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  • 1.
    Amir, Omar A.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Berggren, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Ndaro, Simon
    Jiddawi, Narriman
    Feeding ecology of the Indo-Pacific bottlenose dolphin (Tursiops aduncus) incidentally caught in the gillnet fisheriesoff Zanzibar, Tanzania2005Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 63, nr 3, s. 429-437Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The stomach contents of 26 Indo-Pacific bottlenose dolphins (Tursiops aduncus) incidentally caught in gillnet fisheries aroundUnguja Island (Zanzibar) between February 2000 and August 2002 were examined. The relative importance of each prey species wasassessed through indices of relative importance. In total, 1403 prey items comprising 50 species of bony fish and three species ofsquid were identified from food remains. Five species of fish, Uroconger lepturus, Synaphobranchus kaupii, Apogon apogonides,Lethrinus crocineus, Lutjanus fulvus, and three species of squid, Sepioteuthis lessoniana, Sepia latimanus and Loligo duvauceli, werethe most important prey species. Based on an index that included frequency of occurrence, percentage by number and by weight,Uroconger lepturus proved to be the most important prey species of mature dolphins whereas Apogon apogonides was the preferredprey of immature dolphins. These results indicate that Indo-Pacific bottlenose dolphins off the coast of Zanzibar forage ona relatively large number of prey species, but that only a few small- and medium-sized neritic fish and cephalopods contributesubstantially to the diet. Further, the ecology and behavior of the preferred fish prey species indicate that the dolphins forage overreef or soft bottom substrata and near the shore.

  • 2.
    Andersson, A.
    et al.
    Umeå University;Umeå Marine Science Centre.
    Brugel, S.
    Umeå University;Umeå Marine Science Centre.
    Paczkowska, J.
    Umeå University;Umeå Marine Science Centre.
    Rowe, O. F.
    Umeå University;Umeå Marine Science Centre;Univ Helsinki, Finland.
    Figueroa, D.
    Umeå University;Umeå Marine Science Centre.
    Kratzer, S.
    Stockholm University.
    Legrand, Catherine
    Linnéuniversitetet, Fakulteten för Hälso- och livsvetenskap (FHL), Institutionen för biologi och miljö (BOM).
    Influence of allochthonous dissolved organic matter on pelagic basal production in a northerly estuary2018Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 204, s. 225-235Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phytoplankton and heterotrophic bacteria are key groups at the base of aquatic food webs. In estuaries receiving riverine water with a high content of coloured allochthonous dissolved organic matter (ADOM), phytoplankton primary production may be reduced, while bacterial production is favoured. We tested this hypothesis by performing a field study in a northerly estuary receiving nutrient-poor, ADOM-rich riverine water, and analyzing results using multivariate statistics. Throughout the productive season, and especially during the spring river flush, the production and growth rate of heterotrophic bacteria were stimulated by the riverine inflow of dissolved organic carbon (DOC). In contrast, primary production and photosynthetic efficiency (i.e. phytoplankton growth rate) were negatively affected by DOC. Primary production related positively to phosphorus, which is the limiting nutrient in the area. In the upper estuary where DOC concentrations were the highest, the heterotrophic bacterial production constituted almost 100% of the basal production (sum of primary and bacterial production) during spring, while during summer the primary and bacterial production were approximately equal. Our study shows that riverine DOC had a strong negative influence on coastal phytoplankton production, likely due to light attenuation. On the other hand DOC showed a positive influence on bacterial production since it represents a supplementary food source. Thus, in boreal regions where climate change will cause increased river inflow to coastal waters, the balance between phytoplankton and bacterial production is likely to be changed, favouring bacteria. The pelagic food web structure and overall productivity will in turn be altered. (C) 2018 The Authors. Published by Elsevier Ltd.

  • 3. Andersson, A.
    et al.
    Brugel, S.
    Paczkowska, J.
    Rowe, O. F.
    Figueroa, D.
    Kratzer, Susanne
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Legrand, C.
    Influence of allochthonous dissolved organic matter on pelagic basal production in a northerly estuary2018Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 204, s. 225-235Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phytoplankton and heterotrophic bacteria are key groups at the base of aquatic food webs. In estuaries receiving riverine water with a high content of coloured allochthonous dissolved organic matter (ADOM), phytoplankton primary production may be reduced, while bacterial production is favoured. We tested this hypothesis by performing a field study in a northerly estuary receiving nutrient-poor, ADOM-rich riverine water, and analyzing results using multivariate statistics. Throughout the productive season, and especially during the spring river flush, the production and growth rate of heterotrophic bacteria were stimulated by the riverine inflow of dissolved organic carbon (DOC). In contrast, primary production and photosynthetic efficiency (i.e. phytoplankton growth rate) were negatively affected by DOC. Primary production related positively to phosphorus, which is the limiting nutrient in the area. In the upper estuary where DOC concentrations were the highest, the heterotrophic bacterial production constituted almost 100% of the basal production (sum of primary and bacterial production) during spring, while during summer the primary and bacterial production were approximately equal. Our study shows that riverine DOC had a strong negative influence on coastal phytoplankton production, likely due to light attenuation. On the other hand DOC showed a positive influence on bacterial production since it represents a supplementary food source. Thus, in boreal regions where climate change will cause increased river inflow to coastal waters, the balance between phytoplankton and bacterial production is likely to be changed, favouring bacteria. The pelagic food web structure and overall productivity will in turn be altered.

  • 4.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Brugel, Sonia
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Paczkowska, Joanna
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Rowe, Owen F.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF). Department of Food and Environmental Sciences, Division of Microbiology and Biotechnology, University of Helsinki, Helsinki, Finland.
    Figueroa, Daniela
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Kratzer, S.
    Legrand, C.
    Influence of allochthonous dissolved organic matter on pelagic basal production in a northerly estuary2018Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 204, s. 225-235Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Phytoplankton and heterotrophic bacteria are key groups at the base of aquatic food webs. In estuaries receiving riverine water with a high content of coloured allochthonous dissolved organic matter (ADOM), phytoplankton primary production may be reduced, while bacterial production is favoured. We tested this hypothesis by performing a field study in a northerly estuary receiving nutrient-poor, ADOM-rich riverine water, and analyzing results using multivariate statistics. Throughout the productive season, and especially during the spring river flush, the production and growth rate of heterotrophic bacteria were stimulated by the riverine inflow of dissolved organic carbon (DOC). In contrast, primary production and photosynthetic efficiency (i.e. phytoplankton growth rate) were negatively affected by DOC. Primary production related positively to phosphorus, which is the limiting nutrient in the area. In the upper estuary where DOC concentrations were the highest, the heterotrophic bacterial production constituted almost 100% of the basal production (sum of primary and bacterial production) during spring, while during summer the primary and bacterial production were approximately equal. Our study shows that riverine DOC had a strong negative influence on coastal phytoplankton production, likely due to light attenuation. On the other hand DOC showed a positive influence on bacterial production since it represents a supplementary food source. Thus, in boreal regions where climate change will cause increased river inflow to coastal waters, the balance between phytoplankton and bacterial production is likely to be changed, favouring bacteria. The pelagic food web structure and overall productivity will in turn be altered.

    Fulltekst (pdf)
    fulltext
  • 5. Andersson, Agneta
    et al.
    Höglander, Helena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Karlsson, Chatarina
    Huseby, Siv
    Key role of phosphorus and nitrogen in regulating cyanobacterial community composition in the northern Baltic Sea2015Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 164, s. 161-171Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite cyanobacteria being a key phytoplankton group in the Baltic Sea, the factors governing their community structure are still poorly understood. Here, we studied the occurrence of the orders Chroococcales, Oscillatoriales and Nostocales, and potentially explanatory variables at five locations in the northern Baltic Sea from June September, 1998-2012. Cyanobacteria constituted 1-36% of the total phytoplankton biomass along the north south gradient. In the Bothnian Bay, Chroococcales and Oscillatoriales dominated the cyanobacterial community, whereas in the Bothnian Sea and northern Baltic Proper, Nostocales was the dominant group. The dominance of Chroococcales was coupled to low salinity and low total phosphorus, whereas Oscillatoriales correlated with high total nitrogen and low salinity. Nostocales correlated to high total phosphorus, inorganic phosphorus and salinity. Chroococcales showed an increase over time in the offshore Bothnian Bay, whereas Nostocales increased in the coastal Bothnian Sea and coastal Baltic Proper. The increase of Nostocales in the coastal Bothnian Sea was explained by a rise in total phosphorus and decrease in dissolved inorganic nitrogen compared to an increase of total nitrogen and phosphorus in the coastal Baltic Proper. No significant trends were observed in the cyanobacterial community in the offshore Bothnian Sea and the offshore northern Baltic Proper. We concluded that Chroococcales may be a useful indicator for increased phosphorus levels in waters with low phosphorus concentrations, whereas Nostocales could be used as a quality indicator for increasing phosphorus concentrations in waters with low inorganic N/P ratios (< 20), such as in the coastal Bothnian Sea and Baltic Proper.

  • 6.
    Andersson, Agneta
    et al.
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och geovetenskap. Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Höglander, Helena
    Karlsson, Chatarina
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Huseby, Siv
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Umeå marina forskningscentrum (UMF).
    Key role of phosphorus and nitrogen in regulating cyanobacterial community composition in the northern Baltic Sea2015Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 164, s. 161-171Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Despite cyanobacteria being a key phytoplankton group in the Baltic Sea, the factors governing their community structure are still poorly understood. Here, we studied the occurrence of the orders Chroococcales, Oscillatoriales and Nostocales, and potentially explanatory variables at five locations in the northern Baltic Sea from June–September, 1998–2012. Cyanobacteria constituted 1–36% of the total phytoplankton biomass along the north–south gradient. In the Bothnian Bay, Chroococcales and Oscillatoriales dominated the cyanobacterial community, whereas in the Bothnian Sea and northern Baltic Proper, Nostocales was the dominant group. The dominance of Chroococcales was coupled to low salinity and low total phosphorus, whereas Oscillatoriales correlated with high total nitrogen and low salinity. Nostocales correlated to high total phosphorus, inorganic phosphorus and salinity. Chroococcales showed an increase over time in the offshore Bothnian Bay, whereas Nostocales increased in the coastal Bothnian Sea and coastal Baltic Proper. The increase of Nostocales in the coastal Bothnian Sea was explained by a rise in total phosphorus and decrease in dissolved inorganic nitrogen compared to an increase of total nitrogen and phosphorus in the coastal Baltic Proper. No significant trends were observed in the cyanobacterial community in the offshore Bothnian Sea and the offshore northern Baltic Proper. We concluded that Chroococcales may be a useful indicator for increased phosphorus levels in waters with low phosphorus concentrations, whereas Nostocales could be used as a quality indicator for increasing phosphorus concentrations in waters with low inorganic N/P ratios (&lt;20), such as in the coastal Bothnian Sea and Baltic Proper.

  • 7.
    Andersson, Lars
    et al.
    SMHI, Samhälle och säkerhet.
    Rahm, Lars
    SMHI, Forskningsavdelningen, Oceanografi.
    THERMALLY DRIVEN CIRCULATION WITHIN AN EXPERIMENTAL ENCLOSURE1990Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 30, nr 2, s. 111-129Artikkel i tidsskrift (Fagfellevurdert)
  • 8.
    Andersson, Lars
    et al.
    Ocean. Lab. SMHI.
    Rahm, Lars
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Thermally driven circulation within an experimental enclosure1990Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 30, s. 111-129Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

      

  • 9.
    Andersson, Lars
    et al.
    SMHI, Samhälle och säkerhet.
    RYDBERG, L
    EXCHANGE OF WATER AND NUTRIENTS BETWEEN THE SKAGERRAK AND THE KATTEGAT1993Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 36, nr 2, s. 159-181Artikkel i tidsskrift (Fagfellevurdert)
  • 10.
    Andrén, Elinor
    Stockholm University.
    Changes in the composition of the diatom flora during the last century indicate increased eutrophication of the oder estuary, south-western Baltic Sea1999Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 48, s. 665-676Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Four short sediment cores from the Oder estuary, south-western Baltic Sea, were studied with respect to their siliceous microfossil and organic carbon content. The sediments were dated by Pb-210. The objective was to detect and date changes in the composition of the diatom flora and link these changes to increased human impact in the drainage area during recent centuries. Two of the cores showed an unperturbed sedimentary sequence representing a complete historical record. A change in the composition of the diatom assemblages attributable to anthropogenic factors was recorded. This was dated to about 1900 in the Oderhaff. The change consisted of an increase in species that thrive in eutrophic waters and those indicating increased salinity or the availability of inorganic nutrients.

  • 11. Andrén, Elinor
    et al.
    Telford, Richard J.
    Jonsson, Per
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Reconstructing the history of eutrophication and quantifying total nitrogen reference conditions in Bothnian Sea coastal waters2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 198, s. 320-328Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reference total nitrogen (TN) concentrations for the Gardsfjarden estuary in the central Bothnian Sea, which receives discharge from an industrial point-source, have been estimated from diatom assemblages using a transfer function. Sedimentological and diatom evidence imply a good ecological status before 1920 with an assemblage dominated by benthic taxa indicating excellent water transparency, high diatom species richness and less organic sedimentation resulting in homogeneous well oxygenated sediments. A change in the diatom assemblage starts between 1920 and 1935 when the species richness declines and the proportion of planktic taxa increases. Increased organic carbon sedimentation after 1920 led to hypoxic bottom waters, and the preservation of laminae in the sediments. The trend in the reconstructed TN-values agrees with the history of the discharge from the mill, reaching maximum impact during the high discharge between 1945 and 1990. The background condition for TN in Gardsfjarden is 260-300 mu L-1, reconstructed until 1920.

  • 12.
    Andrén, Elinor
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Telford, Richard J.
    University of Bergen.
    Jonsson, Per
    Stockholm University.
    Reconstructing the history of eutrophication and quantifying total nitrogen reference conditions in Bothnian Sea coastal waters2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 198, s. 320-328Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Reference total nitrogen (TN) concentrations for the Gårdsfjärden estuary in the central Bothnian Sea, which receives discharge from an industrial point-source, have been estimated from diatom assemblages using a transfer function. Sedimentological and diatom evidence imply a good ecological status before 1920 with an assemblage dominated by benthic taxa indicating excellent water transparency, high diatom species richness and less organic sedimentation resulting in homogeneous well oxygenated sediments. A change in the diatom assemblage starts between 1920 and 1935 when the species richness declines and the proportion of planktic taxa increases. Increased organic carbon sedimentation after 1920 led to hypoxic bottom waters, and the preservation of laminae in the sediments. The trend in the reconstructed TN-values agrees with the history of the discharge from the mill, reaching maximum impact during the high discharge between 1945 and 1990. The background condition for TN in Gårdsfjärden is 260-300 μg L-1, reconstructed until 1920.

    Fulltekst (pdf)
    fulltext
  • 13.
    Berkström, Charlotte
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Gullström, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Lindborg, Regina
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK). Stockholms universitet, Stockholm Resilience Centre.
    Mwandya, Augustine W.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Yahya, Saleh A. S.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Kautsky, Nils
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Nyström, Magnus
    Stockholms universitet, Stockholm Resilience Centre.
    Exploring 'knowns' and 'unknowns' in tropical seascape connectivity with insights from East African coral reefs2012Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 107, s. 1-21Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Applying a broader landscape perspective to understand spatio-temporal changes in local populations and communities has been increasingly used in terrestrial systems to study effects of human impact and land use change. With today’s major declines in fishery stocks and rapid degradation of natural coastal habitats, the understanding of habitat configuration and connectivity over relevant temporal and spatial scales is critical for conservation and fisheries management of the seascape. Coral reefs, seagrass beds and mangroves are key-components of the tropical seascape. The spatial distribution of these habitat-types may have strong influences on cross-habitat migration and connectivity patterns among organisms. However, the consequences of seascape fragmentation and ecological connectivity are largely unknown. Here, we review the literature to provide an overview of current knowledge with regards to connectivity and food-web interactions within the tropical seascape. We show that information on fish acting as mobile links and being part of nutrient transfer and trophic interactions is scarce. We continue by making an in-depth analysis of the seascape around Zanzibar (Eastern Africa) to fill some of the knowledge gaps identified by the literature survey. Our analysis shows that (i) fifty percent of all fish species found within the Zanzibar seascape use two or multiple habitat-types, (ii) eighteen percent of all coral reef-associated fish species use mangrove and seagrass beds as juvenile habitat, and (iii) macrocarnivores and herbivores are highly represented among those coral reef fish species that use mangrove and seagrass beds as juvenile habitat. We argue that understanding the inter-linkages within and between habitat-types is essential for successful management of the tropical seascape.

  • 14.
    Conley, D.J.
    et al.
    DMU.
    Stockenberg, A.
    SU.
    Johnstone, R.
    University of Queensland.
    Wulff, F.
    SU.
    Rahm, Lars
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Sediment-water nutrient fluxes along a eutrophicated gradient in the Gulf of Finland, Baltic Sea1997Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 45, s. 591-598Artikkel i tidsskrift (Fagfellevurdert)
  • 15.
    Crona, Beatrice
    et al.
    Stockholm univ..
    Rönnbäck, Patrik
    Högskolan på Gotland, Institutionen för kultur, energi och miljö.
    Community structure and temporal variability of juvenile fish assemblages in natural and replanted mangroves, Sonneratia alba Sm., of Gazi Bay, Kenya2007Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 74, nr 1-2, s. 44-52Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The juvenile fish community associated with natural, degraded and replanted Sonneratia alba mangroves in Gazi Bay was sampled during the South East and North East monsoons between April 2002 and June 2003. A total of 1800 individuals belonging to 49 taxa and 34 families were collected from the intertidal forest using stake nets. Fish abundance ranged from 0.93 ± 0.20 ind. m−2 (SEM02) to 1.16 ± 0.18 ind. m−2 (SEM03) between seasons and between 0.54 ± 0.07 ind. m−2 and 1.64 ± 0.33 ind. m−2 for individual sites across seasons. Five taxa accounted for approximately 70% of the total fish abundance, with Gobidae and Gerres oyena dominating. ANOSIM revealed seasonal differences in fish species composition and abundance (p = 0.01) due to fluctuating abundances of primarily Terapon sp. and Thryssa sp. The majority (65%) of fishes were reef associates, which implies a tight coupling between mangroves and coral reefs. The high proportion (75%) of commercial species indicates that fringing S. alba mangroves of Gazi Bay are important in sustaining coastal fisheries in the area. The fact that the replanted mangroves of Gazi Bay harbor a significant number of commercially important species as juveniles suggest their function as nursery habitats for nekton may well have been restored. This study is original in quantitatively evaluating the use of replanted intertidal mangroves by juvenile fish in the West Indian Ocean; a topic poorly studied worldwide to date.

  • 16.
    Crona, Beatrice
    et al.
    Dept. systems ecology, Stockholm univ..
    Rönnbäck, Patrik
    Högskolan på Gotland, Institutionen för kultur, energi och miljö.
    Use of replanted mangroves as nursery grounds by shrimp communities in Gazi Bay, Kenya2005Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 65, nr 3, s. 535-544Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study quantitatively assessed the distribution of postlarval and juvenile shrimps in natural, degraded and replanted stands of Sonneratia alba mangroves in Gazi Bay, Kenya in 2002–2003. Two plantations (matrix and integrated) differing in historical status and planting strategy were studied. Sampling was conducted using stake nets (2 mm mesh), each net enclosing 9 m2 of intertidal microhabitat. A total of 615 shrimps from 19 species/taxa were caught, including several penaeid species of major commercial importance. Penaeids dominated the catch (66%) followed by Macrobrachium spp. (16%) and Acetes sp. (6%). Shrimp abundance ranged from 0.42 to 10.0 ind. per net (9 m2) for individual sites across spring tides and significant differences were detected between sites and over time (p<0.001). Results showed no significant difference in diversity of species/taxa between sites. However, multivariate analysis revealed significant differences in community assemblages between sites, except for the natural stand and integrated plantation. These two sites harbored higher abundances of the majority of all taxa caught. The observed distribution patterns are discussed with regard to measured environmental parameters such as elevation, structural complexity and sediment characteristics.

  • 17.
    Danielsson, Åsa
    et al.
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Carman, R.
    SU.
    Rahm, Lars
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Aigars, J.
    SU.
    Spatial estimation of nutrient distributions in the Gulf of Riga sediments using cokriging.1998Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 46, s. 713-722Artikkel i tidsskrift (Fagfellevurdert)
  • 18. Das, Saudamini
    et al.
    Crépin, Anne-Sophie
    Stockholms universitet, Naturvetenskapliga fakulteten, Stockholm Resilience Centre. The Beijer Institute of Ecological Economics, Sweden.
    Mangroves can provide protection against wind damage during storms2013Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 134, s. 98-107Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Research has established that mangroves can protect lives and property from storms by buffering the impacts of storm surges. However, their effects in attenuating wind velocity and providing protection from wind damage during storms are not known. This study examined whether mangroves attenuate damage from cyclonic winds and found that they provide substantial protection to properties, even relatively far away from mangroves and the coast. We devised a theoretical model of wind protection by mangroves and calibrated and applied this model using data from the 1999 cyclone in the Odisha region of India. The model predicted and quantified the actual level of damage reasonably accurately and showed that mangroves reduced wind damage to houses. The wind protection value of mangroves in reducing house damage amounted to approximately US$177 per hectare at 1999 prices. This provides additional evidence of the storm protection ecosystem services that mangroves supply in the region and an additional reason to invest in mangrove ecosystems to provide better adaptability to coastal disasters such as storms.

  • 19.
    Eggertsen, Linda
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Federal University of Rio de Janeiro, Brazil; Federal University Fluminense, Brazil.
    Ferreira, Carlos E. L.
    Fontoura, Luisa
    Kautsky, Nils
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Gullström, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Berkström, Charlotte
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik. Swedish University of Agricultural Sciences, Sweden.
    Seaweed beds support more juvenile reef fish than seagrass beds in a south-western Atlantic tropical seascape2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 196, nr 5, s. 97-108Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Seascape connectivity is regarded essential for healthy reef fish communities in tropical shallow systems. A number of reef fish species use separate adult and nursery habitats, and hence contribute to nutrient and energy transfer between habitats. Seagrass beds and mangroves often constitute important nursery habitats, with high structural complexity and protection from predation. Here, we investigated if reef fish assemblages in the tropical south-western Atlantic demonstrate ontogenetic habitat connectivity and identify possible nurseries on three reef systems along the eastern Brazilian coast. Fish were surveyed in fore reef, back reef, Halodule wrightii seagrass beds and seaweed beds. Seagrass beds contained lower abundances and species richness of fish than expected, while Sargassum-dominated seaweed beds contained significantly more juveniles than all other habitats (average juvenile fish densities: 32.6 per 40 m2 in Sargassum beds, 11.2 per 40 m2 in back reef, 10.1 per 40 m2 in fore reef, and 5.04 per 40 m2 in seagrass beds), including several species that are found in the reef habitats as adults. Species that in other regions worldwide (e.g. the Caribbean) utilise seagrass beds as nursery habitats were here instead observed in Sargassum beds or back reef habitats. Coral cover was not correlated to adult fish distribution patterns; instead, type of turf was an important variable. Connectivity, and thus pathways of nutrient transfer, seems to function differently in east Brazil compared to many tropical regions. Sargassum-dominated beds might be more important as nurseries for a larger number of fish species than seagrass beds. Due to the low abundance of structurally complex seagrass beds we suggest that seaweed beds might influence adult reef fish abundances, being essential for several keystone species of reef fish in the tropical south-western Atlantic.

    Fulltekst (pdf)
    fulltext
  • 20. Eklund, B.
    et al.
    Svensson, A. P.
    Jonsson, C.
    Malm, T.
    Toxic effects of decomposing red algae on littoral organisms2005Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 62, nr 4, s. 621-626Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Large masses of filamentous red algae of the genera Polysiphonia, Rhodomela, and Ceramium are regularly washed up on beaches of the central Baltic Sea. As the algal masses start to decay, red coloured effluents leak into the water, and this tinge may be traced several hundred meters off shore. In this study, possible toxic effects of these effluents were tested on littoral organisms from different trophic levels. Effects on fertilisation, germination and juvenile survival of the brown seaweed Fucus vesiculosus were investigated, and mortality tests were performed on the crustaceans Artemia salina and Idotea baltica, as well as on larvae and adults of the fish Pomatoschistus microps. Fucus vesiculosus was the most sensitive species of the tested organisms to the red algal extract. The survival of F. vesiculosus recruits was reduced with 50% (LC50) when exposed to a concentration corresponding to 1.7 g l(-1) dw red algae. The lethal concentration for L baltica, A. salina and P. microps were approximately ten times higher. The toxicity to A. salina was reduced if the algal extract was left to decompose during two weeks but the decline in toxicity was not affected by different light or temperature conditions. This study indicates that the filamentous red algae in the central Baltic Sea may produce and release compounds with negative effects on the littoral ecosystem. The effects may be particularly serious for the key species F. vesiculosus, which reproduce in autumn when filamentous red algal blooms are most severe. (C) 2004 Elsevier Ltd. All rights reserved.

  • 21.
    Eklund, Britta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Review of the use of Ceramium tenuicorne growth inhibition test for testing toxicity of substances, effluents, products sediment and soil2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 195, s. 88-97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A growth inhibition test has been developed based on two clones of the red macroalga Ceramium tenuicorne, one originating from 7 PSU and the other from 20 PSU. The species can be adapted to different salinities and the test can be carried out between 4 and 32 PSU. This test became an ISO standard in 2010 (ISO 107 10) for testing of chemicals and water effluents. In this study new and published data has been compiled on toxicity of single substances, waste waters from pulp mills, leachates from antifouling paints, harbour sediments and soil used for maintenance of leisure boats. The results show that the alga is sensitive to both metals and organic compounds and to biocides used in antifouling paints. By testing leachates from antifouling paints these could be ranked according to their toxicity. Similarly, the toxicity of waste waters from pulp mills was determined and the efficiency of secondary treatment evaluated. Further, the test method proved useful to test the toxicity in sediment samples. Sediments from small town harbours and ship lanes were shown to be harmful and compounds originating from antifouling paints were responsible for a large part of the inhibiting effect. The alga proved to be sensitive to contaminants leaking from boat yard soil. The growth inhibition test is a robust test that has high repeatability and reproducibility and easily can be applied on water, soil and sediment samples without being too costly. The species is found wort-wide in temperate waters, which makes the results relevant for large areas. In the Baltic Sea C tenuicorne is the most common red alga species and is thus particularly relevant for this area. The overall results show that contaminants from boat activities and the use of antifouling paints in particular pose a threat to the environment.

  • 22.
    Eklöf, J.S.
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    de la Torre-Castro, M.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen. Stockholms universitet, Stockholm Resilience Centre.
    Gullström, Martin
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Uku, J.
    Muthiga, N.
    Lyimo, T.
    Bandeira, S.O.
    Sea urchin overgrazing of seagrasses: A review of current knowledge on causes, consequences and management2008Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 79, nr 4, s. 569-580Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Sea urchins are one of the most common seagrass macro-grazers in contemporary seagrass systems. Occasionally their grazing rates exceed seagrass growth rates, a phenomenon sometimes referred to as overgrazing. Because of a reported increasing frequency of overgrazing events, concomitant with loss of seagrass-associated ecosystem services, it has been suggested that overgrazing is one of the key threats to tropical and subtropical seagrasses. In light of this, we review the current knowledge on causes, consequences. and management of sea urchin overgrazing of seagrasses. Initially we argue that the definition of overgrazing must include scale and impairment of ecosystem services, since this is the de facto definition used in the literature, and will highlight the potential societal costs of seagrass overgrazing. A review of 16 identified cases suggests that urchin overgrazing is a global phenomenon, ranging from temperate to tropical coastal waters and involving at least 11 seagrass and 7 urchin species. Even though most overgrazing events Seem to affect areas of <0.5 km(2), and recovery often occurs within a few years, overgrazing can have a range of large, long-term indirect effects such as loss of associated fauna and decreased sediment stabilization. A range of drivers behind overgrazing have been suggested, including bottom-up (nutrient enrichment). top-down (reduced predation control due to e.g. overfishing), "side-in" mechanisms (e.g. changes in water temperature) and natural population fluctuations. Based on recent studies, there seems to be fairly strong support for the top-down and bottom-up hypotheses. However, many potential drivers often co-occur and interact, especially in areas with high anthropogenic pressure, suggesting that multiple disturbances-by simultaneously reducing predation control, increasing urchin recruitment and reducing the resistance of seagrasses-could pave the way for overgrazing. In management, the most common response to overgrazing has been to remove urchins, but limited knowledge of direct and indirect effects makes it difficult to assess the applicability and sustainability of this method. Based on the wide knowledge gaps, which severely limits management, we suggest that future research should focus on (1) identification and quantification of ecosystem and societal scale effects of overgrazing; (2) assessment of the relative importance and interactions of different drivers; and (3) development of a holistic proactive and reactive long-term management agenda.

  • 23. Engel, Friederike G.
    et al.
    Alegria, Javier
    Andriana, Rosyta
    Donadi, Serena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Gusmao, Joao B.
    van Leeuwe, Maria A.
    Matthiessen, Birte
    Eriksson, Britas Klemens
    Mussel beds are biological power stations on intertidal flats2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 191, s. 21-27Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Intertidal flats are highly productive areas that support large numbers of invertebrates, fish, and birds. Benthic diatoms are essential for the function of tidal flats. They fuel the benthic food web by forming a thin photosynthesizing compartment in the top-layer of the sediment that stretches over the vast sediment flats during low tide. However, the abundance and function of the diatom film is not homogenously distributed. Recently, we have realized the importance of bivalve reefs for structuring intertidal ecosystems; by creating structures on the intertidal flats they provide habitat, reduce hydrodynamic stress and modify the surrounding sediment conditions, which promote the abundance of associated organisms. Accordingly, field studies show that high chlorophyll a concentration in the sediment co-vary with the presence of mussel beds. Here we present conclusive evidence by a manipulative experiment that mussels increase the local biomass of benthic microalgae; and relate this to increasing biomass of microalgae as well as productivity of the biofilm across a nearby mussel bed. Our results show that the ecosystem engineering properties of mussel beds transform them into hot spots for primary production on tidal flats, highlighting the importance of biological control of sedimentary systems.

  • 24. Engqvist, Anders
    et al.
    Stenström, Petter
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Mark- och vattenteknik.
    Flow regimes and long-term water exchange of the Himmerfjarden estuary2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 83, nr 2, s. 159-174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A numerical model of processes determining the water exchange encountered in Baltic coastal archipelagos is calibrated and validated against salinity and temperature field data spanning two decades with approximately bi-weekly resolution assessed in the Himmerfjärden estuary. This area is resolved into 17 basins interconnected by 38 individual straits of varying geometrical properties using GIS-based methods. All formulations of the strait exchange flows are free from parameters that need calibration and permit computations of the flow through a strait contraction with or without a coincident sill under a flow classification scheme, of which the first one (a) consists of two groups of multiple layers including aspirated layers from levels beneath the sill crest. The other regimes are as follows. (b) Pure barotropic flow; (c) rotationally controlled flow and (d) plug-flow, which serves as resort solution for flow situations that cannot be solved with (a) and also for computation of the barotropic part of the total flow. For long canals where friction effects act to reduce the flow, a fifth exchange regime is used. The vertical mixing formulation is based on energy balances between supplied wind energy and its work against buoyancy forces. The values of semi-empirical parameters involved in the mixing scheme have been established by calibration against measured data of the first decade period. A statistical evaluation is performed comparing the model results with the measurements of the second decade. It is found that the accuracy of the model is yet limited by the poor temporal resolution in the boundary and the thermal forcing. The overall accuracy of this approach is found to be comparable to earlier model studies in the same area. Since the exchange flows are now based on first principles and are applied to four times more basins, it seems that this more articulated model approach can confidently be applied to more complex archipelago areas.

  • 25.
    Engqvist, Anders
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Stenström, Petter
    Royal Inst Technol, Dept Land & Water Resources Engn.
    Flow regimes and long-term water exchange of the Himmerfjärden estuary.2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 83, nr 2, s. 159-174Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A numerical model of processes determining the water exchange encountered in Baltic coastal archipelagos is calibrated and validated against salinity and temperature field data spanning two decades with approximately bi-weekly resolution assessed in the Himmerfjarden estuary. This area is resolved into 17 basins interconnected by 38 individual straits of varying geometrical properties using GIS-based methods. All formulations of the strait exchange flows are free from parameters that need calibration and permit computations of the flow through a strait contraction with or without a coincident sill under a flow classification scheme, of which the first one (a) consists of two groups of multiple layers including aspirated layers from levels beneath the sill crest. The other regimes are as follows. (b) Pure barotropic flow; (c) rotationally controlled flow and (d) plug-flow, which serves as resort solution for flow situations that cannot be solved with (a) and also for computation of the barotropic part of the total flow. For long canals where friction effects act to reduce the flow, a fifth exchange regime is used. The vertical mixing formulation is based on energy balances between supplied wind energy and its work against buoyancy forces. The values of semi-empirical parameters involved in the mixing scheme have been established by calibration against measured data of the first decade period. A statistical evaluation is performed comparing the model results with the measurements of the second decade.It is found that the accuracy of the model is yet limited by the poor temporal resolution in the boundary and the thermal forcing. The overall accuracy of this approach is found to be comparable to earlier model studies in the same area. Since the exchange flows are now based on first principles and are applied to four times more basins, it seems that this more articulated model approach can confidently be applied to more complex archipelago areas.

  • 26.
    Eriksson, Britas Klemens
    et al.
    Department of Plant Ecology, Uppsala University, Uppsala, Sweden.
    Bergström, Lena
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Ekologi och geovetenskap.
    Local distribution patterns of macroalgae in relation to environmental variables in the northern Baltic Proper2005Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 62, nr 1-2, s. 109-117Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The relationship between macroalgal assemblages and abiotic factors was quantified by gradient analyses in an area where long-term changes in macroalgal depth distributions have previously been documented. Biomass data from 4, 6, 8 and 10 m depth in an area of similar salinity (5) and substrate (rock) in the northern Baltic Proper was constrained by a set of environmental variables defining different aspects of abiotic control of species distributions (sediment cover, effective fetch, clarity index, the curvature and slope of the bottom, and direction of exposure) in multivariate analyses at different scales. Fucus vesiculosus dominated the biomass at 4, 6 and 8 m depth, andFurcellaria lumbricalis at 10 m. The applied models explained 30.7–53.3% of the total variance in community structure, and 49.3–60.9% when analysed separately for each depth. A separate analysis of species depth distributions demonstrated that effective fetch was most strongly related to upper limits of the algal belts, sediment cover to the lower limit and density of the F. vesiculosusbelt, and clarity index to the lower limits of F. vesiculosus, perennial red algae, and of the red algal and Sphacelaria spp. belts. The results show a strong correlation between environmental variables and vegetation structure even on a small, local scale in the northern Baltic Proper, indicating a high suitability of the phytobenthic zone for environmental monitoring. The results add to previous studies that show a strong importance of abiotic factors on large-scale variation in phytobentic community composition in the Baltic Sea.

  • 27. Eriksson, P.G.
    et al.
    Svensson, J.M.
    Högskolan i Halmstad, Sektionen för ekonomi och teknik (SET), Bio- och miljösystemforskning (BLESS), Våtmarkscentrum.
    Carrer, M.
    Dipto. Proc. Chimici dell'Ingegneria, Université di Padova, Padua, Italy.
    Temporal changes and spatial variation of soil oxygen consumption, nitrification and denitrification rates in a tidal salt marsh of the Lagoon of Venice, Italy2003Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 58, nr 4, s. 861-871Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The aim of the present study was to investigate seasonal and spatial patterns of soil oxygen consumption, nitrification, denitrification and fluxes of dissolved inorganic nitrogen (DIN) in a tidal salt marsh of the Lagoon of Venice, Italy. In the salt marsh, intact soil cores including overlying water were collected monthly at high tide from April to October in salt marsh creeks and in areas covered by the dominant vegetation, Limonium serotinum. In May, cores were also collected in areas with vegetation dominated by Juncus maritimus and Halimione portulacoides. In laboratory incubations at in situ temperature in the dark, flux rates of oxygen and DIN were monitored in the overlying water of the intact cores. 15N-nitrate was added to the overlying water and nitrification and denitrification were measured using isotope-dilution and -pairing techniques. The results show that highest soil oxygen consumption coincided with the highest water temperature in June and July. The highest denitrification rates were recorded in spring and autumn coinciding with the highest nitrate concentrations. Soil oxygen consumption and nitrification rates differed between sampling sites, but denitrification rates were similar among the different vegetation types. The highest rates were recorded in areas covered with L. serotinum. Burrowing soil macrofauna enhanced oxygen consumption, nitrification and denitrification in April and May. The data presented in this study indicate high temporal as well as spatial variations in the flux of oxygen and DIN, and nitrogen transformations in the tidal salt marshes of the Venice lagoon during the growth season. The results identify the salt marshes of the Venice lagoon as being metabolically very active ecosystems with a high capacity to process nitrogen.

  • 28.
    Eriksson Wiklund, Ann-Kristin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Andersson, A.
    Benthic competition and population dynamics of Monoporeia affinis and Marenzelleria sp in the northern Baltic Sea2014Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 144, s. 46-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    During the last two decades major changes of the benthic fauna have occurred in the northern Baltic Sea, the Gulf of Bothnia. The native amphipod, Monoporeia affinis, has shown a large-scale abundance decrease, while polychaetes, Marenzelleria spp. have invaded the system. Marenzelleria co-exist with the native fauna in the southern Baltic Sea, but in the north the pelagic production might be too low to allow co-existence. Thus, M. affinis might have been out-competed by Marenzelleria in the Gulf of Bothnia. This hypothesis was tested in a competition experiment with a high and a low fresh phytoplankton food supply. When exposed to high food supply both species showed stable or increased biomass over the four week test period. In low food supply, however, M. affinis was found to have a competitive advantage. The experimental data were also related to Baltic Sea monitoring data on primary production, sedimentation and invertebrate abundances. Data from the northern Baltic Sea show that the dominance in the benthic community by M. affinis was replaced by Marenzelleria around 2001. The amphipod decrease might be explained by a marked decrease in primary production during this period. Combining monitoring and experimental data suggests that the invasion of Marenzelleria did not cause the decrease of M. affinis in the northern Baltic Sea; it rather took advantage of the density gap that had occurred. A shift may thus have been established in the Bothnian Sea benthic community.

  • 29.
    Eriksson Wiklund, Ann-Kristin
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Vilhelmsson, S.
    Stockholms universitet.
    Wiklund, Stig Johan
    Stockholms universitet.
    Eklund, Britta
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för tillämpad miljövetenskap (ITM).
    Contaminants and habitat choice in the Baltic Sea: Behavioural experiments with the native species, Monoporeia affinis, and the invasive genus, Marenzelleria2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 81, s. 238-246Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The invasive polychaete genus, Marenzelleria and the native amphipod, Monoporeia affinis are food and habitat competitors in the Baltic Sea. Previous studies have shown that moderate densities of Marenzelleria can affect the behaviour of M. affinis. To examine the short-term interactive effects of interspecific habitat choice and environmental contaminants a series of habitat colonisation experiments were performed. The contaminants examined included harbor sediments and sediment spiked with the antifouling substances, Cu, Zn and Irgarol. Polychaetes and amphipods were exposed to contaminants in single-species and two-species experiments. In spiked-sediment experiments, M. affinis showed clear dose-dependent response. These experiments verified that behavioural response of M. affinis to different habitats is a sensitive method for testing toxicity under controlled conditions. In experiments with three different harbor sediments and reference sediment both species showed the lowest preference for the reference sediment. This sediment also had the lowest content of quality food, indicating that factors such as food quality and quantity may override the disturbing effects of contaminants in natural sediments. The presence of Marenzelleria spp. did not affect amphipod habitat choice, indicating no short-term effects, which implies that both species can co-exist provided sufficient food is available.

  • 30. Erlandsson, Johan
    et al.
    McQuaid, Christopher D.
    Stanczak, Sara
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Recruit/algal interaction prevents recovery of overexploited mussel beds: Indirect evidence that post-settlement mortality structures mussel populations2011Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 92, nr 1, s. 132-139Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The mechanisms maintaining community structure following an ecosystem shift are poorly understood and we propose that they must inherently be biological. Over-exploitation can provide a natural experiment with man as a predator driving a change in community structure, possibly an ecosystem shift. We examined a possible mechanism that maintains algal beds as an alternative state on the east coast of South Africa where the mussel Perna perna has been overexploited. Even on unexploited shores, about 50% of mussel larvae settle onto algae, but it is unclear whether they later recruit into adult beds. On such shores we used two indirect field approaches to understand the fate of recruits, testing whether inhibition of mussel recruitment by macroalgae could constitute a biological mechanism preventing reversion from the algal to the pre-disturbance mussel-dominated state. First, we examined possible ontogenetic migration of recruits from algae to adult mussels, testing the prediction that the ratio large:small recruits in adult beds is greater where algae are liberally interspersed with mussels. Second, we examined whether, like adults, recruits show spatial structure that is related to the distribution of topographic depressions, testing the hypothesis that large and small recruits show different co-variation with depressions, microhabitats where algae commonly occur. We found no evidence that recruits on algae actively move to nearby mussel beds as neither the ratio large:small recruits nor the abundances of small or large recruits showed any relationship with algal cover/variability. Small and large recruits showed different co-variation with topographic depressions on spatially structured transects. Like adults, large recruits commonly exhibited negative relationships with depressions. Thus, large recruits neither occur on algae nor migrate from algae to the primary substratum or onto adult beds. Consequently our results (a) highlight the importance of post-settlement mortality in structuring these mussel populations, and (b) suggest that the interception of larvae by algae forms a biological mechanism that can maintain macroalgal beds that develop following exploitative disturbance by man, thus preventing or at least drastically delaying the natural recovery of mussel beds.

  • 31.
    Faxneld, Suzanne
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Jörgensen, Tove L.
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Tedengren, Michael
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Effects of elevated water temperature, reduced salinity and nutrient enrichment on the metabolism of the coral Turbinaria mesenterina2010Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 88, nr 4, s. 482-487Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Water quality is declining in many coastal areas, which has caused coral degradation worldwide. In addition, reduced water quality may aggravate the impacts of seawater temperature. In this study the effects of increased temperature (31 degrees C), nitrate enrichment (+5 mu M NO3-), low salinity (20) and combinations of these stressors were investigated compared to ambient water (25 degrees C, 30, 0.3 mu M NO3-) on the metabolism and survival of the coral Turbinaria mesenterina from the Tonkin Gulf, Vietnam. The results showed that all specimens exposed to a combination of all three stressors (i.e. high temperature + high nitrate + low salinity) died after 24 h exposure, while those that had been exposed to high nitrate + low salinity at ambient temperature did not show any effects on the metabolism or survival. Furthermore, corals exposed to low salinity + high temperature displayed a decrease in gross primary production/respiration (GP/R) ratio and the mortality rate was 50%. In addition, all corals exposed to increased temperature, alone or in combination with another stressor, displayed a GP/R-24h ratio below 1.0, suggesting that they depend on stored energy to cover their metabolic requirements. The results showed that corals may tolerate short-term exposure to stressors such as low salinity + high nitrate concentration in ambient temperature, while additional increased temperature lead to rapid mortality, hence suggesting a synergistic effect. Thus, the effect of climate change might be more severe in nearshore coastal areas where corals already are exposed to several disturbances.

  • 32. Ferreira, Joao G.
    et al.
    Andersen, Jesper H.
    Borja, Angel
    Bricker, Suzanne B.
    Camp, Jordi
    da Silva, Margarida Cardoso
    Garces, Esther
    Heiskanen, Anna-Stiina
    Humborg, Christoph
    Stockholms universitet, Stockholm Resilience Centre, Baltic Nest Institute.
    Ignatiades, Lydia
    Lancelot, Christiane
    Menesguen, Alain
    Tett, Paul
    Hoepffner, Nicolas
    Claussen, Ulrich
    Overview of eutrophication indicators to assess environmental status within the European Marine Strategy Framework Directive2011Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 93, nr 2, s. 117-131Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In 2009, following approval of the European Marine Strategy Framework Directive (MSFD, 2008/56/EC), the European Commission (EC) created task groups to develop guidance for eleven quality descriptors that form the basis for evaluating ecosystem function. The objective was to provide European countries with practical guidelines for implementing the MSFD, and to produce a Commission Decision that encapsulated key points of the work in a legal framework. This paper presents a review of work carried out by the eutrophication task group, and reports our main findings to the scientific community. On the basis of an operational, management-oriented definition, we discuss the main methodologies that could be used for coastal and marine eutrophication assessment. Emphasis is placed on integrated approaches that account for physico-chemical and biological components, and combine both pelagic and benthic symptoms of eutrophication, in keeping with the holistic nature of the MSFD. We highlight general features that any marine eutrophication model should possess, rather than making specific recommendations. European seas range from highly eutrophic systems such as the Baltic to nutrient-poor environments such as the Aegean Sea. From a physical perspective, marine waters range from high energy environments of the north east Atlantic to the permanent vertical stratification of the Black Sea. This review aimed to encapsulate that variability, recognizing that meaningful guidance should be flexible enough to accommodate the widely differing characteristics of European seas, and that this information is potentially relevant in marine ecosystems worldwide. Given the spatial extent of the MSFD, innovative approaches are required to allow meaningful monitoring and assessment. Consequently, substantial logistic and financial challenges will drive research in areas such as remote sensing of harmful algal blooms, in situ sensor development, and mathematical models. Our review takes into account related legislation, and in particular the EU Water Framework Directive (WFD - 2000/60/EC), which deals with river basins, including estuaries and a narrow coastal strip, in order to examine these issues within the framework of integrated coastal zone management.

  • 33. Florin, Ann-Britt
    et al.
    Lavados, Gaston
    Stockholms universitet, Naturvetenskapliga fakulteten, Systemekologiska institutionen.
    Feeding habits of juvenile flatfish in relation to habitat characteristics in the Baltic Sea2010Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 86, nr 4, s. 607-612Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    To investigate feeding habits of juvenile flounder (Platichthys flesus) and turbot (Psetta maxima) in relation to habitat characteristics a field survey with push net sampling was conducted in nursery areas with different ecological characteristics in the northern Baltic proper. Sampling sites were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from flatfishes and epifauna, samples of macrofauna, meiofauna and hyperbenthic planktons were collected from each site together with data on vegetation, depth, salinity, temperature and turbidity. The diet differed between species where flounder diet was dominated by chironomids, copepods and oligochaetes while turbot apart from chironomids had a high incidence of amphipods, gobies and mysids. In both species there was a shift in diet with size, although this shift was influenced by the habitat. Among the environmental variables investigated, wave exposure was found to significantly influence flounder diet. Food preference in the most exposed areas was dominated by oligochaetes and copepods instead of chironomids, which dominated in sheltered areas. This study shows that habitat characteristics can have a major influence on feeding habits of juvenile flatfish.

  • 34. Florin, Ann-Britt
    et al.
    Sundblad, Göran
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Limnologi.
    Bergström, Ulf
    Characterisation of juvenile flatfish habitats in the Baltic Sea2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 82, nr 2, s. 294-300Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Survival and growth of the earliest life-stages is considered a key factor in determining the abundance of many marine fish species. For flatfishes, the availability of high quality nursery areas is essential for successful recruitment. Regarding the Baltic Sea, there are large gaps in knowledge on factors that influence the distribution of flatfishes during this sensitive stage. To identify the characteristics of important nursery areas in the Baltic for flounder (Platichthys flesus) and turbot (Psetta maxima), a field survey with push net sampling was conducted in the northern Baltic proper during autumn 2006. The sampling stations were stratified to cover several different habitat types defined by substrate and wave exposure. Apart from density of young-of-the-year (YOY) flatfishes, a number of ecological characteristics of the habitat were recorded. Physical habitat variables included substrate type, salinity, depth, turbidity, vegetation and habitat structure. Variables describing biotic processes, such as prey availability and abundance of competitors, were also sampled. The relationships between the spatial distribution of species and these ecological characteristics were fitted to presence/absence data of juvenile flatfish using generalized additive models (GAM). The best habitat descriptors for flounder in order of contribution were: substrate, habitat structure, salinity, wave exposure and occurrence of filamentous algae. Positive effects of increasing wave exposure, salinity and structure were detected while a high cover of filamentous algae had a negative effect. Sand and gravel were preferred over soft and stony substrates. For turbot the best habitat descriptors in order of contribution were: occurrence of filamentous algae, substrate and turbidity. Turbot showed a preference for areas with a low cover of filamentous algae, high turbidity and sandy substrate. Prey availability and abundance of competitors were not included in the models, indicating that the distribution of flatfishes at the scales studied (tens of kilometres) is mainly governed by physical habitat properties. These results constitute the basis for future efforts on mapping of essential flatfish habitats in the Baltic Sea.

  • 35. Gastgifvars, Maria
    et al.
    Lauri, Hannu
    Sarkanen, Annakaisa
    Myrberg, Kai
    Andrejev, Oleg
    Ambjörn, Cecilia
    SMHI, Affärsverksamhet.
    Modelling surface drifting of buoys during a rapidly-moving weather front in the Gulf of Finland, Baltic Sea2006Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 70, nr 4, s. 567-576Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Gulf of Finland is an elongated estuary located in the north-eastern extremity of the Baltic Sea. This semi-enclosed sea-area is subject to heavy sea traffic, and is one of the main risk areas for oil accidents in the Baltic. The continuous development and validation of operational particle drift and oil-spill forecasting systems is thus seen to be essential for this sea-area. Here, the results of a three-day drift experiment in May 2003 are discussed. The field studies were performed using GPS-positioned surface floating buoys. The aim of this paper is to evaluate how well models can reproduce the drift of these buoys. Model simulations, both in forecast and hindcast modes. were carried out by three different 3D hydrodynamic models, the results of which are evaluated by comparing the calculated drifts with observations. These models were forced by HIRLAM (High Resolution Limited Area Model) and ECMWF (European Centre for Medium-Range Weather Forecasts) meteorological forecast fields. The simulated drift of the buoys showed a good agreement with observations even when, during the study period, a rapidly-changing wind situation was observed to affect the investigation area; in this situation the winds turned about 100 degrees in half an hour. In such a case it is a very complicated task to forecast the drifters' routes: there is a need to regularly update the meteorological forcing fields and to use these regularly-updated fields throughout the simulations. It is furthermore recommended that forecasts should be made using several circulation models and several meteorological forecasts, in order to get an overview of the accuracy of the forecasted drifts and related differences in between the forecasts. (c) 2006 Elsevier Ltd. All rights reserved.

  • 36.
    Gidhagen, Lars
    SMHI, Forskningsavdelningen, Luftmiljö.
    COASTAL UPWELLING IN THE BALTIC SEA - SATELLITE AND INSITU MEASUREMENTS OF SEA-SURFACE TEMPERATURES INDICATING COASTAL UPWELLING1987Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 24, nr 4, s. 449-462Artikkel i tidsskrift (Fagfellevurdert)
  • 37.
    Granéli, Edna
    Plankton Ecology Research Group, Department of Marine Ecology, P.O. Box 124, S-221 00, Lund, Sweden.
    Nutrient limitation of phytoplankton biomass in a brackish water bay highly influenced by river discharge1987Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 25, nr 5, s. 555-565Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Laboratory nutrient enrichment experiments (n=30) with the indigenous phytoplankton community from the brackish (mean salinity 16‰) Laholm Bay, south-east Kattegat, were performed during the period August 1981 to August 1983. The results show that nitrogen is the most limiting nutrient for potential phytoplankton biomass formation, despite a high input of inorganic nitrogen to the bay from rivers draining heavily fertilized agricultural areas. Phosphorus, silica, trace metal or chelator (EDTA) additions to Laholm Bay phytoplankton had no significant effect on biomass yield. 

  • 38. Griniene, Evelina
    et al.
    Lesutiene, Jurate
    Gorokhova, Elena
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för miljövetenskap och analytisk kemi.
    Zemlys, Petras
    Gasiunaite, Zita R.
    Lack of ciliate community integrity in transitional waters: A case study from the Baltic Sea2019Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 226, artikkel-id UNSP 106259Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Baltic Sea, one of the world's largest brackish water environments, is particularly suitable for studies aiming to understand biodiversity in saltwater-freshwater mixing zones, i.e., transitional waters at different spatial and temporal scales. To evaluate diversity fluctuations in the pelagic microbial communities experiencing frequent brackish water intrusions, we analyzed seasonal dynamics of ciliates inhabiting transitional waters of the Curonian Lagoon. During the intrusion periods, the community presented a mixture of fresh- and brackish taxa, with no specific autochthonous component unique to the transitional waters. In the plume area, outside of the lagoon, we found that (i) high biodiversity was due to mixing of two distinct assemblages, and (ii) freshwater taxa are rather resistant to salinity change, their abundance decreases almost linearly with the increasing salinity, following conservative mixing model. Small unidentified Lohmanniella occurring exclusively in the plume zone during our survey possibly presents an autochthonous component based on locally available resource. Also mixed assemblage of the plume is characterised by absence of large predatory ciliate species.

  • 39. Gullström, Martin
    et al.
    Lundén, Bengt
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för naturgeografi och kvartärgeologi (INK).
    Bodin, Maria
    Kangwe, Juma W.
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Öhman, Marcus C.
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Mtolera, Matern S. P.
    Björk, Mats
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Assessment of vegetation changes in seagrass communities of tropical Chwaka Bay (Zanzibar) using satellite remote sensing2006Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 67, nr 3, s. 399-408Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Spatial and temporal dynamics of submerged aquatic vegetation (SAV) cover were studied in the relatively pristine and seagrass-dominated area of Chwaka Bay, Zanzibar (Tanzania) by using satellite remote sensing. Through complementary field work the potential of the technique for change detection was verified. The general changes in SAV cover were examined using Landsat images from 1986, 1987, 1998, 2001 and 2003. Two of these images, from 1987 (Landsat TM) and 2003 (Landsat ETM+), were specifically analysed to create a map of the change in SAV cover. Overall, the general distribution of SAV stayed fairly stable over the period investigated, but the result also showed regions where significant alterations, both losses and gains, had occurred between the two years. Based on our findings and anecdotal information from local fishermen and seaweed farmers potential causative factors are discussed. It was concluded that a repeated mapping with satellite remote sensing is a suitable tool to monitor changes of seagrass and seaweed distribution in shallow tropical environments.

  • 40.
    Hansen, Joakim
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Wikström, Sofia
    Kautsky, Lena
    Stockholms universitet, Naturvetenskapliga fakulteten, Botaniska institutionen.
    Effects of water exchange and vegetation on the macroinvertebrate fauna composition of shallow land-uplift bays in the Baltic Sea2008Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 77, nr 3, s. 535-547Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Shallow bays with soft sediment bottoms are common habitats along the Swedish and Finnish Baltic Sea coastline. These bays undergo a process of geomorphometric evolution with the natural isostatic land-uplift process, whereby open bays and sounds decrease in depth and are gradually isolated from the sea, forming bays with narrow openings. This study tested the relationship between the morphometric isolation of the bays from the sea and the macroinvertebrate fauna community of these bays. Additionally, we tested the specific role of the submerged vegetation as an indicator of the macroinvertebrate fauna community. We chose two environmental factors for the analyses, water exchange of the bays and the taxon richness of the macroflora in the bays. We found a hierarchical relationship between water exchange, flora taxon richness, and fauna biomass and taxon richness using structural equation modelling: decreased biomass and taxon richness of fauna were related to decreased flora taxon richness, which in turn was related to decreased water exchange. Using multivariate redundancy analysis, the two environmental factors included in the model were found to explain 47.7% of the variation in the fauna taxon composition and 57.5% of the variation in the functional feeding groups of the fauna. Along the morphometric isolation gradient of the bays, the fauna assemblages changed from a community dominated by gastropods, bivalves, and crustaceans, to a community mainly consisting of a few insect taxa. Moreover, the proportion of predators, gathering collectors, and shredders increased while that of filtering collectors and scrapers decreased. Our results indicate that the density and taxon richness of macroinvertebrate fauna are higher in less morphometrically isolated bays than in more isolated bays in the Baltic Sea. Furthermore, we suggest that the taxon richness of macroflora can serve as an indicator of the fauna community.

  • 41.
    Hansson, Sture
    et al.
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Larsson, Ulf
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Walve, Jakob
    Stockholms universitet, Naturvetenskapliga fakulteten, Institutionen för ekologi, miljö och botanik.
    Site fidelity in perch (Perca fluviatilis) and roach (Rutilus rutilus) in two Baltic Sea coastal areas2019Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 226, artikkel-id UNSP 106261Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Perch (Perca fluviatilis) and roach (Rutilus rutilus) are among the more common coastal fish species in the Baltic Sea. They are often targeted in environment monitoring programs as well as in ecological research, in which knowledge of their basic biology, including migration and feeding ranges, are needed in the sampling design and for interpretation of data. Body condition (length-mass relationship) differences between stations separated by at most a few kilometres show that both species are reasonably sedentary even in areas without obvious migration barriers. Collecting representative samples, even from a reasonably small water body, may thus require careful planning.

  • 42.
    Humborg, Christoph
    et al.
    SU.
    Danielsson, Åsa
    Linköpings universitet, Institutionen för tema, Tema vatten i natur och samhälle. Linköpings universitet, Filosofiska fakulteten.
    Sjöberg, Björn
    GU.
    Gren, Mattias
    GU.
    Nutrient land-sea fluxes in oligothrophic and pristine estuaries of the Gulf of Bothnia, Baltic Sea2003Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 56, nr 3-4, s. 781-793Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Estuaries are often seen as important filters between land and the sea for inorganic and organic nutrients. This paper aims at estimating the estuarine fluxes of dissolved inorganic nitrogen (DIN), dissolved inorganic phosphorus (DIP) and dissolved silicate for the major oligothrophic and pristine rivers running into the Bothnian Bay (BB) and the Bothnian Sea (BS), the northern subarctic subbasins of the Baltic Sea. Long-term data sets for these rivers and their estuaries as well as for the BB and BS were analyzed to assess whether these estuaries are sinks for inorganic nutrients. Most studied estuaries can be characterized as salt wedge estuaries with little exchange between the fresh seaward-flowing river water and the inward-flowing seawater. Estimates of water transit times ranged between 1 and 14 days. In most estuaries of the BB, N-depleted river water meets P-depleted seawater during the growth period. These findings were corroborated by mixing diagrams showing that the inner areas of the estuaries were N-depleted in summer. In the BS, on the other hand, both rivers and seawater were mostly N-depleted during summer. Thus, for most estuaries of this region of the Baltic Sea, primary productivity is presumably lower than or equal to that of offshore. The low productivity is also reflected in the sediments. The coastal sediments did not differ from the offshore stations in accumulation rates as well as the content of organic matter and nutrients, indicating that estuarine nutrient burial is not always higher as normally observed in other temperate systems. Finally, the estuaries of the pristine rivers in the northernmost part of the BB import DIN during summer, whereas the estuaries of the rivers in the BS import DIP during winter, from the sea. ⌐ 2003 Elsevier Science B.V. All rights reserved.

  • 43. Ikauniece, Anda
    et al.
    Meier, Markus
    SMHI, Forskningsavdelningen, Oceanografi.
    Kalnina, Laimdota
    Introduction for the SI "Understanding the Baltic Sea"2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 195, s. 1-3Artikkel i tidsskrift (Fagfellevurdert)
  • 44.
    Karlsson, Magnus
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Malmaeus, Mikael
    Josefsson, Sarah
    Wiberg, Karin
    Håkanson, Lars
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Geovetenskapliga sektionen, Institutionen för geovetenskaper, Luft-, vatten- och landskapslära.
    Application of a mass-balance model to predict PCDD/F turnover in a Baltic coastal estuary2010Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 88, nr 2, s. 209-218Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A dynamical, process-based mass-balance model was applied to quantify the transports of polychlorinated-p-dibenzodioxins and dibenzofurans (PCDD/Fs) to, within and from the Kallrigafjarden Bay, a coastal estuary in the Baltic Sea, and to predict the PCDD/F levels in the water and sediments of the bay. Before the modelling, a one-year sampling programme was implemented in 2007-2008 to measure the flows of PCDD/Fs in tributaries entering the system, the fluxes from the adjacent sea and the levels in water, sediment and fish within the estuary. The collected data set was used as input data to the model and for validation purposes.

    The model was originally developed and tested for suspended particulate matter and phosphorus in Baltic coastal areas. In this work, it was run monthly without any tuning of the original model variables. The simulation results compared favourably with the field measurements of levels of 15 PCDD/F congeners in the water and sediments of the bay. The dominating fluxes of PCDD/Fs were the exchange with the adjacent sea, followed by riverine input, atmospheric deposition and sediment burial.

    Although the sediment-water exchange was of minor importance for the overall mass-balance due to the rapid water turnover and limited areas favourable for the long-term deposition of fine sedimentary matter, sensitivity analyses indicated that the model's predictive capability was improved with about 5% by taking the sediment burial and release into account.

  • 45. Karlsson, O Magnus
    et al.
    Malmaeus, J Mikael
    Josefsson, Sarah
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Wiberg, Karin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Kemiska institutionen.
    Håkanson, Lars
    Application of a mass-balance model to predict PCDD/F turnover in a Baltic coastal estuary2010Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 88, nr 2, s. 209-18Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A dynamical, process-based mass-balance model was applied to quantify the transports of polychlorinated-p-dibenzodioxins and dibenzofurans (PCDD/Fs) to, within and from the Kallrigafjärden Bay, a coastal estuary in the Baltic Sea, and to predict the PCDD/F levels in the water and sediments of the bay. Before the modelling, a one-year sampling programme was implemented in 2007–2008 to measure the flows of PCDD/Fs in tributaries entering the system, the fluxes from the adjacent sea and the levels in water, sediment and fish within the estuary. The collected data set was used as input data to the model and for validation purposes.The model was originally developed and tested for suspended particulate matter and phosphorus in Baltic coastal areas. In this work, it was run monthly without any tuning of the original model variables. The simulation results compared favourably with the field measurements of levels of 15 PCDD/F congeners in the water and sediments of the bay. The dominating fluxes of PCDD/Fs were the exchange with the adjacent sea, followed by riverine input, atmospheric deposition and sediment burial.Although the sediment-water exchange was of minor importance for the overall mass-balance due to the rapid water turnover and limited areas favourable for the long-term deposition of fine sedimentary matter, sensitivity analyses indicated that the model’s predictive capability was improved with about 5% by taking the sediment burial and release into account.

  • 46. La, H. S.
    et al.
    Ha, H. K.
    Kang, C. Y.
    Wåhlin, A. K.
    Shin, H. C.
    Acoustic backscatter observations with implications for seasonal and vertical migrations of zooplankton and nekton in the Amundsen shelf (Antarctica)2015Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 152, s. 124-133Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    High-temporal resolution profiles of acoustic backscatter were collected in the Dotson Trough on the Amundsen shelf in the Antarctica, using a bottom-moored, upward-looking acoustic Doppler current profiler (ADCP). This data set was used to examine the impact of seasonal variations in surface solar radiation (SSR), sea ice concentration (SIC), and Circumpolar Deep Water (CDW) thickness on acoustic backscatter in the lower water column (250−540-m depth). A recorded high acoustic backscatter (−75 to −70 dB) at depth &gt;400 m from April to November compared to the rest of the year (−90 to −80 dB) suggests that zooplankton and nekton migrated towards the bottom during winter. The depth of maximum mean volume backscattering strength showed a significant correlation with SSR, SIC and CDW thickness. A daily cycle of vertical migration was also recorded. This varied with changing surface ice conditions. When sea ice cover was low, the acoustic backscatter descended at sunrise, and ascended at sunset. When sea ice cover was high, the daily migration was not pronounced, and the layer of high acoustic backscatter remained near the bottom. This is the first study of seasonal and vertical migration of zooplankton and nekton that has been conducted on the Amundsen Sea shelf, one of the world’s most productive areas. The findings provide implications to understand the behavior of zooplankton and nekton below the euphotic zone in the Southern Ocean.

  • 47.
    Langhamer, Olivia
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och evolution. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Biologiska sektionen, Institutionen för ekologi och genetik, Zooekologi.
    Wilhelmsson, Dan
    Engström, Jens
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Tekniska sektionen, Institutionen för teknikvetenskaper, Elektricitetslära.
    Artificial reef effect and fouling impacts on offshore wave power foundations and buoys: a pilot study2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 82, nr 3, s. 426-432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Little is known about the effects of offshore energy installations on the marine environment, and further research could assist in minimizing environmental risks as well as in enhancing potential positive effects on the marine environment. While biofouling on marine energy conversion devices on one hand has the potential to be an engineering concern, these structures can also affect biodiversity by functioning as artificial reefs. The Lysekil Project is a test park for wave power located at the Swedish west coast. Here, buoys acting as point absorbers on the surface are connected to generators anchored on concrete foundations on the seabed. In this study we investigated the colonisation of foundations by invertebrates and fish, as well as fouling assemblages on buoys. We examined the influence of surface orientation of the wave power foundations on epibenthic colonisation, and made observations of habitat use by fish and crustaceans during three years of submergence. We also examined fouling assemblages on buoys and calculated the effects of biofouling on the energy absorption of the wave power buoys. On foundations we demonstrated a succession in colonisation over time with a higher degree of coverage on vertical surfaces. Buoys were dominated by the blue mussel Mytilus edulis. Calculations indicated that biofouling have no significant effect in the energy absorption on a buoy working as a point absorber. This study is the first structured investigation on marine organisms associated with wave power devices

  • 48. Langhamer, Olivia
    et al.
    Wilhelmsson, Dan
    Stockholms universitet, Naturvetenskapliga fakulteten, Zoologiska institutionen.
    Engström, Jens
    Artificial reef effect and fouling impacts on offshore wave power foundations and buoys- a pilot study2009Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 82, nr 3, s. 426-432Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Little is known about the effects of offshore energy installations on the marine environment, and further research could assist in minimizing environmental risks as well as in enhancing potential positive effects on the marine environment. While biofouling on marine energy conversion devices on one hand has the potential to be an engineering concern, these structures can also affect biodiversity by functioning as artificial reefs. The Lysekil Project is a test park for wave power located at the Swedish west coast. Here, buoys acting as point absorbers on the surface are connected to generators anchored on concrete foundations on the seabed. In this study we investigated the colonisation of foundations by invertebrates and fish, as well as fouling assemblages on buoys. We examined the influence of surface orientation of the wave power foundations on epibenthic colonisation, and made observations of habitat use by fish and crustaceans during three years of submergence. We also examined fouling assemblages on buoys and calculated the effects of biofouling on the energy absorption of the wave power buoys. On foundations we demonstrated a succession in colonisation over time with a higher degree of coverage on vertical surfaces. Buoys were dominated by the blue mussel Mytilus edulis. Calculations indicated that biofouling have no significant effect in the energy absorption on a buoy working as a point absorber. This study is the first structured investigation on marine organisms associated with wave power devices.

  • 49.
    Larsson, Josefine
    et al.
    Södertörns högskola, Miljövetenskap.
    Lind, E. E.
    SLU.
    Corell, H.
    Göteborgs universitet.
    Grahn, Mats
    Södertörns högskola, Biologi.
    Smolarz, K.
    University of Gdańsk, Gdynia, Poland.
    Lönn, Mikael
    Södertörns högskola, Biologi.
    Regional genetic differentiation in the blue mussel from the Baltic Sea area2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 195, s. 98-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Connectivity plays an important role in shaping the genetic structure and in evolution of local adaptation. In the marine environment barriers to gene flow are in most cases caused by gradients in environmental factors, ocean circulation and/or larval behavior. Despite the long pelagic larval stages, with high potential for dispersal many marine organisms have been shown to have a fine scale genetic structuring. In this study, by using a combination of high-resolution genetic markers, species hybridization data and biophysical modeling we can present a comprehensive picture of the evolutionary landscape for a keystone species in the Baltic Sea, the blue mussel. We identified distinct genetic differentiation between the West Coast, Baltic Proper and Bothnian Sea regions, with lower gene diversity in the Bothnian Sea. Oceanographic connectivity together with salinity and to some extent species identity provides explanations for the genetic differentiation between the West Coast and the Baltic Sea (Baltic Proper and Bothnian Sea). The genetic differentiation between the Baltic Proper and Bothnian Sea cannot be directly explained by oceanographic connectivity, species identity or salinity, while the lower connectivity to the Bothnian Sea may explain the lower gene diversity. © 2016.

  • 50.
    Larsson, Josefine
    et al.
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Lind, E. E.
    SLU.
    Corell, H.
    Göteborgs universitet.
    Grahn, Mats
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Miljövetenskap.
    Smolarz, K.
    University of Gdańsk, Gdynia, Poland.
    Lönn, Mikael
    Södertörns högskola, Institutionen för naturvetenskap, miljö och teknik, Matematikens didaktik.
    Regional genetic differentiation in the blue mussel from the Baltic Sea area2017Inngår i: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, s. 98-109Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Connectivity plays an important role in shaping the genetic structure and in evolution of local adaptation. In the marine environment barriers to gene flow are in most cases caused by gradients in environmental factors, ocean circulation and/or larval behavior. Despite the long pelagic larval stages, with high potential for dispersal many marine organisms have been shown to have a fine scale genetic structuring. In this study, by using a combination of high-resolution genetic markers, species hybridization data and biophysical modeling we can present a comprehensive picture of the evolutionary landscape for a keystone species in the Baltic Sea, the blue mussel. We identified distinct genetic differentiation between the West Coast, Baltic Proper and Bothnian Sea regions, with lower gene diversity in the Bothnian Sea. Oceanographic connectivity together with salinity and to some extent species identity provides explanations for the genetic differentiation between the West Coast and the Baltic Sea (Baltic Proper and Bothnian Sea). The genetic differentiation between the Baltic Proper and Bothnian Sea cannot be directly explained by oceanographic connectivity, species identity or salinity, while the lower connectivity to the Bothnian Sea may explain the lower gene diversity. © 2016.

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