Sea

Marenzelleria spp. are among the most successful non-native benthic species in the Baltic Sea. These burrowing polychaetes dig deeper than most native Baltic species, performing previously lacking ecosystem functions. We examine evidence from experiments, field sampling and modelling that the introduction of Marenzelleria spp. affects nutrient cycling and biogeochemical processes at the sediment water interface. Over longer time scales, bioirrigation by Marenzelleria spp. has the potential to increase phosphorus retention in bottom deposits because of deeper oxygen penetration into sediments and formation of a deeper oxidized layer. In contrast, nitrogen fluxes from the sediment increase. As a consequence of a decline of the phosphate concentration and/or rising nitrogen/phosphorus ratio, some Northern Baltic ecosystems may experience improvement of the environment because of mitigation of eutrophication and harmful cyanobacteria blooms. Although it is difficult to unambiguously estimate the ecosystem-level consequences of invasion, in many cases it could be considered as positive due to increased structural and functional diversity. The long-term interactions with the native fauna still remain unknown, however, and in this paper we highlight the major knowledge gaps. (C) 2015 Institute of Oceanology of the Polish Academy of Sciences., Production and hosting by Elsevier Sp. z o.o.Peer reviewe

Assessment of extreme hydrological conditions in the Bothnian Bay, Baltic Sea, and the impact of the nuclear power plant “Hanhikivi-1” on the local thermal regime

The results of the study aimed to assess the influence of future nuclear power plant “Hanhikivi-1” upon the local thermal conditions in the Bothnian Bay in the Baltic Sea are presented. A number of experiments with different numerical models were also carried out in order to estimate the extreme hydro-meteorological conditions in the area of the construction. The numerical experiments were fulfilled both with analytically specified external forcing and with real external forcing for 2 years: a cold year (2010) and a warm year (2014). The study has shown that the extreme values of sea level and water temperature and the characteristics of wind waves and sea ice in the vicinity of the future nuclear power plant can be significant and sometimes catastrophic. Permanent release of heat into the marine environment from an operating nuclear power plant will lead to a strong increase in temperature and the disappearance of ice cover within a 2 km vicinity of the station. These effects should be taken into account when assessing local climate changes in the future

Accounting for Dissolved Organic Nutrients in an SPBEM-2 Model: Validation and Verification

Modern models of the Baltic Sea eutrophication describe only a bioavailable fraction of the nutrient input from land, thus introducing uncertainty into forcing. In order to alleviate this uncertainty, the coupled 3D hydrodynamical-biogeochemical St. Petersburg Eutrophication Model (SPBEM) has been expanded with variables representing dissolved organic nutrients. The model modification involves an explicit description of the labile and refractory fractions of dissolved organic nitrogen and phosphorus, in addition to their particulate forms, represented by the detritus variables. The modified SPBEM-2 allows for a full account of the total amounts of nutrients reported in field measurements and presented in environmental documents. Particularly, a model description of detritus, as the only bulk organic matter variable, has been replaced by more realistic parameterizations with adequate rates of settling and mineralization. The extensive validation and verification of the model performance in the Gulf of Finland from 2009 to 2014, based on over 4000 oceanographic stations, shows that SPBEM-2 plausibly reproduces all the major large-scale features and phenomena of the ecosystem dynamics in the Gulf of Finland, especially in its surface productive layer. These demonstrated capabilities of SPBEM-2 make the model a useful tool, both in studies of biogeochemical interactions and in historical and scenario simulations

Model set-up at COCOA study sites

COCOA will investigate physical, biogeochemical and biological processes in a combined and coordinated fashion to improve the understanding of the interaction of these processes on the removal of nutrients along the land-sea interface. The results from the project will be used to estimate nutrient retention capacity in the coastal zone of the entire Baltic Sea coast. An ensemble of biogeochemical models will be used in combination with field studies at seven different coastal study sites around the Baltic Sea. The present report is a deliverable of COCOA work package 5 (WP5). Within the objective of WP5 process understanding and process descriptions will be improved in state-of-the-art biogeochemical models of the Baltic Sea coastal zone. This report presents brief information about the models available for the COCOA project and defines the needed input to the models that will be set-up at severallearning sites. The aim is to perform ensemble modelling at several sites, using at least two different models at each site. A pilot study to estimate nutrient retention capacity in the Stockholm Archipelago with the existing Swedish model system is ongoing and first results are presented and the concept of nutrient retention is briefly discussed.The existing models for different learning sites presented in the report are;1) The Swedish model system SCM (Öre river estuary and the Stockholm archipelago)- A multi-box-model approach2) The Danish model system FLEXSEM (Roskilde fjord)- A combined box-model and 3-D model approach3) The Finnish model system ESIM-BFMSI (Tvärminne Archipelago)- A 1D box-model approach4) The Polish model system M3D UG/ProDeMo (Puck Bay)- A 3-D model approach. Operational model.5) The Lithuanian model system SYFEM/AQUABC (Curonian Lagoon)- A combined box-model and 3-D model approach 6) The Swedish open Baltic model system RCO-SCOBI (for the open Baltic Sea and the Gulfof Gdansk/Vistula).- A 3-D model approachIn addition a biogeochemical model (Boudreau, 1996) for the Gulf of Finland (Russian StateHydrometeorological University model) is used to study the quantitative effect ofMarenzelleria on the Gulf of Finland ecosystem.Process studies at selected sites will be performed with a reactive transport model developedat Utrecht University. Focus will be on the role of iron and phosphorus cycling. Processstudies with the Danish model system will support the development of new parameterizationsof nutrient fluxes taking benthic habitat into account. The new parameterizations of thenutrient fluxes will in addition also be implemented into SCM and the models will be used toestimate nutrient fluxes, retention times and the filter capacity of the coastal zones.The In Kind contributions from previously (in the literature) well described open Baltic Seamodels RCO-SCOBI, BALTSEM, ERGOM and SPBEM that will be used for the descriptionof open sea conditions are also briefly mentioned in the report with references to the relevantliterature.6) The Swedish open Baltic model system RCO-SCOBI (for the open Baltic Sea and the Gulf of Gdansk/Vistula).- A 3-D model approachIn addition a biogeochemical model (Boudreau, 1996) for the Gulf of Finland (Russian State Hydrometeorological University model) is used to study the quantitative effect of Marenzelleria on the Gulf of Finland ecosystem.Process studies at selected sites will be performed with a reactive transport model developed at Utrecht University. Focus will be on the role of iron and phosphorus cycling. Process studies with the Danish model system will support the development of new parameterizations of nutrient fluxes taking benthic habitat into account. The new parameterizations of the nutrient fluxes will in addition also be implemented into SCM and the models will be used to estimate nutrient fluxes, retention times and the filter capacity of the coastal zones.The In Kind contributions from previously (in the literature) well described open Baltic Sea models RCO-SCOBI, BALTSEM, ERGOM and SPBEM that will be used for the description of open sea conditions are also briefly mentioned in the report with references to the relevant literature

Hypoxia is increasing in the coastal zone of the Baltic sea

Målet med examensarbetet är att svara på frågan: "Är det resurssparande att öka detaljeringsgraden i BIM-modellen genom virtuellt uppreglade gipsväggar?" Rapporten behandlar en BIM-laboration som genomförts i samarbete med NCC i projektet Signalfabriken i Sundbyberg. Med programmet Lindab Revit Tools (LRT) reglades gipsväggar upp virtuellt och adderades till projektets byggnadsinformationsmodell (BIM). Materialet kvalitetssäkrades vid samgranskningsmöten och användes för att generera A3-handlingar för test i produktion. Testet och handlingen diskuterades med representanter från olika delar av byggprocessen och en reviderad handling utvecklades samt godkändes. Laborationen upprepades med syftet att effektivisera processen och erfarenheterna från detta ledde till att frågeställningen fick följande svar: Ja, om endast komplicerade områden modelleras. Ja, för hela modellen om programvaran utvecklas.Nej, om LRT används för att virtuellt regla upp alla gipsväggar i projektet. Förutom dessa svar innehåller rapporten ett förslag på A3-handling som optimerats för användning i produktion. En lista på rekommenderade förändringar i programvaran. En beskrivning av hela processen för ett område där resursåtgången angetts i tid. Denna rapport riktar sig till läsare med byggingenjörsexamen eller motsvarande kunskapsnivå. This report aims to answer the question: "Can an increased level of detail in the Building Information Model by virtually constructed framing for drywalls save resources?" The report concerns a BIM laboration conducted in collaboration with NCC in the project Signalfabriken in Sundbyberg. Lindab Revit Tools (LRT) was used to virtually construct framing for drywalls that was added to the building information model of the project. The virtual material was subject to clash detection analysis and then used to generate A3-sheets for use in the production line. The result of this test and the quality of the sheet was discussed by representatives from different parts of the construction process. A revised sheet was formed from this discussion and then approved by NCC. The process was repeated to find the most efficient process and the experiences from this led to these answers for the original question: Yes, when only complex areas are modeledYes, if all areas are modeled and LRT is improvedNo, if LRT is used to virtually construct all dry walls in the project Besides these answers the report includes: a suggestion for a sheet optimized for use in the production line, a list of improvements for LRT and a description of the process in full for a curtain area together with the details of how much time resources were spent. This report is directed towards construction engineers and readers with equivalent level of knowledge

Hypoxia is increasing in the coastal zone of the Baltic sea

Hypoxia is a well-described phenomenon in the offshore waters of the Baltic Sea with both the spatial extent and intensity of hypoxia known to have increased due to anthropogenic eutrophication, however, an unknown amount of hypoxia is present in the coastal zone. Here we report on the widespread unprecedented occurrence of hypoxia across the coastal zone of the Baltic Sea. We have identified 115 sites that have experienced hypoxia during the period 1955-2009 increasing the global total to ca. 500 sites, with the Baltic Sea coastal zone containing over 20% of all known sites worldwide. Most sites experienced episodic hypoxia, which is a precursor to development of seasonal hypoxia. The Baltic Sea coastal zone displays an alarming trend with hypoxia steadily increasing with time since the 1950s effecting nutrient biogeochemical processes, ecosystem services, and coastal habitat

Hypoxia Is Increasing in the Coastal Zone of the Baltic Sea

Hypoxia is a well-described phenomenon in the offshore waters of the Baltic Sea with both the spatial extent and intensity of hypoxia known to have increased due to anthropogenic eutrophication, however, an unknown amount of hypoxia is present in the coastal zone. Here we report on the widespread unprecedented occurrence of hypoxia across the coastal zone of the Baltic Sea. We have identified 115 sites that have experienced hypoxia during the period 1955–2009 increasing the global total to ca. 500 sites, with the Baltic Sea coastal zone containing over 20% of all known sites worldwide. Most sites experienced episodic hypoxia, which is a precursor to development of seasonal hypoxia. The Baltic Sea coastal zone displays an alarming trend with hypoxia steadily increasing with time since the 1950s effecting nutrient biogeochemical processes, ecosystem services, and coastal habitat