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  • 51. Omstedt, Anders
    et al.
    Edman, Moa
    Claremar, Bjorn
    Frodin, Peter
    Gustafsson, Erik
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Humborg, Christoph
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Hägg, Hanna
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Mörth, Magnus
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Rutgersson, Anna
    Schurgers, Guy
    Smith, Benjamin
    Wällstedt, Teresia
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Yurova, Alla
    Future changes in the Baltic Sea acid-base (pH) and oxygen balances2012Ingår i: Tellus. Series B, Chemical and physical meteorology, ISSN 0280-6509, E-ISSN 1600-0889, Vol. 64, s. 19586-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Possible future changes in Baltic Sea acid-base (pH) and oxygen balances were studied using a catchment-sea coupled model system and numerical experiments based on meteorological and hydrological forcing datasets and scenarios. By using objective statistical methods, climate runs for present climate conditions were examined and evaluated using Baltic Sea modelling. The results indicate that increased nutrient loads will not inhibit future Baltic Sea acidification; instead, the seasonal pH cycle will be amplified by increased biological production and mineralization. All examined scenarios indicate future acidification of the whole Baltic Sea that is insensitive to the chosen global climate model. The main factor controlling the direction and magnitude of future pH changes is atmospheric CO2 concentration (i.e. emissions). Climate change and land-derived changes (e. g. nutrient loads) affect acidification mainly by altering the seasonal cycle and deep-water conditions. Apart from decreasing pH, we also project a decreased saturation state of calcium carbonate, decreased respiration index and increasing hypoxic area - all factors that will threaten the marine ecosystem. We demonstrate that substantial reductions in fossil-fuel burning are needed to minimise the coming pH decrease and that substantial reductions in nutrient loads are needed to reduce the coming increase in hypoxic and anoxic waters.

  • 52.
    Philippe, M. Cury
    et al.
    Institut de Recherche pour le Développement.
    Boyd, Ian L.
    Scottish Oceans Institute, University of St Andrews.
    Bonhommeau, Sylvain
    Ifremer, UMR EME 212, Centre de Recherche Halieutique Méditerranéenne et Tropicale.
    Österblom, Henrik
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Global seabird response to forage fish depletion-one-third for the birds2011Ingår i: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 334, nr 6063, s. 1703-1706Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Determining the form of key predator-prey relationships is critical for understanding marine ecosystem dynamics. Using a comprehensive global database, we quantified the effect of fluctuations in food abundance on seabird breeding success. We identified a threshold in prey (fish and krill, termed “forage fish”) abundance below which seabirds experience consistently reduced and more variable productivity. This response was common to all seven ecosystems and 14 bird species examined within the Atlantic, Pacific, and Southern Oceans. The threshold approximated one-third of the maximum prey biomass observed in long-term studies. This provides an indicator of the minimal forage fish biomass needed to sustain seabird productivity over the long term.

  • 53. Reed, Daniel C.
    et al.
    Slomp, Caroline P.
    Gustafsson, Bo G.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Sedimentary phosphorus dynamics and the evolution of bottom-water hypoxia: A coupled benthic-pelagic model of a coastal system2011Ingår i: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 56, nr 3, s. 1075-1092Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The present study examines oxygen and phosphorus dynamics at a seasonally hypoxic site in the Arkona basin of the Baltic Sea. A coupled benthic-pelagic reactive-transport model is used to describe the evolution of bottom-water solute concentrations, as well as pore-water and sediment profiles. Aerobic respiration dominates remineralization, with iron reduction, denitrification, and sulphate reduction playing secondary roles, while other pathways are negligible. Sediments represent a significant oxygen sink chiefly due to the aerobic degradation of organic matter, as well as nitrification and iron oxyhydroxide precipitation. Most phosphorus deposited in sediments is in organic matter, yet cycling is dominated by iron-bound phosphorus due to rapid dissimilatory iron reduction coupled with aerobic iron oxyhydroxide formation. Sustained hypoxia results in an initial decrease in sediment phosphorus content due to dissolution of phosphorus-bearing iron oxyhydroxides, resulting in a pulse of phosphate to overlying waters. Although an organic-rich layer is formed under low-oxygen conditions, enhanced remineralization of organic phosphorus relative to organic carbon tempers sedimentary phosphorus accumulation. Upon reoxygenation of bottom waters after a decade of sustained hypoxia, oxygen concentrations do not immediately achieve values observed prior to hypoxia because the organic-rich layer creates a higher benthic oxygen demand. Artificial reoxygenation of bottom waters leads to a substantial increase in the iron-bound phosphorus pool; the total phosphorus content of the sediment, however, is unaffected. A relapse into hypoxia would consequently produce a large pulse of phosphate to the overlying waters potentially exacerbating the situation.

  • 54. Ruoho-Airola, Tuija
    et al.
    Eilola, Kari
    Savchuk, Oleg P.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Parviainen, Maija
    Tarvainen, Virpi
    Atmospheric Nutrient Input to the Baltic Sea from 1850 to 2006: A Reconstruction from Modeling Results and Historical Data2012Ingår i: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, nr 6, s. 549-557Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, a consistent basin-wise monthly time series of the atmospheric nutrient load to the Baltic Sea during 1850-2006 was compiled. Due to the lack of a long time series (1850-1960) of nutrient deposition to the Baltic Sea, the data set was compiled by combining a time series of deposition data at the Baltic Nest Institute from 1970 to 2006, published historical monitoring data and deposition estimates, as well as recent modeled Representative Concentration Pathways (RCP) emission estimates. The procedure for nitrogen compounds included estimation of the deposition in a few intermediate reference years, linear interpolation between them, and the decomposition of annual deposition into a seasonal deposition pattern. As no reliable monitoring results were found for the atmospheric deposition of phosphorus during the early period of our study, we used published estimates for the temporal and spatial pattern of the phosphorus load.

  • 55.
    Savchuk, Oleg
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Large-Scale Dynamics of Hypoxia in the Baltic Sea2010Ingår i: Handbook of Environmental Chemistry / [ed] E.V. Yakushev, Springer Verlag Berlin Heidelberg , 2010Kapitel i bok, del av antologi (Övrigt vetenskapligt)
    Abstract [en]

    Large-scale hypoxia is an inherent natural property of the Baltic Sea caused by geographically and climatically determined insufficiency of oxygen supply to the deep water layers. During 1961–2005, the hypoxic zone covered by waters with oxygen concentration less than 2 mL L–1 extended on average over a huge area of about 50,000 km2, albeit with large seasonal (a few thousand km2) and, especially inter-annual (dozens of thousand km2) variations, the later caused by an irregular ventilation with sporadic inflows of saline oxygen-enriched waters. The expansion of hypoxia induces a reduction of dissolved inorganic nitrogen pool due to denitrification and an increase of dissolved phosphate pool by internal loading, these changes reaching hundred thousand tonnes of N and P. The resulting excess of phosphate pool over the “Redfield” demand by phytoplankton is favourable for the dinitrogen fixation by cyanobacteria in amounts sufficient to compensate for denitrification and to counteract possible reductions of the nitrogen land loads

  • 56.
    Savchuk, Oleg P.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Wulff, Fredrik
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Long-term modeling of large-scale nutrient cycles in the entire Baltic Sea2009Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 629, s. 209-224Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Management of eutrophication in marine ecosystems requires a good understanding of nutrient cycles at the appropriate spatial and temporal scales. Here, it is shown that the biogeochemical processes controlling large-scale eutrophication of the Baltic Sea can be described with a fairly aggregated model: simple as necessary Baltic long-term large scale (SANBALTS). This model simulates the dynamics of nitrogen, phosphorus, and silica driven by the external inputs, the major physical transports, and the internal biogeochemical fluxes within the seven major sub-basins. In a long-term hindcast (1970–2003), the model outputs reasonably matched observed concentrations and fluxes. The model is also tested in a scenario where nutrient inputs are reduced to levels that existed over 100 years ago. The simulated response of the Baltic Sea trophic state to this very large reduction is verified by a similar simulation made with a much more complex process-oriented model. Both models indicate that after initial, rather rapid changes the system goes into much slower evolution, and nutrient cycles would not become balanced even after 130 years.

  • 57.
    Savchuk, O.P.
    et al.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Eremina, T.R.
    Isaev, A.V.
    Neelov, I.A.
    Response of eutrophication in the eastern Gulf of Finland to nutrient load reduction scenarios.2009Ingår i: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 629, s. 225-237Artikel i tidskrift (Refereegranskat)
  • 58. Smedberg, E.
    et al.
    Humborg, C.
    Stockholms universitet, Stockholm Resilience Centre.
    Jacobsson, M.
    Mörth, C-M.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Landscape elements and river chemistry as affected by river regulation – a 3-D perspective.2009Ingår i: Hydrology and Earth System Sciences, ISSN 1027-5606, E-ISSN 1607-7938, Vol. 13, s. 1597-1606Artikel i tidskrift (Refereegranskat)
  • 59. Soomere, T.
    et al.
    Andrejev, O.
    Sokolov, Alexander
    Stockholms universitet, Stockholm Resilience Centre.
    Quak, E.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Management of coastal pollution by means of smart placement of human activities2011Ingår i: Journal of Coastal Research, ISSN 0749-0208, E-ISSN 1551-5036, Vol. 57, s. 951-955Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We describe recent developments in the new technique that addresses the potential for a systematic increase in the time until an adverse impact (for example, an oil spill) reaches a vulnerable sea area and a corresponding decrease in the probability of the impact reaching such an area after an accident has happened. The risk of coastal pollution is estimated using statistical analysis of a large pool of numerically simulated trajectories of water particles in the surface layer. A decrease in the risk level is possible by means of minimizing the probability for a coastal hit or by maximizing the time span until the pollution reaches the coast. Environmental gain is then achieved by placing the dangerous activities into sea areas (or redirecting ship traffic accordingly), from which the transport of the adverse impact to the coast is less likely or takes the most time. As a key new development, we introduce and analyze a measure of risk that systematically accounts for the potential increase in the sailing distance associated with the proposed approach. The resulting gain from the use of the corresponding optimal fairways is estimated for the test area of the Gulf of Finland in the Baltic Sea.

  • 60. Soomere, Tarmo
    et al.
    Andrejev, Oleg
    Myrberg, Kai
    Sokolov, Alexander
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    The use of Lagrangian trajectories for the identification of the environmentally safe fairways2011Ingår i: Marine Pollution Bulletin, ISSN 0025-326X, E-ISSN 1879-3363, Vol. 62, nr 7, s. 1410-1420Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We propose and test a method for the optimisation of marine fairways to minimise the risk to high-value areas, based on statistical analysis of Lagrangian trajectories of current-driven pollution transport. The offshore areas are quantified according to the probability of pollution released in these areas to reach vulnerable regions. The method contains an eddy-resolving circulation model, a scheme for tracking of Lagrangian trajectories, a technique for the calculation of quantities characterising the potential of different sea areas to supply adverse impacts, and routines to construct the optimum fairway. The gain is expressed in terms of the probability of pollution transport to the nearshore and the associated time (particle age). The use of the optimum fairway would decrease the probability of coastal pollution by 40% or increase the average time of reaching the pollution to the coast from 5.3 to about 9 days in the Gulf of Finland, the Baltic Sea.

  • 61.
    Stange, Kari
    et al.
    Stockholms universitet, Stockholm Resilience Centre.
    Olsson, Per
    Stockholms universitet, Stockholm Resilience Centre.
    Österblom, Henrik
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Managing organizational change in an international scientific network: a study of ICES reform processes2012Ingår i: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 36, nr 3, s. 681-688Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Organizations involved in the governance of natural resources are challenged to adjust to the call for more holistic management approaches. This often necessitates organizational change. Here change processes in the International Council for the Exploration of the Sea (ICES) during the years 1998–2009 are investigated using semi-structured interviews combined with observations and review of documents. Several organizational reforms were implemented during the time period studied. The major drivers were the need to improve efficiency and a striving for better integration between different components within the organization. The reform processes were driven forward by individuals who navigated between opportunities and constrains embedded in the network structure of ICES. This required good leadership and communication skills. Broad consultations were important to ensure support within the ICES community. By increasing the understanding of the dynamics of change in organizations, which operate at the science–policy interface developments in desired directions can be facilitated.

  • 62.
    Sun, Xiaole
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Andersson, Per
    Naturhistoriska riksmuseet, Laboratoriet för isotopgeologi.
    Humborg, Christoph
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM). Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Gustafsson, Bo
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Conley, Daniel J.
    Lunds universitet.
    Crill, Patrick
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper.
    Mörth, Carl-Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Climate Dependent Diatom Production is Preserved in Biogenic Si Isotope Signatures2011Ingår i: Biogeosciences, ISSN 1726-4170, E-ISSN 1726-4189, Vol. 8, nr 11, s. 3491-3499Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this study was to reconstruct diatom production in the subarctic northern tip of the Baltic Sea, Bothnian Bay, based on down-core analysis of Si isotopes in biogenic silica (BSi). Dating of the sediment showed that the samples covered the period 1820 to 2000. The sediment core record can be divided into two periods, an unperturbed period from 1820 to 1950 and a second period affected by human activities (from 1950 to 2000). This has been observed elsewhere in the Baltic Sea. The shift in the sediment core record after 1950 is likely caused by large scale damming of rivers. Diatom production was inferred from the Si isotope composition which ranged between δ30Si −0.18‰ and +0.58‰ in BSi, and assuming fractionation patterns due to the Raleigh distillation, the production was shown to be correlated with air and water temperature, which in turn were correlated with the mixed layer (ML) depth. The sedimentary record showed that the deeper ML depth observed in colder years resulted in less production of diatoms. Pelagic investigations in the 1990's have clearly shown that diatom production in the Baltic Sea is controlled by the ML depth. Especially after cold winters and deep water mixing, diatom production was limited and dissolved silicate (DSi) concentrations were not depleted in the water column after the spring bloom. Our method corroborates these findings and offers a new method to estimate diatom production over much longer periods of time in diatom dominated aquatic systems, i.e. a large part of the world's ocean and coastal seas.

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  • 63. Swaney, D. P.
    et al.
    Humborg, Christoph
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute. Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Emeis, K.
    Kannen, A.
    Silvert, W.
    Tett, P.
    Pastres, R.
    Solidoro, C.
    Yamamuro, M.
    Henocque, Y.
    Nicholls, R.
    Five critical questions of scale for the coastal zone2012Ingår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 96, s. 9-21Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Social and ecological systems around the world are becoming increasingly globalized. From the standpoint of understanding coastal ecosystem behavior, system boundaries are not sufficient to define causes of change. A flutter in the stock market in Tokyo or Hong Kong can affect salmon producers in Norway or farmers in Togo. The globalization of opportunistic species and the disempowerment of people trying to manage their own affairs on a local scale seem to coincide with the globalization of trade. Human-accelerated environmental change, including climate change, can exacerbate this sense of disenfranchisement. The structure and functioning of coastal ecosystems have been developed over thousands of years subject to environmental forces and constraints imposed mainly on local scales. However, phenomena that transcend these conventional scales have emerged with the explosion of human population, and especially with the rise of modern global culture. Here, we examine five broad questions of scale in the coastal zone: (1) How big are coastal ecosystems and why should we care? (2) Temporal scales of change in coastal waters and watersheds: Can we detect shifting baselines due to economic development and other drivers? (3) Are footprints more important than boundaries? (4) What makes a decision big? The tyranny of small decisions in coastal regions. (5) Scales of complexity in coastal waters: the simple, the complicated or the complex? These questions do not have straightforward answers. There is no single scale for coastal ecosystems; their multiscale nature complicates our understanding and management of them. Coastal ecosystems depend on their watersheds as well as spatially-diffuse footprints associated with modern trade and material flows. Change occurs both rapidly and slowly on human time scales, and observing and responding to changes in coastal environments is a fundamental challenge. Apparently small human decisions collectively have potentially enormous consequences for coastal environmental quality, and our success in managing the effects of these decisions will determine the quality of life in the coastal zone in the 21st century and beyond. Vigilant monitoring, creative synthesis of information, and continued research will be necessary to properly understand and govern our coastal environments into the future.

  • 64. Timmermann, Karen
    et al.
    Norkko, Joanna
    Janas, Urszula
    Norkko, Alf
    Gustafsson, Bo G.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Bonsdorff, Erik
    Modelling macrofaunal biomass in relation to hypoxia and nutrient loading2012Ingår i: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 105-108, s. 60-69Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Nutrient loading of aquatic ecosystems results in more food for benthic macrofaunal communities but also increases the risk of hypoxia, resulting in a reduction or complete loss of benthic biomass. This study investigates the interaction between eutrophication, hypoxia and benthic biomass with emphasis on the balance between gains and loss of benthic biomass due to changes in nutrient loadings. A physiological fauna model with 5 functional groups was linked to a 3D coupled hydrodynamic-ecological Baltic Sea model. Model results revealed that benthic biomass increased between 0 and 700% after re-oxygenating bottom waters. Nutrient reduction scenarios indicated improved oxygen concentrations in bottom waters and decreased sedimentation of organic matter up to 40% after a nutrient load reduction following the Baltic Sea Action Plan. The lower food supply to benthos reduced the macrofaunal biomass up to 35% especially in areas not currently affected by hypoxia, whereas benthic biomass increased up to 200% in areas affected by eutrophication-induced hypoxia. The expected changes in benthic biomass resulting from nutrient load reductions and subsequent reduced hypoxia may not only increase the food supply for benthivorous fish, but also significantly affect the biogeochemical functioning of the ecosystem.

  • 65.
    Tomczak, Macief
    et al.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Niiranen, Susa
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute. Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Hjerne, Olle
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Blenckner, Thorsten
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Ecosystem flow dynamics in the Baltic Proper-Using a multi-trophic dataset as a basis for food-web modelling2012Ingår i: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 230, s. 123-147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Baltic Proper is a semi-enclosed, highly productive basin of the Baltic Sea with a low biodiversity, where only a few key species drive the system's dynamics. Recently, an ecosystem regime shift was described having pronounced changes at all trophic levels, driven by changes in fishery and climate and leading to a food-web reorganisation. An Ecopath with Ecosim Baltic Proper food-web model (BaltProWeb) was developed to simulate and better understand trophic interactions and their flows. The model contains 22 functional groups that represent the main food-web components. BaltProWeb was calibrated to long-term monitoring data (1974-2006), covering multiple trophic levels and is forced by fisheries and environmental drivers. Our model enables the quantification of the flows through the food-web from primary producers to top predators including fisheries over time. The model is able to explain 51% of the variation in biomass of multiple trophic levels and to simulate the regime shift from a cod dominated to a sprat dominated system. Results show a change from benthic to more pelagic trophic flows. Before the reorganisation macrozoobenthos was identified as an important functional group transferring energy directly from lower trophic levels to top predators. After the regime shift, the pelagic trophic flows dominated. Uncertainties and limitations of the modelling approach and results in relation to ecosystem-based management are discussed.

  • 66. Tomczak, M.T.
    et al.
    Müller-Karulis, B.
    Jär, L.
    Kotta, L
    Martin, G.
    Minde, A
    Põllumäe, A
    Razinkovas, A
    Strake, S.
    Bucas, M
    Blenckner, T.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Analysis of trophic networks and carbon flows in south-eastern Baltic coastal ecosystems2009Ingår i: Progress in Oceanography, ISSN 0079-6611, E-ISSN 1873-4472, Vol. 81, s. 111-131Artikel i tidskrift (Refereegranskat)
  • 67. Ustups, Didzis
    et al.
    Mueller-Karulis, Bärbel
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute. Institute of Food Safety, Animal Health and Environment, BIOR, Latvia.
    Bergström, Ulf
    Makarchouk, Andrej
    Sics, Ivo
    The influence of environmental conditions on early life stages of flounder (Platichthys flesus) in the central Baltic Sea2013Ingår i: Journal of Sea Research, ISSN 1385-1101, E-ISSN 1873-1414, Vol. 75, s. 77-84Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Flounder (Platichthys flesus) is a temperate marine fish that is well adapted to the brackish waters of the Baltic Sea. There are two sympatric flounder populations in the Baltic Sea, pelagic and demersal spawners, which differ in their spawning habitat and egg characteristics. In the present study, pelagic spawning flounder of the central Baltic Sea was studied. We examined whether variations in hydrological regime can explain fluctuations in flounder early life stages that have occurred over the past 30 years (1970-2005). Using generalized additive modeling to explain the abundance of flounder eggs and larvae in a Latvian ichthyoplankton dataset, we evaluate the hypothesis that the available reproductive volume, defined as the water column with dissolved oxygen larger than 1 ml/l and salinity between 10.6 and 12 PSU, affects the survival of flounder ichthyoplankton and determines recruitment success. Both reproductive volume and spawning stock biomass were significant factors determining flounder ichthyoplankton abundance. Different measures of water temperature did not contribute significantly to the variability of eggs or larvae. However, recruitment did not correlate to the supply of larvae. The findings presented in this study on the relationship between flounder reproduction, spawning stock biomass and reproductive volume, as well as the lack of correlation to recruitment, are valuable for the understanding of flounder ecology in the Baltic Sea, and for developing the management of the species.

  • 68.
    Valman, Matilda
    Stockholms universitet, Samhällsvetenskapliga fakulteten, Statsvetenskapliga institutionen. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Institutional stability and change in the Baltic Sea: 30 years of issues, crises and solutions2013Ingår i: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 38, s. 54-64Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The shift from a classic sector-by-sector management system to an operational ecosystem approach is perceived as the way forward towards sustainable use of marine systems. The nine states bordering the Baltic Sea as well as the European Community signed the Baltic Sea Action Plan (BSAP) in 2007, intended to provide practical means for implementing the ecosystem approach in the region. However, whether this shift towards a new governance approach also constitutes a case of institutional change remains unclear. This study evaluates institutional change over 30 years in order to understand the process of emergence of the ecosystem approach for this international institution. This study adds to the otherwise largely theoretical debate on institutional change by testing two models of institutional change – gradualist versus punctuated equilibrium – against data from the Helsinki Commission. Relying on a novel methodology involving quantitative text analyses of 574 documents this study suggests that the signing of the BSAP did not cause change in the institution, nor was it the cause of an abrupt institutional change. Overall, findings support a gradualist model of institutional change where the BSAP is layered upon preexisting institutional structures. Results also indicate that institutional change has occurred in some parts of the institution, whereas other parts remain remarkably stable. It proves that in order to intentionally change an institution it is vital that the change processes cohere at all levels of the institution. The study also underlines the mismatch between ecosystems and institutions. Given the relatively slow dynamics identified here, it is unclear whether institutions are able to adapt to rapid and unpredictable ecosystem shifts.

  • 69.
    Vonk, Jorien E.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Alling, Vanja
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Rahm, Lars
    Mörth, Carl-Magnus
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för geologiska vetenskaper. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Humborg, Christoph
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM). Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Gustafsson, Örjan
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    A centennial record of fluvial organic matter input from the discontinuous permafrost catchment of Lake Tornetrask2012Ingår i: Journal of Geophysical Research, ISSN 0148-0227, E-ISSN 2156-2202, Vol. 117, s. G03018-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    High-latitude regions are underlain by the most organic carbon (OC)-rich soils on earth and currently subject to intense climate warming, potentially increasing remobilization and mineralization of soil OC. Sub-Arctic Scandinavia is located on the 0 degrees C mean annual isotherm and is therefore particularly vulnerable to climate change. This study aimed to establish a baseline for soil OC release over the past century into Lake Tornetrask, the largest lake in sub-Arctic Scandinavia, through bulk geochemical and molecular radiocarbon analyses in chronologically constrained sediment cores. Our results suggest a dominance of peat-derived terrestrial OC inflow. We show that the annual terrestrial OC inflow to the lake is similar to 12 times higher than the in-lake produced particulate OC, and consists for a large part (ca. 60%) of old OC from deep reservoirs in the catchment. The sedimentary record shows signs of increasing inflow of more degraded terrestrial matter since similar to 1975, as indicated by increasing % TOC concentrations, a lower delta C-13 value and lower TOC: TN ratios. Based on simultaneous changes in local climate and reported signs of permafrost degradation (e.g., active layer deepening, mire/peat erosion), the observed changes in the sedimentary record of Scandinavia's largest mountain lake likely reflect a climate warming-induced change in terrestrial OC inflow.

  • 70.
    Wulff, F
    et al.
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Humborg, C
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Rodriguez Medina, M
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Mörth, C-M
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Savchuk, O
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Sokolov, A
    Stockholms universitet, Stockholm Resilience Centre. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Revision of the country allocation of nutrient reductions in the Baltic Sea: Hydrological adjusted riverine loads and atmospheric loads from different countries2009Rapport (Övrig (populärvetenskap, debatt, mm))
  • 71.
    Österblom, Henrik
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för systemekologi. Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Casini, Michele
    Olsson, Olof
    Bignert, Anders
    Fish, seabirds and trophic cascades in the Baltic Sea2006Ingår i: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 323, s. 233-238Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     

     

     

    In the relatively simple Baltic Sea ecosystem, zooplankton-feeding sprat

     

     

    Sprattus sprattus

    is a major food source for breeding seabirds and piscivorous fish, and an important resource for

    commercial fisheries. Large-scale and long-term ecosystem changes resulting mainly from over fishing

    and recruitment failure of cod

     

     

    Gadus morhua

    , which is the main fish predator of sprat, have

    affected natural-history patterns in a piscivorous seabird, the common guillemot

     

     

    Uria aalge

    , in a complex

    way. As the sprat stock increased, leading to lower energy content of fish, common guillemot

    chick body mass at fledging decreased. However, chick fledging body mass recovered in recent years

    as the sprat stock diminished, which brought about corresponding increases in sprat weight-at-age

    and energy content. The cod and sprat fishery affect the common guillemots in the Baltic Sea, but the

    effects differ depending on the management strategy.

  • 72.
    Österblom, Henrik
    et al.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Sissenwine, M.
    Symes, D.
    Kadin, Martina
    Stockholms universitet, Stockholm Resilience Centre.
    Daw, Tim
    Stockholms universitet, Stockholm Resilience Centre. University of East Anglia, England.
    Folke, Carl
    Stockholms universitet, Stockholm Resilience Centre. Royal Swedish Academy of Science, The Beijer Institute of Ecological Economics, Sweden.
    Incentives, social-ecological feedbacks and European fisheries2011Ingår i: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 35, nr 5, s. 568-574Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The European Common Fisheries Policy (CFP) has failed to deliver on social, economic and ecological goals. This failure is in part the result of a number of social-ecological feedback mechanisms. The policy is currently undergoing reform, with unknown practical outcomes. Here, relatively successful fisheries policies outside the European Union are reviewed. Through interviews and workshops with scientists, managers and other stakeholders, complemented with literature reviews, practices that can create incentives for long-term sustainability are investigated. The focus is on how the provision of clear and trusted scientific evidence can stimulate defensible decisions, in turn creating incentives for compliance, leading to positive social-ecological outcomes. Despite differences between Europe and the investigated case studies, the prospects of an increased regionalization within the European CFP provides the best starting point for implementing best practice identified in this study.

  • 73.
    Österblom, Henrik
    et al.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Sumaila, U. Rashid
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Bodin, Örjan
    Stockholms universitet, Stockholm Resilience Centre.
    Sundberg, Jonas Hentati
    Press, Anthony J.
    Adapting to Regional Enforcement: Fishing Down the Governance Index2010Ingår i: PLOS ONE, ISSN 1932-6203, Vol. 5, nr 9, s. e12832-Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Background: Illegal, Unreported and Unregulated (IUU) fishing is a problem for marine resource managers, leading to depletion of fish stocks and negative impacts on marine ecosystems. These problems are particularly evident in regions with weak governance. Countries responsible for sustainable natural resource management in the Southern Ocean have actively worked to reduce IUU fishing in the region over a period of 15 years, leading to a sequence of three distinct peaks of IUU fishing. Methodology/Principal Findings: We reviewed existing public records relating to IUU fishing in the Southern Ocean between 1995-2009 and related this information to the governance capacity of flag states responsible for IUU vessels. IUU operators used a number of methods to adapt to enforcement actions, resulting in reduced risks of detection, apprehension and sanctioning. They changed fishing locations, vessel names and flag states, and ports for offloading IUU catches. There was a significant decrease in the proportion of IUU vessels flagged to CCAMLR countries, and a significant decrease in the average governance index of flag states. Despite a decreasing trend of IUU fishing, further actions are hampered by the regional scope of CCAMLR and the governance capacity of responsible states. Conclusions/Significance: This is the first study of long-term change in the modus operandi of IUU fishing fishing operators, illustrating that IUU operators can adapt to enforcement actions and that such dynamics may lead to new problems elsewhere, where countries have a limited capacity. This outsourcing of problems may have similarities to natural resource extraction in other sectors and in other regions. IUU fishing is the result of a number of factors, and effectively addressing this major challenge to sustainable marine resource extraction will likely require a stronger focus on governance. Highly mobile resource extractors with substantial funds are able to adapt to changing regulations by exploiting countries and regions with limited capacity.

  • 74.
    Österblom, Henrik
    et al.
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Sumaila, Ussif Rashid
    Toothfish crises, actor diversity and the emergence of compliance mechanisms in the Southern Ocean2011Ingår i: Global Environmental Change, ISSN 0959-3780, E-ISSN 1872-9495, Vol. 21, nr 3, s. 972-982Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Illegal, unregulated and unreported (IUU) fishing is a challenging form of non-compliance in many marine ecosystems. IUU fishing has attracted substantial political attention in the Southern Ocean, where a series of crises created windows of opportunity for change. A crises-response framework was used for examining these dynamics between 1995 and 2009. Crises were defined in relation to their perceived threat, decision time and surprise. Published material was combined with the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLRs) expert interviews, to evaluate changing perceptions of IUU fishing and corresponding actions. A first crisis led to an increased use of informal shortcuts and a concentration of power. A second crisis created windows of opportunities for policy entrepreneurs and stimulated policy innovation. A third crisis led to the implementation of existing contingency plans. These responses were consistent with predictions from the crisis-response framework used. The series of crises threatened the credibility of CCAMLR and changed the incentives for engaging in coalitions, which led to the development of both management and enforcement approaches to compliance. State and non-state actors became increasingly involved in developing these diverse compliance mechanisms, thereby actively contributing to the adaptive capacity of CCAMLR. Synergies between fisheries industry, environmental conservation, and state sovereignty interests were effectively utilized. Individual actors, organizations and countries providing leadership had strong incentives for doing so. Trust and reputation was important for the compliance mechanisms leading to a substantial reduction of IUU fishing.

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