Change search
Refine search result
1 - 49 of 49
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Biggs, Reinette
    et al.
    Stockholm University, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre.
    Folke, Carl
    Stockholm University, Stockholm Resilience Centre.
    Gordon, Line
    Stockholm University, Stockholm Resilience Centre.
    Norström, Albert
    Stockholm University, Stockholm Resilience Centre.
    Peterson, Garry
    Stockholm University, Stockholm Resilience Centre.
    Regime Shifts2011In: Sourcebook in Theoretical Ecology / [ed] A Hastings, L Gross, University of California Press, 2011Chapter in book (Other academic)
  • 2.
    Blenckner, Thorsten
    et al.
    Stockholm University, Stockholm Resilience Centre.
    Döring, Ralf
    Ebeling, Michael
    Hoff, Ayoe
    Tomczak, Maciej
    FishSTERN: a first attempt at an ecological-economic evaluation of fishery management scenarios in the Baltic Sea region2011Report (Other academic)
  • 3.
    Blenckner, Thorsten
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Kannen, Andreas
    Barausse, Alberto
    Fischer, Christian
    Heymans, Johanna J.
    Luisetti, Tiziana
    Todorova, Valentin
    Valman, Matilda
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Mee, Laurence
    Past and future challenges in managing European seas2015In: Ecology & society, ISSN 1708-3087, E-ISSN 1708-3087, Vol. 20, no 1, article id 40Article in journal (Refereed)
    Abstract [en]

    Marine environments have undergone large-scale changes in recent decades as a result of multiple anthropogenic pressures, such as overfishing, eutrophication, habitat fragmentation, etc., causing often nonlinear ecosystem responses. At the same time, management institutions lack the appropriate measures to address these abrupt transformations. We focus on existing examples from social-ecological systems of European seas that can be used to inform and advise future management. Examples from the Black Sea and the Baltic Sea on long-term ecosystem changes caused by eutrophication and fisheries, as well as changes in management institutions, illustrate nonlinear dynamics in social-ecological systems. Furthermore, we present two major future challenges, i.e., climate change and energy intensification, that could further increase the potential for nonlinear changes in the near future. Practical tools to address these challenges are presented, such as ensuring learning, flexibility, and networking in decision-making processes across sectors and scales. A combination of risk analysis with a scenario-planning approach might help to identify the risks of ecosystem changes early on and may frame societal changes to inform decision-making structures to proactively prevent drastic surprises in European seas.

  • 4.
    Blenckner, Thorsten
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Llope, Marcos
    Moellmann, Christian
    Voss, Rudi
    Quaas, Martin F.
    Casini, Michele
    Lindegren, Martin
    Folke, Carl
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Stenseth, Nils Chr.
    Climate and fishing steer ecosystem regeneration to uncertain economic futures2015In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 282, no 1803, article id 20142809Article in journal (Refereed)
    Abstract [en]

    Overfishing of large predatory fish populations has resulted in lasting restructurings of entire marine food webs worldwide, with serious socioeconomic consequences. Fortunately, some degraded ecosystems show signs of recovery. A key challenge for ecosystem management is to anticipate the degree to which recovery is possible. By applying a statistical food-web model, using the Baltic Sea as a case study, we show that under current temperature and salinity conditions, complete recovery of this heavily altered ecosystem will be impossible. Instead, the ecosystem regenerates towards a new ecological baseline. This new baseline is characterized by lower and more variable biomass of cod, the commercially most important fish stock in the Baltic Sea, even under very low exploitation pressure. Furthermore, a socio-economic assessment shows that this signal is amplified at the level of societal costs, owing to increased uncertainty in biomass and reduced consumer surplus. Specifically, the combined economic losses amount to approximately 120 million E per year, which equals half of today's maximum economic yield for the Baltic cod fishery. Our analyses suggest that shifts in ecological and economic baselines can lead to higher economic uncertainty and costs for exploited ecosystems, in particular, under climate change.

  • 5.
    Blenckner, Thorsten
    et al.
    Stockholm University, Stockholm Resilience Centre.
    Noges, Tiina
    Tranvik, Lars
    Pettersson, Kurt
    Naddafi, Rahmat
    Preface2011In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 660, no 1, p. 1-2Article in journal (Refereed)
  • 6.
    Blenckner, Thorsten
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Österblom, Henrik
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Larsson, Per
    Andersson, Agneta
    Elmgren, Ragnar
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Baltic Sea ecosystem-based management under climate change: Synthesis and future challenges2015In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 44, p. 507-515Article in journal (Refereed)
    Abstract [en]

    Ecosystem-based management (EBM) has emerged as the generally agreed strategy for managing ecosystems, with humans as integral parts of the managed system. Human activities have substantial effects on marine ecosystems, through overfishing, eutrophication, toxic pollution, habitat destruction, and climate change. It is important to advance the scientific knowledge of the cumulative, integrative, and interacting effects of these diverse activities, to support effective implementation of EBM. Based on contributions to this special issue of AMBIO, we synthesize the scientific findings into four components: pollution and legal frameworks, ecosystem processes, scale-dependent effects, and innovative tools and methods. We conclude with challenges for the future, and identify the next steps needed for successful implementation of EBM in general and specifically for the Baltic Sea.

  • 7. Casini, Michele
    et al.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Moellmann, Christian
    Gardmark, Anna
    Lindegren, Martin
    Llope, Marcos
    Kornilovs, Georgs
    Plikshs, Maris
    Stenseth, Nils Christian
    Predator transitory spillover induces trophic cascades in ecological sinks2012In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 109, no 21, p. 8185-8189Article in journal (Refereed)
    Abstract [en]

    Understanding the effects of cross-system fluxes is fundamental in ecosystem ecology and biological conservation. Source-sink dynamics and spillover processes may link adjacent ecosystems by movement of organisms across system boundaries. However, effects of temporal variability in these cross-system fluxes on a whole marine ecosystem structure have not yet been presented. Here we show, using 35 y of multitrophic data series from the Baltic Sea, that transitory spillover of the top-predator cod from its main distribution area produces cascading effects in the whole food web of an adjacent and semi-isolated ecosystem. At varying population size, cod expand/contract their distribution range and invade/retreat from the neighboring Gulf of Riga, thereby affecting the local prey population of herring and, indirectly, zooplankton and phytoplankton via top-down control. The Gulf of Riga can be considered for cod a true sink habitat, where in the absence of immigration from the source areas of the central Baltic Sea the cod population goes extinct due to the absence of suitable spawning grounds. Our results add a metaecosystem perspective to the ongoing intense scientific debate on the key role of top predators in structuring natural systems. The integration of regional and local processes is central to predict species and ecosystem responses to future climate changes and ongoing anthropogenic disturbances.

  • 8. Conversi, Alessandra
    et al.
    Dakos, Vasilis
    Gårdmark, Anna
    Ling, Scott
    Folke, Carl
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Royal Swedish Academy of Sciences, Sweden.
    Mumby, Peter J.
    Greene, Charles
    Edwards, Martin
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Casini, Michele
    Pershing, Andrew
    Möllmann, Christian
    A holistic view of marine regime shifts2015In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 370, no 1659, article id 20130279Article, review/survey (Refereed)
    Abstract [en]

    Understanding marine regime shifts is important not only for ecology but also for developing marine management that assures the provision of ecosystem services to humanity. While regime shift theory is well developed, there is still no common understanding on drivers, mechanisms and characteristic of abrupt changes in real marine ecosystems. Based on contributions to the present theme issue, we highlight some general issues that need to be overcome for developing a more comprehensive understanding of marine ecosystem regime shifts. We find a great divide between benthic reef and pelagic ocean systems in how regime shift theory is linked to observed abrupt changes. Furthermore, we suggest that the long-lasting discussion on the prevalence of top-down trophic or bottom-up physical drivers in inducing regime shifts may be overcome by taking into consideration the synergistic interactions of multiple stressors, and the special characteristics of different ecosystem types. We present a framework for the holistic investigation of marine regime shifts that considers multiple exogenous drivers that interact with endogenous mechanisms to cause abrupt, catastrophic change. This framework takes into account the time-delayed synergies of these stressors, which erode the resilience of the ecosystem and eventually enable the crossing of ecological thresholds. Finally, considering that increased pressures in the marine environment are predicted by the current climate change assessments, in order to avoid major losses of ecosystem services, we suggest that marine management approaches should incorporate knowledge on environmental thresholds and develop tools that consider regime shift dynamics and characteristics. This grand challenge can only be achieved through a holistic view of marine ecosystem dynamics as evidenced by this theme issue.

  • 9.
    Downing, Andrea S.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences. Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hajdu, Susanna
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Hjerne, Olle
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Otto, Saskia A.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Larsson, Ulf
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Winder, Monika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Zooming in on size distribution patterns underlying species coexistence in Baltic Sea phytoplankton2014In: Ecology Letters, ISSN 1461-023X, E-ISSN 1461-0248, Vol. 17, no 10, p. 1219-1227Article in journal (Refereed)
    Abstract [en]

    Scale is a key to determining which processes drive community structure. We analyse size distributions of phytoplankton to determine time scales at which we can observe either fixed environmental characteristics underlying communities structure or competition-driven size distributions. Using multiple statistical tests, we characterise size distributions of phytoplankton from 20-year time series in two sites of the Baltic Sea. At large temporal scales (5-20 years), size distributions are unimodal, indicating that fundamental barriers to existence are here subtler than in other systems. Frequency distributions of the average size of the species weighted by biovolume are multimodal over large time scales, although this is the product of often unimodal short-term (<1 year) patterns. Our study represents a much-needed structured, high-resolution analysis of phytoplankton size distributions, revealing that short-term analyses are necessary to determine if, and how, competition shapes them. Our results provide a stepping-stone on which to further investigate the intricacies of competition and coexistence.

  • 10.
    Griffiths, Jennifer R.
    et al.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Kadin, Martina
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Nascimento, Francisco J. A.
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Tamelander, Tobias
    Törnroos, Anna
    Bonaglia, Stefano
    Stockholm University, Faculty of Science, Department of Geological Sciences. Lund University, Sweden.
    Bonsdorff, Erik
    Brüchert, Volker
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Gårdmark, Anna
    Järnström, Marie
    Kotta, Jonne
    Lindegren, Martin
    Nordström, Marie C.
    Norkko, Alf
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre. University of Helsinki, Finland.
    Olsson, Jens
    Weigel, Benjamin
    Zydelis, Ramunas
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Winder, Monika
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    The importance of benthic-pelagic coupling for marine ecosystem functioning in a changing world2017In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 23, no 6, p. 2179-2196Article, review/survey (Refereed)
    Abstract [en]

    Benthic-pelagic coupling is manifested as the exchange of energy, mass, or nutrients between benthic and pelagic habitats. It plays a prominent role in aquatic ecosystems, and it is crucial to functions from nutrient cycling to energy transfer in food webs. Coastal and estuarine ecosystem structure and function are strongly affected by anthropogenic pressures; however, there are large gaps in our understanding of the responses of inorganic nutrient and organic matter fluxes between benthic habitats and the water column. We illustrate the varied nature of physical and biological benthic-pelagic coupling processes and their potential sensitivity to three anthropogenic pressures - climate change, nutrient loading, and fishing - using the Baltic Sea as a case study and summarize current knowledge on the exchange of inorganic nutrients and organic material between habitats. Traditionally measured benthic-pelagic coupling processes (e.g., nutrient exchange and sedimentation of organic material) are to some extent quantifiable, but the magnitude and variability of biological processes are rarely assessed, preventing quantitative comparisons. Changing oxygen conditions will continue to have widespread effects on the processes that govern inorganic and organic matter exchange among habitats while climate change and nutrient load reductions may have large effects on organic matter sedimentation. Many biological processes (predation, bioturbation) are expected to be sensitive to anthropogenic drivers, but the outcomes for ecosystem function are largely unknown. We emphasize how improved empirical and experimental understanding of benthic-pelagic coupling processes and their variability are necessary to inform models that can quantify the feedbacks among processes and ecosystem responses to a changing world.

  • 11.
    Gustafsson, Bo G.
    et al.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Schenk, Frederik
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Eilola, Kari
    Meier, H. E. Markus
    Muller-Karulis, Barbel
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Neumann, Thomas
    Ruoho-Airola, Tuija
    Savchuk, Oleg P.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Zorita, Eduardo
    Reconstructing the Development of Baltic Sea Eutrophication 1850-20062012In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, no 6, p. 534-548Article in journal (Refereed)
    Abstract [en]

    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.

  • 12. Gårdmark, Anna
    et al.
    Lindegren, Martin
    Neuenfeldt, Stefan
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre, Baltic Nest Institute.
    Heikinheimo, Outi
    Müller-Karulis, Barbel
    Stockholm University, Faculty of Science, Stockholm Resilience Centre, Baltic Nest Institute. Institute of Food Safety, Animal Health and Environment BIOR, Latvia.
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre, Baltic Nest Institute.
    Tomczak, Maciej T.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre, Baltic Nest Institute.
    Aro, Eero
    Wikström, Anders
    Moellmann, Christian
    Biological ensemble modeling to evaluate potential futures of living marine resources2013In: Ecological Applications, ISSN 1051-0761, E-ISSN 1939-5582, Vol. 23, no 4, p. 742-754Article in journal (Refereed)
    Abstract [en]

    Natural resource management requires approaches to understand and handle sources of uncertainty in future responses of complex systems to human activities. Here we present one such approach, the biological ensemble modeling approach,'' using the Eastern Baltic cod (Gadus morhua callarias) as an example. The core of the approach is to expose an ensemble of models with different ecological assumptions to climate forcing, using multiple realizations of each climate scenario. We simulated the long-term response of cod to future fishing and climate change in seven ecological models ranging from single-species to food web models. These models were analyzed using the biological ensemble modeling approach'' by which we (1) identified a key ecological mechanism explaining the differences in simulated cod responses between models, (2) disentangled the uncertainty caused by differences in ecological model assumptions from the statistical uncertainty of future climate, and (3) identified results common for the whole model ensemble. Species interactions greatly influenced the simulated response of cod to fishing and climate, as well as the degree to which the statistical uncertainty of climate trajectories carried through to uncertainty of cod responses. Models ignoring the feedback from prey on cod showed large interannual fluctuations in cod dynamics and were more sensitive to the underlying uncertainty of climate forcing than models accounting for such stabilizing predator-prey feedbacks. Yet in all models, intense fishing prevented recovery, and climate change further decreased the cod population. Our study demonstrates how the biological ensemble modeling approach makes it possible to evaluate the relative importance of different sources of uncertainty in future species responses, as well as to seek scientific conclusions and sustainable management solutions robust to uncertainty of food web processes in the face of climate change.

  • 13.
    Humborg, Christoph
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Estrup Andersen, Hans
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Gadegast, Mathias
    Giesler, Reiner
    Hartmann, Jens
    Hugelius, Gustaf
    Stockholm University, Faculty of Science, Department of Physical Geography and Quaternary Geology.
    Huerdler, Jens
    Kortelainen, Pirkko
    Blicher-Mathiesen, Gitte
    Venohr, Markus
    Weyhenmeyer, Gesa
    Environmental Impacts - Freshwater Biogeochemistry2015In: Second Assessment of Climate Change for the Baltic Sea Basin / [ed] The BACC II Author Team, Springer, 2015, p. 307-336Chapter in book (Refereed)
    Abstract [en]

    Climate change effects on freshwater biogeochemistry and riverine loads of biogenic elements to the Baltic Sea are not straight forward and are difficult to distinguish from other human drivers such as atmospheric deposition, forest and wetland management, eutrophication and hydrological alterations. Eutrophication is by far the most well-known factor affecting the biogeochemistry of the receiving waters in the various sub-basins of the Baltic Sea. However, the present literature review reveals that climate change is a compounding factor for all major drivers of freshwater biogeochemistry discussed here, although evidence is still often based on short-term and/or small-scale studies.

  • 14.
    Humborg, Cristoph
    et al.
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Mörth, Carl Magnus
    Stockholm University, Faculty of Science, Department of Geology and Geochemistry.
    Sundbom, Marcus
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Borg, Hans
    Stockholm University, Faculty of Science, Department of Applied Environmental Science (ITM).
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Giesler, R.
    Ittekkot, V.
    CO2 supersaturation along the aquatic conduit in Swedish watersheds as constrained by terrestrial respiration, aquatic respiration and weathering2010In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 6, no 7, p. 1966-1978Article in journal (Refereed)
    Abstract [en]

    We tested the hypothesis that CO2 supersaturation along the aquatic conduit over Sweden can be explained by processes other than aquatic respiration. A first generalized-additive model (GAM) analysis evaluating the relationships between single water chemistry variables and pCO(2) in lakes and streams revealed that water chemistry variables typical for groundwater input, e.g., dissolved silicate (DSi) and Mg2+ had explanatory power similar to total organic carbon (TOC). Further GAM analyses on various lake size classes and stream orders corroborated the slightly higher explanatory power for DSi in lakes and Mg2+ for streams compared with TOC. Both DSi and TOC explained 22-46% of the pCO(2) variability in various lake classes (0.01-> 100 km2) and Mg2+ and TOC explained 11-41% of the pCO(2) variability in the various stream orders. This suggests that aquatic pCO(2) has a strong groundwater signature. Terrestrial respiration is a significant source of the observed supersaturation and we may assume that both terrestrial respiration and aquatic respiration contributed equally to pCO(2) efflux. pCO(2) and TOC concentrations decreased with lake size suggesting that the longer water residence time allow greater equilibration of CO2 with the atmosphere and in-lake mineralization of TOC. For streams, we observed a decreasing trend in pCO(2) with stream orders between 3 and 6. We calculated the total CO2 efflux from all Swedish lakes and streams to be 2.58 Tg C yr-1. Our analyses also demonstrated that 0.70 Tg C yr-1 are exported to the ocean by Swedish watersheds as HCO3- and CO(3)2- of which about 0.56 Tg C yr-1 is also a residual from terrestrial respiration and constitute a long-term sink for atmospheric CO2. Taking all dissolved inorganic carbon (DIC) fluxes along the aquatic conduit into account will lower the estimated net ecosystem C exchange (NEE) by 2.02 Tg C yr-1, which corresponds to 10% of the NEE in Sweden.

  • 15.
    Kadin, Martina
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Casini, Michele
    Gardmark, Anna
    Torres, Maria Angeles
    Otto, Saskia A.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. University of Hamburg, Germany.
    Trophic Interactions, Management Trade-Offs and Climate Change: The Need for Adaptive Thresholds to Operationalize Ecosystem Indicators2019In: Frontiers in Marine Science, E-ISSN 2296-7745, article id UNSP 249Article in journal (Refereed)
    Abstract [en]

    Ecosystem-based management (EBM) is commonly applied to achieve sustainable use of marine resources. For EBM, regular ecosystem-wide assessments of changes in environmental or ecological status are essential components, as well as assessments of the effects of management measures. Assessments are typically carried out using indicators. A major challenge for the usage of indicators in EBM is trophic interactions as these may influence indicator responses. Trophic interactions can also shape trade-offs between management targets, because they modify and mediate the effects of pressures on ecosystems. Characterization of such interactions is in turn a challenge when testing the usability of indicators. Climate variability and climate change may also impact indicators directly, as well as indirectly through trophic interactions. Together, these effects may alter interpretation of indicators in assessments and evaluation of management measures. We developed indicator networks - statistical models of coupled indicators - to identify links representing trophic interactions between proposed food-web indicators, under multiple anthropogenic pressures and climate variables, using two basins in the Baltic Sea as a case study. We used the networks to simulate future indicator responses under different fishing, eutrophication and climate change scenarios. Responsiveness to fishing and eutrophication differed between indicators and across basins. Almost all indicators were highly dependent on climatic conditions, and differences in indicator trajectories > 10% were found only in comparisons of future climates. In some cases, effects of nutrient load and climate scenarios counteracted each other, altering how management measures manifested in the indicators. Incorporating climate change, or other regionally non-manageable drivers, is thus necessary for an accurate interpretation of indicators and thereby of EBM measure effects. Quantification of linkages between indicators across trophic levels is similarly a prerequisite for tracking effects propagating through the food web, and, consequently, for indicator interpretation. Developing meaningful indicators under climate change calls for iterative indicator validations, accounting for natural processes such as trophic interactions and for trade-offs between management objectives, to enable learning as well as setting target levels or thresholds triggering actions in an adaptive manner. Such flexible strategies make a set of indicators operational over the long-term and facilitate success of EBM.

  • 16.
    Kadin, Martina
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Olsson, Olof
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hentati-Sundberg, Jonas
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Willerström Ehrning, Ebba
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Common Guillemot Uria aalge parents adjust provisioning rates to compensate for low food quality2016In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 158, no 1, p. 167-178Article in journal (Refereed)
    Abstract [en]

    The quantity and quality of food available within the foraging area set important constraints for chick-rearing birds, but responses to low quality are not well understood. This study explored the potential for parent birds to adjust quantity (feeding rate) and quality (energy content) in chick provisioning, by studying Common Guillemots Uria aalge on Stora Karlso, Baltic Sea, predominantly utilizing Sprat Sprattus sprattus, during conditions of high food quantity but reduced food quality. Quality is central to reproductive success in this single-prey loader. From the chick's perspective, provisioning rates should be increased to compensate for low food quality and to fulfil its growing needs with increasing age. However, the high energy cost of flying in Guillemots makes it important for parent birds to minimize commutes to feeding areas. Provisioning parameters were recorded during three dawn-to-dusk watches each breeding season from 2005 to 2013, when clupeids, presumably Sprat, constituted 98% of chick diet. Generalized additive mixed models showed that both feeding rate and size of clupeids (a proxy for energy content) varied between years and changed non-linearly with chick age, but that there was no change within breeding seasons. Chick age and year explained 36% of the variation in feeding rate but only 2% of the variation in the size of clupeids in chick diets. We conclude that parent birds tried to adjust both feeding rate and prey size, but were less successful with the latter. A strong negative correlation was found between annual feeding rates and size of clupeids, evaluated as the differences relative to the baseline year, and adjusted for the effects of chick age. Although the differences between years were small, the relationship indicates a compensation mechanism that does not seem to impact adult survival, and by which increased feeding rates can partly counteract reduced chick energy intake when food quality is low.

  • 17.
    Lade, Steven J.
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hentati-Sundberg, Jonas
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Boonstra, Wiebren J.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Orach, Kirill
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Quaas, Martin F.
    Österblom, Henrik
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Schlüter, Maja
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    An empirical model of the Baltic Sea reveals the importance of social dynamics for ecological regime shifts2015In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 112, no 35, p. 11120-11125Article in journal (Refereed)
    Abstract [en]

    Regime shifts triggered by human activities and environmental changes have led to significant ecological and socioeconomic consequences in marine and terrestrial ecosystems worldwide. Ecological processes and feedbacks associated with regime shifts have received considerable attention, but human individual and collective behavior is rarely treated as an integrated component of such shifts. Here, we used generalized modeling to develop a coupled social-ecological model that integrated rich social and ecological data to investigate the role of social dynamics in the 1980s Baltic Sea cod boom and collapse. We showed that psychological, economic, and regulatory aspects of fisher decision making, in addition to ecological interactions, contributed both to the temporary persistence of the cod boom and to its subsequent collapse. These features of the social-ecological system also would have limited the effectiveness of stronger fishery regulations. Our results provide quantitative, empirical evidence that incorporating social dynamics into models of natural resources is critical for understanding how resources can be managed sustainably. We also show that generalized modeling, which is well-suited to collaborative model development and does not require detailed specification of causal relationships between system variables, can help tackle the complexities involved in creating and analyzing social-ecological models.

  • 18. Lindegren, Martin
    et al.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Stenseth, Nils C.
    Nutrient reduction and climate change cause a potential shift from pelagic to benthic pathways in a eutrophic marine ecosystem2012In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 18, no 12, p. 3491-3503Article in journal (Refereed)
    Abstract [en]

    The degree to which marine ecosystems may support the pelagic or benthic food chain has been shown to vary across natural and anthropogenic gradients for e.g., in temperature and nutrient availability. Moreover, such external forcing may not only affect the flux of organic matter but could trigger large and abrupt changes, i.e., trophic cascades and ecological regime shifts, which once having occurred may prove potentially irreversible. In this study, we investigate the state and regulatory pathways of the Kattegat; a eutrophied and heavily exploited marine ecosystem, specifically testing for the occurrence of regime shifts and the relative importance of multiple drivers, e.g., climate change, eutrophication and commercial fishing on ecosystem dynamics and trophic pathways. Using multivariate statistics and nonlinear regression on a comprehensive data set, covering abiotic factors and biotic variables across all trophic levels, we here propose a potential regime shift from pelagic to benthic regulatory pathways; a possible first sign of recovery from eutrophication likely triggered by drastic nutrient reductions (involving both nitrogen and phosphorus), in combination with climate-driven changes in local environmental conditions (e.g., temperature and oxygen concentrations).

  • 19. Lynham, J.
    et al.
    Halpern, B. S.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Essington, T.
    Estes, J.
    Hunsicker, M.
    Kappel, C.
    Salomon, A. K.
    Scarborough, C.
    Selkoe, K. A.
    Stier, A.
    Costly stakeholder participation creates inertia in marine ecosystems2017In: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 76, p. 122-129Article in journal (Refereed)
    Abstract [en]

    Ecosystems often shift abruptly and dramatically between different regimes in response to human or natural disturbances. When ecosystems tip from one regime to another, the suite of available ecosystem benefits changes, impacting the stakeholders who rely on these benefits. These changes often create some groups who stand to incur large losses if an ecosystem returns to a previous regime. When the participation cost in the decision-making process is extremely high, this can lock in ecosystem regimes, making it harder for policy and management to shift ecosystems out of what the majority of society views as the undesirable regime. Public stakeholder meetings often have high costs of participation, thus economic theory predicts they will be dominated by extreme views and often lead to decisions that do not represent the majority viewpoint. Such extreme viewpoints can create strong inertia even when there is broad consensus to manage an ecosystem towards a different regime. In the same manner that reinforcing ecological feedback loops make it harder to exit an ecosystem regime, there are decision-making feedback loops that contribute additional inertia.

  • 20. MacKenzie, Brian R.
    et al.
    Meier, H. E. Markus
    Lindegren, Martin
    Neuenfeldt, Stefan
    Eero, Margit
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Tomczak, Maciej T.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Niiranen, Susa
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Impact of Climate Change on Fish Population Dynamics in the Baltic Sea: A Dynamical Downscaling Investigation2012In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, no 6, p. 626-636Article in journal (Refereed)
    Abstract [en]

    Understanding how climate change, exploitation and eutrophication will affect populations and ecosystems of the Baltic Sea can be facilitated with models which realistically combine these forcings into common frameworks. Here, we evaluate sensitivity of fish recruitment and population dynamics to past and future environmental forcings provided by three ocean-biogeochemical models of the Baltic Sea. Modeled temperature explained nearly as much variability in reproductive success of sprat (Sprattus sprattus; Clupeidae) as measured temperatures during 1973-2005, and both the spawner biomass and the temperature have influenced recruitment for at least 50 years. The three Baltic Sea models estimate relatively similar developments (increases) in biomass and fishery yield during twenty-first century climate change (ca. 28 % range among models). However, this uncertainty is exceeded by the one associated with the fish population model, and by the source of global climate data used by regional models. Knowledge of processes and biases could reduce these uncertainties.

  • 21. Maldonado, A. D.
    et al.
    Uusitalo, L.
    Tucker, A.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Aguilera, P. A.
    Salmerón, A.
    Prediction of a complex system with few data: Evaluation of the effect of model structure and amount of data with dynamic bayesian network models2019In: Environmental Modelling & Software, ISSN 1364-8152, E-ISSN 1873-6726, Vol. 118, p. 281-297Article in journal (Refereed)
    Abstract [en]

    A major challenge in environmental modeling is to identify structural changes in the ecosystem across time, i.e., changes in the underlying process that generates the data. In this paper, we analyze the Baltic Sea food web in order to 1) examine potential unobserved processes that could affect the ecosystem and 2) make predictions on some variables of interest. To do so, dynamic Bayesian networks with different setups of hidden variables (HVs) were built and validated applying two techniques: rolling-origin and rolling-window. Moreover, two statistical inference approaches were compared at regime shift detection: fully Bayesian and Maximum Likelihood Estimation. Our results confirm that, from the predictive accuracy point of view, more data help to improve the predictions whereas the different setups of HVs did not make a critical difference in the predictions. Finally, the different HVs picked up patterns in the data, which revealed changes in different parts of the ecosystem.

  • 22.
    Meier, Markus
    et al.
    Stockholm University, Faculty of Science, Department of Meteorology .
    Andersson, Helen C.
    Arheimer, Berit
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Chubarenko, Boris
    Donnelly, Chantal
    Eilola, Kari
    Gustafsson, Bo G.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Hansson, Anders
    Havenhand, Jonathan
    Hoglund, Anders
    Kuznetsov, Ivan
    MacKenzie, Brian R.
    Müller-Karulis, Barbel
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Neumann, Thomas
    Niiranen, Susa
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Piwowarczyk, Joanna
    Raudsepp, Urmas
    Reckermann, Marcus
    Ruoho-Airola, Tuija
    Savchuk, Oleg P.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Schenk, Frederik
    Schimanke, Semjon
    Vali, Germo
    Weslawski, Jan-Marcin
    Zorita, Eduardo
    Comparing reconstructed past variations and future projections of the Baltic sea ecosystem first results from multi model ensemble simulations2012In: Environmental Research Letters, ISSN 1748-9326, E-ISSN 1748-9326, Vol. 7, no 3, p. 034005-Article in journal (Refereed)
    Abstract [en]

    Multi-model ensemble simulations for the marine biogeochemistry and food web of the Baltic Sea were performed for the period 1850-2098, and projected changes in the future climate were compared with the past climate environment. For the past period 1850-2006, atmospheric, hydrological and nutrient forcings were reconstructed, based on historical measurements. For the future period 1961-2098, scenario simulations were driven by regionalized global general circulation model (GCM) data and forced by various future greenhouse gas emission and air-and riverborne nutrient load scenarios (ranging from a pessimistic 'business-as-usual' to the most optimistic case). To estimate uncertainties, different models for the various parts of the Earth system were applied. Assuming the IPCC greenhouse gas emission scenarios A1B or A2, we found that water temperatures at the end of this century may be higher and salinities and oxygen concentrations may be lower than ever measured since 1850. There is also a tendency of increased eutrophication in the future, depending on the nutrient load scenario. Although cod biomass is mainly controlled by fishing mortality, climate change together with eutrophication may result in a biomass decline during the latter part of this century, even when combined with lower fishing pressure. Despite considerable shortcomings of state-of-the-art models, this study suggests that the future Baltic Sea ecosystem may unprecedentedly change compared to the past 150 yr. As stakeholders today pay only little attention to adaptation and mitigation strategies, more information is needed to raise public awareness of the possible impacts of climate change on marine ecosystems.

  • 23. Moellmann, Christian
    et al.
    Lindegren, Martin
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bergström, Lena
    Casini, Michele
    Diekmann, Rabea
    Flinkman, Juha
    Muller-Karulis, Bärbel
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre.
    Neuenfeldt, Stefan
    Schmidt, Joern O.
    Tomczak, Maciej
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre.
    Voss, Ruediger
    Gårdmark, Anna
    Implementing ecosystem-based fisheries management: from single-species to integrated ecosystem assessment and advice for Baltic Sea fish stocks2014In: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 71, no 5, p. 1187-1197Article in journal (Refereed)
    Abstract [en]

    Theory behind ecosystem-based management (EBM) and ecosystem-based fisheries management (EBFM) is now well developed. However, the implementation of EBFM exemplified by fisheries management in Europe is still largely based on single-species assessments and ignores the wider ecosystem context and impact. The reason for the lack or slow implementation of EBM and specifically EBFM is a lack of a coherent strategy. Such a strategy is offered by recently developed integrated ecosystem assessments (IEAs), a formal synthesis tool to quantitatively analyse information on relevant natural and socio-economic factors, in relation to specified management objectives. Here, we focus on implementing the IEA approach for Baltic Sea fish stocks. We combine both tactical and strategic management aspects into a single strategy that supports the present Baltic Sea fish stock advice, conducted by the International Council for the Exploration of the Sea (ICES). We first review the state of the art in the development of IEA within the current management framework. We then outline and discuss an approach that integrates fish stock advice and IEAs for the Baltic Sea. We intentionally focus on the central Baltic Sea and its three major fish stocks cod (Gadus morhua), herring (Clupea harengus), and sprat (Sprattus sprattus), but emphasize that our approach may be applied to other parts and stocks of the Baltic, as well as other ocean areas.

  • 24. Möllmann, Christian
    et al.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Casini, Michele
    Gårdmark, Anna
    Lindegren, Martin
    Beauty is in the eye of the beholder: management of Baltic cod stock requires an ecosystem approach2011In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 431, p. 293-297Article in journal (Refereed)
    Abstract [en]

    In a recent ‘As We See It’ article, Cardinale & Svedäng (2011; Mar Ecol Prog Ser 425:297–301) used the example of the Eastern Baltic (EB) cod stock to argue that the concept of ecosystem regime shifts, especially the potential existence of alternative stable states (or dynamic regimes), blurs the fact that human exploitation (i.e. fishing) is the strongest impact on marine ecosystems. They further concluded that single-species approaches to resource management are functioning and that ecosystem-based approaches are not necessary. We (1) argue that the recent increase in the EB cod stock is inherently uncertain, (2) discuss the critique of the regime shift concept, and (3)  describe why the EB cod stock dynamics demonstrates the need for an ecosystem approach to fisheries management.

  • 25. Naddafi, Rahmat
    et al.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Eklöv, Peter
    Pettersson, Kurt
    Physical and chemical properties determine zebra mussel invasion success in lakes2011In: Hydrobiologia, ISSN 0018-8158, E-ISSN 1573-5117, Vol. 669, no 1, p. 227-236Article in journal (Refereed)
    Abstract [en]

    To address the question whether the abundance of an invasive species can be explained by physical and chemical properties of the invaded ecosystems, we gathered density data of invasive zebra mussels and the physical and chemical data of ecosystems they invaded. We assembled published data from 55 European and 13 North American lakes and developed a model for zebra mussel density using a generalized additive model (GAM) approach. Our model revealed that the joint effect of surface area, total phosphorus and calcium concentrations explained 62% of the variation in Dreissena density. Our study indicates that large and less productive North American lakes can support larger local populations of zebra mussels. Our results suggest that the proliferation of an exotic species in an area can partially be explained by physical and chemical properties of the recipient environment.

  • 26.
    Niiranen, Susa
    et al.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Hjerne, Olle
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Tomczak, Maciej T.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Uncertainties in a Baltic Sea Food-Web Model Reveal Challenges for Future Projections2012In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 41, no 6, p. 613-625Article in journal (Refereed)
    Abstract [en]

    Models that can project ecosystem dynamics under changing environmental conditions are in high demand. The application of such models, however, requires model validation together with analyses of model uncertainties, which are both often overlooked. We carried out a simplified model uncertainty and sensitivity analysis on an Ecopath with Ecosim food-web model of the Baltic Proper (BaltProWeb) and found the model sensitive to both variations in the input data of pre-identified key groups and environmental forcing. Model uncertainties grew particularly high in future climate change scenarios. For example, cod fishery recommendations that resulted in viable stocks in the original model failed after data uncertainties were introduced. In addition, addressing the trophic control dynamics produced by the food-web model proved as a useful tool for both model validation, and for studying the food-web function. These results indicate that presenting model uncertainties is necessary to alleviate ecological surprises in marine ecosystem management.

  • 27.
    Niiranen, Susa
    et al.
    Stockholm University, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre.
    Yletyinen, Johanna
    Stockholm University, Stockholm Resilience Centre.
    Otto, Saskia
    Stockholm University, Stockholm Resilience Centre.
    Meier, H. E. Markus
    Stockholm University, Faculty of Science, Department of Meteorology .
    Hjerne, Olle
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Tomczak, Maciej T
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    The potential risk of regime shifts and changes in ecosystem dynamics in the future Baltic SeaArticle in journal (Refereed)
  • 28.
    Niiranen, Susa
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Richter, A.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Stige, L. C.
    Valmarn, Matilda
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Eikeset, A. -M.
    Global connectivity and cross-scale interactions create uncertainty for Blue Growth of Arctic fisheries2018In: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 87, p. 321-330Article in journal (Refereed)
    Abstract [en]

    The Arctic faces high expectations of Blue Growth due to future projections of easier access and increased biological productivity. These expectations are, however, often based on global and regional climate change projections and largely ignore the complexity of social-ecological interactions taking place across different temporal and spatial scales. This paper illustrates how such cross-scale interactions at, and across, different dimensions (e.g., ecological, socioeconomic and governance) can affect the development of Arctic fisheries; and potentially create uncertainties for future Blue Growth projections. Two Arctic marine systems, The Barents Sea and the Central Arctic Ocean (CAO), are used as focus areas. The former hosts productive fisheries and is mostly covered by the EEZs of Norway and Russia, while the latter is still mainly covered by sea-ice and is a high seas area with no multilevel governance system in place. The examples show that, both systems are affected by a number of processes, beyond the environmental change, spanning a wide range of dimensions, as well as spatial and temporal scales. To address the complexity of the Arctic marine systems calls for an increase in holistic scientific understanding together with adaptive management practices. This is particularly important in the CAO, where no robust regional management structures are in place. Recognizing how cross-scale dynamics can cause uncertainties to the current fisheries projections and implementing well-functioning adaptive management structures across different Arctic sub-systems can play a key role in whether the Blue Growth potential in Arctic fisheries is realized or lost.

  • 29.
    Niiranen, Susa
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    Yletyinen, Johanna
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. University of Olso, Norway.
    Tomczak, Maciej T.
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hjerne, Olle
    Stockholm University, Faculty of Science, Department of Ecology, Environment and Plant Sciences.
    MacKenzie, Brian R.
    Müller-Karulis, Bärbel
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Neumann, Thomas
    Meier, H. E. Markus
    Stockholm University, Faculty of Science, Department of Meteorology . Swedish Meteorological and Hydrological Institute, Sweden.
    Combined effects of global climate change and regional ecosystem drivers on an exploited marine food web2013In: Global Change Biology, ISSN 1354-1013, E-ISSN 1365-2486, Vol. 19, no 11, p. 3327-3342Article in journal (Refereed)
    Abstract [en]

    Changes in climate, in combination with intensive exploitation of marine resources, have caused large-scale reorganizations in many of the world's marine ecosystems during the past decades. The Baltic Sea in Northern Europe is one of the systems most affected. In addition to being exposed to persistent eutrophication, intensive fishing, and one of the world's fastest rates of warming in the last two decades of the 20th century, accelerated climate change including atmospheric warming and changes in precipitation is projected for this region during the 21st century. Here, we used a new multi-model approach to project how the interaction of climate, nutrient loads and cod fishing may affect the future of the open Central Baltic Sea food web. Regionally downscaled global climate scenarios were, in combination with three nutrient load scenarios, used to drive an ensemble of three regional biogeochemical models (BGMs). An Ecopath with Ecosim food web model was then forced with the BGM results from different nutrient-climate scenarios in combination with two different cod fishing scenarios. The results showed that regional management is likely to play a major role in determining the future of the Baltic Sea ecosystem. By the end of the 21st century, for example, the combination of intensive cod fishing and high nutrient loads projected a strongly eutrophicated and sprat-dominated ecosystem, while low cod fishing in combination with low nutrient loads resulted in a cod-dominated ecosystem with eutrophication levels close to present. Also, non-linearities were observed in the sensitivity of different trophic groups to nutrient loads or fishing depending on the combination of the two. Finally, many climate variables and species biomasses were projected to levels unseen in the past. Hence, the risk for ecological surprises needs to be addressed, particularly when the results are discussed in the ecosystem-based management context.

  • 30.
    Nyström, Magnus
    et al.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Norström, Albert V.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    de la Torre-Castro, Maricela
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Eklöf, Johan S.
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Folke, Carl
    Österblom, Henrik
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Steneck, Robert S.
    Thyresson, Matilda
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Troell, Max
    Confronting Feedbacks of Degraded Marine Ecosystems2012In: Ecosystems (New York. Print), ISSN 1432-9840, E-ISSN 1435-0629, Vol. 15, no 5, p. 695-710Article in journal (Refereed)
    Abstract [en]

    In many coastal areas, marine ecosystems have shifted into contrasting states having reduced ecosystem services (hereafter called degraded). Such degraded ecosystems may be slow to revert to their original state due to new ecological feedbacks that reinforce the degraded state. A better understanding of the way human actions influence the strength and direction of feedbacks, how different feedbacks could interact, and at what scales they operate, may be necessary in some cases for successful management of marine ecosystems. Here we synthesize interactions of critical feedbacks of the degraded states from six globally distinct biomes: coral reefs, kelp forests, seagrass beds, shallow soft sediments, oyster reefs, and coastal pelagic food webs. We explore to what extent current management captures these feedbacks and propose strategies for how and when (that is, windows of opportunity) to influence feedbacks in ways to break the resilience of the degraded ecosystem states. We conclude by proposing some challenges for future research that could improve our understanding of these issues and emphasize that management of degraded marine states will require a broad social-ecological approach to succeed.

  • 31.
    Otto, Saskia A.
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. University of Hamburg, Germany.
    Kadin, Martina
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Casini, Michele
    Torres, Maria A.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    A quantitative framework for selecting and validating food web indicators2018In: Ecological Indicators, ISSN 1470-160X, E-ISSN 1872-7034, Vol. 84, p. 619-631Article in journal (Refereed)
    Abstract [en]

    Finding suitable state indicators is challenging and cumbersome in stochastic and complex ecological systems. Typically, a great focus is given to criteria such as data availability, scientific basis, or measurability. Features associated with the indicator's performance such as sensitivity or robustness are often neglected due to the lack of quantitative validation tools. In this paper, we present a simple but flexible framework for selecting and validating the performance of food web indicators. In specific, we suggest a 7-step process in which indicator performances at a regional scale are quantified and visualized allowing for the selection of complementary indicator suites. We demonstrate its application by comparing the performance of pelagic food web indicators for three basins of the Baltic Sea and by assessing the food web status based on selected indicator suites. Our analysis sheds light on spatial differences in indicator performances with respect to direct and indirect pressures, the role of non-linearity and non-additivity in pressure responses, as well as relationships between indicators caused by species interactions. Moreover, our results suggest that the present food web states in the Bornholm and Gotland basins of the Baltic Sea deviate distinctly from an earlier reference period. We advocate the use of our quantitative framework as decision-support tool for selecting suites of complementary indicators under given management schemes such as the EU Marine Strategy Framework Directive.

  • 32. Pierson, D.C.
    et al.
    Weyhenmeyer, G. A.
    Arvola, L.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre.
    An automated method to monitor lake ice phenology2011In: Limnology & Oceanography - Methods, Vol. 9, p. 74-83Article in journal (Refereed)
    Abstract [en]

    A simple method to automatically measure the date of ice-on, the date of ice-off, and the duration of lake ice cover is described. The presence of ice cover is detected by recording water temperature just below the ice/water interface and just above the lake bottom using moored temperature sensors. The occurrence of ice-on rapidly leads to detectible levels of inverse stratification, defined as existing when the upper sensor records a temperature at least 0.1°C below that of the bottom sensor, whereas the occurrence of ice-off leads to the return of isothermal mixing. Based on data from 10 lakes over a total of 43 winter seasons, we found that the timing and duration of inverse stratification monitored by recording temperature sensors compares well with ice cover statistics based on human observation. The root mean square difference between the observer-based and temperature-based estimates was 7.1 d for ice-on, 6.4 d for ice-off, and 10.0 d for the duration of ice cover. The coefficient of determination between the two types of estimates was 0.93, 0.86, and 0.91, respectively. The availability of inexpensive self-contained temperature loggers should allow expanded monitoring of ice cover in a large and diverse array of lakes. Such monitoring is needed to improve our ability to monitor the progression of global climate change, and to improve our understanding of the relationship between climate and ice cover over a wide range of temporal and spatial scales.

  • 33.
    Rocha, Juan
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Yletyinen, Johanna
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Biggs, Reinette
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stellenbosch University, South Africa.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Peterson, Garry
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Marine regime shifts: drivers and impacts on ecosystems services2015In: Philosophical Transactions of the Royal Society of London. Biological Sciences, ISSN 0962-8436, E-ISSN 1471-2970, Vol. 370, no 1659, article id 20130273Article in journal (Refereed)
    Abstract [en]

    Marine ecosystems can experience regime shifts, in which they shift from being organized around one set of mutually reinforcing structures and processes to another. Anthropogenic global change has broadly increased a wide variety of processes that can drive regime shifts. To assess the vulnerability of marine ecosystems to such shifts and their potential consequences, we reviewed the scientific literature for 13 types of marine regime shifts and used networks to conduct an analysis of co-occurrence of drivers and ecosystem service impacts. We found that regime shifts are caused by multiple drivers and have multiple consequences that co-occur in a non-random pattern. Drivers related to food production, climate change and coastal development are the most common co-occurring causes of regime shifts, while cultural services, biodiversity and primary production are the most common cluster of ecosystem services affected. These clusters prioritize sets of drivers for management and highlight the need for coordinated actions across multiple drivers and scales to reduce the risk of marine regime shifts. Managerial strategies are likely to fail if they only address well-understood or data-rich variables, and international cooperation and polycentric institutions will be critical to implement and coordinate action across the scales at which different drivers operate. By better understanding these underlying patterns, we hope to inform the development of managerial strategies to reduce the risk of high-impact marine regime shifts, especially for areas of the world where data are not available or monitoring programmes are not in place.

  • 34.
    Scharin, Henrik
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Swedish Environmental Protection Agency, Sweden.
    Ericsdotter, Siv
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Elliott, Michael
    Turner, R. Kerry
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hyytiäinen, Kari
    Ahlvik, Lassi
    Ahtiainen, Heini
    Artell, Janne
    Hasselström, Linus
    Söderqvist, Tore
    Rockström, Johan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Processes for the sustainable stewardship of marine environments2016In: Ecological Economics, ISSN 0921-8009, E-ISSN 1873-6106, Vol. 128, p. 55-67Article in journal (Refereed)
    Abstract [en]

    Sustainable stewardship of the marine environment necessitates a holistic approach encompassing all the relevant drivers, activities and pressures causing problems for the natural state of the system and their impact on human societies today and in the future. This article provides a framework as well as a decision support process and tool that could guide such an approach. In this process, identifying costs and benefits of mitigation is a first step in deciding on measures and enabling instruments, which has to be accompanied by analyses regarding distributional effects (i.e. who gains or loses) related to different targets and policy instruments. As there are risks of future irreversible regime shifts and even system collapses, the assessments have to be broadened to include scenarios on possible future developments as well as ethical considerations. In particular, a deeper sustainable management strategy may be needed to respond to possible future increases in the rate of environmental change, amongst growing evidence of external pressures, interactions and non-linear dynamics. This adaptive management strategy should focus on building the resilience required to cope with and adapt to change.

  • 35.
    Tomczak, Macief
    et al.
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Niiranen, Susa
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute. Stockholm University, Faculty of Science, Department of Systems Ecology.
    Hjerne, Olle
    Stockholm University, Faculty of Science, Department of Systems Ecology.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre, Baltic Nest Institute.
    Ecosystem flow dynamics in the Baltic Proper-Using a multi-trophic dataset as a basis for food-web modelling2012In: Ecological Modelling, ISSN 0304-3800, E-ISSN 1872-7026, Vol. 230, p. 123-147Article in journal (Refereed)
    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.

  • 36.
    Tomczak, Maciej T.
    et al.
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Heymans, Johanna J.
    Yletyinen, Johanna
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Nordic Centre for Research on Marine Ecosystems and Resources under Climate Change ((NorMER).
    Niiranen, Susa
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Otto, Saskia A.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Ecological Network Indicators of Ecosystem Status and Change in the Baltic Sea2013In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 8, no 10, article id e75439Article in journal (Refereed)
    Abstract [en]

    Several marine ecosystems under anthropogenic pressure have experienced shifts from one ecological state to another. In the central Baltic Sea, the regime shift of the 1980s has been associated with food-web reorganization and redirection of energy flow pathways. These long-term dynamics from 1974 to 2006 have been simulated here using a food-web model forced by climate and fishing. Ecological network analysis was performed to calculate indices of ecosystem change. The model replicated the regime shift. The analyses of indicators suggested that the system's resilience was higher prior to 1988 and lower thereafter. The ecosystem topology also changed from a web-like structure to a linearized food-web.

  • 37.
    Valman, Matilda
    et al.
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute. Stockholm University, Stockholm Resilience Centre. Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Duit, Andreas
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    HELCOM, we have a problem: gradually unfolding crises and problem detection in international organisationsIn: Global Environmental Change, ISSN 0959-3780, E-ISSN 1872-9495Article in journal (Refereed)
  • 38.
    Valman, Matilda
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Duit, Andreas
    Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Organizational responsiveness: The case of unfolding crises and problem detection within HELCOM2016In: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 70, p. 49-57Article in journal (Refereed)
    Abstract [en]

    How and to what extent do international organizations detect, process and react to different types of change within their policy domains? This study addresses this question by combining a unique data set consisting of policy documents from the Helsinki Commission (HELCOM) with data measuring ecosystem change in the Baltic Sea during the period 1980-2013. Here HELCOM's responses to two types of ecosystem changes are investigated: fast and visible (summer algae blooms) and slow and opaque (anoxic areas). Finally, this study assesses if the organizational reform of 2007, which introduced the ecosystem approach, has had any effects on HELCOM responsiveness. It is found that HELCOM, contrary to expectations, is only responding systematically to slow-moving and opaque processes but that this response confirms the anticipated organizational bottom-up pattern. The ecosystem approach reform seems to have had a negative effect on the responsiveness of HELCOM; however, a general trend is that HELCOM over time has become more responsive in the lower levels of the organization. The lack of an immediate effect regarding the ecosystem approach reform can serve as a reminder of the absence of panaceas in policy making in general, and in environmental governance in particular.

  • 39. Varjopuro, Riku
    et al.
    Andrulewicz, Eugeniusz
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Dolch, Tobias
    Heiskanen, Anna-Stuna
    Pihlajamäki, Mia
    Brandt, Urs Steiner
    Valman, Matilda
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute. Stockholm University, Faculty of Social Sciences, Department of Political Science.
    Gee, Kira
    Potts, Tavis
    Psuty, Iwona
    Coping with persistent environmental problems: systemic delays in reducing eutrophication of the Baltic Sea2014In: Ecology & society, ISSN 1708-3087, E-ISSN 1708-3087, Vol. 19, no 4, p. 48-Article in journal (Refereed)
    Abstract [en]

    In this paper we focus on systemic delays in the Baltic Sea that cause the problem of eutrophication to persist. These problems are demonstrated in our study by addressing three types of delays: (1) decision delay: the time it takes for an idea or perceived need to be launched as a policy; (2) implementation delay: the time from the launch of a policy to the actual implementation; (3) ecosystem delay: the time difference between the implementation and an actual measurable effects. A policy process is one characterized by delays. It may take years from problem identification to a decision to taking action and several years further for actual implementation. Ecosystem responses to measures illustrate that feedback can keep the ecosystem in a certain state and cause a delay in ecosystem response. These delays can operate on decadal scales. Our aim in this paper is to analyze these systemic delays and especially to discuss how the critical delays can be better addressed in marine protection policies by strengthening the adaptive capacity of marine protection. We conclude that the development of monitoring systems and reflexive, participatory analysis of dynamics involved in the implementation are keys to improve understanding of the systemic delays. The improved understanding is necessary for the adaptive management of a persistent environmental problem. In addition to the state of the environment, the monitoring and analysis should be targeted also at the implementation of policies to ensure that the societies are investing in the right measures.

  • 40. Varjupuro, R.
    et al.
    Heiskanen, A-S.
    Eriksson, A.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Karnicki, Z.
    Kuzebski, E.
    Nekoro, Marmar
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Viet Nguyen, T.
    Pitkänen, W.
    Radtke, K.
    Österblom, Henrik
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Challenges for the Holistic management of Eutrophication and Cod Fisheries in the Baltic Sea2011Report (Other academic)
    Abstract [en]

    The current deliverable (D7.1.) aims to review the challenges of the established policies for providing a holistic ecosystem approach for management of the inter-linked environmental problems in the Baltic Sea Region.

    Based on the review of the issues that are of major concern, as well as the recent scientific knowledge of the ecological coupling of eutrophication, changes in the food web structure and decline of the cod stocks (e.g. Mällman et al. 2008, Österblom et al. 2010), we decided to focus our analysis on the two inter-linked problems of eutrophication and cod fisheries.

    In this report, we briefly describe the ecosystem of the Baltic Sea as well as the nature of these two environmental issues. We provide an overview of major environmental policies that are governing these two inter-linked problems. We also discuss the current challenges in the implementation of these established policies in the context of requirements for holistic ecosystem based management of the Baltic Sea.

  • 41. Viitasalo, Markku
    et al.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Gårdmark, Anna
    Kaartokallio, Hermanni
    Kautsky, Lena
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre.
    Kuosa, Harri
    Lindegren, Martin
    Norkko, Alf
    Olli, Kalle
    Wikner, Johan
    Environmental Impacts - Marine Ecosystems2015In: Second Assessment of Climate Change for the Baltic Sea Basin / [ed] The BACC II Author Team, Springer, 2015, p. 363-380Chapter in book (Refereed)
    Abstract [en]

    Increase in sea surface temperature is projected to change seasonal succession and induce dominance shifts in phytoplankton in spring and promote the growth of cyanobacteria in summer. In general, climate change is projected to worsen oxygen conditions and eutrophication in the Baltic Proper and the Gulf of Finland. In the Gulf of Bothnia, the increasing freshwater discharge may increase the amount of dissolved organic carbon (DOC) in the water and hence reduce phytoplankton productivity. In winter, reduced duration and spatial extent of sea ice will cause habitat loss for ice-dwelling organisms and probably induce changes in nutrient dynamics within and under the sea ice. The projected salinity decline will probably affect the functional diversity of the benthic communities and induce geographical shifts in the distribution limits of key species such as bladder wrack and blue mussel. In the pelagic ecosystem, the decrease in salinity together with poor oxygen conditions in the deep basins will negatively influence the main Baltic Sea piscivore, cod. This has been suggested to cause cascading effects on clupeids and zooplankton.

  • 42. Weigel, Benjamin
    et al.
    Andersson, Helen C.
    Meier, H. E. Markus
    Stockholm University, Faculty of Science, Department of Meteorology . Swedish Meteorological and Hydrographical Institute (SMHI), Sweden.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute. Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Snickars, Martin
    Bonsdorff, Erik
    Long-term progression and drivers of coastal zoobenthos in a changing system2015In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 528, p. 141-159Article in journal (Refereed)
    Abstract [en]

    Coastal zones are facing climate-driven change coupled with escalating eutrophication. With increasing shifts in hydrographic conditions during the past few decades, a focal task is to understand how environmental drivers affect zoobenthic communities, which play a crucial role in ecosystem functioning. By using long-term data, spanning 40 yr (1973 to 2013) in the northern Baltic Sea, we showed a disparity in zoobenthic responses with pronounced changes in community composition and a trend towards decreased biomass in sheltered areas, while biomasses increased in exposed areas of the coastal zone. We used generalized additive modeling to show that bottom oxygen saturation, sea surface temperature and organic load of the sediments were the main environmental drivers behind contrasting patterns in biomass progression. Oxygen saturation alone explained over one third of the deviation in the biomass developments in sheltered areas, while exposed areas were mainly limited by organic content of the sediments. We analyzed high-resolution climate-scenario simulations, following the Intergovernmental Panel on Climate Change scenarios for the Baltic Sea region in combination with different nutrient load scenarios, for the end of the 21st century. The scenario outcomes showed negative trends in bottom oxygen concentrations throughout the coastal and archipelago zone along with overall increasing temperatures and primary production, and decreasing salinity. Our results suggest that these projected future conditions will strengthen the observed pattern in decreasing zoobenthic production in the immediate coastal zones. Moreover, the potential intensification of unfavorable conditions ex-panding seaward may lead to an expansion of biomass loss to more exposed sites.

  • 43. Weigel, Benjamin
    et al.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bonsdorff, Erik
    Maintained functional diversity in benthic communities in spite of diverging functional identities2016In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 125, no 10, p. 1421-1433Article in journal (Refereed)
    Abstract [en]

    Ecological studies based on time-series often investigate community changes centered on species abundance or biomass but rarely expose the consequential functional aspects underlying such changes. Functional diversity measures have proven to be more accurate predictors for ecosystem functioning than traditional taxonomic approaches and hence gained much attention. There are only limited studies available that analyse the functional implications behind decadal changes of entire communities. We studied zoobenthic communities of two habitats, sheltered and exposed, of a coastal system subject to contrasting changes in community composition over the past four decades. Besides eutrophication and climate-related impacts, the system has been invaded by a non-native polycheate Marenzelleria spp., adding altered functional properties to the communities. The functional dispersion (FDis) metric was used as a measure for comparing the functional diversity of the contrasting habitats, with special focus on the role of Marenzelleria for the entire communities. We highlight changes in the functional identity of the communities, expressed as community-weighted means of trait expression (CWM), using multivariate techniques, and investigate the relationship between taxonomic and functional changes. Despite contrasting community developments in the two habitats, with characteristics traditionally suggesting different environmental quality, we found that the FDis in both habitats remained similar and increased with the introduction of Marenzelleria. Although showing maintained functional diversity across time and space, the functional identity (CWM) of communities changed irrespective of taxonomical differences. Examples include inter alia alterations in palatability proxies, feeding position and sediment transportation types, indicating changed functionality of zoobenthos in coastal systems. We show, when focussing on qualitative functional changes of communities, it is important to evaluate the underlying functional identity, and not only rely on measures of the diversity of functions per se, as the quality indication of expressed functional traits can be concealed when using multi-functionality approaches.

  • 44.
    Yletyinen, Johanna
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bodin, Örjan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Weigel, Benjamin
    Nordström, Marie C.
    Bonsdorff, Erik
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Regime shifts in marine communities: a complex systems perspective on food web dynamics2016In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 283, no 1825, article id 20152569Article in journal (Refereed)
    Abstract [en]

    Species composition and habitats are changing at unprecedented rates in the world's oceans, potentially causing entire food webs to shift to structurally and functionally different regimes. Despite the severity of these regime shifts, elucidating the precise nature of their underlying processes has remained difficult. We address this challenge with a new analytic approach to detect and assess the relative strength of different driving processes in food webs. Our study draws on complexity theory, and integrates the network-centric exponential random graph modelling (ERGM) framework developed within the social sciences with community ecology. In contrast to previous research, this approach makes clear assumptions of direction of causality and accommodates a dynamic perspective on the emergence of food webs. We apply our approach to analysing food webs of the Baltic Sea before and after a previously reported regime shift. Our results show that the dominant food web processes have remained largely the same, although we detect changes in their magnitudes. The results indicate that the reported regime shift may not be a system-wide shift, but instead involve a limited number of species. Our study emphasizes the importance of community-wide analysis on marine regime shifts and introduces a novel approach to examine food webs.

  • 45.
    Yletyinen, Johanna
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Butler, Will
    Ottersen, Geir
    Andersen, Ken H.
    Bonanomi, Sara
    Diekert, Florian K.
    Folke, Carl
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Lindegren, Martin
    Nordström, Marie C.
    Richter, Andries
    Rogers, Lauren
    Romagnoni, Giovanni
    Weigel, Benjamin
    Whittington, Jason D.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Stenseth, Nils C.
    When is a fish stock collapsed?Manuscript (preprint) (Other academic)
  • 46.
    Yletyinen, Johanna
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre. University of Canterbury, New Zealand.
    Hentati-Sundberg, Jonas
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bodin, Örjan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Fishing strategy diversification and fishers' ecological dependency2018In: Ecology & society, ISSN 1708-3087, E-ISSN 1708-3087, Vol. 23, no 3, article id 28Article in journal (Refereed)
    Abstract [en]

    Sustainable fisheries management plays a critical role in supporting healthy marine ecosystems and the livelihoods of millions of people. An emerging view on fisheries management emphasizes the need to manage fisheries as complex social-ecological systems. Yet, our understanding of the outcomes of fisheries management from a social-ecological perspective is limited in comparison to that provided by either the biophysical or the social perspective alone. In the Baltic Sea, management interventions focused on ecosystem recovery contributed to unintended changes from 1996 to 2009 in the fishing strategy diversity practiced by Swedish fishers. We evaluate how the changes in strategy diversification affected the capacity of Swedish fishers to adapt to future ecosystem changes. To do this, we constructed and analyzed social-ecological fisheries networks. Our analysis confirmed the previously reported development of a narrower combination of fishing strategies among large-scale fishers, parallel with a diversification in small-scale fishers' strategies. However, the results demonstrated that switching fishing strategies has, in fact, increased in magnitude, and the fishers were more equally distributed in different fishing strategies in 2009 than in 1996. Further, we detected a development toward lower ecological dependency between fishing strategies within the community, although the strategies remained connected through ecological interactions. In conclusion, our analysis of the social-ecological interdependencies suggests that the previously reported changes in the fishing strategy diversity increased the adaptability of the Swedish Baltic Sea fishers to changing ecological conditions. On the other hand, the changes may have made the Baltic Sea more vulnerable to poor management. This empirical study emphasizes the importance of a social-ecological approach on fisheries research and management. Our results show that appreciating the complexity and changing nature of fisher behavior is crucial when assessing fisheries management outcomes, and when designing policies that aim to maintain adaptability in the uncertain and dynamic fish industry.

  • 47.
    Yletyinen, Johanna
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Hentati-Sundberg, Jonas
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Bodin, Örjan
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    How patterns of interactions between and among fishing strategies and targeted fish species affect adaptive capacity: an integrated analysis of the Baltic Sea fishery 1996-2009Manuscript (preprint) (Other academic)
  • 48.
    Österblom, Henrik
    et al.
    Stockholm University, Stockholm Resilience Centre.
    Gardmark, A.
    Bergstrom, L.
    Muller-Karulis, B.
    Folke, C.
    Lindegren, M.
    Casini, M.
    Olsson, P.
    Diekmann, R.
    Blenckner, Thorsten
    Stockholm University, Stockholm Resilience Centre.
    Humborg, Cristoph
    Stockholm University, Stockholm Resilience Centre.
    Moellmann, C.
    Making the ecosystem approach operational-Can regime shifts in ecological- and governance systems facilitate the transition?2010In: Marine Policy, ISSN 0308-597X, E-ISSN 1872-9460, Vol. 34, no 6, p. 1290-1299Article in journal (Refereed)
    Abstract [en]

    Effectively reducing cumulative impacts on marine ecosystems requires co-evolution between science, policy and practice. Here, long-term social-ecological changes in the Baltic Sea are described, illustrating how the process of making the ecosystem approach operational in a large marine ecosystem can be stimulated. The existing multi-level governance institutions are specifically set up for dealing with individual sectors, but do not adequately support an operational application of the ecosystem approach. The review of ecosystem services in relation to regime shifts and resilience of the Baltic Sea sub-basins, and their driving forces, points to a number of challenges. There is however a movement towards a new governance regime. Bottom-up pilot initiatives can lead to a diffusion of innovation within the existing governance framework. Top-down, enabling EU legislation, can help stimulating innovations and re-organizing governance structures at drainage basin level to the Baltic Sea catchment as a whole. Experimentation and innovation at local to the regional levels is critical for a transition to ecosystem-based management. Establishing science-based learning platforms at sub-basin scales could facilitate this process.

  • 49.
    Österblom, Henrik
    et al.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Merrie, Andrew
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Metian, Marc
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Boonstra, Wiebren J.
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Blenckner, Thorsten
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Watson, James R.
    Rykaczewski, Ryan R.
    Ota, Yoshitaka
    Sarmiento, Jorge L.
    Christensen, Villy
    Schlüter, Maja
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Birnbaum, Simon
    Stockholm University, Faculty of Social Sciences, Department of Political Science. Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Gustafsson, Bo G.
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Humborg, Christoph
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Mörth, Carl-Magnus
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Muller-Karulis, Bärbel
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Tomczak, Maciej T.
    Stockholm University, Faculty of Science, Stockholm University Baltic Sea Centre, Baltic Nest Institute.
    Troell, Max
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Folke, Carl
    Stockholm University, Faculty of Science, Stockholm Resilience Centre.
    Modeling Social—Ecological Scenarios in Marine Systems2013In: BioScience, ISSN 0006-3568, E-ISSN 1525-3244, Vol. 63, no 9, p. 735-744Article in journal (Refereed)
    Abstract [en]

    Human activities have substantial impacts on marine ecosystems, including rapid regime shifts with large consequences for human well-being. We highlight the use of model-based scenarios as a scientific tool for adaptive stewardship in the face of such consequences. The natural sciences have a long history of developing scenarios but rarely with an in-depth understanding of factors influencing human actions. Social scientists have traditionally investigated human behavior, but scholars often argue that behavior is too complex to be repre-ented by broad generalizations useful for models and scenarios. We address this scientific divide with a framework for integrated marine social ecological scenarios, combining quantitative process-based models from the biogeochemical and ecological disciplines with qualitative studies on governance and social change. The aim is to develop policy-relevant scenarios based on an in-depth empirical understanding from both the natural and the social sciences, thereby contributing to adaptive stewardship of marine social-ecological systems.

1 - 49 of 49
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf