uu.seUppsala University Publications
Change search
Refine search result
1234567 101 - 150 of 473
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 101.
    Brunberg, Anna-Kristina
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Boström, Bengt
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Coupling between benthic biomass of Microcystis and phosphorus release from the sediments of a highly eutrophic lake.1992In: Hydrobiologia, Vol. 235/236, p. 375-385Article in journal (Refereed)
  • 102.
    Brunberg, Anna-Kristina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Carlsson, Therese
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Brydsten, Lars
    Strömgren, Mårten
    Forsmark site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.2004Report (Other academic)
  • 103.
    Brunberg, Anna-Kristina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Carlsson, Therse
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Brydsten, Lars
    Strömgren, Mårten
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Oskarshamn site investigation. Identification of catchments, lake-related drainage parameters and lake habitats.2004Report (Other academic)
  • 104.
    Brunberg, Anna-Kristina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Nilsson, Eva
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Limnology.
    Blomqvist, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology, Limnology.
    Characteristics of oligotrophic hardwater lakes in a postglacial land-rise area in mid-Sweden2002In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 47, no 8, p. 1451-1462Article in journal (Refereed)
    Abstract [en]

    1. We describe some remarkable ephemeral, oligotrophic hardwater lakes formed becauseof land rise in the coastal areas of the Baltic Sea, that are unique in Sweden and probablyalso worldwide. Two younger, coastal lakes were studied by regular sampling for 1 yearand compared with an older (i.e. greater altitude) lake, that passed through theoligotrophic hardwater stage some 3–4000 years ago.

    2. Despite some differences in composition of the catchment, the two younger lakes weresimilar with regard to water chemistry and plankton community composition. Theconcentration of phosphorus was low while nitrogen was high, resulting in very high N/Pquotients (101 and 131). Although water colour was moderate, the concentration of organiccarbon was extremely high (average values of ‡ 20 lg TOC L–1), consisting mainly ofdissolved compounds (DOC).

    3. While the plankton was poorly developed, sediments in both lakes were covered by alayer of photosynthesising micro-organisms. This substantial 'microbial mat', which hasnot been described in detail before, was up to 15 cm thick and dominated by cyanobacteriaand purple sulphur bacteria. The concentration of sediment phosphorus was extremelylow (352 lg g–1 dw) in one of the lakes and dominated by organic-bound (residual)phosphorus.

    4. Deep sediments in the older lake, representing its oligotrophic hardwater period,differed in phosphorus composition from the currently oligotrophic hardwater lakes byhaving a strong dominance of HCl-extractable (Ca-bound) phosphorus. This indicates thatphosphorus, initially organic-bound within the microbial mat, is subsequently bound tocalcium. We hypothesise that this is promoted by the environmental conditions created bythe benthic photosynthetic activity, in combination with the prevailing hardwaterconditions.

    5. The rich and flourishing microbial community on the sediments may also explain thehigh concentration of DOC in the lake.

  • 105.
    Brunke, M.
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Sukhodolov, H.
    Fischer, S.
    Wilczek, C.
    Pusch, M.
    Pusch, E.
    Benthic and hyporheic habitats of a large lowland river (Elbe, Germany): influence of river engineering.2002In: Verh. Internat. Verein. Limnol., Vol. 28, p. 153-156.Article in journal (Refereed)
  • 106. Brydsten, Lars
    et al.
    Carlsson, Therese
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Brunberg, Anna-Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Blomqvist, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    A method for determination of morphometry, sediment distribution, and habitat diversity of lake basins and its application to three lakes in Uppland.2004Report (Other academic)
  • 107.
    Bryhn, Andreas Christoffer
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Earth Sciences, Department of Earth Sciences, Air and Water Science.
    Hessen, Dag O
    Blenckner, Thorsten
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Predicting particulate pools of nitrogen, phosphorus and organic carbon in lakes2007In: Aquatic Sciences, ISSN 1015-1621, E-ISSN 1420-9055, Vol. 69, no 4, p. 484-494Article in journal (Refereed)
    Abstract [en]

    The variation between lakes with respect to concentrations of particulate nutrient pools was studied in 126 Norwegian lakes covering a wide range in lake-specific properties. Particulate phosphorus (P) always constituted close to 60% of total P (TP) concentrations. Particulate nitrogen (N) and organic carbon (C) concentrations, on the other hand, were sensitive to several lake characteristics, particularly to TP concentrations. Through optimisation procedures and multivariate regression, the present study presents general empirical models for predicting particulate nutrient concentrations. Furthermore, significant trend shifts in the relationships between TP vs. particulate N and TP vs. particulate organic C were observed at TP = 6 mu g l(-1) and TP = 80 mu g l(-1), suggesting non-linearities in these relationships along the TP gradient. A trend shift in the TP vs. chlorophyll relationship was observed at TP = 90. Taking such non-linearities into account may decrease the uncertainty in predicting particulate N, particulate organic C and chlorophyll.

  • 108. Burkert, Ulrike
    et al.
    Hyenstrand, Per
    Drakare, Stina
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Blomqvist, Peter
    Effects of the mixotrophic flagellate Ochromonas sp. on colony formation in Microcystis aeruginosa2001In: Aquatic Ecology, Vol. 35, p. 9-17Article in journal (Refereed)
  • 109.
    Candolin, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Engström-Öst, Jonna
    Salesto, Tiina
    Human-induced eutrophication enhances reproductive success through effects on parenting ability in sticklebacks2008In: Oikos, ISSN 0030-1299, E-ISSN 1600-0706, Vol. 117, no 3, p. 459-465Article in journal (Refereed)
    Abstract [en]

    Human-induced processes are altering habitats at an unprecedented rate and scale. This has changed the biodiversity and biomass in many areas, but also led to phenotypic and genetic alterations of populations. Here we investigated the effects of the ongoing eutrophication in the Baltic Sea on the reproductive success of threespine stickleback males Gasterosteus aculeatus, through effects on reproductive behaviour and parenting ability. We allowed males to complete breeding cycles in a competitive setting under increased macro algae cover or increased turbidity caused by phytoplankton growth. Both environmental factors improved the parenting ability of the males and enhanced reproductive output. Increased alga growth and turbidity reduced aggressive interactions between males during the parental phase, probably due to reduced visibility, which slowed down a deterioration of condition. This increased the reproductive lifespan of the males and enabled them to complete more breeding cycles, as found when males were allowed to complete as many breeding cycles as they could under increased algae cover. In addition, increased turbidity improved oxygen conditions, which enhanced hatching success and reduced the need for vigorous fanning behaviour. Increased turbidity, however, relaxed selection on male size. Together with earlier results on relaxed sexual selection under changed environmental conditions, this suggests that the effect of eutrophication on stickleback populations is complex. It increases the reproductive output of populations, since more individuals are spawning within eutrophicated areas and their hatching success is increased, but it relaxes sexual and natural selection at the reproductive stage. Whether this will shift selection and population regulation to other life stages, such as the juvenile stage, deserves further investigations.

  • 110.
    Candolin, Ulrika
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Salesto, Tiina
    The effects of vegetation cover on nesting behaviour of sticklebacks2006In: Behavioral Ecology and Sociobiology, Vol. 59, p. 689-693Article in journal (Refereed)
  • 111.
    Candolin, Ulrika
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Salesto, Tiina
    Evers, Maren
    Changed environmental conditions weaken sexual selection in sticklebacks2007In: Journal of Evolutionary Biology, ISSN 1010-061X, E-ISSN 1420-9101, Vol. 20, p. 233-239Article in journal (Refereed)
    Abstract [en]

    Environmental heterogeneity can cause the intensity and direction of selection to vary in time and space. Yet, the effects of human-induced environmental changes on sexual selection and the expression of mating traits of native species are poorly known. Currently, the breeding habitats of the three-spined sticklebackGasterosteus aculeatus are changing in the Baltic Sea because of eutrophication and increased growth of algae. Here we show that enhanced growth of filamentous algae increases the costs of mating by inducing an increase in the time and energy spent on courtship and mate choice. This is not followed by a concomitant increase in mate attraction, but instead the strength of selection on male red nuptial coloration and courtship activity is relaxed. Thus, the high investment into the costly sexually selected traits is maladaptive under the new conditions, and the mating system mediates a negative effect of the environmental change on the population. We attribute these environmentally induced changes in the benefit of the mating traits and in the strength of sexual selection to reduced visibility in dense vegetation. Anthropogenic disturbances hence affect the selection pressures that mould the species, which could have long-term effects on the viability and evolution of the populations. 

  • 112.
    Carey, Cayelan C.
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Haney, James F.
    Cottingham, Kathryn L.
    First report of microcystin-LR in the cyanobacterium Gloeotrichia echinulata2007In: Environmental Toxicology, ISSN 1520-4081, E-ISSN 1522-7278, Vol. 22, no 3, p. 337-339Article in journal (Refereed)
    Abstract [en]

    Gloeotrichia echinulata is a bloom-forming cyanobacterium that is common in eutrophic lakes, and less prevalent but increasing in oligotrophic lakes. We used an enzyme-linked immunosorbent assay analysis to test for the presence of the hepatotoxin microcystin-LR (MC-LR) in G. echinulata collected from an oligotrophic lake in central New Hampshire, USA. We found that G. echinulata contained MC-LR at mean concentrations of 97.07 +/- 7.78 (1 s.e.) ng MC-LR g(-1) dry wt colonies. This suggests that recent outbreaks of G. echinulata in oligotrophic lakes used as water sources throughout New England (USA) may pose a health concern. The toxicity of G. echinulata reported here suggests the need for future monitoring of microcystins in oligotrophic lakes.

  • 113.
    Carlsson, Therese
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Brunberg, Anna-Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Brydsten, Lars
    Strömgren, Mårten
    Forsmark site investigation. Characterisation of running waters, including vegetation, substrate and technical encroachments2005Report (Other (popular science, discussion, etc.))
  • 114.
    Carlsson, Therese
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Brunberg, Anna-Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Brydsten, Lars
    Strömgren, Mårten
    Oskarshamn site investigation. Characterisation of running waters, including vegetation, substrate and technical encroachments.2005Report (Other academic)
  • 115. Christoffersen, Kirsten S.
    et al.
    Jeppesen, Erik
    Moorhead, Daryl L.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Food-web relationships and community structures in high-latitude lakes.2008In: Polar Lakes and Rivers: Limnology of Arctic and Antarctic Aquatic Ecosystems, Oxford, 2008, p. 269-289Chapter in book (Other (popular science, discussion, etc.))
  • 116. Cory, Neil
    et al.
    Andrén, Cecilia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bishop, Kevin
    Modelling inorganic Aluminium with WHAM in environmental monitoring2007In: Applied Geochemistry, ISSN 0883-2927, E-ISSN 1872-9134, Vol. 22, no 6, p. 1196-1201Article in journal (Refereed)
    Abstract [en]

    Due to the varying toxicity of different Al species, information about Al concentration and speciation is important when assessing water quality. Modelling Al speciation can support operational monitoring programmes where Al speciation is not measured directly. Modelling also makes it possible to retroactively speciate older samples where laboratory fractionation was not undertaken. Organic-rich waters are a particular challenge for both laboratory analysis and models. This paper presents the modelling of Al speciation in Swedish surface waters using the Windermere Humic Acid Model (WHAM). The model was calibrated with data from operational monitoring, the Swedish national survey of lakes and rivers, and covers a broad spectrum of physical and chemical conditions. Calibration was undertaken by varying the amount of DOC active in binding Al. A sensitivity analysis identified the minimum parameters required as model input variables primarily to be total Al, organic C, pH, F, and secondly Fe, Ca and Mg. The observed and modelled Ali had no significant differences (Spearman rank, p < 0.01), however, lake samples modelled better than rivers. Samples were placed in the correct toxicological category in 89–95% of the cases. The importance of the size of the calibration data set was assessed, and reducing the calibration data set resulted in poorer correlations, but had little impact on the toxicological placement. Overall, the modelling gave satisfactory results from samples covering a broad spectrum of physical and chemical conditions. This indicates the potential value of WHAM as a tool in operational monitoring of surface waters.

  • 117. Cory, Neil
    et al.
    Andrén, Cecilia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bishop, Kevin
    Modelling of aluminium speciation as a complement to laboratory-based analysis2004Report (Other scientific)
  • 118.
    Cory, Neil
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Andrén, Cecilia
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bishop, Kevin
    WHAM increases the understanding of Aluminium-chemistry in environmental monitoring2005In: Acid Rain 2005, Prag, Tjeckoslovakien, 12-17 juni, 2005, 2005Conference paper (Other (popular scientific, debate etc.))
  • 119.
    Dadebo, Elias
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Ahlgren, Gunnel
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Ahlgren, Ingemar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Aspects of reproductive biology of Labeo horie Heckel (Pisces: Cyprinidae) in Lake Chamo, Ethiopia2003In: African Journal of Ecology, Vol. 41, p. 31-38Article in journal (Refereed)
  • 120.
    Dadebo, Elias
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Ahlgren, Ingemar
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Ahlgren, Gunnel
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Maturation, sex ratio and fecundity of the Nile perch, Lates niloticus (L.) (Pisces: Centropomidae) in Lake Chamo, Ethiopia2005In: SINET: Ethiop. J. Sci., ISSN 0379-2897, Vol. 28, no 2, p. 151-160Article in journal (Refereed)
  • 121. Daneshvar, Atlasi
    et al.
    Svanfelt, Jesper
    Kronberg, Leif
    Prévost, Michele
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Seasonal variations in the occurrence and fate of basic and neutral pharmaceuticals in a Swedish river-lake system2010In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 80, no 3, p. 301-309Article in journal (Refereed)
    Abstract [en]

    The seasonal variations in the occurrence of carbamazepine, atenolol, metoprolol, sotalol, and acebutolol were studied at seven sites along River Fyris from December 2007 to December 2008. Samples were collected from the effluent of a waste water treatment plant (WWTP), at one upstream site, and five downstream sites of the WWTP). During one occasion in May 2008, water samples were collected at different locations and depths in the recipient lake. All analytes except of acebutolol were present in both the river and the lake at quantifiable amounts at all sampling occasions. Carbamazepine was found in similar concentrations (about 90 ng L-1) at all sampling sites and all studied depths (0.5-40 m) in the lake, indicating high environmental persistence of this compound. A clear seasonal pattern was observed for the natural attenuation of the beta-blockers in the river, with the highest attenuation occurring in summer and the lowest in winter. The loss of beta-blockers on a distance of 1320 m reached up to 75% during summer time but was insignificant during winter. The seasonal variations in the loss followed the seasonal variations in water temperature and chlorophyll a mass flow suggesting that biotransformation and adsorption are the main processes responsible for the loss of the studied pharmaceuticals in River Fyris downstream the WWTP.

  • 122. Daneshvar, Atlasi
    et al.
    Svanfelt, Jesper
    Kronberg, Leif
    Weyhenmeyer, Gesa A.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Winter accumulation of acidic pharmaceuticals in a Swedish river2010In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 17, no 4, p. 908-916Article in journal (Refereed)
    Abstract [en]

    In this study, seasonal variations in the concentration profile of four analgesics and one lipid regulator were monitored on their way from a wastewater treatment plant (WWTP) effluent, along a river, and into a lake. From December 2007 to December 2008, water samples were collected monthly (n = 12) from an upstream point, the effluent, four downstream points of the WWTP, and at the point where the river merges with the lake, and the concentrations of ibuprofen, naproxen, bezafibrate, diclofenac, and ketoprofen were determined. The analytical methodology involved solid-phase extraction of the target compounds from water samples followed by liquid chromatography coupled with tandem mass spectrometry for compound separation and detection. The studied pharmaceuticals were found in the effluent at concentrations ranging from 31 to 1,852 ng l(-1) depending on the season. In the river and lake, the concentrations were much lower (6-400 ng l(-1)) mainly due to dilution but also to a season-dependent contribution from natural transformation processes. The mean mass flow of all analgesics was highest during winter while the highest mean mass flow of the lipid regulator bezafibrate was observed in spring. The WWTP is the main source of the target compounds in the aquatic environment. The observed winter accumulation signifies the importance of natural transformation processes, which can only be estimated based on mass flow data, on the fate of pharmaceuticals in the environment.

  • 123.
    De Brabandere, Heidi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Forsgard, Niklas
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Israelsson, Lena
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Petterson, Jean
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Waldebäck, Monica
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Sjöberg, Per J. R.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Screening for Organic Phosphorus Compounds in Aquatic Sediments by Liquid Chromatography Coupled to ICP-AES and ESI-MS/MS2008In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 80, no 17, p. 6689-6697Article in journal (Refereed)
    Abstract [en]

    The structures of organic phosphorous (P) compounds in aquatic sediments are to a large extent unknown although these compounds are considered to play an important role in regulating lake trophic status. To enhance identification of these compounds, a liquid chromatography (LC) method for their separation was developed. The stationary phase was porous graphitic carbon (PGC), and the mobile phases used in the gradient elution were compatible with both inductive coupled plasma atomic emission spectroscopy (ICP-AES) and electrospray ionization tandem mass spectrometry (ESI-MS/MS). With LC-ICP-AES, eight different P containing peaks could be observed in the P chromatogram indicating that at least eight different P compounds were separated. With the setup of an information dependent acquisition (IDA) with ESI-MS/MS, the mass over charge (m/z) of compounds containing a phosphate group (H2PO3, m/z 97) could be measured and further fragmentation experiments gave additional information on the structure of almost 40 separated P compounds, several were verified to be nucleotides. ICP-AES was very suitable in the development of the LC method and allowed screening and quantification of P compounds. The presented LC-ESI-MS/MS technique was able to identify several sediment organic P compounds.

  • 124.
    De Brabandere, Heidi
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Sjöberg, Per J. R.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Danielsson, Rolf
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Ahlgren, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Waldebäck, Monica
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Physical and Analytical Chemistry, Analytical Chemistry.
    Sediment extraction and clean-up for organic phosphorus analysis by electrospray ionization tandem mass spectrometry2008In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 74, no 5, p. 1175-1183Article in journal (Refereed)
    Abstract [en]

    A method to prepare NaOH sediment extracts for organic P compound analysis with electrospray ionization tandem mass spectrometry (ESI-MS-MS) was developed on natural samples. Ion exchange, rotary evaporation and mass cut-off filtering proved to be suitable for sample preparation. Samples were analyzed with ESI-MS-MS, and reproducibility and repeatability of the method was calculated. In addition, 31P-nuclear magnetic resonance spectroscopy (31P NMR) was used to measure recovery of different P compound groups such as orthophosphate (Ortho-P), orthophosphate monoesters (Monoester-P), orthophosphate diesters (Diester-P) and pyrophosphates (Pyro-P).

    The developed sample preparation method resulted in an easy-to-spray liquid for the ESI-MS-MS instrumentation. The overall P recovery was 65% and 31P NMR showed that Diester-P, possibly in the form of DNA, was apparently lost through the filtering step most likely due to their size. Variances in the total intensities of the MS scans (relative standard deviation (R.S.D.) 35–54%) were for about 50% due to repeated MS runs. Covariances of the peaks in the MS spectra were calculated to be for about 30% due to the sample preparation procedure. Finally, with the ESI-MS-MS approach, 11 peaks in the mass spectra were found likely to represent phosphate containing compounds.

  • 125.
    Denward, Måns
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Anesio, Alexandre
    Granéli, Wilhelm
    Tranvik, Lars
    Solar radiation effects on decomposition of macrophyte litter in a lake littoral2001In: Archiv fur Hydrobiologie, Vol. 152, no 1, p. 69-80Article in journal (Refereed)
  • 126.
    Denward, Måns CT
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Edling, H
    Tranvik, Lars
    Effects of solar radiation on bacterial and fungal growth on aquatic plant litter1999In: Freshwater Biology, Vol. 41, p. 575-582Article in journal (Refereed)
  • 127. Downing, J. A.
    et al.
    Duarte, C. M.
    Tranvik, Lars J.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Striegl, R. G.
    McDowell, W. H.
    Kortelainen, P.
    Caraco, N. F.
    Melack, J. M.
    Middelburg, J. J.
    The global abundance and size distribution of lakes, ponds, and impoundments2006In: Limnology and Oceanography, ISSN 0024-3590, E-ISSN 1939-5590, Vol. 51, no 5, p. 2388-2397Article in journal (Refereed)
    Abstract [en]

    One of the major impediments to the integration of lentic ecosystems into global environmental analyses has been fragmentary data on the extent and size distribution of lakes, ponds, and impoundments. We use new data sources, enhanced spatial resolution, and new analytical approaches to provide new estimates of the global abundance of surface-water bodies. A global model based on the Pareto distribution shows that the global extent of natural lakes is twice as large as previously known (304 million lakes; 4.2 million km(2) in area) and is dominated in area by millions of water bodies smaller than 1 km(2). Similar analyses of impoundments based on inventories of large, engineered dams show that impounded waters cover approximately 0.26 million km(2). However, construction of low-tech farm impoundments is estimated to be between 0.1% and 6% of farm area worldwide, dependent upon precipitation, and represents > 77,000 km(2) globally, at present. Overall, about 4.6 million km(2) of the earth's continental "land" surface (> 3%) is covered by water. These analyses underscore the importance of explicitly considering lakes, ponds, and impoundments, especially small ones, in global analyses of rates and processes.

  • 128.
    Drakare, Stina
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Blomqvist, Peter
    Bergström, Ann-Kristin
    Jansson, Mats
    Primary production and phytoplankton composition in relation to DOC input and bacterioplankton production in humic lake Örträsket2002In: Freshwater Biology, Vol. 47, no 1, p. 41-52Article in journal (Refereed)
  • 129.
    Drakare, Stina
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Blomqvist, Peter
    Bergström, Ann-Kristin
    Jansson, Mats
    Relationships between picophytoplankton and their environment along a gradient of lakes of different water colour and nutrient content2003In: Freshwater Biology, Vol. 48, p. 729-740Article in journal (Refereed)
  • 130.
    Drakare, Stina
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Lennon, Jack J.
    Hillebrand, Helmut
    The imprint of the geographical, evolutionary and ecological context on species-area relationships.2006In: Ecology Letters, Vol. 9, p. 215-227Article in journal (Refereed)
  • 131.
    Drakare, Stina
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Liess, Antonia
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Local factors control the community composition of cyanobacteria in lakes while heterotrophic bacteria follow a neutral model2010In: Freshwater Biology, ISSN 0046-5070, E-ISSN 1365-2427, Vol. 55, no 12, p. 2447-2457Article in journal (Refereed)
    Abstract [en]

    1. Neutral community models are derived from the proposition that basic probabilities of species loss (extinction, emigration) and gain (immigration, speciation) explain biological community structure, such that species with many individuals are very likely to be widespread. Niche models on the other hand assume that interactions between species and differential resource use mediate species coexistence, thus invoking environmental factors to explain community patterns. 2. In this study, we compared neutral and niche models to test how much of the spatial variability of assemblages of heterotrophic bacteria and phytoplankton in 13 lakes they could explain. Analysis of phytoplankton was restricted to cyanobacteria, so that they could be studied with the same molecular fingerprinting method, automated ribosomal intergenic spaces analysis (ARISA), as heterotrophic bacteria. We determined local biotic and abiotic lake variables as well as lake age, glacial history and distance between sites. 3. The neutral community model had a good fit to the community composition of heterotrophic bacteria (R-2 = 0.69), whereas it could not produce a significant model for the community composition of cyanobacteria. 4. The community composition of cyanobacteria was instead correlated to environmental variables. The best model, a combination of total organic carbon, biomass of eukaryotic phytoplankton, pH and conductivity, could explain 8% of the variation. In contrast, variation in the community composition of heterotrophic bacteria was not predicted by any of the environmental variables. Historical and spatial variables were not correlated to the community composition of either group. 5. The pattern found for heterotrophic bacteria suggests that stochastic processes are important. The correlation of cyanobacteria with local environmental variables alone is consistent with the niche model. We suggest that cyanobacteria, a group of organisms containing bloom-forming species, may be less likely to fit a neutral community model, since these blooms are usually triggered by a particular combination of environmental conditions.

  • 132. Dugopolski, Rebecca A.
    et al.
    Rydin, Emil
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Brett, Michael T.
    Short-term effects of a buffered alum treatment on Green Lake sediment phosphorus speciation2008In: Lake and reservoir management, ISSN 1040-2381, E-ISSN 2151-5530, Vol. 24, no 2, p. 181-189Article in journal (Refereed)
    Abstract [en]

    Green Lake, Washington, was treated with a dose of 24 mg Al/L aluminum   sulfate (alum) and sodium aluminate during March-April 2004 to reduce   dissolved phosphorus concentrations to ameliorate a variety of   eutrophication-related problems. Four sediment cores collected six   months after the alum treatment in Green Lake were used to examine the   short-term effects of alum on sediment phosphorus speciation. Peaks in   aluminum bound phosphorus (Al-P) and total aluminum (Tot-Al) were   observed in three of the four cores analyzed, resulting in an average   ratio of added Al to Al-P formed (Al:Al-P) of 112:1. By comparing this   ratio to the average ratio of similar to 11:1 found in other   alum-treated Washington lakes, it can be inferred that approximately   10% of the binding capacity of the added Al had been utilized. Assuming   a final ratio of Al:Al-P of 11:1, the added Al has the potential   capacity to bind a total of 21.6 g/m(2) of P. The amount of sediment   inorganic P that supports internal loading (Fe-P and labile-P) in the   fall of 2004 was determined to be 2.8 g/m(2). Thus the quantity of alum   added to Green Lake should be sufficient to inactivate the remaining   inorganic mobile-P and to control future P mobilization from the pool   of organic sediment P.

  • 133. Ehn, J
    et al.
    Granskog, M A
    Reinart, A
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limologi.
    Erm, A
    Optical properties of melting landfast sea ice and underlying seawater in Santala Bay, Gulf of Finland.2004In: J. Geophys. Res.: Oceans, Vol. 109, p. C09003-Article in journal (Refereed)
  • 134.
    Eiler, A
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Farnleitner, A H
    Zechmeister, T C
    Herzig, A
    Hurban, C
    Wesner, W
    Krachler, R
    Velimirov, B
    Kirschner, A K T
    Factors controlling extremely productive heterotrophic bacterial communities in shallow soda pools.2003In: Microb Ecol, ISSN 0095-3628, Vol. 46, no 1, p. 43-54Article in journal (Refereed)
  • 135.
    Eiler, Alexander
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Evidence for the ubiquity of mixotrophic bacteria in the upper ocean: implications and consequences.2006In: Applied and Environmental Microbiology, ISSN 0099-2240, Vol. 72, no 12, p. 7431-7Article in journal (Refereed)
  • 136.
    Eiler, Alexander
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    The Niches of Bacterial Populations in Productive Waters: Examples from Coastal Waters and Four Eutrophic Lakes2006Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Recent research in microbial ecology has focused on how aquatic bacterial communities are assembled. Only a few of these studies follow a “Gleasonian” approach where the roles of single bacterial populations are in focus. In this thesis, novel molecular tools were used to describe the distribution and evolutionary relationships of microbes in productive aquatic environments. Many new phylogenetic groups of bacteria were identified, likely representing bacterial populations restricted to productive freshwaters. I also addressed the dynamics and functional role of individual bacterial populations in eutrophic lakes and brackish environments with a focus on either biogeochemically significant or potentially pathogenic representatives. Flavobacteria blooms were observed, on occasions characterized by high heterotrophic production. In addition to high temporal dynamics microbial community composition and function differed on the spatial scale, as exemplified by free-living and Cyanobacteria-associated habitats. At the community scale, microbial processes, such as biomass production and substrate uptake could be predicted from the presence and absence of individual bacterial populations. I also studied the niches of potentially pathogenic Vibrio populations in various coastal waters. Using a novel culture-independent method, a V. cholerae population was detected along the entire Swedish coastline. Results from an environmental survey and a laboratory mesocosm experiment reveal that phytoplankton-derived dissolved organic matter enhance the growth of V. cholerae and other Vibrio spp. and hence create a largely overlooked niche for these heterotrophic bacteria. This thesis and future work on the role of individual bacterial populations will facilitate predictions of biogeochemical cycles and the distribution of bacteria in the context of global climate change and local eutrophication.

    List of papers
    1. Composition of freshwater bacterial communities associated with cyanobacterial blooms in four Swedish lakes.
    Open this publication in new window or tab >>Composition of freshwater bacterial communities associated with cyanobacterial blooms in four Swedish lakes.
    2004 In: Environmental Microbiology, Vol. 6, no 12, p. 1228–1243-Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95272 (URN)
    Available from: 2006-12-20 Created: 2006-12-20Bibliographically approved
    2. Blooms of Flavobacteria in four productive lakes
    Open this publication in new window or tab >>Blooms of Flavobacteria in four productive lakes
    Article in journal (Refereed) Submitted
    Identifiers
    urn:nbn:se:uu:diva-95273 (URN)
    Available from: 2006-12-20 Created: 2006-12-20Bibliographically approved
    3. Links between bacterial production, amino acid utilization and community composition in productive lakes
    Open this publication in new window or tab >>Links between bacterial production, amino acid utilization and community composition in productive lakes
    2007 (English)In: ISME Journal, ISSN 1751-7362, Vol. 1, no 6, p. 532-544Article in journal (Refereed) Published
    Abstract [en]

    Influence of distribution and abundance of bacterial taxa on ecosystem function are poorly understood for natural microbial communities. We related 16S rRNA-based terminal restriction fragment length polymorphism to bacterial production and arginine uptake kinetics to test if functional features of bacterioplankton in four lakes could be predicted from community composition. Maximum arginine uptake rate (arginine Vmax) ranged from 10% to 100% of bacterial production. Owing to high growth efficiencies on arginine (63–77%), the bacterial community could potentially saturate its carbon demand using this single organic substrate, for example, during sudden surges of free amino acids. However, due to low in situ concentrations of arginine in these lakes (<0.9 g l-1), actual uptake rates at ambient concentrations rarely exceeded 10% of Vmax. Bacterial production and arginine Vmax could be predicted from a subset of bacterial ribotypes, tentatively affiliated with several bacterial divisions (Cyanobacteria, Actinobacteria, Bacteroidetes and Proteobacteria). Multivariate statistical analysis indicates that there were both highly important and less important ribotypes for the prediction of bacterial production and arginine Vmax. These populations were either negatively or positively related to the respective functional feature, indicating contrasting ecological roles. Our study provides a statistically robust demonstration that, apart from environmental conditions, patterns in bacterial community composition can also be used to predict lake ecosystem function.

    Keywords
    amino-acid utilization, bacteria, community composition, lakes, production
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-95274 (URN)10.1038/ismej.2007.64 (DOI)000250232700007 ()18043654 (PubMedID)
    Available from: 2006-12-20 Created: 2006-12-20 Last updated: 2011-01-20Bibliographically approved
    4. Diurnal variations in the auto- and heterotrophic activity of cyanobacterial phycospheres (Gloeotrichia echinulata) and the identity of attached bacteria
    Open this publication in new window or tab >>Diurnal variations in the auto- and heterotrophic activity of cyanobacterial phycospheres (Gloeotrichia echinulata) and the identity of attached bacteria
    2005 In: Freshwater Biology, Vol. 51, p. 298-311Article in journal (Refereed) Published
    Identifiers
    urn:nbn:se:uu:diva-95275 (URN)
    Available from: 2006-12-20 Created: 2006-12-20Bibliographically approved
    5. Environmental influences on Vibrio populations in northern temperate and boreal coastal waters (Baltic and Skagerrak Seas)
    Open this publication in new window or tab >>Environmental influences on Vibrio populations in northern temperate and boreal coastal waters (Baltic and Skagerrak Seas)
    2006 (English)In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 72, no 9, p. 6004-6011Article in journal (Refereed) Published
    Abstract [en]

    Even if many Vibrio spp. are endemic to coastal waters, their distribution in northern temperate and boreal waters is poorly studied. To identify environmental factors regulating Vibrio populations in a salinity gradient along the Swedish coastline, we combined Vibrio-specific quantitative competitive PCR with denaturant gradient gel electrophoresis-based genotyping. The total Vibrio abundance ranged from 4 X 10(3) to 9.6 X 10(4) cells liter(-1), with the highest abundances in the more saline waters of the Skagerrak Sea. Several Vibrio populations were present throughout the salinity gradient, with abundances of single populations ranging from 5 X 10(4) to 7 X 10(4) cells liter(-1). Clear differences were observed along the salinity gradient, where three populations dominated the more saline waters of the Skagerrak Sea and two populations containing mainly representatives of V anguillarum and V. aestuarianus genotypes were abundant in the brackish waters of the Baltic Sea. Our results suggest that this apparent niche separation within the genus Vibrio may also be influenced by alternate factors such as nutrient levels and high abundances of dinoflagellates. A V. choleraelV. mimicus population was detected in more than 50% of the samples, with abundances exceeding 10(3) cells liter(-1), even in the cold (annual average water temperature of around 5 degrees C) and low-salinity (2 to 4 parts per thousand) samples from the Bothnian Bay (latitude, 65 degrees N). The unsuspected and widespread occurrence of this population in temperate and boreal coastal waters suggests that potential Vibrio pathogens may also be endemic to cold and brackish waters and hence may represent a previously overlooked health hazard.

    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-95276 (URN)10.1128/AEM.00917-06 (DOI)000240474000041 ()16957222 (PubMedID)
    Available from: 2006-12-20 Created: 2006-12-20 Last updated: 2017-12-14Bibliographically approved
    6. Growth response of Vibrio cholerae and other Vibrio spp. to cyanobacterial dissolved organic matter and temperature in Brackish Water
    Open this publication in new window or tab >>Growth response of Vibrio cholerae and other Vibrio spp. to cyanobacterial dissolved organic matter and temperature in Brackish Water
    2007 (English)In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 60, no 3, p. 411-418Article in journal (Refereed) Published
    Abstract [en]

    Environmental control of growth and persistence of vibrios in aquatic environments is poorly understood even though members of the genus Vibrio are globally important pathogens. To study how algal-derived organic matter and temperature influenced the abundance of different Vibrio spp., Baltic Sea microcosms inoculated with Vibrio cholerae, Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio alginolyticus and native bacterioplankton, were exposed to different temperatures (12–25°C) and amended with dissolved organic matter from Nodularia spumigena (0–4.2 mg C L−1). Vibrio abundance was monitored by culture-dependent and molecular methods. Results suggested that Vibrio populations entered a viable but nonculturable state during the incubations. Abundance of Vibrio spp. and total bacterioplankton were orders of magnitude higher in microcosms amended with organic matter compared with reference microcosms. Vibrio cholerae abundances ranged from 0.9 to 1.9 × 105 cells mL−1 in treatments amended with 4.2 mg C L−1. Vibrio cholerae abundance relative to total bacterioplankton and other Vibrio spp. also increased >10-fold. In addition, V. vulnificus abundance increased in mesocosms with the highest organic matter addition (0.9–1.8 × 104 cells mL−1). Temperature alone did not significantly affect abundances of total bacterioplankton, total Vibrio spp. or individual Vibrio populations. By contrast, cyanobacterial-derived organic matter represented an important factor regulating growth and abundance of V. cholerae and V. vulnificus in brackish waters.

    Keywords
    Vibrio cholerae, Vibrio spp., Cyanobacteria, DOM, brackish water, growth
    National Category
    Biological Sciences
    Identifiers
    urn:nbn:se:uu:diva-95277 (URN)10.1111/j.1574-6941.2007.00303.x (DOI)000246708800007 ()17386033 (PubMedID)
    Available from: 2006-12-20 Created: 2006-12-20 Last updated: 2017-12-14Bibliographically approved
  • 137.
    Eiler, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Beier, Sara
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Säwström, Christin
    Karlsson, Jan
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    High Ratio of Bacteriochlorophyll Biosynthesis Genes to Chlorophyll Biosynthesis Genes in Bacteria of Humic Lakes2009In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 75, no 22, p. 7221-7228Article in journal (Refereed)
    Abstract [en]

    Recent studies highlight the diversity and significance of marinephototrophic microorganisms such as picocyanobacteria, phototrophicpicoeukaryotes, and bacteriochlorophyll- and rhodopsin-holdingphototrophic bacteria. To assess if freshwater ecosystems alsoharbor similar phototroph diversity, genes involved in the biosynthesisof bacteriochlorophyll and chlorophyll were targeted to exploreoxygenic and aerobic anoxygenic phototroph composition in awide range of lakes. Partial dark-operative protochlorophyllideoxidoreductase (DPOR) and chlorophyllide oxidoreductase (COR)genes in bacteria of seven lakes with contrasting trophic statuseswere PCR amplified, cloned, and sequenced. Out of 61 sequencesencoding the L subunit of DPOR (L-DPOR), 22 clustered with aerobicanoxygenic photosynthetic bacteria, whereas 39 L-DPOR sequencesrelated to oxygenic phototrophs, like cyanobacteria, were observed.Phylogenetic analysis revealed clear separation of these freshwaterL-DPOR genes as well as 11 COR gene sequences from their marinecounterparts. Terminal restriction fragment length analysisof L-DPOR genes was used to characterize oxygenic aerobic andanoxygenic photosynthesizing populations in 20 lakes differingin physical and chemical characteristics. Significant differencesin L-DPOR community composition were observed between dystrophiclakes and all other systems, where a higher proportion of genesaffiliated with aerobic anoxygenic photosynthetic bacteria wasobserved than in other systems. Our results reveal a significantdiversity of phototrophic microorganisms in lakes and suggestniche partitioning of oxygenic and aerobic anoxygenic phototrophsin these systems in response to trophic status and coupled differencesin light regime.

  • 138.
    Eiler, Alexander
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Bertilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Composition of freshwater bacterial communities associated with cyanobacterial blooms in four Swedish lakes2004In: Environmental Microbiology, Vol. 6, p. 1228-1243Article in journal (Refereed)
    Abstract [en]

    The diversity of freshwater bacterioplankton communities has not been extensively studied despite their key role in foodwebs and the cycling of carbon and associated major elements. In order to explore and characterize the composition of bacterioplankton associated with cyanobacterial blooms, large 16S rRNA clone libraries from four lakes experiencing such blooms were analysed. The four libraries contained 1461 clones, of which 559 were prokaryotic sequences of non-cyanobacterial origin. These clones were classified into 158 operational taxonomic units affiliated mainly with bacterial divisions commonly found in freshwater systems, e.g. Proteobacteria, Bacteriodetes, Actinobacteria, Verrucomicrobia and Planctomycetes. Richness and evenness of non-cyanobacterial clones were similar to other clone libraries obtained for freshwater bacterioplankton, suggesting that bacterial communities accompanying cyanobacterial blooms are as diverse as non-bloom communities. Many of the identified operational taxonomic units grouped with known freshwater clusters but the libraries also contained novel clusters of bacterial sequences that may be characteristic for cyanobacterial blooms. About 25% of the operational taxonomic units were detected in more than one lake. Even so, 16S rRNA heterogeneity analysis demonstrated large differences in community composition between lakes regardless of their similar characteristics and close proximity. Hence even the similar environmental conditions created by different cyanobacterial blooms may foster very dissimilar bacterial communities, which could indicate that the genetic diversity in lake bacteria have been underestimated in the past.

  • 139.
    Eiler, Alexander
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Bertilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Detection and quantification of Vibrio populations using denaturant gradient gel electrophoresis2006In: Journal of Microbiological Methods, Vol. 67, p. 339-348Article in journal (Refereed)
  • 140.
    Eiler, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Flavobacteria blooms in four eutrophic lakes: Linking population dynamics of freshwater bacterioplankton to resource availability2007In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 73, no 11, p. 3511-3518Article in journal (Refereed)
    Abstract [en]

    Heterotrophic bacteria are major contributors to biogeochemical cycles and influence water quality. Still, the lack of representative isolates and the few quantitative surveys leave the ecological role and significance of single bacterial populations to be revealed. Here we analyzed the diversity and dynamics of freshwater Flavobacteria populations in four eutrophic temperate lakes. From each lake, clone libraries were constructed using primers specific for either the class Flavobacteria or Bacteria. Sequencing of 194 Flavobacteria clones from 8 libraries revealed a diverse freshwater Flavobacteria community and distinct differences among lakes. Abundance and seasonal dynamics of Flavobacteria were assessed by quantitative PCR with class-specific primers. In parallel, the dynamics of individual populations within the Flavobacteria community were assessed with terminal restriction fragment length polymorphism analysis using identical primers. The contribution of Flavobacteria to the total bacterioplankton community ranged from 0.4 to almost 100% (average, 24%). Blooms where Flavobacteria represented more than 30% of the bacterioplankton were observed at different times in the four lakes. In general, high proportions of Flavobacteria appeared during episodes of high bacterial production. Phylogenetic analyses combined with Flavobacteria community fingerprints suggested dominance of two Flavobacteria lineages. Both drastic alterations in total Flavobacteria and in community composition of this class significantly correlated with bacterial production, emphasizing that resource availability is an important driver of heterotrophic bacterial succession in eutrophic lakes.

  • 141.
    Eiler, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Gonzalez-Rey, Carlos
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Allen, Sophie
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Growth response of Vibrio cholerae and other Vibrio spp. to cyanobacterial dissolved organic matter and temperature in Brackish Water2007In: FEMS Microbiology Ecology, ISSN 0168-6496, E-ISSN 1574-6941, Vol. 60, no 3, p. 411-418Article in journal (Refereed)
    Abstract [en]

    Environmental control of growth and persistence of vibrios in aquatic environments is poorly understood even though members of the genus Vibrio are globally important pathogens. To study how algal-derived organic matter and temperature influenced the abundance of different Vibrio spp., Baltic Sea microcosms inoculated with Vibrio cholerae, Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio alginolyticus and native bacterioplankton, were exposed to different temperatures (12–25°C) and amended with dissolved organic matter from Nodularia spumigena (0–4.2 mg C L−1). Vibrio abundance was monitored by culture-dependent and molecular methods. Results suggested that Vibrio populations entered a viable but nonculturable state during the incubations. Abundance of Vibrio spp. and total bacterioplankton were orders of magnitude higher in microcosms amended with organic matter compared with reference microcosms. Vibrio cholerae abundances ranged from 0.9 to 1.9 × 105 cells mL−1 in treatments amended with 4.2 mg C L−1. Vibrio cholerae abundance relative to total bacterioplankton and other Vibrio spp. also increased >10-fold. In addition, V. vulnificus abundance increased in mesocosms with the highest organic matter addition (0.9–1.8 × 104 cells mL−1). Temperature alone did not significantly affect abundances of total bacterioplankton, total Vibrio spp. or individual Vibrio populations. By contrast, cyanobacterial-derived organic matter represented an important factor regulating growth and abundance of V. cholerae and V. vulnificus in brackish waters.

  • 142.
    Eiler, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Johansson, Mona
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Environmental influences on Vibrio populations in northern temperate and boreal coastal waters (Baltic and Skagerrak Seas)2006In: Applied and Environmental Microbiology, ISSN 0099-2240, E-ISSN 1098-5336, Vol. 72, no 9, p. 6004-6011Article in journal (Refereed)
    Abstract [en]

    Even if many Vibrio spp. are endemic to coastal waters, their distribution in northern temperate and boreal waters is poorly studied. To identify environmental factors regulating Vibrio populations in a salinity gradient along the Swedish coastline, we combined Vibrio-specific quantitative competitive PCR with denaturant gradient gel electrophoresis-based genotyping. The total Vibrio abundance ranged from 4 X 10(3) to 9.6 X 10(4) cells liter(-1), with the highest abundances in the more saline waters of the Skagerrak Sea. Several Vibrio populations were present throughout the salinity gradient, with abundances of single populations ranging from 5 X 10(4) to 7 X 10(4) cells liter(-1). Clear differences were observed along the salinity gradient, where three populations dominated the more saline waters of the Skagerrak Sea and two populations containing mainly representatives of V anguillarum and V. aestuarianus genotypes were abundant in the brackish waters of the Baltic Sea. Our results suggest that this apparent niche separation within the genus Vibrio may also be influenced by alternate factors such as nutrient levels and high abundances of dinoflagellates. A V. choleraelV. mimicus population was detected in more than 50% of the samples, with abundances exceeding 10(3) cells liter(-1), even in the cold (annual average water temperature of around 5 degrees C) and low-salinity (2 to 4 parts per thousand) samples from the Bothnian Bay (latitude, 65 degrees N). The unsuspected and widespread occurrence of this population in temperate and boreal coastal waters suggests that potential Vibrio pathogens may also be endemic to cold and brackish waters and hence may represent a previously overlooked health hazard.

  • 143.
    Eiler, Alexander
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Langenheder, Silke
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Bertilsson, Stefan
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Tranvik, Lars J
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. limnologi.
    Heterotrophic bacterial growth efficiency and community structure at different natural organic carbon concentrations.2003In: Appl Environ Microbiol, ISSN 0099-2240, Vol. 69, no 7, p. 3701-9Article in journal (Refereed)
  • 144.
    Eiler, Alexander
    et al.
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Olsson, Jan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Bertilsson, Stefan
    Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution. Uppsala University, Teknisk-naturvetenskapliga vetenskapsområdet, Faculty of Science and Technology, Biology, Department of Ecology and Evolution, Limnology. Limnologi.
    Dirunal variations in the auto- and heterotrophic activity of cyanobacterial phycospheres (Gloeotrichia echinulata) and the identity of attached bacteria2006In: Freshwater Biology, Vol. 51, p. 298-311Article in journal (Refereed)
  • 145.
    Eklind, Ylva
    et al.
    SLU.
    Sundberg, Cecilia
    SLU.
    Smårs, Sven
    SLU.
    Steger, Kristin
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Sundh, Ingvar
    SLU.
    Kirchmann, Holger
    SLU.
    Jönsson, Håkan
    SLU.
    Carbon Turnover and Ammonia Emissions during Composting of Biowaste at Different Temperatures2007In: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 36, no 5, p. 1512-1520Article in journal (Refereed)
    Abstract [en]

    The effects of different process temperatures (40, 55, and 67°C) during composting of source-separated household waste were studied in a 200 L compost reactor at an oxygen concentration of 16%. The overall decomposition measured as carbon mineralization, decomposition of different carbon constituents, and the dynamics of nitrogen mineralization and the microbial community, are reported. Ammonia emissions at 67°C were more than double those at lower temperatures, and they were lowest at 40°C. The decomposition rate, measured as CO2 emission, was highest at 55°C. Decomposition of crude fat was slower at 40°C than at 55 and 67°C. The peak in microbial biomass was largest in the run at 40°C, where substantial differences were seen in the microbial community structure and succession compared to thermophilic temperatures. Biowaste composting can be optimized to obtain both a high decomposition rate and low ammonia emissions by controlling the process at about 55°C in the initial, high-rate stage. To reduce ammonia emissions it seems worthwhile to reduce the temperature after an initial high-temperature stage.

  • 146.
    Eklöv, Peter
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Evolutionary Biology. Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Chemical cues from multiple predator-prey interactions induce changes in behavior and growth of anuran larvae2000In: Oecologia, Vol. 123, no 2, p. 192-199Article in journal (Refereed)
    Abstract [en]

    Chemical signals are used as information by prey to assess predation risk in their environment.

  • 147.
    Eklöv, Peter
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Biology, Department of Ecology and Evolution, Limnology.
    Halvarsson, Charlotta
    The trade-off between foraging activity and predation risk for Rana temporaria in different food environments2000In: Canadian Journal of Zoology, ISSN 0008-4301, E-ISSN 1480-3283, Vol. 78, no 5, p. 734-739Article in journal (Refereed)
    Abstract [en]

     

    We evaluated the trade-off between foraging activity and predation risk for larvae of an anuran species presented with different types of food resources. In the laboratory we examined the effects of benthic and phytoplankton resources and the two types combined on the activity and mortality of larvae of the common frog, Rana temporaria, exposed to predatory larva, Dytiscus marginalis.

    Predation mortality of tadpoles increased with the duration of the experiment and was highest in the presence of the phytoplankton resource alone. This was explained by a decrease in prey activity in the benthic- and combined-resource treatments when the predator was present, whereas in the phytoplankton treatment, the activity of the tadpoles were similar in the presence or absence of the predator.

    In the presence of the predator, prey mainly used the bottom of the aquarium in the benthic- and combined-resource treatments. In contrast, in the phytoplankton treatment they used the water column more than in the other treatments. In the presence of the predator, the prey had a lower consumption rate in the phytoplankton treatment than in the other treatments.

    Predator activity did not change among treatments. The results suggest that the trade-off between foraging activity and predation mortality for anuran larvae is strongly affected by the types of food resources present in the environment.