| 1. |
- Bartolino, Valerio, et al.
(författare)
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Forecasting fish stock dynamics under climate change: Baltic herring (Clupea harengus) as a case study
- 2014
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Ingår i: Fisheries Oceanography. - : Wiley. - 1054-6006 .- 1365-2419. ; 23:3, s. 258-269
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Tidskriftsartikel (refereegranskat)abstract
- Climate change and anthropogenic disturbances may affect marine populations and ecosystems through multiple pathways. In this study we present a framework in which we integrate existing models and knowledge on basic regulatory processes to investigate the potential impact of future scenarios of fisheries exploitation and climate change on the temporal dynamics of the central Baltic herring stock. Alternative scenarios of increasing sea surface temperature and decreasing salinity of the Baltic Sea from a global climate model were combined with two alternative fishing scenarios, and their direct and ecosystem-mediated effects (i.e., through predation by cod and competition with sprat) on the herring population were evaluated for the period 2010-2050. Gradual increase in temperature has a positive impact on the long-term productivity of the herring stock, but it has the potential to enhance the recovery of the herring stock only in combination with sustainable fisheries management (i.e., F-msy). Conversely, projections of herring spawning stock biomass (SSB) were generally low under elevated fishing mortality levels (F-high), comparable with those experienced by the stock during the 1990s. Under the combined effects of long-term warming and high fishing mortality uncertainty in herring SSB projections was higher and increasing for the duration of the forecasts, suggesting a synergistic effect of fishery exploitation and climate forcing on fish populations dynamics. Our study shows that simulations of long-term fish dynamics can be an informative tool to derive expectations of the potential long-term impact of alternative future scenarios of exploitation and climate change.
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| 2. |
- Cardinale, M, et al.
(författare)
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CES. 2009. Report of the Workshop on Combining Climatic Scenarios and Medium‐Term Predictions for Baltic Herring and Sprat stocks (WKCSMPB), 13–16 October 2009, Ponza, Italy. ICES CM 2009/BCC:03. : ICES WKCSMPB REPORT 2009
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The direct and indirect effects of density dependence (i.e. parental stock effects) and climate‐induced hydrographic change on five different Baltic herring stocks and on Baltic sprat, investigated by WKHRPB and WKSSRB (ICES 2007b and 2008) to develop stock specific recruitment‐environment relationships, were revisited and updated. The predictors to be included in the final recruitment models were selected on the basis of the parsimonious principle, statistical significance of the predictors and the ecological criterion being fulfilled simultaneously (Cardinale et al. 2009). In previous work, temperature was detected to be an important predictor for several stocks of clupeids. Weight at age (WAA) was the major factor explaining recruitment for Main Basin herring (MBH) while spawning stock biomass (SSB) was important for Baltic sprat (BS) and Gulf of Riga herring (GRH). For MBH, food supply was also a significant predictor, suggesting that a part of the changes in climate and hydrographic conditions may affect herring indirectly via prey availability. The best recruitment model for Baltic sprat (BS) linked recruitment success to its spawning stock biomass (SSB), sea surface temperature in August (NASA8), predation mortality by cod (PM), and Bottom Depth Anomaly (BDA) which is a proxy of drift/retention of sprat larvae (ICES 2008). The final recruitment models provided by Cardinale et al. (2009) were tested with updated data series only for MBH, GRH and BS as no satisfactory final model was found for the other stocks (Cardinale et al. 2009). Further, as the main aim was to include climatic scenarios for recruitment predictions, number of recruits (thereafter referred also as recruitment) was used for all stocks instead of recruitment success. Thus, models developed for MBH, GRH and BS were re‐fitted with updated input data and with number of recruits as response variable using both a linear and a GAM model to allow for medium‐term recruitment predictions under different climatic scenarios. SSB time series were generated using the BALMAR food‐web model (Lindegren et al. 2009), a linear state‐space model based on a theoretical approach for predicting longterm responses of populations to environmental change (Ives 1995; Ives et al. 2003). SSB time series were generated assuming two different levels of fishing mortalities (Fmed, Fmsy or Fmp). Predictions of SST were generated using higher resolution Regional Climate Models (RCMs). The results show that in the next 30 years recruitment of herring stocks will generally increase or stay relatively stable at values observed in the last decade for any of the scenarios considered. This is likely to be mainly an effect of a predicted increase in SST. On the other hand, the effect of SSB is small for MBH mainly due to the narrow range of predicted SSB values over the next 3 decades. In the case of GRH, a similar pattern was observed although the increase in recruitment is not as large as for MBH. For sprat, a satisfactory model was not found for predicting recruitment and further analysis are needed.
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| 3. |
- Carlos, Diaz-Gil, et al.
(författare)
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Spatio-temporal composition and dynamics of zooplankton in the Kalmar Sound (western Baltic Sea) in 2009-2010
- 2014
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Ingår i: Boreal Environment Research. - 1239-6095 .- 1797-2469. ; 19:4, s. 323-335
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Tidskriftsartikel (refereegranskat)abstract
- In pelagic food webs, zooplankton is the link between lower and higher trophic levels. It is thus essential to know how the zooplankton community structure varies with its environment. We investigated the seasonal and spatial variation in the zooplankton diversity and community structure during two consecutive years in the Kalmar Sound, along the Swedish east coast, an area with a strong bathymetric gradient and of high ecological importance for e.g. commercial fish species. Two zooplankton communities were identified in the area: a coastal/estuarine community in the south and an open-water community in the north. They were separated mainly by differing salinity and temperature conditions. Biodiversity increased from spring to autumn and was higher in the open waters.
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| 4. |
- Reusch, T. B. H., et al.
(författare)
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The Baltic Sea as a time machine for the future coastal ocean
- 2018
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Ingår i: Science Advances. - : American Association for the Advancement of Science (AAAS). - 2375-2548. ; 4:5
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Tidskriftsartikel (refereegranskat)abstract
- Coastal global oceans are expected to undergo drastic changes driven by climate change and increasing anthropogenic pressures in coming decades. Predicting specific future conditions and assessing the best management strategies to maintain ecosystem integrity and sustainable resource use are difficult, because of multiple interacting pressures, uncertain projections, and a lack of test cases for management. We argue that the Baltic Sea can serve as a time machine to study consequences and mitigation of future coastal perturbations, due to its unique combination of an early history of multistressor disturbance and ecosystem deterioration and early implementation of cross-border environmental management to address these problems. The Baltic Sea also stands out in providing a strong scientific foundation and accessibility to long-term data series that provide a unique opportunity to assess the efficacy of management actions to address the breakdown of ecosystem functions. Trend reversals such as the return of top predators, recovering fish stocks, and reduced input of nutrient and harmful substances could be achieved only by implementing an international, cooperative governance structure transcending its complex multistate policy setting, with integrated management of watershed and sea. The Baltic Sea also demonstrates how rapidly progressing global pressures, particularly warming of Baltic waters and the surrounding catchment area, can offset the efficacy of current management approaches. This situation calls for management that is (i) conservative to provide a buffer against regionally unmanageable global perturbations, (ii) adaptive to react to new management challenges, and, ultimately, (iii) multisectorial and integrative to address conflicts associated with economic trade-offs.
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| 5. |
- Tomczak, Maciej T., et al.
(författare)
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Evaluation of Trends and Changes in the Gulf of Gdansk Ecosystem-an Integrated Approach
- 2016
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Ingår i: Estuaries and Coasts. - : Springer Science and Business Media LLC. - 1559-2723 .- 1559-2731. ; 39:3, s. 593-604
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Tidskriftsartikel (refereegranskat)abstract
- An integrated trend assessment was conducted for the Gulf of GdaAsk (GoG), Baltic Sea for the period 1994-2010 to describe changes and potentially important drivers of the ecosystem. We found changes in the biota, including an increase in open sea taxa (flatfish, sprat and cod), a decrease in typical coastal species such as eelpout and lumpfish and an increase in primary production. The analyses further suggest that changes in the food web were driven by a combination of anthropogenic pressures (e.g., nutrient loadings and fisheries) and possible interactions with climatic disturbance. Our analyses show that significant changes occurred in the GoG ecosystem between 1994 and 2010. The primary drivers and mechanisms of these changes are discussed. We describe this alteration of the GoG within the context of similar temporal patterns identified in adjacent areas.
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