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- Bergström, Per, 1980, et al.
(författare)
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Inventering, metodutveckling och modellering i marin miljö i Marstrandsskärgården
- 2009
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Länsstyrelsen i Västra Götalands län uppdrog år 2007 åt Institutionen för Marin ekologi att med stöd av Marbipp-verktyget dels inventera grundområdena i Marstrandsskärgården i Kungälvs kommun dels utveckla/utvärdera olika inventeringsmetoder i grunda områden. År 2008 erhölls ett tilläggsuppdrag avseende arbete med habitatmodellering med data från 2007 och från nya inventeringar genomförda år 2008 av länsstyrelsen. Inventeringen har dels utförts med småbåt och vattenkikare på sedvanligt vis, dessutom har punkter slumpats ut i området till grund för en efterföljande modellering. En ny metod med transekter och avläsning med hjälp av ekolod har också prövats. Med stöd från resultat från inventeringarna och information om bland annat vågexponering är det möjligt att klassificera olika bottenhabitat enligt det europeiska systemet för habitatklassificering EUNIS (European Nature Information System). Denna klassificering har efter modellering av substrat och vegetation i icke inventerade områden genomförts för hela undersökningsområdet. Modelleringen utfördes på två separata dataset, ett innehållande inventeringsinformation från punktlokaler (dyk, bottenhugg, droppvideo och vattenkikare) samt ett med information från inventeringar över större ytor (vattenkikare och ekolodsmätningar). Modelleringen visar på att Marstrandsområdet domineras av vegetationsfria lerbottnar (A5.3) följt av moderat exponerade infralittorala hårdbottnar (A3.2) och makrofyt dominerade sublittorala sediment. I modellen som baseras på punktlokaler dominerar mjukbottnarna helt, medan i den andra modellen är det jämnare fördelat mellan mjukbottnarna och de infralittorala hårdbottnarna.
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| 2. |
- Sterner, Thomas, 1952, et al.
(författare)
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Låt yrkesfiskarna äga fiskevattnen
- 2007
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Ingår i: Göteborgs-Posten. ; :2007-12-17
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Stål, Johan, 1974, et al.
(författare)
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Coastal habitat support to fish and fisheries in Sweden : Integrating ecosystem functions into fisheries management
- 2008
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Ingår i: Ocean and Coastal Management. - : Elsevier BV. - 0964-5691 .- 1873-524X. ; 51:09-aug, s. 594-600
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Tidskriftsartikel (refereegranskat)abstract
- This study adopts an interdisciplinary approach, where ecological data on habitat structure and fish populations are combined with results from economic valuation case studies to assess effects of habitat disturbance. The focus is on three major habitats (soft sediment bottoms, seagrass beds and rocky bottoms with macroalgae), five fish species (cod, plaice, eel, mackerel and sea trout) and three types of fisheries (commercial, subsistence and recreational fisheries). The results have important implications for coastal zone management, demonstrating both ecologically and economically how coastal habitats support fisheries.
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| 6. |
- Stål, Johan, 1974, et al.
(författare)
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Food utilisation by coastal fish assemblages in rocky and soft bottoms on the Swedish west coast: Inference for identification of essential fish habitats
- 2007
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Ingår i: Estuarine Coastal and Shelf Science. - : Elsevier BV. - 0272-7714. ; 71:3-4, s. 593-607
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Tidskriftsartikel (refereegranskat)abstract
- The concept of essential fish habitats (EFHs) is widely accepted for conservational and management purposes. EFHs are often considered as high quality habitats for fisheries species and subsequently of high values for society. In this study, fish and Substrate-Associated Prey (SAP) were sampled during the productive summer season 1998 (fish) and 2003 and 2004 (SAP) in shallow coastal rocky- and soft-bottom habitats on the Swedish west coast. The aim was to study the spatial and monthly variation of SAP as well as abundance and biomass of fish, and to examine if food items found in the diet of the fish assemblage were derived from SAP. We also examined if the diet of Ctenolabrus rupestris, a resident and abundant fish species in the shallow coastal habitats, and the diet of four seasonally abundant and commercially important fish species (Gadus morhua, Pleuronectes platessa, Salmo trutta and Scomber scombrus) were derived from SAP. There were significantly higher mean species number and abundance of the SAP assemblage on rocky compared to soft bottoms and the highest values were found on the rocky bottoms in August and in the shallowest (0-3 m) depth strata. There were no significant differences in number of fish species caught in the two habitats, although mean number of fish and mean biomass were significantly higher on rocky bottoms. Both habitats showed the same seasonal variation and the highest values of number of fish species, abundance and biomass were observed in June. On rocky bottoms, gastropods and amphipods were the most frequent food items in the diet of the entire fish assemblage and these items were also the most abundant SAP in this habitat. The dominant food items of the soft-bottom fish assemblage were decapods and fish, which were not common SAP. However, except for S. scombrus, the diet of the selected fish species showed a strong association to the SAP availability. Gadus morhua displayed the strongest association to SAP on rocky bottoms and P. platessa and C. rupestris to SAP on soft bottoms. Further, for C. rupestris, multivariate statistical analysis showed a significant association to the SAP assemblage on both rocky and soft bottoms. These results provide vital new information for the management and conservation of Essential Fish Habitats on the Swedish west coast. (c) 2006 Published by Elsevier Ltd.
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| 7. |
- Stål, Johan, 1974, et al.
(författare)
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Quantitative assessment of the area of shallow habitat for fish on the Swedish west coast
- 2007
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Ingår i: ICES Journal of Marine Science. - : Oxford University Press (OUP). - 1054-3139 .- 1095-9289. ; 64:3, s. 446-452
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Tidskriftsartikel (refereegranskat)abstract
- Stål, J., and Pihl, L. 2007. Quantitative assessment of the area of shallow habitat for fish on the Swedish west coast. – ICES Journal of Marine Science, 64: 446–452. Much effort has been focused recently on juvenile and adult fish habitat use in shallow coastal areas. However, to understand fully the importance of such habitats for fish production it is necessary also to quantify the area of existing habitat types. We inventory and quantify the area of major habitat types in a 1000 km2 area of the Swedish west coast, on a scale appropriate for coastal-zone management. An echosounder and GPS-transmitter mounted on a small boat were used to estimate the distribution of habitat along transects in seven regions of differing coastal morphology. The signal from the echosounder separated major habitat types, and recordings were verified by video documentation and visually. The information was used with GIS-software to estimate the quantitative extent of bottom habitats at depth ranges of 0–3, 3–6, and 6–10 m. Of the major habitat types, soft substrata dominated all except one region, and increased in size with depth in all regions. There were rocky substrata in all regions, but as steep rock walls in the north and more gently sloping substrata with pebbles and boulders in the south. Approximately half the rocky habitat was in the shallowest depth range. Seagrass meadows on soft substrata were mainly in the shallow protected archipelago of the central coast.
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| 10. |
- Wennhage, Håkan, 1965, et al.
(författare)
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Distribution and quality of plaice (Pleuronectes platessa) nursery grounds on the Swedish west coast
- 2007
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Ingår i: Journal of Sea Research. - : Elsevier BV. - 1385-1101. ; 57:2-3, s. 218-229
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Tidskriftsartikel (refereegranskat)abstract
- Plaice (Pleuronectes platessa) has spatially restricted nursery grounds located in shallow soft bottom areas, where the nursery areas only make up a small fraction of the species distribution range. The importance of different coastal areas for recruitment is expected to depend on the quality and size of the nursery grounds. This paper describes the geographical extension of plaice nursery grounds at a regional level along the Swedish west coast. Densities of juvenile plaice were used as the response variable of habitat quality and were compiled based on records from autumn sampling in the various regions. Different aspects of nursery ground quality were related to the density of 0-group plaice, to evaluate the contribution of different factors to the geographical pattern observed. Larval supply was found to be the most important component of nursery quality showing a close relationship with the density of juvenile plaice on a regional scale. The relative contribution of plaice recruits from Swedish nursery grounds to the Skagerrak/Kattegat stock was evaluated using historical data. Swedish nursery grounds were estimated to contribute 77% of the recruits to the adult stock in the area. (c) 2006 Elsevier B.V. All rights reserved.
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