Suchergebnisse

Preface -- Contents -- Chapter 1: Evolution of the Baltic Sea -- 1.1 Development of the Baltic Sea After the Last Ice Age -- 1.2 Formation of Biota in the Baltic Sea -- References -- Chapter 2: Abiotic Conditions in the Contemporary Baltic Sea -- 2.1 Water Balance -- 2.2 Water Salinity -- 2.2.1 The Role of Currents -- 2.2.2 Vertical Mixing of Water Layers -- 2.3 Water Temperature -- 2.4 Oxygen Conditions -- 2.5 Light Conditions -- 2.6 Natural Regional System of the Baltic Sea -- 2.6.1 Macro-regions -- 2.6.2 Regions and Subregions -- References -- Chapter 3: Life in the Baltic Sea -- 3.1 Salinity-Induced Ecophysiological Problems of Organisms in the Baltic Sea -- 3.2 Multitude of Ecosystems -- 3.3 Living Organisms -- 3.4 Vegetation and Primary Production -- 3.5 Bottom Vegetation -- 3.6 Heterotrophic Microorganisms -- 3.7 Zooplankton -- 3.8 Zoobenthos -- 3.9 Fish -- 3.9.1 Marine Pelagic Fish -- 3.9.1.1 Baltic Herring Clupea harengus membras L. -- 3.9.1.2 Spring Spawning Herring Clupea harengus membras L. -- 3.9.1.3 Autumn Spawning Herring Clupea harengus membras L. -- 3.9.1.4 Baltic Sprat Sprattus sprattus balticus (Schn.) -- 3.9.2 Marine Demersal Fish -- 3.9.2.1 Baltic Cod Gadus morhua callarias (L.) -- 3.9.2.2 Flounder Platichthys flesus trachurus (Duncker) -- 3.9.2.3 Plaice Pleuronectes platessa L. -- 3.9.2.4 Dab Limanda limanda (L.) -- 3.9.2.5 Turbot Psetta maxima (L.) -- 3.9.3 Diadromous Fish -- 3.9.3.1 Salmon Salmo salar L. -- 3.9.3.2 Sea Trout Salmo trutta L. -- 3.9.3.3 European Whitefish Coregonus lavaretus (L.) s. l. -- 3.9.3.4 Vendace Coregonus albula (L.) -- 3.9.3.5 Eel Anguilla anguilla (L.) -- 3.9.3.6 Garfish Belone belone (L.) -- 3.9.3.7 River Lamprey Lampetra fluviatilis (L.) -- 3.9.4 Freshwater Fish -- 3.9.4.1 Perch Perca fluviatilis L. -- 3.9.4.2 Pikeperch Sander lucioperca (L) -- 3.9.4.3 Pike Esox lucius L

Abstract
Fish is an important part of nutrition and well‐being. The challenge of Finnish wild fish is contaminants which accumulate in some species in higher concentrations, partially limit the usability of the fish in the food/feed market and weaken the assessment of the state of the marine environment. The aim of this study was to obtain data on the amounts of nutrients and contaminants in domestic fish species that are commercially important or should be increased in use according to national plans. The aim was also to produce information for updating the national fish use recommendations.
The concentrations of contaminants in Finnish fish were mostly below the maximum levels set by the EU. The trend of dioxin and PCB compound concentrations in the Baltic Sea has been declining since the 1980s, and the concentrations in Baltic herring appear to have settled around or below the maximum levels in all sea areas and size classes. The PFAS concentrations in the studied fish samples were within the maximum limits, except for Baltic herring in the Archipelago Sea and the Bothnian Sea. Additionally, the PFAS concentrations in Baltic herring rose quite sharply between 2009 and 2023. During the current study, PFAS concentrations in Baltic herring from the same sea area and size classes increased significantly from autumn 2022 to spring 2023. The seasonal trend was suspected to be related to the fish's diet, but factors affecting PFAS concentrations in fish, such as the impact of seasons and fitness (function of weight and size of the fish), need further investigation, and PFAS concentrations in Baltic herring should be monitored.
PBDE concentrations in Finnish fish were found to be very low, although they exceeded the environmental quality standard. Mercury concentrations in fish, except for two samples, were lower than the maximum levels set by Commission Regulation (EU) 2023/915. The proportion of methylmercury in total mercury was 56–94% in different fish species. Inorganic arsenic concentrations in all fish samples were below the detection limit of 0.01 mg/kg.
The highest concentrations of omega‐3 fatty acids were measured in Baltic herring and vendace. Fish caught from marine areas had higher vitamin D concentrations than those from inland waters, and there was significant variation in concentrations within fish species.
With current food consumption and concentration data, the health benefits of fish consumption outweigh the health risks associated with contaminants in fish for all age groups. The greatest health benefits are seen in those over 45 years old, where fish consumption reduces the burden of diseases such as cardiovascular diseases and breast cancer, as well as overall mortality. On a national scale, the current use of domestic and imported fish is estimated to reduce the disease burden annually by nearly 70,000 disability‐adjusted life years (DALYs).
As a conclusion, the health benefits of fish consumption outweigh the harms of contaminants in all age groups. Increasing the consumption of fish in accordance with nutritional recommendations would benefit the health of the population. For children and expectant or breastfeeding mothers, a diverse fish consumption is useful. The safe use recommendations of the Finnish Food Authority help this risk group to direct their fish consumption to fishing areas and fish species with the lowest amounts of contaminants.

Herring exports to the Baltic from the Netherlands in the seventeenth and eighteenth centuries were closely related to exports of the previous year rather than to aggregate levels of trade. Dutch domination of the European market for salted herring in the seventeenth century thus cannot be explained by some external factor but rather by the internal nature of the Dutch fishery: by technology, organization, and the institutions which administered it. Regulation was designed to maximize rents but, as other fishermen gained the skills of their Dutch competitors, that strategy'turned into one which at first limited sales and then returns to the Dutch industry.… O, wot een gulden Neeringhen voedsel brengt ons toe de Conincklijke Heringh;hoe menig duysend ziel bij dezen handel leeft enwinnende sijn brood God dank en eere gheeft.

International hydroacoustic surveys have been conducted in the Baltic Sea since 1978. The starting point was the cooperation between the Institute of Marine Research (IMR) in Lysekil, Sweden, and the Institute fur Hochseefisherei und Fishverarbeitung in Rostock, German Democratic Republic, in October ¨ 1978, which produced the first acoustic estimates of total biomass of herring and sprat in the Baltic main basin (Håkansson et al., 1979). Since then there has been at least one annual hydroacoustic survey for herring and sprat and results have been reported to ICES. The Baltic International Acoustic Survey (BIAS), is mandatory for the countries that have exclusive economic zone (EEZ) in the Baltic Sea, and is a part of the Data Collection Framework as stipulated by the European Council and the Commission (Council Regulation (EC) No 199/2008 and the Commission Data Collection Framework (DCF) web page1 ). The IMR in Lysekil is part of the Department of Aquatic Resources within Swedish University of Agricultural Sciences and is responsible for the Swedish part of the EU DCF and surveys in the marine environment. The Institute assesses the status of the marine ecosystems, develops and provides biological advices for the sustainable use of the aquatic resources. The BIAS survey is co-ordinated and managed by the ICES working group WGBIFS. The main objective of BIAS is to assess herring and sprat resources in the Baltic Sea. The survey provides data to the ICES Baltic Fisheries Assessment Working Group (WGBFAS).

International hydroacoustic surveys have been conducted in the Baltic Sea since 1978. The starting point was the cooperation between Institute of Marine Research (IMR) in Lysekil, Sweden and the Institute fur Hochseefisherei und Fishverarbeitung in Rostock, German Democratic Republic in October 1978, ¨ which produced the first acoustic estimates of total biomass of herring and sprat in the Baltic Main basin (H˚akansson et al., 1979). Since then there has been at least one annual hydroacoustic survey for herring and sprat stocks and results have been reported to ICES. The Baltic International Acoustic Survey (BIAS), is mandatory for the countries that have exclusive economic zone (EEZ) in the Baltic Sea, and is a part of the Data Collection Framework as stipulated by the European Council and the Commission (Council Regulation (EC) No 199/2008 and the Commission Data Collection Framework (DCF) web page1 ). IMR in Lysekil is part of the Department of Aquatic Resources within Swedish University of Agricultural Sciences and is responsible for the Swedish part of the EU DCF and surveys in the marine environment. The Institute assesses the status of the marine ecosystems, develops and provides biological advices for managers for the sustainable use of aquatic resources. The BIAS survey are co-ordinated and managed by the ICES working group WGBIFS. The main objective of BIAS is to assess herring and sprat resources in the Baltic Sea. The survey will provide data to the ICES Baltic Fisheries Assessment Working Group (WGBFAS).

International hydroacoustic surveys have been conducted in the Baltic Sea since 1978. The starting point was the cooperation between the Institute of Marine Research (IMR) in Lysekil, Sweden and the Institute für Hochseefisherei und Fishverarbeitung in Rostock, German Democratic Republic in October 1978, which produced the first acoustic estimates of total biomass of herring and sprat in the Baltic Main basin (H˚akansson et al., 1979). Since then there has been at least one annual hydroacoustic survey for herring and sprat stocks and results have been reported to ICES. The Baltic International Acoustic Survey (BIAS), is mandatory for the countries that have exclusive economic zone (EEZ) in the Baltic Sea, and is a part of the Data Collection Framework as stipulated by the European Council and the Commission (Council Regulation (EC) No 199/2008 and the Commission DCF web page1 ). IMR in Lysekil is part of the Department of Aquatic Resources within the Swedish University of Agricultural Sciences and is responsible for the Swedish part of the EU Data Collection Framework and surveys in the marine environment. The Institute assesses the status of the marine ecosystems, develops and provides biological advices for managers for the sustainable use of aquatic resources. The BIAS survey is co-ordinated and managed by the ICES working group WGBIFS. The main objective of BIAS is to assess herring and sprat resources in the Baltic Sea. The survey will provide data to the ICES Baltic Fisheries Assessment Working Group (WGBFAS).

AbstractMultispecies bio-economic models are useful tools to give insights into ecosystem thinking and ecosystem-based management. This paper developed an age-structured multispecies bio-economic model that includes the food web relations of the grey seal, salmon, and herring, along with salmon and herring fisheries in the Baltic Sea. The results show that the increasing seal population influences salmon fisheries and stock, but the impacts on the harvest are stronger than on the stock if the targeted management policies are obeyed. If seal population growth and a low herring stock occur simultaneously, the salmon harvest could face a serious threat. In addition, scenarios of the multispecies management approach in this paper reveal a benefit that our model can evaluate the performance of different fisheries with identical or different management strategies simultaneously. The results show the most profitable scenario is that both fisheries pursuit aggregated profits and reveal a trade-off between herring fisheries and salmon fisheries. Our model indicates that the herring harvest level and the approaches to managing herring fisheries can influence the performance of salmon fisheries. The study also demonstrates a way to develop a multispecies bio-economic model that includes both migratory fish and mammalian predators.

Abstract
Perfluoroalkyl substances (PFASs) were investigated in five Baltic fish species (sprat, herring, salmon, trout, and cod). Each species' median lower bound (LB) concentration of ∑14 PFASs was as follows: in sprat it was 3.54 µg/kg wet weight (w.w.), in cod 2.15 µg/kg w.w., in salmon 2.10 µg/kg w.w., in trout 2.03 µg/kg w.w. and in herring 1.74 µg/kg w.w.. Regarding the species' median LB of ∑4 PFASs (perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), and perfluorohexane sulfonic acid (PFHxS)), sprat was the most contaminated with 2.90 µg/kg w.w. and herring was the least with 1.17 µg/kg w.w.. Among all PFASs, PFOS was found in the highest concentrations (range 0.04–9.16 µg/kg w.w.) and the percentage share in the total concentration of ∑14 PFASs was between 56 and 73%. The average proportion of linear PFOS (L-PFOS) in the total PFOS (branched and linear) was the highest in salmon at 89% and trout at 87%, and in the other three species it ranged from 75 to 80%. Different consumption scenarios were assumed and the intake of PFASs was calculated for children and adults. Dietary intake via fish consumption was 3.20–25.13 ng/kg of body weight (b.w.) for children and 1.68–8.30 ng/kg b.w. for adults. Baltic fish caught along Polish coastal areas are a significant source of PFASs, especially for children.

International hydroacoustic surveys have been conducted in the Baltic Sea since 1978. The starting point was the cooperation between Institute of Marine Research (IMR) in Lysekil, Sweden and the Institute fur Hochseefisherei und Fishverarbeitung in Rostock, German Democratic Republic in October 1978, ¨ which produced the first acoustic estimates of total biomass of herring and sprat in the Baltic Main basin (H˚akansson et al., 1979). Since then there has been at least one annual hydroacoustic survey for herring and sprat stocks and results have been reported to ICES. The Baltic International Acoustic Survey (BIAS), is mandatory for the countries that have exclusive economic zone (EEZ) in the Baltic Sea, and is a part of the Data Collection Framework as stipulated by the European Council and the Commission (Council Regulation (EC) No 199/2008 and the Commission DCF web page4). IMR in Lysekil is part of the Department of Aquatic Resources within Swedish University of Agricultural Sciences and is responsible for the Swedish part of the EU Data Collection Framework and surveys in the marine environment. The Institute assesses the status of the marine ecosystems, develops and provides biological advices for managers for the sustainable use of aquatic resources. The BIAS survey in September/October are co-ordinated and managed by the ICES working group WGBIFS. The main objective of BIAS is to assess clupeoid resources in the Baltic Sea. The survey will provide data to the ICES Baltic Fisheries Assessment Working Group (WGBFAS).

The implementation challenge of ecosystem-based (fisheries) management (EB(F)M) has entailed calls for integrated governance (IG) approaches in the marine field. We arranged an expert workshop to study the preconditions and applicability of IG, and to suggest how IG could be arranged in practice. Focusing on the management of the dioxin problem shared by the herring and salmon fisheries in the Baltic Sea, and using a coupled 'insight network'- SWOT (strengths, weaknesses, opportunities, threats) methodology, we evaluated two scenarios: 1) IG of herring and salmon fisheries to benefit from collaboration between these fisheries that suffer from the same problem, and 2) IG between the fisheries sector and the food/public health sector to incorporate food safety in fisheries governance. Our results demonstrate that a variety of societal, political, institutional, operational, instrumental, and biological factors affect the applicability of IG in marine contexts, and work as preconditions for IG. While societal needs for IG were obvious in our case, as major challenges for it we identified the competing cross-sectoral objectives, path dependencies, and limitations of experts to think and work across fields. The study suggests that establishing an IG framework by adding new aspects upon the current governance structures may be easier to accept and adapt to, than creating new strategic or advisory bodies or other new capacities. Viewing IG as a framework for understanding cross-sectoral issues instead of one that requires a defined level and form of integrated assessment and management may be a way towards social learning, and thereby towards the implementation of more sophisticated, open and broad EB(F)M frameworks. ; Peer reviewed

Abstract The implementation challenge of ecosystem-based (fisheries) management (EB(F)M) has entailed calls for integrated governance (IG) approaches in the marine field. We arranged an expert workshop to study the preconditions and applicability of IG, and to suggest how IG could be arranged in practice. Focusing on the management of the dioxin problem shared by the herring and salmon fisheries in the Baltic Sea, and using a coupled 'insight network'- SWOT (strengths, weaknesses, opportunities, threats) methodology, we evaluated two scenarios: 1) IG of herring and salmon fisheries to benefit from collaboration between these fisheries that suffer from the same problem, and 2) IG between the fisheries sector and the food/public health sector to incorporate food safety in fisheries governance. Our results demonstrate that a variety of societal, political, institutional, operational, instrumental, and biological factors affect the applicability of IG in marine contexts, and work as preconditions for IG. While societal needs for IG were obvious in our case, as major challenges for it we identified the competing cross-sectoral objectives, path dependencies, and limitations of experts to think and work across fields. The study suggests that establishing an IG framework by adding new aspects upon the current governance structures may be easier to accept and adapt to, than creating new strategic or advisory bodies or other new capacities. Viewing IG as a framework for understanding cross-sectoral issues instead of one that requires a defined level and form of integrated assessment and management may be a way towards social learning, and thereby towards the implementation of more sophisticated, open and broad EB(F)M frameworks.

AbstractThe concentrations of dioxins [polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs)], and dioxin-like polychlorinated biphenyls (DL-PCBs) in Atlantic herring depend on the fishing area. These substances originate from various anthropogenic sources and accumulate in the environment and in food. The influence of country-specific contaminant concentrations on human dietary exposure was studied exemplary for herring to show the influence of fish origin. PCDD/F and DL-PCB concentrations in herring from the Norwegian Sea and the Baltic Sea were combined with country-specific herring consumption. Herring concentrations showed geographical variation. For herring consumers, the 50th percentile dietary exposure to the total sum of PCDD/Fs and DL-PCBs amounted to 1.2 and 8.9 pg WHO-2005-TEQ/kg BW/week for Norway and Germany, respectively. The different exposure was mainly related to higher concentrations in herring from the Baltic Sea, rather than in herring from the Norwegian Sea. If contaminant concentrations are influenced by geographical origin, this should be integrated into the dietary exposure assessments. For herring, relevant fishing areas should be integrated into the sampling strategy to generate concentration data. The usage of country-specific data could refine exposure assessments.