| 1. |
- Andersson, Jan, et al.
(författare)
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Inventering och modellering av fisk- och kräftdjurssamhället i Stigfjorden sommaren 2012
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Under 31 juli-3 augusti 2012 utförde Kustlaboratoriet vid SLU Aqua ett inventeringsfiske med småryssjor i Stigfjorden mellan Orust och Tjörn med syfte att beskriva fisksamhället i fjorden och att kartlägga viktiga fiskhabitat. Totalt fiskades 80 stationer på djup från ytan ner till 20 m. Området uppvisade ovanligt höga tätheter av juvenil rödspotta, gråsej och torsk. Även fångsterna av stensnultra och tånglake var höga, och bland kräftdjuren dominerade strandkrabban. Resultaten från Stigfjorden jämförs med resultat från tidigare och samtida undersökningar av samma karaktär. Den rumsliga fördelningen av olika arter i förhållande till habitatet beskrevs statistiskt med hjälp av generella additiva modeller, där fångsterna i ryssjorna relateras till data på olika miljövariabler. De statistiska modellerna i kombination med kartor över miljövariabler i området användes sedan för att i GIS producera heltäckande kartor över potentiella habitat för arterna. De arter som modellerades var torsk <18 cm, torsk >18 cm, ål, rödspotta, vitling, stensnultra, tånglake och strandkrabba. Modellernas förklaringsgrad var generellt god, och vattendjup utgjorde den variabel som var viktigast för fördelningen av de flesta arter. Ungtorsk och rödspotta förekom i högst tätheter i de djupare delarna av fjorden, medan gulål, tånglake och strandkrabba, där de två förstnämnda tillsammans med torsken är rödlistade, främst återfanns i de grunda delarna av fjorden. Sammantaget tyder resultaten på att Stigfjorden håller viktiga livsmiljöer för ett flertal fiskarter, framför allt som uppväxtområde för arter som t ex rödspotta och gråsej.
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| 2. |
- Andersson, Magnus, et al.
(författare)
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Fiskbestånd och miljö i hav och sötvatten : Resurs- och miljööversikt 2012
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Detta är den nionde utgåvan av den samlade översikten över fisk- och kräftdjursbeståndens status i våra vatten. Kunskap om fiskbestånden och miljön är en förutsättning för att utnyttjandet av fiskresurserna skall bli bärkraftigt. För svenska vattenområden beskrivs miljöutvecklingen i ett ekosystemsperspektiv, dels för att tydliggöra fiskens ekologiska roll och beskriva yttre miljöfaktorer som påverkar fiskbestånden, dels för att belysa fiskets effekter på miljön.Fiskbestånd och miljö i hav och sötvatten är utarbetad av Sveriges lantbruksuniversitet (SLU), Institutionen för akvatiska resurser (SLU Aqua), på uppdrag av Havs- och vattenmyndigheten. Rapporten sammanfattar utveckling och beståndsstatus för de kommersiellt viktigaste fisk- och kräftdjursarterna i våra vatten. Bedömningar och förvaltningsråd är baserade på Internationella Havsforskningsrådets (ICES) rådgivning, SLU Aquas nationella och regionala provfiskedata, samt yrkesfiskets rapportering.
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| 3. |
- Ardehed, Angelica, et al.
(författare)
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Divergence within and among Seaweed Siblings (Fucus vesiculosus and F. radicans) in the Baltic Sea
- 2016
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Ingår i: Plos One. - : Public Library of Science (PLoS). - 1932-6203. ; 11:8
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Tidskriftsartikel (refereegranskat)abstract
- Closely related taxa provide significant case studies for understanding evolution of new species but may simultaneously challenge species identification and definition. In the Baltic Sea, two dominant and perennial brown algae share a very recent ancestry. Fucus vesiculosus invaded this recently formed postglacial sea 8000 years ago and shortly thereafter Fucus radicans diverged from this lineage as an endemic species. In the Baltic Sea both species reproduce sexually but also recruit fully fertile new individuals by asexual fragmentation. Earlier studies have shown local differences in morphology and genetics between the two taxa in the northern and western Bothnian Sea, and around the island of Saaremaa in Estonia, but geographic patterns seemin conflict with a single origin of F. radicans. To investigate the relationship between northern and Estonian distributions, we analysed the genetic variation using 9 microsatellite loci in populations from eastern Bothnian Sea, Archipelago Sea and the Gulf of Finland. These populations are located in between earlier studied populations. However, instead of bridging the disparate genetic gap between N-W Bothnian Sea and Estonia, as expected from a simple isolation-by-distance model, the new populations substantially increased overall genetic diversity and showed to be strongly divergent from the two earlier analysed regions, showing signs of additional distinct populations. Contrasting earlier findings of increased asexual recruitment in low salinity in the Bothnian Sea, we found high levels of sexual reproduction in some of the Gulf of Finland populations that inhabit extremely low salinity. The new data generated in this study supports the earlier conclusion of two reproductively isolated but very closely related species. However, the new results also add considerable genetic and morphological complexity within species. This makes species separation at geographic scales more demanding and suggests a need for more comprehensive approaches to further disentangle the intriguing relationship and history of the Baltic Sea fucoids.
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| 4. |
- Belgrano, Andrea, et al.
(författare)
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Mapping and Evaluating Marine Protected Areas and Ecosystem Services: A Transdisciplinary Delphi Forecasting Process Framework
- 2021
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Ingår i: Frontiers in Ecology and Evolution. - : Frontiers Media SA. - 2296-701X. ; 9
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Tidskriftsartikel (refereegranskat)abstract
- Marine Protected Areas (MPAs) are an important tool for management and conservation and play an increasingly recognised role in societal and human well-being. However, the assessment of MPAs often lacks a simultaneous consideration of ecological and socio-economic outcomes, and this can lead to misconceptions on the effectiveness of MPAs. In this perspective, we present a transdisciplinary approach based on the Delphi method for mapping and evaluating Marine Protected Areas for their ability to protect biodiversity while providing Ecosystem Services (ES) and related human well-being benefits – i.e., the ecosystem outputs from which people benefit. We highlight the need to include the human dimensions of marine protection in such assessments, given that the effectiveness of MPAs over time is conditional on the social, cultural and institutional contexts in which MPAs evolve. Our approach supports Ecosystem-Based Management and highlights the importance of MPAs in achieving restoration, conservation, and sustainable development objectives in relation to EU Directives such as the Marine Strategy Framework Directive (MSFD), the Maritime Spatial Planning Directive (MSPD), and the Common Fisheries Policy (CFP).
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| 5. |
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| 6. |
- Bergström, Lena, et al.
(författare)
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Coastal fish indicators response to natural and anthropogenic drivers-variability at temporal and different spatial scales
- 2016
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Ingår i: Estuarine, Coastal and Shelf Science. - : Elsevier BV. - 0272-7714 .- 1096-0015. ; 183, s. 62-72
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Tidskriftsartikel (refereegranskat)abstract
- Ecological indicators are increasingly used in marine and freshwater management but only few are developed towards full operationalization with known patterns of variability and documented responses to natural and anthropogenic environmental drivers. Here, we evaluate potential sources of indicator variability at two different spatial scales in three coastal fish-based indicators of environmental status in the Baltic Sea; abundance of cyprinids, abundance of perch and the proportion of larger perch. The study was performed on a data set covering 41 monitoring areas subject to different levels of anthropogenic impact, at a latitudinal range of 56-66 degrees N and a salinity range of 2-8. Interannual variation was clearly minor relative to spatial variation. Small-scale spatial variation was related to water depth, wave exposure and water temperature. The remaining variation was assessed in relation to differences in natural and anthropogenic drivers between monitoring areas. Cyprinids showed a clear inverse relationship to water transparency, which was used as a proxy for eutrophication, indicating increased abundances in nutrient enriched areas. None of the indicators showed an expected negative relationship to the level of coastal commercial fisheries catches. Rather, a positive relationship for Perch suggested that the coastal fisheries were concentrated to areas with strong perch populations in the studied areas. The effect of salinity and climate (temperature during the growth season) among monitoring areas were small. The results emphasize the importance of assigning area-specific boundary levels to define good environmental status in the coastal fish indicators, in order to account for natural sources of variability. Further, although long-term monitoring in reference areas is crucial for obtaining a historical baseline, our results suggest that the status assessment of coastal fish would generally gain precision by increasingly including spatially based assessments. We propose that similar analytical approaches could be applied to other ecosystem components, especially in naturally heterogenic environments, in order to separate indicator variability attributed to potential anthropogenic impact. (C) 2016 The Authors. Published by Elsevier Ltd.
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| 7. |
- Bergström, Lena, et al.
(författare)
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Distribution of mesopredatory fish determined by habitat variables in a predator-depleted coastal system
- 2016
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Ingår i: Marine Biology. - : Springer Science and Business Media LLC. - 0025-3162 .- 1432-1793. ; 163
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Tidskriftsartikel (refereegranskat)abstract
- Shallow nearshore habitats are highly valued for supporting marine ecosystems, but are subject to intense human-induced pressures. Mesopredatory fish are key components in coastal food webs, and alterations in their abundance may have evident effects also on other parts of the ecosystem. The aim of this study was to clarify the relationship between the abundance of coastal mesopredatory fish, defined as mid-trophic level demersal and benthic species with a diet consisting predominantly of invertebrates, and ambient environmental variables in a fjord system influenced by both eutrophication and overfishing. A field survey was conducted over a coastal gradient comprising 300 data points sampled consistently for fish community and environmental data. Results from multivariate and univariate analyses supported each other, demonstrating that mesopredatory fish abundance at species and functional group level was positively related to the cover of structurally complex vegetation and negatively related to eutrophication, as measured by water transparency. Contrary to other studies showing an inverse relationship to piscivore abundance over time, the spatial distribution of mesopredatory fish was not locally regulated by the abundance of piscivorous fish, probably attributed to piscivores being at historically low levels due to previous overfishing. Mesopredatory fish abundance was highest in areas with high habitat quality and positively related to the abundance of piscivores, suggesting a predominance of bottom-up processes. We conclude that, in parallel with ongoing regulations of fishing pressure, measures to restore habitat function and food web productivity are important for the recovery of coastal fish communities in the area.
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| 8. |
- Bergström, Lena, et al.
(författare)
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Effects of an offshore wind farm on temporal and spatial patterns in the demersal fish community
- 2013
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Ingår i: Marine Ecology Progress Series. - : Inter-Research Science Center. - 0171-8630 .- 1616-1599. ; 485, s. 199-210
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Tidskriftsartikel (refereegranskat)abstract
- The rapid increase in offshore wind energy worldwide has raised concern about its potential risks to marine biodiversity due to habitat alteration, disturbance from noise and electromagnetic fields. This study presents results of surveillance studies performed at the Lillgrund wind farm in Sweden to investigate the integrated effects of these factors on the abundance and distribution patterns of benthic fish communities. The studies revealed no large-scale effects on fish diversity and abundance after establishment of the wind farm when compared to the development in 2 reference areas. Changes in some species and in community composition were observed over time but occurred in parallel in at least one reference area, indicating that fish communities in the wind farm area were mainly driven by the same environmental factors as those in surrounding areas. However, changes at smaller spatial scales were evident. Increased densities of all studied piscivores (cod, eel, shorthorn sculpin), as well as the reef-associated goldsinny wrasse, were observed close to the foundations in the first years of operation. The increase was probably attributed mainly to local changes in distribution rather than to immigration or increased local productivity. Simultaneously, weak or no aggregation of black goby, eelpout and shore crab, all potentially reef-associated but also prey species of the studied piscivores, was observed, which may indicate enhanced top-down control near the foundations.
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| 9. |
- Bergström, Lena, et al.
(författare)
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Effects of offshore wind farms on marine wildlife-a generalized impact assessment
- 2014
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Ingår i: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 9:3
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Tidskriftsartikel (refereegranskat)abstract
- Marine management plans over the world express high expectations to the development of offshore wind energy. This would obviously contribute to renewable energy production, but potential conflicts with other usages of the marine landscape, as well as conservation interests, are evident. The present study synthesizes the current state of understanding on the effects of offshore wind farms on marine wildlife, in order to identify general versus local conclusions in published studies. The results were translated into a generalized impact assessment for coastal waters in Sweden, which covers a range of salinity conditions from marine to nearly fresh waters. Hence, the conclusions are potentially applicable to marine planning situations in various aquatic ecosystems. The assessment considered impact with respect to temporal and spatial extent of the pressure, effect within each ecosystem component, and level of certainty. Research on the environmental effects of offshore wind farms has gone through a rapid maturation and learning process, with the bulk of knowledge being developed within the past ten years. The studies showed a high level of consensus with respect to the construction phase, indicating that potential impacts on marine life should be carefully considered in marine spatial planning. Potential impacts during the operational phase were more locally variable, and could be either negative or positive depending on biological conditions as well as prevailing management goals. There was paucity in studies on cumulative impacts and long-term effects on the food web, as well as on combined effects with other human activities, such as the fisheries. These aspects remain key open issues for a sustainable marine spatial planning.
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| 10. |
- Bergström, Lena, et al.
(författare)
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Effekter av en havsbaserad vindkraftpark på fördelningen av bottennära fisk : En studie vid Lillgrunds vindkraftpark i Öresund
- 2012
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Den här studien baserar sig på fältundersökningar utförda vid Lillgrund vindkraftpark i Öresund och syftar till att klargöra hur anläggningen kan ha påverkat förekomsten av bottennära fisk, det vill säga fisk som lever på eller nära havsbotten. Studien är framförallt fokuserad på effekter i närområdet för enskilda vindkraftverk. Hos flera av fiskarterna noterades en högre förekomst i närområdet för vindkraftverken i jämförelse med på längre avstånd. Effekten syntes från och med det första året av drift och var av likartad omfattning under samtliga tre studerade år. En aggregation nära vindkraftverken noterades hos tånglake, ål, torsk, stensnultra och rötsimpa. Effekten noterades inte hos oxsimpa och skrubbskädda, som också var relativt vanliga i provfisket. Hos strandkrabba noterades en förändrad fördelning, som var olika mellan år. Under de två första åren noterades en lägre förekomst av strandkrabba nära vindkraftverken men under det sista året noterades en aggregation. De observerade effekterna berodde sannolikt på en omfördelning av fisk inom vindkraftparksområdet, snarare än på en ökad produktivitet eller en ansamling av fisk från ett större område. Provfisken inom denna studie och inom kontrollprogrammet för Lillgrund vindkraftpark visar sammantaget att den totala mängden fisk inte ökade i vindkraftparken inom den studerade treårsperioden, och att mängden fisk i området inte heller var högre än före anläggningen, i relation till utvecklingen i referensområden. Mängden fisk hade dock inte heller minskat. Avståndsintervallet inom vilket en ökad förekomst av fisk kunde observeras skattades till mellan 0-50 och 0-160 meter från vindkraftverket, beroende på art. Hos vissa arter sågs därtill en minskad täthet av fisk på längre avstånd från kraftverken, vilket skulle kunna återspegla att fisken attraherades därifrån till närområdet för vindkraftverket. Vindkraftverkens fundament på Lillgrund är omgivna av erosionsskydd. Dessa strukturer erbjuder en omväxlande livsmiljö där det sannolikt finns goda möjligheter för fisk att söka skydd och hitta föda. Det relativt starka samband som noterades mellan mängden fisk och avstånd till vindkraftverk för ett flertal fiskarter antyder att vindkraftverken i första hand attraherar fisk, och att eventuella negativa effekter på fiskens förekomst, orsakad till exempel av elektromagnetiska fält eller yttre ljudmiljö, sannolikt har en i sammanhanget underordnad betydelse.
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