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  • 1.
    Berg, Florian
    et al.
    Univ Bergen, Dept Biol Sci, N-5020 Bergen, Norway.;Inst Marine Res IMR, N-5018 Bergen, Norway..
    Andersson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Swedish Univ Agr Sci, Dept Anim Breeding & Genet, S-75007 Uppsala, Sweden.;Texas A&M Univ, Dept Vet Integrat Biosci, College Stn, TX 77843 USA..
    Folkvord, Arild
    Univ Bergen, Dept Biol Sci, N-5020 Bergen, Norway.;Inst Marine Res IMR, N-5018 Bergen, Norway..
    Respiration rates of herring larvae at different salinities, and effects of previous environmental history2020In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 650, p. 141-152Article in journal (Refereed)
    Abstract [en]

    Metabolic rates of early life history stages of marine fishes show considerable interindividual differences, and are highly influenced by extrinsic factors like temperature or food availability. Measuring oxygen uptake rates is a proxy for estimating metabolic rates. Still, the relationship between respiration rates and ambient or previous salinity conditions as well as parental and developmental acclimation to changes in salinity remains largely unexplored. In the present study, we conducted experiments to investigate the effects of salinity on the routine metabolic rates (RMR) of euryhaline Atlantic herring Clupea harengus larvae at 3 levels of salinity: low (6 psu), intermediate (16 psu) and high (35 psu), reflecting ecologically relevant conditions for herring populations in the Atlantic Ocean and Baltic Sea. The larvae originated from different genetic backgrounds and salinity adaptations to account for cross-generation effects on metabolic rates. Closed respirometry carried out over 24 h on individual fish larvae generally confirmed near isometric respiration rates at all salinity regimes, with rates being 15.4% higher at 6 psu and 7.5% higher at 35 psu compared to 16 psu conditions. However, transgenerational acclimation to different salinity regimes of the parents had no effect on the salinity-specific metabolic rates of their offspring. Our study demonstrates the ability of herring to cope with a wide range of salinity conditions, irrespective of parental environmental history and genetic origin. This phenotypic plasticity is considered to be one of the main contributing factors to the success of herring as a widely distributed fish species in the North Atlantic and adjacent waters.

  • 2.
    Berg, Florian
    et al.
    Univ Bergen, Dept Biol Sci, Post Box 7803, N-5020 Bergen, Norway;IMR, Post Box 1870 Nordnes, N-5018 Bergen, Norway.
    Slotte, Aril
    IMR, Post Box 1870 Nordnes, N-5018 Bergen, Norway.
    Andersson, Leif
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Uppsala University, Science for Life Laboratory, SciLifeLab. Texas A&M Univ, Dept Vet Integrat Biosci, College Stn, TX 77843 USA.
    Folkvord, Arild
    Univ Bergen, Dept Biol Sci, Post Box 7803, N-5020 Bergen, Norway;IMR, Post Box 1870 Nordnes, N-5018 Bergen, Norway.
    Genetic origin and salinity history influence the reproductive success of Atlantic herring2019In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 617, p. 81-94Article in journal (Refereed)
    Abstract [en]

    Atlantic herring populations inhabit environments ranging in salinity from fully marine to nearly freshwater, but their relative reproductive success in these respective environments remains unclear. We conducted factorial crossing experiments using parents from 3 wild populations associated with different salinity environments: the Baltic Sea (similar to 6 psu), an inland brackish lake in Norway (Landvikvannet, similar to 16 psu), and the Atlantic (similar to 30 to 35 psu). Further experiments used crosses within and between Atlantic purebreds and Atlantic/Baltic hybrids reared until first maturity at 3 yr of age. Crossing experiments were conducted at 6, 16 and 35 psu. Fertilization and hatching rates were estimated, and egg sizes were measured. Fertilization rates were highest at 16 psu for all combinations. The paternal genetic and salinity origin influenced fertilization rates at 6 and 35 psu, indicating a genetic adaptation to their original environment. Fertilization rates for males originating from 16 psu were low at 35 psu. Atlantic/Baltic hybrids had lower fertilization rates than Atlantic purebreds at 35 psu. Hatching rates were not influenced by any parental factors or salinity. Maternal effects and salinity influenced egg size. Atlantic females had significantly larger eggs than the Atlantic/Baltic hybrid females. For all genetic groups, egg size decreased with increasing salinity at incubation mainly due to osmotic effects. The observed lower fertilization success at salinities other than those of the parental fish habitat would have evolutionary consequences when herring colonize new habitats with different salinities or if interbreeding occurred between populations originating from different salinity habitats.

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  • 3.
    Berglund, Anders
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Reproductive adaptations in two Palaemon prawn species with differing habitat requirements1984In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 17, no 1, p. 77-83Article in journal (Refereed)
  • 4.
    Berglund, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Rosenqvist, Gunilla
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Svensson, Ingrid
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Animal Ecology.
    Reversed sex-roles and parental energy investment in zygotes of two pipefish (Syngnathidae) species1986In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 29, no 3, p. 209-215Article in journal (Refereed)
  • 5.
    Bertrand, Philip
    et al.
    Départment de Biologie, Chimie et Géographie and Centre d’Études Nordiques, Université du Québec à Rimouski, Rimouski, QC G5L 3A1, Canada;Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Strøm, Hallvard
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Bêty, Joël
    Départment de Biologie, Chimie et Géographie and Centre d’Études Nordiques, Université du Québec à Rimouski, Rimouski, QC G5L 3A1, Canada.
    Steen, Harald
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Kohler, Jack
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Vihtakari, Mikko
    Institute of Marine Research, Fram Centre, Tromsø 9296, Norway.
    Van Pelt, Ward
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, LUVAL.
    Yoccoz, Nigel
    Department of Arctic and Marine Biology, UiT The Arctic University of Norway, Tromsø 9037, Norway.
    Hop, Haakon
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Harris, Stephanie
    Cornell Lab of Ornithology, Cornell University, 159 Sapsucker Woods Road, Ithaca, NY 14850, USA;School of Environmental Sciences, University of Liverpool, Liverpool L3 5DA, UK.
    Patrick, Samantha
    School of Environmental Sciences, University of Liverpool, Liverpool L3 5DA, UK.
    Assmy, Philipp
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Wold, Anette
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Duarte, Pedro
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Moholdt, Geir
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Descamps, Sébastien
    Norwegian Polar Institute, Fram Centre, Tromsø 9296, Norway.
    Feeding at the front line: interannual variation in the use of glacier fronts by foraging black-legged kittiwakes2021In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 677, p. 197-208Article in journal (Refereed)
    Abstract [en]

    Tidewater glacier fronts can represent important foraging areas for Arctic predators. Their ecological importance is likely to change in a warmer Arctic. Their profitability and use by consumers are expected to vary in time, but the underlying mechanisms driving such variation remain poorly known. The subglacial plume, originating from meltwater discharge, is responsible for the entrainment and transport of zooplankton to the surface, making them more readily available for surface-feeding seabirds. Both discharge and zooplankton abundance are known to fluctuate in time and are thus expected to modulate the foraging profitability of glacier fronts. This study tested the predictions that annual use of glacier fronts by black-legged kittiwakes Rissa tridactyla is positively related to the average glacier discharge and prey biomass in the fjord. To do this, we combined a multiyear dataset of environmental drivers and GPS tracks of birds in Kongsfjorden, Svalbard. Our results confirmed the interannual variation in the use of glacier fronts by kittiwakes; however, contrary to our predictions, these variations were negatively correlated to both glacier discharge and zooplankton abundance. These apparent negative relationships likely reflect non-linear effects and complex interactions between local and regional environmental factors that affect the relative profitability of glacier fronts as foraging areas. Despite their high spatial predictability, glacier fronts may not offer consistent foraging opportunities for marine predators over time.

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  • 6.
    Coguiec, Estelle
    et al.
    UiT Arctic Univ Norway, Dept Arctic & Marine Biol, N-9019 Tromso, Norway..
    Last, Kim S.
    Scottish Assoc Marine Sci, Oban PA37 1QA, Argyll, Scotland..
    Cohen, Jonathan H.
    Univ Delaware, Sch Marine Sci & Policy, Lewes, DE 19958 USA..
    Hobbs, Laura
    Scottish Assoc Marine Sci, Oban PA37 1QA, Argyll, Scotland..
    Choquet, Marvin
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Medicine, Department of Medical Biochemistry and Microbiology. Nord Univ, Fac Biosci & Aquaculture, Bodo, Norway..
    Ershova, Elizaveta
    Inst Marine Res, Bergen, Norway..
    Berge, Jorgen
    UiT Arctic Univ Norway, Dept Arctic & Marine Biol, N-9019 Tromso, Norway.;Norwegian Univ Sci & Technol, Ctr Autonomous Marine Operat & Syst AMOS, Dept Biol, Trondheim, Norway..
    Daase, Malin
    UiT Arctic Univ Norway, Dept Arctic & Marine Biol, N-9019 Tromso, Norway..
    Photoperiodism and overwintering in boreal and sub-Arctic Calanus finmarchicus populations2023In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 712, p. 49-65Article in journal (Refereed)
    Abstract [en]

    The copepod Calanus finmarchicus, a key species in the North Atlantic, generally spends the non-productive season by descending into deep waters and entering diapause, a physiological state characterized by reduced metabolism and arrested development. In the open ocean, overwintering depths are below 600 m, where temperature and light conditions are favourable to initiate diapause. However, C. finmarchicus has also been reported diapausing in areas with shallow water depth such as fjords, coastal waters and shelf seas. In these environments, the temperature and light conditions are different, and it has been hypothesized that under such conditions C. finmarchicus may remain active throughout winter. Here, we investigated changes in the swimming activity of C. finmarchicus from shallow fjords in the eastern North Atlantic during overwintering in response to ambient photoperiod. We conducted monthly experiments with populations from 2 fjords from different latitudes (sub-Arctic Ramfjord, 69 degrees N and boreal Loch Etive, 56 degrees N), measuring the locomotor activity of individual C. finmarchicus stage CVs exposed to a natural light:dark cycle. At both locations, peaks in activity in response to the light cycle were observed to shift from nocturnal during the early overwintering phase to diurnal during mid and late overwintering phase, with a minimal intensity observed during the mid-overwintering phase. In Ramfjord, activity and rhythmicity were generally lower than in Loch Etive. We conclude that C. finmarchicus remains active throughout its overwintering period when in shallow (<200 m) locations but down-regulates its locomotor activity during the main overwintering phase, which we describe as a winter resting state as distinct from classical diapause.

  • 7.
    Faust, Ellika
    et al.
    Univ Gothenburg, Dept Marine Sci Tjarno, S-45296 Stromstad, Sweden..
    Andre, Carl
    Univ Gothenburg, Dept Marine Sci Tjarno, S-45296 Stromstad, Sweden..
    Meurling, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal ecology.
    Kochmann, Judith
    Senckenberg Biodiversitat & Klima Forschungszentr, Senckenberg Gesell Nat Forsch, D-60325 Frankfurt, Germany..
    Christiansen, Henrik
    Univ Gothenburg, Dept Marine Sci Tjarno, S-45296 Stromstad, Sweden.;Katholieke Univ Leuven, Lab Biodivers & Evolutionary Genom, B-3000 Leuven, Belgium..
    Jensen, Lasse Fast
    Fisheries & Maritime Museum, DK-6710 Esbjerg V, Denmark..
    Charrier, Gregory
    Univ Bretagne Occidentale, Lab Sci Environm Marin LEMAR, UMR 6539, UBO,CNRS,IRD,Ifremer,IUEM, F-29280 Plouzane, France..
    Laugen, Ane T.
    Novia Univ Appl Sci, Ekenas 10600, Finland.;Swedish Univ Agr Sci, Dept Ecol, S-75007 Uppsala, Sweden..
    Strand, Asa
    Univ Gothenburg, Dept Marine Sci Tjarno, S-45296 Stromstad, Sweden..
    Origin and route of establishment of the invasive Pacific oyster Crassostrea gigas in Scandinavia2017In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 575, p. 95-105Article in journal (Refereed)
    Abstract [en]

    Identifying the routes and rates of introductions is fundamental for the understanding of marine invasions. Recurring introductions over the last 50 yr have led to the establishment of feral Pacific oyster Crassostrea gigas populations throughout Europe. In the northern countries, Sweden and Norway, the species first occurred in large numbers in 2006. Here, we investigated the relative importance of introduction via re-laying of cultured oysters imported for consumption from France, Ireland or the Netherlands, and dispersal of oyster larvae by ocean currents from wild oyster populations in Denmark. Using microsatellite DNA markers, we estimated genetic differentiation among Pacific oysters collected at 4 Swedish locations, 3 Norwegian locations and 9 potential source locations in Denmark, Ireland, the Netherlands and France. All Swedish samples and 1 Norwegian sample(Tromlingene) were genetically similar to each other and the Danish samples and showed significant genetic differentiation from all other populations. Consequently, it appears that the Pacific oyster populations in Sweden, Denmark and Tromlingene are closely connected and/or share a recent origin. The 2 remaining Norwegian samples(Hui and Espevik) differed from each other and all other populations, but showed similarities to wild oyster samples from Scandinavia and Ireland, respectively. Overall, the results underline a complex origin of Norwegian oysters, with gene flow from Swedish/Danish populations, as well as other unidentified sources. The apparent connectivity among most of the Scandinavian populations has implications for regional management of this invasive species, and highlights possible scenarios for other marine invasive species with a similar life history.

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  • 8.
    Grubisic, Lorena M.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Brutemark, Andreas
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Wikner, Johan
    Bamstedt, Ulf
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Effects of stratification depth and dissolved organic matter on brackish bacterioplankton communities2012In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 453, p. 37-48Article in journal (Refereed)
    Abstract [en]

    Bacterioplankton growth is often directly or indirectly controlled by external energy subsidies via organic matter inputs or solar radiation. We carried out a mesocosm experiment to assess how bacterioplankton communities responded to elevated levels of dissolved organic matter (DOM) and experimentally controlled stratification depth. The month-long experiment consisted of 2500 l mesocosms subjected to 4 experimental manipulations in triplicate: the stratification depth was set to either 1.5 or 3.5 m, with or without experimental addition of ambient levels of chromophoric DOM. DOM addition had a significant effect on bacterial community composition as assessed by terminal restriction fragment length polymorphism of amplified 16S rRNA genes. In contrast, there were no effects of the DOM amendment on bacterial biomass or production. Mixing depth and the coupled effective light climate in the photic zone also had a significant effect on bacterial community composition. Furthermore, shallow mixing depth was associated with enhanced primary production, whereas DOM addition had a negative effect on phyto plankton biomass and productivity. Our results suggest that bacterial community composition is coupled to primary production under the studied coastal nutrient regime, and point to a key role of DOM quality in controlling bacterioplankton communities.

  • 9.
    Henderiks, Jorijntje
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Palaeobiology.
    Winter, Amos
    Elbraechter, Malte
    Feistel, Rainer
    van der Plas, Anja
    Nausch, Guenther
    Barlow, Ray
    Environmental controls on Emiliania huxleyi morphotypes in the Benguela coastal upwelling system (SE Atlantic)2012In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 448, p. 51-66Article in journal (Refereed)
    Abstract [en]

    Two distinct morphotypes of the coccolithophore Emiliania huxleyi were observed as part of the phytoplankton succession offshore of Namibia, where coastal upwelling created strong gradients in sea surface temperature (SST), salinity, and nutrient conditions. The sampled surface waters hosted a characteristic succession of phytoplankton communities: diatoms bloomed in newly upwelled waters above the shelf, whereas dense coccolithophore communities dominated by E. huxleyi were found farther offshore, in progressively aging upwelled waters. A substantially calcified E. huxleyi morphotype (labeled Type A*) dominated plankton assemblages at stations influenced by upwelling, that immediately succeeded coastal diatom blooms. This morphotype caused a chlorophyll and 19'-hexanoyloxyfucoxanthin (19'-HF) maximum with >1 x 10(6) cells l(-1), straddling a pycnocline at 17 m depth where the in situ N:P ratio was approximate to 13. Farther offshore, within <20 nautical miles distance, populations of Type A* drastically declined, and a more delicate morphotype with thin distal shield elements and open central area (Type B/C) was found. This morphotype was most abundant (similar to 0.2 x 10(6) cells l(-1)) in high-phosphate, nitrogen-depleted surface waters (N:P approximate to 8), where it co-existed with other coccolithophores, most notably Syracosphaera spp. Extensive surface blooms of coccolithophores observed by satellites in the same region in the past were identified by microscopy as being produced by E. huxleyi and S. pulchra. However, blooms of E. huxleyi at greater depths in the euphotic zone, such as those observed in this study, will go undetected by satellites and thus underestimate coccolithophore biomass and calcification within upwelling regions.

  • 10.
    Häubner, Norbert
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
    Tallmark, Bo
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Animal Ecology.
    Snoeijs, Pauli
    Department of Systems Ecology, Stockholm University.
    Phytoplankton biomass controls tocopherol concentrations in Baltic Sea zooplanktonIn: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599Article in journal (Refereed)
    Abstract [en]

    Nearly all organisms are constantly exposed to oxidative threat, because every reaction where oxygen is involved gives rise to oxidants. Efficient protection is provided by antioxidants. Vitamin E (tocopherol) is an essential plant-derived antioxidant and poorly studied so far in marine food webs. In 2004 and 2005 eight offshore expeditions were conducted in the Baltic Sea to explore the dynamics of α-tocopherol in the pelagic food web. In order to analyze tocopherol production and transition to the next food web level, two plankton size classes were sampled; <100 µm (dominated by phytoplankton) and >200 µm (dominated by calanoid copepods). HPLC analysis revealed lowest values of α-tocopherol per L seawater in March in both size classes and highest in May for <100 µm (31.5 ng L-1) and August for >200 µm (1.3 ng L-1). No consistent seasonal pattern could be observed in α-tocopherol per unit biomass for the zooplankton. Concentrations ranged in <100 µm from 0.05 to 0.10 ng µg C-1 and in >200 µm from 0.05 to 0.11 ng µg C-1.  Partial least square regression (PLS) revealed nutrional status and species composition of the phytoplankton biomass as driving factors of α-tocopherol production in phytoplankton. Abiotic factors, as depth and temperature were only of significant influence in May. In zooplankton, the α-tocopherol concentration was negatively associated with phytoplankton biomass in May. Therefore we concluded that assimilation efficiency of zooplankton in combination with high phytoplankton biomass is the bottle-neck in tocopherol transport from phytoplankton to higher levels in the food web.

  • 11.
    Johansson, G
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Plant Ecology.
    Snoeijs, P
    Macroalgal photosynthetic responses to light in relation to thallus morphology and depth zonation2002In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 244, p. 63-72Article in journal (Refereed)
    Abstract [en]

    We show how photosynthesis and UV sensitivity of algae are related to thallus morphology and depth distributions. This was studied for typical depth zonations of red and brown macroalgae in the Skagerrak (ca. 25 psu) and the Baltic Sea (6.5 psu). The algae were collected from the water surface down to 20.5 m of depth, whereby each species was sampled at its maximum abundance depth. Altogether, we measured photosynthetic and respiratory rates of 19 red and 13 brown algal species as O2 evolution at different light intensities. Photosynthesis versus irradiance curves (PI curves) showed that light-saturated net photosynthetic rates (Pmax), respiratory rates in darkness (Rd) and the initial slope (α) were strongly related to algal morphology with higher values for thinner species. The compensation irradiance (Ic) and saturating irradiance (Ik) were strongly related to water depth with lower values at greater depth. A novel approach to analyse PI data with principal component analysis (PCA) is presented. The method makes it possible to assign a quantitative morphological gradient to algal species based on photosynthetic properties. Such a gradient can be used in ecological studies as an alternative to more subjective discrete subdivisions into functional-form groups. Another type of PCA analysis, with the relative shapes of the PI curves as input data, summarises α and convexity but discards all interference of morphology. This results in a gradient of genuine physiological responses, which in our study was strongly correlated to maximum abundance depth. The UV sensitivity of the same 32 algal species was determined as the change in net O2 evolution after exposure to UV light and the recovery after this treatment. Deeper-growing algae were more sensitive to UV and species with thinner thalli recovered better after UV treatment in the Skagerrak. No such trends were observed for the algae in the northern Baltic Sea, which suggests that no real deep-water species occur here. This is further supported by the lack of a clear pattern in Ic and Ik values with depth for the algae in the Baltic Sea. Our results advocate that the reduced species diversity of the Baltic Sea is also coupled to a loss of functional groups in the sense of general photosynthetic performance and not only in the sense of pure morphology (loss of canopy-forming species).

  • 12.
    Lönnstedt, Oona
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology.
    Frisch, Achley J.
    Habitat bleaching disrupts threat responses and persistence in anemonefish2014In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 517, p. 265-270Article in journal (Refereed)
    Abstract [en]

    Climate-induced habitat bleaching is linked to dramatic declines in diversity and abundance of coral reef fish; however, mechanisms underlying these declines are poorly understood. Here, we used in situ studies to demonstrate that bleaching can influence persistence of reef fish by affecting behaviours, including responses to a potential predation threat. When encountering the predatory rock cod Cephalophalis cyanostigma, anemonefish Amphiprion akindynos occupying healthy unbleached host anemones Heteractis crispa respond by feeding less and spending more time within the anemone tentacles. When the host anemone was experimentally bleached, these visual risk responses were compromised: A. akindynos continued to feed and did not seek shelter. The impaired behavioural response may prove detrimental to anemonefish populations as abundance levels of fish on bleached anemones was reduced by 60% within 3 d, which may have been the result of increased predation. Our data illustrate how climate-induced habitat degradation can drive declines of reef fish by potentially altering outcomes of predator–prey interactions.

  • 13.
    Roberts, E. M.
    et al.
    Univ Bergen, Dept Biol Sci, POB 7803, N-5020 Bergen, Norway.;Univ Bergen, KG Jebsen Ctr Deep Sea Res, POB 7803, N-5020 Bergen, Norway..
    Bowers, D. G.
    Bangor Univ, Sch Ocean Sci, Menai Bridge LL59 5AB, Anglesey, Wales..
    Meyer, H. K.
    Univ Bergen, Dept Biol Sci, POB 7803, N-5020 Bergen, Norway.;Univ Bergen, KG Jebsen Ctr Deep Sea Res, POB 7803, N-5020 Bergen, Norway..
    Samuelsen, A.
    Nansen Environm & Remote Sensing Ctr NERSC, Thormohlensgate 47, N-5006 Bergen, Norway.;Bjerknes Ctr Climate Res, Thormohlensgate 47, N-5006 Bergen, Norway..
    Rapp, H. T.
    Univ Bergen, Dept Biol Sci, POB 7803, N-5020 Bergen, Norway.;Univ Bergen, KG Jebsen Ctr Deep Sea Res, POB 7803, N-5020 Bergen, Norway.;Norwegian Res Ctr NORCE, NORCE Environm, Nygardsgaten 112, N-5008 Bergen, Norway..
    Cárdenas, Paco
    Uppsala University, Disciplinary Domain of Medicine and Pharmacy, Faculty of Pharmacy, Department of Medicinal Chemistry, Farmakognosi.
    Water masses constrain the distribution of deep-sea sponges in the North Atlantic Ocean and Nordic Seas2021In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 659, p. 75-96Article in journal (Refereed)
    Abstract [en]

    Water masses are bodies of water with distinctive physical and biogeochemical properties. They impart vertical structure to the deep ocean, participate in circulation, and can be traced over great distances, potentially influencing the distributions of deep-sea fauna. The classic potential temperature-salinity (theta-s) diagram was used to investigate deep-sea sponge (demosponge genus Geodia) association with water masses over the North Atlantic Ocean and Nordic Seas. A novel analysis was conducted, based on sampling the curvature of climatological mean theta-s curves at sponge locations. Sponges were particularly associated with turning points in the theta-s curves, indicative of intermediate and deep water masses. Arctic geodiid species (G. hentscheli and G. parva) were associated with Arctic intermediate and deep waters in the Nordic Seas, and with dense overflows into the northern North Atlantic. Boreal species (G. atlantica, G. barretti, G. macandrewii, and G. phlegraei) were associated with upper and intermediate water masses in the Northeast Atlantic and with upper, Atlantic-derived waters in the Nordic Seas. Taken together with distributional patterns, a link with thermohaline currents was also inferred. We conclude that water masses and major current pathways structure the distribution of a key deep-sea benthic faunal group on an ocean basin scale. This is most likely because of a combination of the physical constraints they place on the dispersal of early life-history stages, ecophysiological adaptation (evolved tolerances) to specific water masses, and the benefits to filter-feeders of certain phenomena linked to water column structure (e.g. nepheloid layers, internal waves/ tides, density-driven currents).

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  • 14. Snickars, Martin
    et al.
    Sundblad, Göran
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Sandström, Alfred
    Ljunggren, Lars
    Bergström, Ulf
    Johansson, Gustav
    Mattila, Johanna
    Habitat selectivity of substrate-spawning fish: modelling requirements for the Eurasian perch Perca fluviatilis2010In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 398, p. 235-243Article in journal (Refereed)
    Abstract [en]

    Substrate spawning fish are believed to be selective in their choice of spawning habitat,yet few studies have shown the relative importance of different characteristics in terms of habitatquality. We used an extensive and detailed dataset to identify the factors that govern both large-scale(1 000 to 100 000 m) and local-scale (10 to 100 m) selection by a substrate-spawning fish, the Eurasian perchPerca fluviatilis L. Distribution of spawning habitat was strongly dependent on habitat characteristicsdefined by substrate, wave exposure, temperature and depth. The most important predictor was thetype of spawning substrate, which generally consisted of different types of vegetation. Substratesproviding rigidity and structural complexity were preferred, despite abundant presence of other substratetypes. Shallow depth and sheltered areas were also selected habitat characteristics. Theresponse to temperature was scale-dependent, with a stronger selection expressed at the local scale.The specific selectivity suggests that spawning patterns can be successfully modelled with sufficientdetail using only a few fundamental environmental variables. Wave exposure and depth are readilyavailable for large-scale spatial predictions, while temperature and substrate require further developmentin most coastal areas. The high specificity of the characteristics determining habitat qualitysuggests that it should be possible to apply this modelling approach for identification and conservationof spawning habitats of Eurasian perch and other substrate-spawning fishes in coastal waters.

  • 15.
    Stedt, J.
    et al.
    Lund Univ, Dept Biol, S-22362 Lund, Sweden.
    Wahlberg, M.
    Univ Southern Denmark, Dept Biol, DK-5230 Odense, Denmark.
    Carlstrom, J.
    Swedish Museum Nat Hist, Dept Environm Res & Monitoring, S-10405 Stockholm, Sweden.
    Nilsson, P. A.
    Lund Univ, Dept Biol, S-22362 Lund, Sweden.
    Amundin, M.
    Kolmarden Wildlife Pk, S-61893 Kolmarden, Sweden.
    Oskolkov, N.
    Uppsala University, Science for Life Laboratory, SciLifeLab. Lund Univ, Dept Biol, S-22362 Lund, Sweden.;Nat Bioinformat Infrastruct Sweden NBIS.
    Carlsson, P.
    Lund Univ, Dept Biol, S-22362 Lund, Sweden.
    Micro-scale spatial preference and temporal cyclicity linked to foraging in harbour porpoises2023In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 708, p. 143-161Article in journal (Refereed)
    Abstract [en]

    Habitat heterogeneity is a crucial driver for species distribution across scales. Harbour porpoise Phocoena phocoena basin-wide distribution is linked to prey availability, and small-scale (kilometres to tens of kilometres) differences in distribution are prevalent. However, information on porpoise distribution and foraging-behaviour variations on a micro-scale (similar to 100 m to kilometres) is limited. To monitor harbour porpoise distribution and foraging activity on a micro-scale, we deployed passive acoustic dataloggers, logging porpoise acoustic activity at 6 sites in a small, high porpoise-density area in southern Sweden. Data were collected for almost a year, giving detailed time series on porpoise activity. The time series were analysed using dynamic time warping to compare activity patterns between sites. Large differences were found between sites separated by only a few hundred meters, indicating micro-scale spatial preference. Spectral analysis for temporal cyclicity in activity revealed a dominant peak for 24 h cycles with higher activity at night for all sites. All sites also had a second peak for 29.5 d, linked to the lunar cycle with higher activity during full moon. Activity was overall highest during autumn and winter (September-December). Spatial and temporal patterns were linked to foraging, showing a positive correlation between porpoise presence and the percent of time present with detected foraging. The study demonstrates that harbour porpoise spatial distribution on a micro-scale should be considered in e.g. behavioural, management and conservation studies and actions. In addition, we show that time series statistical methodology is informative and appropriate for analysis of acoustic temporal data.

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  • 16.
    Sylvander, Peter
    et al.
    Department of Systems Ecology, Stockholm University.
    Häubner, Norbert
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Ecological Botany.
    Snoeijs, Pauli
    Department of Systems Ecology, Stockohlm University.
    The thiamine (vitamin B1) content of phytoplankton is affected by temperature, photon density and salinityIn: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599Article in journal (Refereed)
    Abstract [en]

    Thiamine (vitamin B1) is produced by plants, algae and bacteria and must be acquired through the food web by higher trophic levels. In this study we investigate the biosynthesis of thiamine in six phytoplankton species belonging to five different phyla under different environmental conditions. The chlorophyte Dunaliella tertiolecta, the dinoflagellate Prorocentrum minimum and the prymnesiophyte Rhodomonas salina were found to be thiamine auxotrophs, while the cyanobacterium Nodularia spumigena and the diatoms Phaeodactylum tricornutum and Skeletonema costatum were capable of thiamine synthesis. Measured net thiamine production in the latter three species varied with temperature, photon density and salinity. These effects were different for the cyanobacterium and the diatoms and strongest for salinity. In N. spumigena, the total thiamine concentration increased threefold with increased salinity. P. tricornutum accumulated seven times more thiamine diphosphate when salinity was decreased. Temperature also had pronounced effects on thiamine concentration, while photon density only affected thiamine levels in combination with temperature. In N. spumigena and P. tricornutum, total thiamine levels increased with higher temperature. We demonstrate a high variability among phytoplankton species in thiamine biosynthesis, as well as in the level of thiamine production in response to environmental factors. Thus, regime shifts in phytoplankton community composition through large-scale environmental change can alter the vitamin B1 availability for higher trophic levels. This may have serious consequences for the access of zooplankton, fish, birds and mammals to this essential vitamin in changing ecosystems.

     

  • 17.
    Torstensson, Anders
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Genetics, Limnology. Univ Washington, Sch Oceanog, Seattle, WA 98195 USA.;Swedish Meteorol & Hydrol Inst, S-42671 Vastra Frolunda, Sweden..
    Showalter, G. M.
    Univ Washington, Sch Oceanog, Seattle, WA 98195 USA..
    Margolin, A. R.
    Virginia Inst Marine Sci, Coll William & Mary, Gloucester Point, VA 23602 USA..
    Shadwick, E. H.
    Virginia Inst Marine Sci, Coll William & Mary, Gloucester Point, VA 23602 USA.;CSIRO Oceans & Atmosphere, Hobart, Tas 7001, Australia..
    Deming, J. W.
    Univ Washington, Sch Oceanog, Seattle, WA 98195 USA..
    Smith, W. O., Jr.
    Virginia Inst Marine Sci, Coll William & Mary, Gloucester Point, VA 23602 USA.;Shanghai Jiao Tong Univ, Sch Oceanog, Shanghai 200240, Peoples R China..
    Chemical and biological vertical distributions within central Arctic (>82 degrees N) sea ice during late summer2023In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 703, p. 17-30Article in journal (Refereed)
    Abstract [en]

    We assessed the distribution of biota (autotrophs and heterotrophs) and associated carbonate chemistry variables in Arctic sea ice at latitudes >82 degrees N during late summer and early autumn 2018. The sampled sea ice was relatively thick (average 1.4 m) with variable snow cover (mean 7 cm) and low bulk salinities throughout. Most measured variables, including carbonate chemistry parameters, were low in the upper half of the ice cores, but increased with depth. Measurements of particulate organic carbon (POC), chlorophyll a (chl a), bacterial abundance, and particulate extracellular polysaccharide (pEPS) in the cores strongly suggested that detrital carbon was the major particulate organic pool. Near the ice-water interface, autotrophic material comprised ca. 50% of the total POC, whereas pEPS and bacterial carbon accounted for ca. 8 and 1% of the total POC, respectively. Under-ice water was nutrient poor, providing only a small input of nutrients to support autotrophic growth, at least during the time of our sampling. While the Arctic Ocean has substantial interannual variability in sea-ice concentration and thickness, these measurements enrich the available database and suggest that during years when autumn sea ice is >1 m thick, sea-ice biota are limited in activity and biomass.

  • 18.
    Westin, Lars
    Gotland University, Department of Biology.
    Migration failure in stocked eels Anguilla anguilla2003In: Marine Ecology Progress Series, ISSN 0171-8630, E-ISSN 1616-1599, Vol. 254, p. 307-311Article in journal (Refereed)
    Abstract [en]

    Silver eels Anguilla anguilla L., stocked as elvers in a freshwater lake on the island of Gotland, were caught in an outlet stream leading to the Baltic Sea. After tagging, they were released either into the lake or into the stream above a fine-meshed trap, and were recaptured after a period of 3 to 120 mo. During the period between tagging and recapture, the majority lost weight and decreased in length and fat content. It is hypothesized that the stocked eels had had no opportunity to imprint the directional cues necessary for migration; i.e. they were unable to recognize the outlet stream as the starting point of migration and lacked the orientation mechanism necessary to locate the outlet to the Baltic Sea. The lake itself comprises an initial trap, and the Baltic Sea a secondary trap. It is concluded that stocked eels lack imprinting, and that consequently their contribution to recruitment is null.

1 - 18 of 18
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