| 1. |
- Almroth Rosell, Elin, 1977, et al.
(författare)
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A new approach to model oxygen dependent benthic phosphate fluxes in the Baltic Sea
- 2015
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Ingår i: Journal of Marine Systems. - : Elsevier BV. - 0924-7963 .- 1879-1573. ; 144, s. 127-141
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Tidskriftsartikel (refereegranskat)abstract
- The new approach to model the oxygen dependent phosphate release by implementing formulations of the oxygen penetration depths (OPD) and mineral bound inorganic phosphorus pools to the Swedish Coastal and Ocean Biogeochemical model (SCOBI) is described. The phosphorus dynamics and the oxygen concentrations in the Baltic proper sediment are studied during the period 1980-2008 using SCOBI coupled to the 3D-Rossby Centre Ocean model. Model data are compared to observations from monitoring stations and experiments. The impact from oxygen consumption on the determination of the OPD is found to be largest in the coastal zones where also the largest OPD are found. In the deep water the low oxygen concentrations mainly determine the OPD. Highest modelled release rate of phosphate from the sediment is about 59 x 10(3) t P year(-1) and is found on anoxic sediment at depths between 60-150 m, corresponding to 17% of the Baltic proper total area. The deposition of organic and inorganic phosphorus on sediments with oxic bottom water is larger than the release of phosphorus, about 43 x 10(3) t P year(-1). For anoxic bottoms the release of total phosphorus during the investigated period is larger than the deposition, about 19 x 10(3) t P year(-1). In total the net Baltic proper sediment sink is about 23.7 x 10(3) t P year(-1). The estimated phosphorus sink efficiency of the entire Baltic Sea is on average about 83% during the period.
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| 2. |
- Almroth Rosell, Elin, 1977, et al.
(författare)
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Transport of fresh and resuspended particulate organic material in the Baltic Sea — a model study
- 2011
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Ingår i: Journal of Marine Systems. - : Elsevier BV. - 0924-7963. ; 87:1, s. 1-12
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Tidskriftsartikel (refereegranskat)abstract
- A fully coupled high-resolution 3-dimensional biogeochemical–physical ocean model including an empirical wave model was used to investigate the long-term average (1970–2007) distributions and transports of resuspended matter and other types of suspended organic matter in the Baltic Sea. Modelled bottom types were compared to observations and the results showed that the model successfully managed to capture the horizontal, as well as the vertical, distribution of the different bottom types: accumulation, transport and erosion bottoms. The model also captured well the nutrient element contents in the sediments. On average the largest contribution of resuspended organic carbon to the transport of total organic carbon is found at erosion and transport bottoms. Although the relative transport of resuspended organic carbon at deeper accumulation bottoms in general is low (< 10% of total), the central parts of the sub-basins act on average as sinks that import organic matter while the more shallow areas and the coastal regions acts as sources of organic carbon in the water column. This indicates that the particulate organic matter produced in erosion and transport areas might be kept in suspension long enough to be transported and settle in less energetic areas, i.e. on accumulation bottoms.
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| 3. |
- Andersson, Agneta, et al.
(författare)
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Projected future climate change and Baltic Sea ecosystem management
- 2015
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Ingår i: Ambio. - : Springer. - 0044-7447 .- 1654-7209. ; 44:Supplement 3, s. S345-S356
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Tidskriftsartikel (refereegranskat)abstract
- Climate change is likely to have large effects on the Baltic Sea ecosystem. Simulations indicate 2-4 degrees C warming and 50-80 % decrease in ice cover by 2100. Precipitation may increase similar to 30 % in the north, causing increased land runoff of allochthonous organic matter (AOM) and organic pollutants and decreased salinity. Coupled physical-biogeochemical models indicate that, in the south, bottom-water anoxia may spread, reducing cod recruitment and increasing sediment phosphorus release, thus promoting cyanobacterial blooms. In the north, heterotrophic bacteria will be favored by AOM, while phytoplankton production may be reduced. Extra trophic levels in the food web may increase energy losses and consequently reduce fish production. Future management of the Baltic Sea must consider the effects of climate change on the ecosystem dynamics and functions, as well as the effects of anthropogenic nutrient and pollutant load. Monitoring should have a holistic approach, encompassing both autotrophic (phytoplankton) and heterotrophic (e.g., bacterial) processes.
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| 4. |
- Eilola, Kari, et al.
(författare)
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Impact of saltwater inflows on phosphorus cycling and eutrophication in the Baltic Sea : a 3D model study
- 2014
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Ingår i: Tellus. Series A, Dynamic meteorology and oceanography. - : Stockholm University Press. - 0280-6495 .- 1600-0870. ; 66, s. 23985-
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Tidskriftsartikel (refereegranskat)abstract
- The impact of dense saltwater inflows on the phosphorus dynamics in the Baltic Sea is studied from tracer experiments with a three-dimensional physical model. Model simulations showed that the coasts of the North West Gotland Basin and the Gulf of Finland, the Estonian coast in the East Gotland Basin are regions where tracers from below the halocline are primarily lifted up above the halocline. After 1 yr tracers are accumulated at the surface along the Swedish east coast and at the western and southern sides of Gotland. Elevated concentrations are also found east and southeast of Gotland, in the northern Bornholm Basin and in the central parts of the East Gotland Basin. The annual supplies of phosphorus from the deeper waters to the productive surface layers are estimated to be of the same order of magnitude as the waterborne inputs of phosphorus to the entire Baltic Sea. The model results suggest that regionally the impact of these nutrients may be quite large, and the largest regional increases in surface concentrations are found after large inflows. However, the overall direct impact of major Baltic inflows on the annual uplift of nutrients from below the halocline to the surface waters is small because vertical transports are comparably large also during periods without major inflows. Our model results suggest that phosphorus released from the sediments between 60 and 100 m depth in the East Gotland Basin contributes to the eutrophication, especially in the coastal regions of the eastern Baltic Proper.
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| 5. |
- Eilola, Kari, et al.
(författare)
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SMHI reportsSMHI rep., Oceanogr : Swedish Meteorological and Hydrological Institute reports. OceanographySMHISMHI report. Oceanography 2007:37OceanographyROSMHI RO
- 2017
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is related to the BONUS project “Nutrient Cocktails in COAstal zones of the Baltic Sea” alias COCOA. The aim of BONUS COCOA is to 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 report is especially related to BONUS COCOA WP 6 in which the main objective is extrapolation of results from the BONUS COCOA learning sites to coastal sites around the Baltic Sea in general. Specific objectives of this deliverable (D6.4) were to connect observed process rates with modelling data and ecosystem characteristics.In the report we made statistical analyses of observations from BONUS COCOA study sites together with results from the Swedish Coastal zone Model (SCM). Eight structural variables (water depth, temperature, salinity, bottom water concentrations of oxygen, ammonium, nitrate and phosphate, as well as nitrogen content in sediment) were found common to both the experimentally determined and the model data sets. The observed process rate evaluated in this report was denitrification. In addition regressions were tested between observed denitrification rates and several structural variables (lat itude, longitude, depth, light, temperature, salinity, grain class, porosity, loss of ignition, sediment organic carbon, total nitrogen content in the sediment, sediment carbon/nitrogen-ratio, sediment chlorphyll-a as well as bottom water concentrations of oxygen, ammonium, nitrate, and dissolved inorganic phosphorus and silicate) for pooled data from all learning sites.The statistical results showed that experimentally determined multivariate data set from the shallow, illuminated stations was mainly found to be similar to the multivariate data set produced by the SCM model. Generally, no strong correlations of simple relations between observed denitrification and available structural variables were found for data collected from all the learning sites. We found some non-significant correlation between denitrification rates and bottom water dissolved inorganic phosphorous and dissolved silica but the reason behind the correlations is not clear.We also developed and evaluated a theory to relate process rates to monitoring data and nutrient retention. The theoretical analysis included nutrient retention due to denitrification as well as burial of phosphorus and nitrogen. The theory of nutrient retention showed good correlations with model results. It was found that area-specific nitrogen and phosphorus retention capacity in a sub-basin depend much on mean water depth, water residence time, basin area and the mean nutrient concentrations in the active sediment layer and in the water column.
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| 6. |
- Fransner, Filippa, et al.
(författare)
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Non-Redfieldian Dynamics Explain Seasonal pCO2 Drawdown in the Gulf of Bothnia
- 2018
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Ingår i: Journal of Geophysical Research - Oceans. - 2169-9275 .- 2169-9291. ; 123:1, s. 166-188
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Tidskriftsartikel (refereegranskat)abstract
- High inputs of nutrients and organic matter make coastal seas places of intense air-sea CO2 exchange. Due to their complexity, the role of coastal seas in the global air-sea CO2 exchange is, however, still uncertain. Here, we investigate the role of phytoplankton stoichiometric flexibility and extracellular DOC production for the seasonal nutrient and CO2 partial pressure (pCO2) dynamics in the Gulf of Bothnia, Northern Baltic Sea. A 3-D ocean biogeochemical-physical model with variable phytoplankton stoichiometry is for the first time implemented in the area and validated against observations. By simulating non-Redfieldian internal phytoplankton stoichiometry, and a relatively large production of extracellular dissolved organic carbon (DOC), the model adequately reproduces observed seasonal cycles in macronutrients and pCO2. The uptake of atmospheric CO2 is underestimated by 50% if instead using the Redfield ratio to determine the carbon assimilation, as in other Baltic Sea models currently in use. The model further suggests, based on the observed drawdown of pCO2, that observational estimates of organic carbon production in the Gulf of Bothnia, derived with the method, may be heavily underestimated. We conclude that stoichiometric variability and uncoupling of carbon and nutrient assimilation have to be considered in order to better understand the carbon cycle in coastal seas.
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| 7. |
- Gustafsson, Bo G., et al.
(författare)
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Reconstructing the Development of Baltic Sea Eutrophication 1850-2006
- 2012
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Ingår i: Ambio. - : Springer Science and Business Media LLC. - 0044-7447 .- 1654-7209. ; 41:6, s. 534-548
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Tidskriftsartikel (refereegranskat)abstract
- A comprehensive reconstruction of the Baltic Sea state from 1850 to 2006 is presented: driving forces are reconstructed and the evolution of the hydrography and biogeochemical cycles is simulated using the model BALTSEM. Driven by high resolution atmospheric forcing fields (HiResAFF), BALTSEM reproduces dynamics of salinity, temperature, and maximum ice extent. Nutrient loads have been increasing with a noteworthy acceleration from the 1950s until peak values around 1980 followed by a decrease continuing up to present. BALTSEM shows a delayed response to the massive load increase with most eutrophic conditions occurring only at the end of the simulation. This is accompanied by an intensification of the pelagic cycling driven by a shift from spring to summer primary production. The simulation indicates that no improvement in water quality of the Baltic Sea compared to its present state can be expected from the decrease in nutrient loads in recent decades.
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| 8. |
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| 9. |
- Kahlert, Maria, et al.
(författare)
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Gaps in current Baltic Sea environmental monitoring – Science versus management perspectives
- 2020
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Ingår i: Marine Pollution Bulletin. - London : Elsevier. - 0025-326X .- 1879-3363. ; 160
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Tidskriftsartikel (refereegranskat)abstract
- Legislations and commitments regulate Baltic Sea status assessments and monitoring. These assessments suffer from monitoring gaps that need prioritization. We used three sources of information; scientific articles, projectreports and a stakeholder survey to identify gaps in relation to requirements set by the HELCOM's Baltic SeaAction Plan, the Marine Strategy Framework Directive and the Water Framework Directive. The most frequentlymentioned gap was that key requirements are not sufficiently monitored in space and time. Biodiversity monitoringwas the category containing most gaps. However, whereas more than half of the gaps in reports related tobiodiversity, scientific articles pointed out many gaps in the monitoring of pollution and water quality. Animportant finding was that the three sources differed notably with respect to which gaps were mentioned mostoften. Thus, conclusions about gap prioritization for management should be drawn after carefully consideringthe different viewpoints of scientists and stakeholders. © 2020 The Authors. Published by Elsevier Ltd.
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| 10. |
- Kahlert, Maria, et al.
(författare)
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Knowledge and monitoring gap analysis with respect to the EU Directives
- 2019
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report presents the results of a review on gaps in Baltic Sea monitoring based on two different information sources: peer-reviewed scientific articles, and BONUS and HELCOM project reports. The reviews are part of the BONUS project FUMARI. Our main questions are:(1) does the current monitoring of the Baltic Sea sufficiently address the requirements set by the Marine Strategy Framework Directive, the Water Framework Directive and the HELCOM´s Baltic Sea Action Plan?(2) what are the most critical shortcomings (gaps) in the current Baltic Sea monitoring programs?We found that scientific articles dealing with Baltic Sea monitoring present a view on main monitoring gap occurrence, that differs from the view presented in reports dealing with the same topic. Both scientific articles and reports agreed that many thematic assessment categories are not monitored sufficiently, often due to insufficient spatial coverage. However, whereas articles often highlight both that a category is not sufficiently monitored, and that there is a lack of indicators, the reports focused more on gaps in data storage or handling, coordination of monitoring, or highlighted plans for new but non-operational indicators. Articles mainly mentioned gaps in relation to Eutrophication, Contaminants, Biodiversity, Commercial fish and shellfish, Food webs, Hydrographical conditions, and No alien species. Reports however indicated primarily Biodiversity gaps, followed by Contaminants and Healthy wildlife, Marine litter, and Sea-floor integrity. Our review also showed that certain categories are underrepresented in the scientific literature, i.e. with few scientists developing indicators or assessing data related to them, potentially indicating a knowledge gap in these fields.
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