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Grimvall A.,Swedish Institute for the Marine Environment | Von Bromssen C.,Swedish University of Agricultural Sciences | Lindstrom G.,Swedish Meteorological and Hydrological Institute
Environmental Monitoring and Assessment | Year: 2014

Advances in process-based modelling of loads of nitrogen and phosphorus carried by rivers have created new possibilities to interpret time series of water quality data. We examined how model runs with constant anthropogenic forcing can be used to estimate and filter out weather-driven variation in observational data and, thereby, draw attention to other features of such data. An assessment of measured and modelled nutrient concentrations at the outlets of 45 Swedish rivers provided promising results for total nitrogen. In particular, joint analyses of observational data and outputs from the catchment model S-HYPE strengthened the evidence that downward trends in nitrogen were due to mitigation measures in agriculture. Evaluation of modelled and observed total phosphorus concentrations revealed considerable bias in the collection or chemical analysis of water samples and also identified weaknesses in the model outputs. Together, our results highlight the need for more efficient two-way communication between environmental modelling and monitoring. © 2014 Springer International Publishing.


Hultin K.A.H.,University of Stockholm | Nilsson E.D.,University of Stockholm | Krejci R.,University of Stockholm | Mrtensson E.M.,University of Stockholm | And 4 more authors.
Journal of Geophysical Research: Atmospheres | Year: 2010

Bubbles bursting from whitecaps are considered to be the most effective mechanism for particulate matter to be ejected into the atmosphere from the Earth's oceans. To realistically predict the climate effect of marine aerosols, global climate models require process-based understanding of particle formation from bubble bursting. During a cruise on the highly biologically active waters of the northeastern Atlantic Ocean in the summer of 2006, the submicrometer primary marine aerosol produced by a jet of seawater impinging on a seawater surface was investigated. The produced aerosol size spectra were centered on 200 nm in dry diameter and were conservative in shape throughout the cruise. The aerosol number production was negatively correlated with dissolved oxygen (DO) in the water (r < -0.6 for particles of dry diameter Dp > 200 nm). An increased surfactant concentration as a result of biological activity affecting the oxygen saturation is thought to diminish the particle production. The lack of influence of chlorophyll on aerosol production indicates that hydrocarbons produced directly by the photosynthesis are not essential for sea spray production. The upward mixing of deeper ocean water as a result of higher wind speed appears to affect the aerosol particle production, making wind speed influence aerosol production in more ways than by increasing the amount of whitecaps. The bubble spectra produced by the jet of seawater was representative of breaking waves at open sea, and the particle number production was positively correlated with increasing bubble number concentration with a peak production of 40-50 particles per bubble. Copyright 2010 by the American Geophysical Union.


Svedang H.,Institute of Marine Research | Svedang H.,Swedish Institute for the Marine Environment | Andre C.,Gothenburg University | Jonsson P.,Institute of Marine Research | And 2 more authors.
Environmental Biology of Fishes | Year: 2010

The question whether temperate marine fishes typically consist of self-sustaining populations or "open" populations still remains unresolved. At the heart of this population connectivity problem lays the nature of the stock separation mechanisms. Fish populations could be segregated either by environmental forcing, accompanied with opportunistic recruitment of juveniles to spawning areas, or by philopatric behaviours (i. e., inclination of an individual to return to or remain in its natal area). Here we report three, partly independent, studies on Atlantic Cod (Gadus morhua) stock separation in the Kattegat and Öresund (eastern North Sea): characterisation of spawning aggregations with genetic markers, tagging experiments, and analysis of chemical constituents in otolith cores of recaptured fish that could be linked to a specific spawning site. While the genetic investigation showed no population segregation, the observed migratory patterns indicated three separate spawning sites at close distances. The natal dependence on the choice of spawning site was tested by measuring the contents of various trace elements in the otolith core of recaptured tagged fish. Quantification of the trace elements: Ba, Br, Co, Cr, Cu, Fe, Mn, Mo, Ni, Sr, Ti, and Zn expressed as ratios to Ca were obtained using scanning micro PIXE. These results indicated that natal origin could be differentiated between spawning sites, supporting the hypothesis that natal homing is an important stock separating mechanism even over short distances (<100 km). © 2010 Springer Science+Business Media B.V.


Cardinale M.,Institute of Marine Research | Svedang H.,Swedish Institute for the Marine Environment
Marine Ecology Progress Series | Year: 2011

The Baltic Sea ecosystem is hypothesized to have undergone a regime shift during the last 3 decades, altering its functioning and the composition of its zooplankton and fish communities. The new stable state has been considered as 'cod hostile' due to reduced spawning success in cod, as well as increased predation on and declining food sources for cod larvae. Nonetheless, the eastern Baltic cod stock has recently recovered after more than 2 decades of low biomass and productivity. The recovery was mainly driven by a sudden reduction in fishing mortality and occurred in the absence of any exceptionally large year classes. The recovery of the cod stock during a 'cod-hostile' ecological regime indicates that fisheries are the main regulator of cod population dynamics in the Baltic Sea. © Inter-Research 2011.


Cardinale M.,Swedish University of Agricultural Sciences | Svedang H.,Swedish University of Agricultural Sciences | Svedang H.,Swedish Institute for the Marine Environment | Bartolino V.,Swedish University of Agricultural Sciences | And 4 more authors.
Journal of Applied Ichthyology | Year: 2012

By reconstructing a centennial time-series of stock spatio-temporal dynamics and commercial landings, the long-term erosion is shown of the spatial structure of haddock and pollack in the Skagerrak and Kattegat that resulted in their regional depletion in the area. The erosion occurred in parallel with the development of the industrial fisheries and the peak in landings was followed by a decline in adult biomass and individual size. Also found was that pollack adult biomass was significantly lower for elevated water temperatures, while the response for haddock was less clear. However the main decline of both stocks and the disappearance of their adult aggregations occurred several decades before the unprecedented warming trend, which started in the Skagerrak and Kattegat only in the mid-1980s. These findings also suggest that haddock in the study area is not responding to the scale on which the management of the neighbouring North Sea haddock stock is currently performed. These results illustrate the hazardous consequences of prolonged overfishing on the population structure of commercially exploited stocks and the lack of knowledge which ultimately leads to spurious assumptions on the recovery potential of many fish stocks. Also argued is that the continuation of commercial fishery at 'sustainable' levels adjusted to the present stock productivity might hinder the recovery of these depleted stocks for a long period of time. © 2012 Blackwell Verlag, Berlin.


Bartolino V.,Swedish University of Agricultural Sciences | Bartolino V.,Gothenburg University | Cardinale M.,Swedish University of Agricultural Sciences | Svedang H.,Swedish University of Agricultural Sciences | And 3 more authors.
Canadian Journal of Fisheries and Aquatic Sciences | Year: 2012

Recent analyses of historical data of fish abundance and distribution have shown the importance of a long temporal perspective in the evaluation of the current status of fish populations, but pose numerous difficulties such as fragmentation and inhomogeneities in the amount of available information in space and time. Using mixed-effects models in a multiscale analysis, we identified an appropriate spatiotemporal scale of investigation of a high-quality, spatially explicit historical data set, and we reconstructed the long-term spatial dynamics of Atlantic cod (Gadus morhua) in the Kattegat- Skagerrak along the 20th century. We identified a northern and southern main aggregation of adult cod in the study area, corresponding to the Skagerrak portion of the North Sea and the Kattegat cod stocks, respectively. The stocks showed specificities in their spatial dynamics, but common extensive loss of coastal aggregations during the last decades when only 13% (Kattegat) and 35% (Skagerrak) of the estimated early century cod biomass was left. Our reconstruction showed that the collapse of the cod stocks in the area followed the peak in landings in the 1960s-1970s, suggesting that the postwar development of the industrial fisheries played a major role in the decrease of local abundances and disappearance of local adult cod aggregations.


Wendt I.,Swedish Institute for the Marine Environment | Backhaus T.,Gothenburg University | Blanck H.,Gothenburg University | Arrhenius A.,Gothenburg University
Ecotoxicology | Year: 2016

Copepods, the largest group of pelagic grazers, are at risk from exposure to antifouling biocides. This study investigated the toxicity of the antifouling biocides 4,5-dichloro-2-octyl-1,2-thiazol-3(2H)-one (DCOIT), triphenylborane pyridine (TPBP) and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) to the copepod Acartia tonsa, using mortality and egg production as endpoints. The toxicity ranking for mortality was as follows: DCOIT (LC50 57 nmol l−1) = TPBP (LC50 56 nmol l−1) > medetomidine (LC50 241 nmol l−1). Egg production was more sensitive than mortality to TPBP (EC50 3.2 nmol l−1), while DCOIT and medetomidine inhibited egg production at roughly the same concentrations (72 and 186 nmol l−1 respectively). Furthermore, TPBP seems to affect egg hatching directly which was not the case for DCOIT and medetomidine. DCOIT and medetomidine might pose an environmental risk as they have been reported to occur in different exposure scenarios or analytical surveys at concentrations only 2–3 times lower than the respective EC10. Reported environmental concentrations of TPBP are few but clearly lower than the EC10 values reported here, suggesting current risk of TPBP to copepods to be moderate. © 2016 Springer Science+Business Media New York


PubMed | Gothenburg University and Swedish Institute for the Marine Environment
Type: Journal Article | Journal: Ecotoxicology (London, England) | Year: 2016

Copepods, the largest group of pelagic grazers, are at risk from exposure to antifouling biocides. This study investigated the toxicity of the antifouling biocides 4,5-dichloro-2-octyl-1,2-thiazol-3(2H)-one (DCOIT), triphenylborane pyridine (TPBP) and 4-[1-(2,3-dimethylphenyl)ethyl]-1H-imidazole (medetomidine) to the copepod Acartia tonsa, using mortality and egg production as endpoints. The toxicity ranking for mortality was as follows: DCOIT (LC50 57nmoll(-1))=TPBP (LC50 56nmoll(-1))>medetomidine (LC50 241nmoll(-1)). Egg production was more sensitive than mortality to TPBP (EC50 3.2nmoll(-1)), while DCOIT and medetomidine inhibited egg production at roughly the same concentrations (72 and 186nmoll(-1) respectively). Furthermore, TPBP seems to affect egg hatching directly which was not the case for DCOIT and medetomidine. DCOIT and medetomidine might pose an environmental risk as they have been reported to occur in different exposure scenarios or analytical surveys at concentrations only 2-3 times lower than the respective EC10. Reported environmental concentrations of TPBP are few but clearly lower than the EC10 values reported here, suggesting current risk of TPBP to copepods to be moderate.


Svedang H.,Swedish Institute for the Marine Environment | Gipperth L.,Swedish Institute for the Marine Environment
Marine Policy | Year: 2012

In response to the shortcomings of the EU's Common Fisheries Policy, the European Commission has suggested regionalising fisheries management. Examples already exist of the more decentralised management of certain fisheries. Since 2007, the Commission has requested national eel management plans (EMPs) from all EU eel-fishing nations, giving national management bodies considerable freedom to develop their own EMPs. To examine the prerequisites for decentralisation, the Swedish EMP was chosen as a case. The European eel is critically endangered due to overfishing and environmental degradation. Analysis of the Swedish EMP reveals serious flaws: the conflict between the objectives of species and fishery preservation has not been clarified nor is the prioritisation clear. The plan has not been critically reviewed and alternative options are not considered. Though the basic data are uncertain, this uncertainty is viewed as support for not adopting any safety margin. Management is therefore directed towards mitigating the negative effects of fishing and other human activities rather than realising the conservation objective. The efficiency of the various protection measures is also disputable; for example, translocation is problematic, as translocated (i.e., stocked) eels display impaired navigational abilities. Another problematic aspect of this conservation strategy is the slow implementation of the EMP. In conclusion, this study emphasises the necessity of legal and social science as well as natural science research to evaluate the efficiency and implementation of fishery management. © 2011 Elsevier Ltd.


Sundblad E.-L.,Swedish Institute for the Marine Environment | Grimvall A.,Swedish Institute for the Marine Environment | Gipperth L.,Swedish Institute for the Marine Environment | Morf A.,Swedish Institute for the Marine Environment
Marine Policy | Year: 2014

The Marine Strategy Framework Directive, adopted by the EU, and several other initiatives to improve marine environmental management emphasize the need to integrate environmental and social analyses. This article proposes and tests a general Behavior-Pressure-State-Impact-Response (BPSIR) framework for identifying and structuring environmentally relevant social data. The framework is compatible with the widely applied Driver-Pressure-State-Impact-Response (DPSIR) framework, but emphasizes actors and their behavior and defines 'impact' more specifically. In particular, it distinguishes between: (i) actors directly involved in activities causing physical, chemical, and biological disturbances, and (ii) actors who indirectly affect marine resource use and the pressures on marine ecosystems. Three case studies of chemical and biological disturbances in the Swedish parts of the North and Baltic seas demonstrate the need to balance current ecosystem monitoring with systematically collected and organized data on social factors, i.e., both direct and indirect actors and stakeholders, their adaptation to policy measures, and the role of general trends in consumption and production. © 2013 Elsevier Ltd.

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