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  • 1.
    Andersson, Mathias H.
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Berggren, Matz
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Öhman, Marcus C
    Stockholm University, Faculty of Science, Department of Zoology.
    Epibenthic colonization of concrete and steel pilingsin a cold-temperate embayment: a feld experiment2009In: Helgoland Marine Research, ISSN 1438-387X, E-ISSN 1438-3888, Vol. 63, no 3, p. 249-260Article in journal (Refereed)
    Abstract [en]

    With large-scale development of offshore wind farms, vertical structures are becoming more common in open water areas. To examine how vertical structures of different materials may be colonized by epibenthic organisms, an experiment was carried out using steel and concrete pilings constructed to resemble those commonly used in wind farm constructions as well as in bridges, jetties and oil platforms. The early recruitment and succession of the epibenthic communities were sampled once a month for the first 5 months and then again after 1 year. Further, the fish assemblages associated with the pillars were sampled and compared to natural areas. The main epibenthic species groups, in terms of coverage, diVered between the two materials at five out of six sampling occasions. Dominant organisms on steel pillars were the barnacle Balanus improvisus,the calcareous tubeworm Pomatoceros triqueter and the tunicate Ciona intestinalis. On the concrete pillars, the hydroid Laomedea sp. and the tunicates Corella parallelogramma and Ascidiella spp. dominated. However, there was no different in coverage at different heights on the pillars or in biomass and species abundance at different directions (north-east or south-west) 5 months after submergence. Fish showed overall higher abundances and species numbers on the pillars (but no difference between steel and concrete)compared to the surrounding soft bottom habitats but not compared to natural vertical rock walls. Two species were attracted to the pillars, indicating a reef effect; Gobiusculus flavescens and Ctenolabrus rupestris. The bottom-dwelling gobies, Pomatoschistus spp., did not show such preferences.

  • 2. Edward, J.K. Patterson
    et al.
    Mathews, G.
    Patterson, Jamila
    Ramkumar, R.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Tamelander, Jerker
    Lindén, Olof
    Status of coral reefs of the Gulf of Mannar, Southeastern India2008In: Coastal Oceans Reserach and Development in the Indian Ocean, 2008Chapter in book (Refereed)
  • 3. Edward, J.K. Patterson
    et al.
    Patterson, Jamila
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology. Ekologi.
    Conservation and management of coral reefs and seagrasses of the Gulf of Mannar and Palk Bay, Southeastern India: Significant contributions from SDMRI during 2000-20082008Book (Other academic)
  • 4. Langhamer, Olivia
    et al.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Colonisation of fish and crabs of wave energy foundations and the effects of manufactured holes- a field experiment2009In: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 68, no 4, p. 151-157Article in journal (Refereed)
    Abstract [en]

    Several Western European countries are planning for a significant development of offshore renewable energy along the European Atlantic Ocean coast, including many thousands of wave energy devices and wind turbines. There is an increasing interest in articulating the added values of the creation of artificial hard bottom habitats through the construction of offshore renewable energy devices, for the benefit of fisheries management and conservation. The Lysekil Project is a test park for wave power located about 100 km north of Gothenburg at the Swedish west coast. A wave energy device consists of a linear wave power generator attached to a foundation on the seabed, and connected by a wire to a buoy at the surface. Our field experiment examined the function of wave energy foundations as artificial reefs. In addition, potentials for enhancing the abundance of associated fish and crustaceans through manufactured holes of the foundations were also investigated. Assemblages of mobile organisms were examined by visual censuses in July and August 2007, 3 months after deployment of the foundations. Results generally show low densities of mobile organisms, but a significantly higher abundance of fish and crabs on the foundations compared to surrounding soft bottoms. Further, while fish numbers were not influenced by increased habitat complexity (holes), it had a significantly positive effect on quantities of edible crab (Cancer pagurus), on average leading to an almost five-fold increase in densities of this species. Densities of spiny starfish (Marthasterias glacialis) were negatively affected by the presence of holes, potentially due to increased predator abundance (e.g. C. pagurus). These results suggest a species-specific response to enhanced habitat complexity.

  • 5. Langhamer, Olivia
    et al.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology. Zoologisk ekologi.
    Wave powerdevices as artificial reefs2007In: Proceedings of 7th European Wave and Tidal Energy Conference, Porto, Portugal.11-13 September 2007, 2007, p. 29-37Conference paper (Refereed)
  • 6. Langhamer, Olivia
    et al.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Engström, Jens
    Artificial reef effect and fouling impacts on offshore wave power foundations and buoys- a pilot study2009In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 82, no 3, p. 426-432Article in journal (Refereed)
    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.

  • 7. Lindén, Olof
    et al.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Vi bör lära av Kanadas misstag2005In: Svenska Dagbladet: Brännpunkt, no 6 septemberArticle in journal (Other (popular science, discussion, etc.))
  • 8. Patterson Edward, J.K.
    et al.
    Mathews, G
    Patterson, Jamila
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology. Zoologisk ekologi.
    Tamelander, Jerker
    Lindén, Olof
    Coral reef of the Gulf of Mannar, southeastern India- Distribution, Diversity and Status2007Book (Other (popular science, discussion, etc.))
  • 9.
    Patterson, Jamila
    et al.
    SDMRI.
    Edward, J.K. Patterson
    Samuel, V. Deepak
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology. Stockholm University, Faculty of Science, Department of Zoology.
    Tamelander, Jerker
    Lindén, Olof
    The role of alternative livelihoods and awareness creation in coral reef conservation in the Gulf of Mannar2008In: Coastal Oceans Researcha and Development in the Indian Ocean, Coastal Oceans Research and Development in the Indian Ocean , 2008Chapter in book (Refereed)
  • 10. Patterson, Jamila
    et al.
    Lindén, Eva
    Bierbier, Christin
    Löfgren, Inger
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Empowerment of fisher women of Siluvaipatti fishing village of Tuticorin, Southeast coast of India through adult education and ICT training.2008In: Convergence, ISSN 0010-8146., Vol. 41, no 2-3, p. 75-81Article in journal (Refereed)
    Abstract [en]

    This paper focuses on adult education and information and communication technologies (ICO training to fisherwoman of Siluvaipatti fishing village in Tuticorin district of Tamil Nadu State, southeastern India. The total families in this village are 209 with population 899 (Male: 442; Female: 457). The education level is generally good in Siluvalpatti when compared to other villages along the Tuticodn coast, e.g., 439 are educated up to school level, 71 college level, over 200 children presently attend school and 67 are uneducated. The village has a primary and a high school, but does not have a primary health centre. The fisher women are actively involved in self help group activities and avail themselves of loans from banks so as to improve their livelihoods. The few uneducated people who participate in adult education could get development loans to acquire much necessary knowledge and understanding. For adult education and training in information communication technologies (ICT), two coordinators were selected from the village and were well trained. Two computers with a printer, along with other study materials were provided. Initially the coordinators started to teach the alphabet of the local Tamil language to uneducated women, and English to low-educated women. The women were taught to read and write their names in Tamil or English, simple words and finally smafl sentences. Several school-going girls and educated young women benefited through the ICT training.

  • 11. Patterson, Jamila
    et al.
    Lindén, Eva
    Edward, JPK
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Löfgren, Inger
    Community-based environmental education in the fihsing village of Tuticorin and its role in conservation of the environment2009In: Australian Journal of Adult Learning, ISSN 1443-1394, Vol. 49, no 2, p. 383-393Article in journal (Refereed)
  • 12.
    Wang, Zhi
    et al.
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Wilhelmsson, Christine
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Hyrsl, Pavel
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Loof, Torsten G.
    Dobes, Pavel
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Klupp, Martina
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Loseva, Olga
    Stockholm University, Faculty of Science, Department of Genetics, Microbiology and Toxicology.
    Moergelin, Matthias
    Ikle, Jennifer
    Cripps, Richard M.
    Herwald, Heiko
    Theopold, Ulrich
    Stockholm University, Faculty of Science, Department of Molecular Biology and Functional Genomics.
    Pathogen Entrapment by Transglutaminase - A Conserved Early Innate Immune Mechanism2010In: PLOS pathogens, ISSN 1553-7366, Vol. 6, no 2, p. e1000763-Article in journal (Refereed)
    Abstract [en]

    Clotting systems are required in almost all animals to prevent loss of body fluids after injury. Here, we show that despite the risks associated with its systemic activation, clotting is a hitherto little appreciated branch of the immune system. We compared clotting of human blood and insect hemolymph to study the best-conserved component of clotting systems, namely the Drosophila enzyme transglutaminase and its vertebrate homologue Factor XIIIa. Using labelled artificial substrates we observe that transglutaminase activity from both Drosophila hemolymph and human blood accumulates on microbial surfaces, leading to their sequestration into the clot. Using both a human and a natural insect pathogen we provide functional proof for an immune function for transglutaminase (TG). Drosophila larvae with reduced TG levels show increased mortality after septic injury. The same larvae are also more susceptible to a natural infection involving entomopathogenic nematodes and their symbiotic bacteria while neither phagocytosis, phenoloxidase or-as previously shown-the Toll or imd pathway contribute to immunity. These results firmly establish the hemolymph/blood clot as an important effector of early innate immunity, which helps to prevent septic infections. These findings will help to guide further strategies to reduce the damaging effects of clotting and enhance its beneficial contribution to immune reactions.

  • 13.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Aspects of offshore renewable energy and the alterations of marine habitats2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Several Western European countries are planning for a massive offshore renewable energy (i.e. wind and wave energy) development (ORED) along the European Atlantic coast and in the Baltic Sea. Acknowledging the scale of ORED, there is an increasing interest in the opportunities offered by the fishery closures and the addition of artificial hard substrata. This is in tandem with uncertainties on positive and negative effects on benthic assemblages and specific species of this large-scale deployment of artificial reefs.

    This thesis focuses on the artificial reef effects of ORED, dealing with benthic assemblages on and in the vicinity of wind- and wave power foundations. Field surveys within offshore wind- and wave farms as well as targeted field experiments were conducted. Results suggest that wind- and wave power foundations can positively affect local abundances and diversity of several species of fish and decapods. Reef profile up to 1 m above the seabed may enhance benthic fish numbers. Structural complexity in the form of single-entrance holes positively affected numbers of edible crab (Cancer pagurus), but no effect on fish was shown. Enhanced structural complexity may, moreover, adversely affect abundances of some species through an induced predation pressure. Micro-habitat use by fish and lobsters (Homarus gammarus) encountered was described, and preferences of the edible crab were shown.

    Filtrating organisms (i.e. blue mussels Mytilus spp. and barnacles Balanus spp.) seem to be particularly favoured by the conditions on offshore energy installations. The material and orientation of the substrate influenced colonisation patterns of epibiota. Moreover, wind turbines may alter the habitat composition on adjacent seabeds.

    ORED could induce local ecological changes and put areas and species of conservation interest at risk. If well planned and co-ordinated, on the other hand, ORED could even be beneficial to the subsurface marine environment in several aspects.

  • 14.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Fish ecological aspects of artificial reef design in cold temperate waters2006Licentiate thesis, monograph (Other academic)
  • 15.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology. Zoologisk ekologi.
    Research capacity building in developing countries: some key issues and strategies2007In: Development cooperation for marine reseach in East and West Africa: Lessons learned and future direction, 2007, p. 24-Conference paper (Other academic)
  • 16.
    Wilhelmsson, Dan
    Stockholm University, Faculty of Science, Department of Zoology.
    Utveckling och miljövård hand i hand2008In: Havsutsikt, Vol. 3, p. 12-13Article in journal (Other (popular science, discussion, etc.))
  • 17.
    Wilhelmsson, Dan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Langhamer, Olivia
    Nya energikällor skapar nya livsmiljöer2009In: Havsutsikt, p. 4-5Article in journal (Other (popular science, discussion, etc.))
  • 18.
    Wilhelmsson, Dan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology. Zoologiska Institutionen.
    Malm, T.Thompson, R.Tchou, J.Sarantakos, G.McCormick, N.Luitjens, S.Gullström, MartinStockholm University, Faculty of Science, Department of Zoology.Patterson Edwards, J. K.Amir, O.Dubi, A.
    Greening Blue Energy: Identifying and managing the biodiversity risks and opportunities of offshore renewable energy2010Collection (editor) (Other academic)
  • 19.
    Wilhelmsson, Dan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Malm, Torelif
    Fouling assemblages on offshore wind power plants and adjacent substrata2008In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 79, no 3, p. 459-466Article in journal (Refereed)
    Abstract [en]

    A significant expansion of offshore wind power is expected in the near future, with thousands of turbines in coastal waters, and various aspects of how this may influence the coastal ecology including disturbance effects from noise, shadows, electromagnetic fields, and changed hydrological conditions are accordingly of concern. Further, wind power plants constitute habitats for a number of organisms, and may locally alter assemblage composition and biomass of invertebrates, algae and fish. In this study, fouling assemblages on offshore wind turbines were compared to adjacent hard substrate. Influences of the structures on the seabed were also investigated. The turbines differed significantly from adjacent boulders in terms of assemblage composition of epibiota and motile invertebrates. Species number and Shannon-Wiener diversity were, also, significantly lower on the wind power plants. It was also indicated that the turbines might have affected assemblages of invertebrates and algae on adjacent boulders. Off shore wind power plant offer atypical substrates for fouling assemblages in terms of orientation, depth range, structure, and surface texture. Some potential ecological implications of the addition of these non-natural habitats for coastal ecology are discussed.

  • 20.
    Wilhelmsson, Dan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Malm, Torleif
    Öhman, Marcus
    Stockholm University, Faculty of Science, Department of Zoology.
    The influence of offshore wind power on demersal fish2006In: ICES Journal of Marine Science, ISSN 1054-3139, E-ISSN 1095-9289, Vol. 63, no 5, p. 775-784Article in journal (Refereed)
    Abstract [en]

    A significant expansion of offshore windpower is expected in northwestern Europe in the near future. Little is known about the impacts it may have on the marine environment. Here, we investigate the potential for wind turbines to function as artificial reefs and fish aggregation devices (FADs), i.e. whether they would locally increase fish densities or alter fish assemblages. Fish communities and habitat composition were investigated using visual transects at two windpower farms off the southeastern coast of Sweden, central Baltic Sea. Fish abundance was greater in the vicinity of the turbines than in surrounding areas, while species richness and Shannon–Wiener diversity (H') were similar. On the monopiles of the turbines, fish community structure was different, and total fish abundance was greater, while species richness and diversity (H') were lower than on the surrounding seabed. Blue mussels and barnacles covered most of the submerged parts of the turbines. On the seabed, more blue mussels and a lesser cover of red algae were recorded around the power plants than elsewhere. Results from this study suggest that offshore windfarms may function as combined artificial reefs and fish aggregation devices for small demersal fish.

  • 21.
    Wilhelmsson, Dan
    et al.
    Stockholm University, Faculty of Science, Department of Zoology.
    Yahya, Saleh
    Stockholm University, Faculty of Science, Department of Zoology.
    Öhman, Marcus
    Stockholm University, Faculty of Science, Department of Zoology.
    Effects of high-relief structures on cold-temperate fish assemblages: a field experiment2006In: Marine Biology Research, ISSN 1745-1000, E-ISSN 1745-1019, Vol. 2, no 2, p. 136-147Article in journal (Refereed)
    Abstract [en]

    High-relief structures may influence the abundance and diversity of reef-associated fish. We conducted a field experiment to investigate whether the presence of vertical structures (PVC pipes) affects fish communities on artificial reefs. The effect of the height of the structures (1 and 3 m) was also tested. Furthermore, the effects on fish of placing artificial reefs on otherwise featureless bottoms were quantified. Algal and macro-invertebrate colonization of the reefs was also recorded. The experiment was carried out on the west coast of Sweden over a period of 1 year. The vertical structures had a positive effect on fish abundance but not on diversity. The height of the structures did not, however, influence the fish communities. Natural as well as urban vertical structures on the seafloor could have a positive effect on local fish abundance. The positive effects of artificial reefs on total fish abundance and diversity were immediate. Of the 10 species recorded, two, the black goby Gobius niger and the goldsinny wrasse Ctenolabrus rupestris , dominated over the whole survey period. There were significant temporal differences in fish abundance, and diversity increased with time.

1 - 21 of 21
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