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  • 201.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Kväve - ett "nyupptäckt" grundämne i svensk marin miljövård1982Report (Other academic)
  • 202.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Nutrient dynamics (in Swedish)1986In: Eutrophication in marine waters surrounding Sweden: a review / [ed] Rutger Rosenberg, Solna: Naturvårdsverket , 1986, , p. 24Chapter in book (Other academic)
  • 203.
    Granéli, Edna
    Plankton Ecology Research Group, Department of Marine Ecology, P.O. Box 124, S-221 00, Lund, Sweden.
    Nutrient limitation of phytoplankton biomass in a brackish water bay highly influenced by river discharge1987In: Estuarine, Coastal and Shelf Science, ISSN 0272-7714, E-ISSN 1096-0015, Vol. 25, no 5, p. 555-565Article in journal (Refereed)
    Abstract [en]

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

  • 204.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Water quality in the vicinity of Fundao Island (Guanabara Bay, Rio de Janeiro)1975In: Journal of the Biological Institute of UFRJArticle in journal (Refereed)
  • 205.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Carlsson, Per
    The Ecological Significance of Phagotrophy in Photosynthetic Flagellates1998In: Physiological ecology of harmful algal blooms: proceedings of the NATO Advanced Study Institute on "The Physiological Ecology of Harmful Algal Blooms", held at the Bermuda Biological Station for Research, Bermuda, USA, May 27 - June 6, 1996 / [ed] Donald Mark Anderson, Allan D. Cembella, Heidelberg: Springer, 1998, p. 539-557Chapter in book (Other academic)
  • 206.
    Granéli, Edna
    et al.
    Department of Marine Ecology, Lund University.
    Carlsson, Per
    Olsson, P
    Sundström, B
    Granéli, W.
    Lindahl, O.
    From anoxia to fish poisoning: the last ten years of phytoplankton blooms in Swedish marine waters1989In: Novel phytoplankton blooms: causes and impacts of recurrent brown tides and other unusual blooms / [ed] Cosper, Elizabeth M., New York: Springer-Verlag , 1989, Vol. In: Cosper EM, Bricelj VM, Carpenter EJ (eds) Novel phytoplankton blooms: causes and impacts of recurrent brown tides and other unusual blooms. Lecture Notes on Coastal and Estuarine Studies, p. 407-427Chapter in book (Refereed)
  • 207.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Carlsson, Per
    Turner, Jefferson
    Tester, P
    Enclosure experiments with phytoplankton communities from the Northern Adriatic Sea: effects of N, P or Si-limitation and copepod grazing on phytoplankton species composition biomass and polysaccharide production1999In: Ecosystems research report No 32: The Adriatic Sea : Proceedings of the workshop 'Physical and biogeochemical processes in the Adriatic Sea', Portonovo (Ancona), Italy, 23 to 27 April 1996 / [ed] T S Hopkins, Luxembourg: EUR-OP , 1999, p. 427-442Chapter in book (Other academic)
  • 208.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Edler, L
    Can chelation of toxic trace metals start a red tide bloom?1983Report (Other academic)
  • 209.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Edler, L.
    Gedziorowska, D
    Nyman, U
    Influence of humic and fulvic acids on Prorocentrum minimum (Pav.)1985In: Toxic dinoflagellates: proceedings of the third International Conference on Toxic Dinoflagellates, St. Andrews, New Brunswick, Canada, June 8-12, 1985 / [ed] DM Andersson, AW White & DG Baden, New York: Elsevier, 1985, p. 201-206Chapter in book (Other academic)
  • 210.
    Granéli, Edna
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Edvardsen, Bente
    University of Oslo, Dept. of Biology.
    Roelke, Daniel L
    Texas A&M University, Departments of Wildlife and Fisheries Sciences and Oceanography.
    Hagström, Johannes
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    The ecophysiology and bloom dynamics of Prymnesium spp.2012In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 14, no SI, p. 260-270Article in journal (Refereed)
    Abstract [en]

    Members of Prymnesium belong to the division Haptophyta, class Prymnesiophyceae, order Prymnesialesand family Prymnesiaceae. As most haptophytes, members of the genus Prymnesium are unicellular andplanktonic. The most known of these species is the ichthyotoxic P. parvum, which may form nearlymonospecific dense blooms in coastal and inland waters. This species possesses extraordinary plasticityconcerning life survival strategies, and is specifically addressed in this review.Toxins produced by P. parvum have hemolytic properties, that not only kill fish but also co-existingplankton. These substances are allelopathic (when other algae are killed) and grazer deterrent (whengrazers are killed). Allelopathy enables P. parvum to utilize inorganic nutrients present in the surroundingwater without competition from other algal species; and by eliminating its grazers P. parvum reduces celllosses. The paralized microalgae and/or zooplankton, are therefter ingested by the P. parvum cells, aprocess called phagotrophy. P. parvum is also able of osmotrophy, i.e. utilization of dissolved organicmatter. In this review, the cellular characteristics, life cycles, bloom formation, and factors affectingtoxicity, allelopathy, phagotrophy, and osmotrophy of P. parvum are discussed.

  • 211.
    Granéli, Edna
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Esplund, Christina
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Blågrönalger i Östersjön (Blue-green algae in the Baltic Sea, In Swedish)2010In: Havet 2010, ISSN 1654-6741, p. 35-38Article in journal (Other academic)
    Abstract [sv]

    Blomningar av blågrönalger i Östersjön är inget nytt fenomen. De förekom redan för 8000 år sedan, i samband med att Östersjön blev ett brackvattenhav. Blomningarna har dock ökat i såväl utbredning som intensitet under de senaste femtio åren. Med mycket stor sannolikhet är det vi människor som ligger bakom ökningen. Det är inte heller bara en bov i dramat, utan tre; övergödning, överfiske och klimatförändring.

  • 212.
    Granéli, Edna
    et al.
    Department of Marine Ecology, University of Lund .
    Granéli, W.
    Eutrophication and dinoflagellate blooms in Swedish coastal waters: Possible causes and counter measures1989In: Proceedings of the International Symposium on Utilization of Coastal Ecosystems: Planning, Pollution and Productivity, 21-27 Nov. 1982, Rio Grande, Brazil / [ed] Labbish Ning Chao & William W Kirby-Smith, USA: Duke Univ. Marine Laboratory , 1989, p. 261-282Chapter in book (Other academic)
  • 213.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Granéli, W.
    Reducing nitrogen transport to Swedish coastal waters - a case study1999In: Conference proceedings: Third European Marine Science and Technology Conference, Lisbon, 23-27 May 1998 / [ed] Barthel, Klaus-Günther, Luxembourg: EUR-OP , 1999, p. 21-34Chapter in book (Other academic)
  • 214.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Granéli, W
    Reduktion av näringstillförsel - en prognos: Kapitel 71986In: Eutrofieringsläget i Kattegatt / [ed] Rutger Rosenberg, Solna: Naturvårdsverket , 1986, , p. 136-141p. 136-141Chapter in book (Other academic)
  • 215.
    Granéli, Edna
    et al.
    Department of Marine Ecology, Lund University.
    Granéli, W.
    Rydberg, L
    Nutrient limitation at the ecosystem and the phytoplankton community level in the Laholm Bay, South-East Kattegat1986In: Ophelia, Vol. 26, p. 181-194Article in journal (Refereed)
  • 216.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Johansson, N
    Nitrogen or phosphorus deficiency increases allelopathy in Prymnesium parvum2001In: Harmful algal blooms: Proceedings of the Ninth International Conference on Harmful Algal Blooms Hobart, Australia, 7-l 1 February 2000 / [ed] Gustaaf M. Hallegraeff, Susan I. Blackburn, Christopher J. Bolch & Richard J. Lewis, Intergovernemental Oceanografic Commission of UNESCO , 2001, p. 328-331Chapter in book (Other academic)
  • 217.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Johansson, N
    Panosso, Renata
    Cellular toxin contents in relation to nutrient conditions for different groups of phycotoxins1998In: Harmful algae = Algas nocivas: proceedings of the VIII International Conference on Harmful Algae, Vigo, Spain, 25-29 June 1997 / [ed] Reguera B, Blanco J, Fernandez LM & Wyatt T, Xunta de Galicia and IOC-UNESCO , 1998, p. 321-324Chapter in book (Other academic)
  • 218.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Juel Hansen, Per
    Allelopathy in harmful algae: A mechanism to compete for resources?2006In: Ecology of Harmful Algae, Springer Berlin/Heidelberg, 2006, p. 189-201Chapter in book (Other academic)
  • 219.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Leonardson, L
    Kvävefixering: Kapitel 5:21986In: Eutrofieringsläget i Kattegatt / [ed] Rutger Rosenberg, Solna: Naturvårdsverket , 1986, , p. 72-74p. 72-74Chapter in book (Other academic)
  • 220.
    Granéli, Edna
    et al.
    Department of Marine Ecology, University of Lund.
    Odete Moreira, Maria
    Effects of river water of different origin on the growth of marine dinoflagellates and diatoms in laboratory cultures1990In: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 136, no 2, p. 89-106Article in journal (Refereed)
    Abstract [en]

    The hypothesis that acid humic-rich river water selectively favours dinoflagellates in comparison to diatoms in coastal waters was tested in two sets of laboratory experiments using unialgal cultures of marine phytoplankton. In the first experiment, three dinoflagellates, i.e., Prorocentrum minimum (Pav.) J. Schiller, P. micans Ehrenberg and Amphidinium carterae Hulburt, and three diatoms, i.e., Attheya decora T. West, Skeletonema costatum (Grev.) Cleve and Phaeodactylum tricornutum Bohlin, were grown in a mixture of 80% coastal (S 20%.) and 20% river water. Water from seven different rivers was used. Four rivers had a high humic content (yellow substance 22.1 ± 0.9 · m−1) but lower inorganic N and P concentrations ("forest rivers") while three rivers ("agricultural rivers") had a lower humic content (10.7 ± 1.3 · m−1) but inorganic nutrient concentrations approximately three times as high as the forest rivers. The growth rates for the dinoflagellates were significantly higher in the medium with forest river water compared to the mixtures with agricultural river water while the opposite was true for the diatoms. In the second type of experiment, the diatom Ditylum brightwellii (T. West) Grun and the dinoflagellate P. minimum were grown, as semicontinuous dilution cultures, in mixtures of 90% coastal water (S 20%.) and 10% river water. Water from four different rivers was used, one draining mainly agricultural soils and the other acidified humic-rich forested soils. River water of agricultural origin supported a higher D. brightwellii biomass and growth rate than river water draining forested soils while for P. minimum the opposite was true. Decreasing cell P quotas and increasing alkaline phosphatase activity indicated that D. brightwellii was P-deficient, especially when agricultural river water was added, while these physiological indices suggested that P. minimum cultures were not P-starved. Our results support the hypothesis that the discharge of acidified river water, rich in humic substances, to coastal waters, can play a role in shifting the species composition from diatoms to dinoflagellates. 

  • 221.
    Granéli, Edna
    et al.
    Department of Marine Ecology, University of Lund .
    Olsson, P
    Sundström, B
    Edler, L.
    In situ studies of the effects of humic acids on dinoflagellates and diatoms1989In: Red tides: Biology, Environmental Science and Toxicology: proceedings of the first International Symposium on Red Tides held November 10-14, 1987, in Takamatsu, Kagawa Prefecture, Japan / [ed] Tomotoshi Okaichi, Donald M. Anderson, Takahisa Nemoto, New York: Elsevier, 1989, p. 209-212Chapter in book (Other academic)
  • 222.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Pavia, Henrik
    Allelopathy in marine ecosystems2006In: Allelopathy: A Physiological Process with Ecological Implications, Springer Netherlands, 2006, p. 415-431Chapter in book (Other academic)
  • 223.
    Granéli, Edna
    et al.
    Department of Marine Botany, University of Lund, Box 124, S-221 00 Lund, Sweden.
    Persson, H
    Edler, L.
    Connection between trace metals, chelators and red tide blooms in the Laholm Bay, SE Kattegat - An experimental approach1986In: Marine Environmental Research, ISSN 0141-1136, E-ISSN 1879-0291, Vol. 18, no 1, p. 61-78Article in journal (Refereed)
    Abstract [en]

    The influence of the trace metals, copper, aluminum and iron, and of the strong complexing agents, EDTA and NTA, on phytoplankton growth in water from a brackish water bay was investigated through bioassay experiments. A diatom (Skeletonema costatum (Grev.) Cleve) and a dinoflagellate (Prorocentrum minimum (Pav.) J. Schiller) were used as test organisms. The growth of both phytoplankton species was strongly inhibited by copper. This inhibition was generally eliminated by EDTA and NTA. Both phytoplankton species were considerably less inhibited by aluminum than by copper at the same total metal concentration. While S. costatum responded to copper and chelator additions in the same way in sea water samples from different seasons, the growth of P. minimum exhibited pronounced seasonal variation. Other parameters than the values of pCu must be considered in order to account for the experimental results. This work supports the theory that alterations in contents of trace metals and natural chelators in sea water are important factors behind shifts in phytoplankton species composition. 

  • 224.
    Granéli, Edna
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Salomon, Paulo
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Factors influencing allelopathy and toxicity in Prymnesium parvum2010In: Journal of the American Water Resources Association, ISSN 1093-474X, E-ISSN 1752-1688, Vol. 46, p. 108-120Article in journal (Refereed)
    Abstract [en]

    Some microalgae are able to kill or inhibit nutrient-competing microalgae, a process called allelopathy. Inhibiting or killing competitors enable these species to monopolize limiting resources, such as nitrogen and phosphorus. Prymnesium parvum is known to produce such allelopathic compounds, substances that seem identical to the ichthyotoxins identified from this species. Biotic and abiotic environmental factors influence not only growth rates but also toxin/allelopathic compounds production by P. parvum cells. Toxin production, as well as allelopathy, including grazer deterrence, increases dramatically in light, temperature, or nutrient stressed P. parvum cells. Correspondingly, toxicity and allelopathy may decrease, or cease completely, if cells are grown with high amounts of N and P in balanced proportions. However, even under nutrient (N and P) sufficient conditions, P. parvum is able to produce toxins/allelopathic compounds, with negative effects on other phytoplankton species or grazers, if cells densities of P. parvum are high relative to other species. This negative effect might shift the plankton community to more toxin resistant species. Filtrates from nutrient-deficient P. parvum cultures have almost the same strong negative effect on grazers and other phytoplankton species as when Prymnesium cells are grown together with the target organisms. Eutrophication, the increased input of N and P to aquatic ecosystems, besides increasing nutrient concentrations, is usually provoking unbalanced N:P condition for the optimal growth of phytoplankton, deviating from the Redfield ratio, i.e., the phytoplankton cellular nitrogen to phosphorus ratio, N:P = 16:1 (by atoms) or 7.2:1 (by weight). Eutrophication thus both enhances P. parvum growth and increases production of toxins and allelopathic compounds. Supplying N-deficient or P-deficient P. parvum cells with the deficient nutrient reduces toxicity to less than half within 24 h after additions. As P. parvum is mixotrophic, uptake of dissolved or particulate organic N (DON or PON) can also reduce toxicity and allelopathy in the same manner as addition of inorganic N to N-starved cells. In conclusion, P. parvum, by increasing its toxicity and allelopathic ability under poor environmental conditions, outcompetes the co-occurring phytoplankton species.

  • 225.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Schulz, S
    Schiewer, U
    Gedziorowska, D
    Kaiser, W
    Plinski, M
    Is the same nutrient limiting potential phytoplankton biomass formation in different coastal areas of the Southern Baltic?1988In: Kieler Meeresforschung, no Sonderheft 6, p. 191-202Article in journal (Refereed)
  • 226.
    Granéli, Edna
    et al.
    UNIV LUND, DEPT MARINE BOT, BOX 124, S-22100 LUND, SWEDEN .
    Sundbäck, K
    The response of planktonic and microbenthic algal assemblages to nutrient enrichment in shallow coastal waters, Southwest Sweden1985In: Journal of Experimental Marine Biology and Ecology, ISSN 0022-0981, E-ISSN 1879-1697, Vol. 85, no 3, p. 253-268Article in journal (Refereed)
    Abstract [en]

    Field and laboratory nutrient (nitrogen and phosphorus) enrichment experiments were performed using natural phytoplankton and microphytobenthic assemblages from the brackish water Öresund, S.W. Sweden. The response of algae from a low-nutrient area (Falsterbo Canal) was compared to that of algae from a polluted, nutrient-rich area (Lomma Bay).

    The biomass (measured as chlorophyll a) of both phytoplankton and microphytobenthos from the Falsterbo Canal increased after the addition of nitrogen. Phytoplankton growth was stimulated by the addition of phosphorus to the nitrogen-rich water of the polluted Lomma Bay. Sediment chlorophyll a showed no significant increase after the addition of nutrients in the Lomma Bay. In containers without sediment, phytoplankton uptake was calculated to account for ≈ 90% of the disappearance of inorganic fixed nitrogen from the water. In the sediment containers the microphytobenthos was estimated to account for ≈20% of the nitrogen uptake. The rest was presumably lost mainly through denitrification.

    When containers with microphytobenthos from Lomma Bay were kept in the dark, phosphorus was released at a rate of up to ≈ 180 μM · m−2 · day−1. We suggest that by producing oxygen microbenthic algae keep the sediment surface oxygenated thereby decreasing phosphorus transport from the sediment to the overlying water. 

  • 227.
    Granéli, Edna
    et al.
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Sundström, B
    Edler, L
    Anderson, DM
    Toxic Marine Phytoplankton1987Book (Other academic)
  • 228.
    Granéli, Edna
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Vidyarathna, Nayani K.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Funari, Enzo
    Istituto Superiore di Sanità, Rome, Italy.
    Cumaranatunga, PRT
    University of Ruhuna, Sri Lanka.
    Scenati, Raffaele
    National Institute of Health, Rome Italy.
    Can increases in temperature stimulate blooms of the toxic benthic dinoflagellate Ostreopsis ovata?2011In: Harmful Algae, ISSN 1568-9883, E-ISSN 1878-1470, Vol. 10, no 2, p. 165-172Article in journal (Refereed)
    Abstract [en]

    Ostreopsis ovata Fukuyo is an epiphytic, toxic dinoflagellate, inhabiting tropical and sub-tropical waters worldwide and also in certain temperate waters such as the Mediterranean Sea. Toxic blooms of O. ovata have been reported in SE Brazil in 1998/99 and 2001/02 and the French-Italian Riviera in 2005 and 2006. These blooms had negative effects on human health and aquatic life. Chemical analyses have indicated that O. ovata cells produce palytoxin, a very strong toxin, only second in toxicity to botulism. Increase in water temperature by several degrees has been suggested as the reason for triggering these blooms. Four laboratory experiments were performed with O. ovata isolated from Tyrrhenian Sea, Italy to determine the effects of water temperature and co-occurring algae on the cell growth and/or the toxicity of O. ovata. The cells were grown under different temperatures ranging from 16 °C to 30 °C, and cell densities, growth rates and the cell toxicities were studied. Results indicated high water temperatures (26-30 °C) increased the growth rate and biomass accumulation of O. ovata. In mixed cultures of O. ovata with other co-occurring algae, biomass decreased due to grazing by ciliates. Cell toxicity on the other hand was highest at lower temperatures, i.e., between 20 and 22 °C. The present study suggests that sea surface temperature increases resulted by global warming could play a crucial role inducing the geographical expansion and biomass accumulation by blooms of O. ovata.

  • 229.
    Granéli, Edna
    et al.
    Department of Marine Ecology, University of Lund.
    Wallström, K
    Larsson, U.
    Granéli, W.
    Elmgren, Ragnar
    Nutrient limitation of primary production in the Baltic Sea area1990In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 19, no 3, p. 142-151Article in journal (Refereed)
    Abstract [en]

    In the Baltic Sea area, including the Kattegat, the external N/P loadingratios are generally well above the 16:1 Redfield ratio for all subareas (theBothnian Bay, the Bothnian Sea, the Baltic proper and the Kattegat).During winter, the inorganic N/P ratio in surface waters varies. Appreciablyhigher values than the loading ratio are found for the northernmostbasin, the low-saline Bothnian Bay, while lower values than the loadingratio are found for the Baltic proper and the Kattegat. Nutrient enrichmenttests indicate general N limitation in the Baltic proper and the Kattegat,although stimulation of algal growth after P enrichment has been found inthe Baltic proper during summer blooms of blue-green algae. Blooms ofblue-green algae are common in the Baltic proper but hardly ever occur inthe Bothnian Bay and the Kattegat. This has been the case for the lastcentury, indicating natural summer N limitation. Full-scale experimentalmanipulation of the external N/P loading ratio has been carried out in theHimmerfjard basin, south of Stockholm. Results suggest nitrogen as themost limiting nutrient in coastal areas of the Baltic proper, uninfluencedby direct nutrient discharges. The knowledge of the effects of alteredexternal nutrient supplies for nutrient limitation in the Baltic Sea systemas a whole is too limited to allow for reliable predictions. However, theBaltic Sea may have developed towards a more pronounced N limitationdue to a twofold historic increase in P supply relative to N supply. Atpresent, the situation may be reversed as N supply is probably increasingmore rapidly than P supply. Management of the Baltic Sea area cannot bebased on removal of either N or P in sewage, but must take both elementsinto consideration, as well as differences between sub-basins andbetween polluted coastal and offshore areas. 

  • 230. Granéli, W.
    et al.
    Graneli, Edna
    Department of Marine Ecology, University of Lund .
    Automatic potentiometric determination of dissolved oxygen1991In: Marine Biology, ISSN 0025-3162, E-ISSN 1432-1793, Vol. 108, no 2, p. 341-348Article in journal (Refereed)
    Abstract [en]

    Commercially available automatic titration systems were tested in 1988 for potentiometric titration of liberated iodine by the Winkler method of oxygen determination. The potentiometric equivalence point was also compared to the manual starch end point. Finally the automatic method was used in order to estimate below-halocline respiration in the Kattegat, Sweden. Standard deviations of 0.007 ml O2 l-1 or 0.1 to 0.3% coefficients of variation (% standard deviation of the mean) were achieved when titrating 25 ml from replicate 60-ml oxygen bottles using the automatic method, or 50 ml manually. The precision for replicate titrations of 50-ml aliquots of 0.001 N KIO3 was < 0.05% (0.002 ml 0.01 N Na2S2O3) for the automatic method. Titration time for 25-ml aliquots was 2 to 4 min, somewhat longer than for manual titrations (1 to 1.5 min). However, during titration the operator is free to perform other tasks. It is not possible to use automatic sample changers, due to rapid iodine volatilization. The equipment can be handled by relatively unskilled analysts and is suitable for use on board research vessels or in field stations [weight for a Mettler(TM) titrator (Mettler Instrumente AG, Greifensee, Switzerland) < 10 kg, volume < 0.1 m3]. Below-halocline oxygen consumption in the SE Kattegat ranged from 0 to 6 ml O2 m-3 h-1 (mean values for September and October 1988 = 1.69 and 0.66 ml O2 m-3 h-1, respectively, with 95% confidence limits of ca. +/- 0.6 ml O2 m-3 h-1). 

  • 231.
    Grill, Andrea
    et al.
    Univ Bern, Switzerland.
    Polic, Daniela
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Guariento, Elia
    Eurac Res, Italy.
    Fiedler, Konrad
    Univ Vienna, Austria.
    Permeability of habitat edges for Ringlet butterflies (Lepidoptera, Nymphalidae, Erebia Dalman 1816) in an alpine landscape2020In: Nota lepidopterologica, ISSN 0342-7536, Vol. 43, p. 29-41Article in journal (Refereed)
    Abstract [en]

    We tracked the movements of adult Ringlet butterflies (Lepidoptera, Nymphalidae, Erebia Dalman, 1816) in high-elevation (> 1800 meters a. s.1.) grasslands in the Austrian Alps in order to test if an anthropogenic boundary (= an asphalt road) had a stronger effect on butterfly movement than natural habitat boundaries (trees, scree, or dwarf shrubs surrounding grassland sites). 373 individuals (136 females, 237 males) belonging to 11 Erebia species were observed in one flight season (July-August 2013) %%tile approaching or crossing habitat edges. Erebia pandrose (Borkhausen, 1788) was the most abundant species with 239 observations. All species studied were reluctant to cross habitat boundaries, but permeability was further strongly affected by the border type. Additional variables influencing movement probability were species identity and the time of the day. In E. pandrose, for which we had sufficient observations to analyse this, individuals were more likely to cross a boundary in the morning and in the late afternoon than at midday. Erebia eutyale (Esper, 1805) and E. nivalis Lorkovie & de Lesse, 1954 were more likely to leave a habitat patch than their studied congeners. The key result of our study is that the paved road had the lowest permeability among all edge types (0.1 likelihood of crossing when approaching the edge). A road cutting across a conservation area (viz. a national park) thus hinders inter-patch exchange among Ringlet butterflies in the alpine zone, even though theoretically they ought to be able to fly across.

  • 232.
    Gross, Elisabeth
    et al.
    University of Konstanz, Germany.
    Legrand, Catherine
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Rengefors, Karin
    Lund University.
    Tillmann, Urban
    Alfred Wegener Institute for Polar Research, Germany.
    Allelochemical interactions among aquatic primary producers2012In: Chemical Ecology in Aquatic Systems / [ed] Christer Brönmark, Lars Anders Hansson, Oxford: Oxford University Press, 2012, 1, p. 196-209Chapter in book (Refereed)
    Abstract [en]

    Allelopathy is the study of biochemically-driven organismic interactions among primary producers. One organism affects others by the release of allelochemicals that are transported to the target cells, and cause a negative (or positive) response. Most aquatic allelochemicals are amphiphilic, thus have a sufficient solubility in the water, and at the same time can bind to and penetrate lipophilic cell membranes. Allelopathic interactions are not static but are influenced by variable environmental stressors. Resource availability can both affect the production and release of allelochemicals by the producing organism, but also influence the susceptibility of the target cells. The biosynthesis and excretion of allelochemicals might involve costs for the producing organism, and these costs will only be balanced if a net gain, i.e. better resource availability such as space or nutrients or secondary benefits, e.g. predator deterrence, are achieved. Allelopathic effects against cooccurring organisms might lead to coevolutionary responses, i.e. a lower susceptibility of target cells or to more advanced allelochemicals. Target organisms from different habitats might be more susceptible, especially if they are not acquainted with the allelochemicals. The transfer of laboratory results on allelopathy to realistic field conditions is complex, and might in the long run benefit from advanced analytical and molecular methods identifying specific target cell responses in situ.

  • 233. Guan, Y.
    et al.
    Webby, R.
    Capua, I.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    H5N1: How to track a flu virus2012In: Nature, ISSN 0028-0836, E-ISSN 1476-4687, Vol. 483, no 7391, p. 535-536Article in journal (Refereed)
  • 234.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Elmberg, Johan
    Kristianstad University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Trends in body mass of ducks over time: the hypotheses in Guillemain et al. revisited.2011In: Ambio, ISSN 0044-7447, E-ISSN 1654-7209, Vol. 40, no 3, p. 338-340Article in journal (Refereed)
  • 235.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Latorre-Margalef, Neus
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Hobson, K. A.
    Environment Canada, Saskatoon, Canada.
    Van Wilgenburg, S. L.
    Environment Canada, Saskatoon, Canada.
    Elmberg, Johan
    Kristianstad University.
    Olsen, Björn
    Uppsala University Hospital.
    Fouchier, R. A. M.
    Erasmus Medical Center, The Netherlands.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Disease Dynamics and Bird Migration – Linking Mallards Anas platyrhynchos and subtype diversity of Influenza A Virus in Time and Space2012In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 7, no 4, article id e35679Article in journal (Refereed)
    Abstract [en]

    The mallard Anas platyrhynchos is a reservoir species for influenza A virus in the northern hemisphere, with particularly high prevalence rates prior to as well as during its prolonged autumn migration. It has been proposed that the virus is brought from the breeding grounds and transmitted to conspecifics during subsequent staging during migration, and so a better understanding of the natal origin of staging ducks is vital to deciphering the dynamics of viral movement pathways. Ottenby is an important stopover site in southeast Sweden almost halfway downstream in the major Northwest European flyway, and is used by millions of waterfowl each year. Here, mallards were captured and sampled for influenza A virus infection, and positive samples were subtyped in order to study possible links to the natal area, which were determined by a novel approach combining banding recovery data and isotopic measurements (d2 H) of feathers grown on breeding grounds. Geographic assignments showed that the core natal areas of studied mallards were in Estonia, southern and central Finland, and northwestern Russia. This study demonstrates a clear temporal succession of latitudes of natal origin during the course of autumn migration. We also demonstrate a corresponding and concomitant shift in virus subtypes. Acknowledging that these two different patterns were based in part upon different data, a likely interpretation worth further testing is that the early arriving birds with more proximate origins have different influenza A subtypes than the more distantly originating late autumn birds. If true, this knowledge would allow novel insight into the origins and transmission of the influenza A virus among migratory hosts previously unavailable through conventional approaches.

  • 236.
    Gunnarsson, Gunnar
    et al.
    Kristianstad University.
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Fransson, Thord
    Direct and indirect effects of winter harshness on the survival of Mallards Anas platyrhynchos in northwest Europe2012In: Ibis, ISSN 0019-1019, E-ISSN 1474-919X, Vol. 154, no 2, p. 307-317Article in journal (Refereed)
    Abstract [en]

    To understand population dynamics it is necessary to understand vital rates, which may be affected by a wide range of factors including environmental variables such as weather. Weather conditions can affect birds vital rates directly through increased mortality due to impaired conditions, or indirectly via changes in body condition and/or behaviour. Most understanding of direct and indirect effects of weather comes from studies of breeding birds, whereas the situation in non-breeding periods is less clear. Here, we analysed annual survival of non-breeding Mallard Anas platyrhynchos, the most hunted waterfowl species in Europe, and assessed whether survival is related directly to winter harshness and/or indirectly via changes in winter recovery distributions. Recovery data on Mallards, initially marked in southeast Sweden, were analysed with an information-theoretic approach using program mark. Over 10 000 Mallards were marked in two time periods, 19641982 and 20022008, of which 13.3 and 4.7%, respectively, were later recovered. Mallards had lower annual survival in the early trapping period (0.580.63) than in the later period (0.690.71), with no clear effects of sex, age or year. Within each study period, winter harshness did not directly correlate with survival. However, milder winters may have contributed indirectly to higher survival in the second period, as winter harshness data were correlated with the distances to recovery positions for females, and also because winter recovery areas have shifted northeast during the past decades, possibly indicating a shortened migratory distance. Migration is costly, and there is therefore a likely linkage between migration behaviour and survival of dabbling ducks, in which direct as well as indirect effects of winter harshness may play a role. Other factors, such as hunting pressure, are also likely to have changed in the past decades, and may also have contributed to improved survival of Mallards in northwest Europe.

  • 237.
    Gómez-Consarnau, Laura
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Akram, Neelam
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lindell, Kristoffer
    Pedersen, Anders
    Neutze, Richard
    Milton, Debra L.
    González, José M.
    Pinhassi, Jarone
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Proteorhodopsin phototrophy promotes survival of marine bacteria during starvation2010In: PLoS biology, ISSN 1544-9173, E-ISSN 1545-7885, Vol. 8, no 4, p. 1-10Article in journal (Refereed)
    Abstract [en]

    Proteorhodopsins are globally abundant photoproteins found in bacteria in the photic zone of the ocean. Although their function as proton pumps with energy-yielding potential has been demonstrated, the ecological role of proteorhodopsins remains largely unexplored. Here, we report the presence and function of proteorhodopsin in a member of the widespread genus Vibrio, uncovered through whole-genome analysis. Phylogenetic analysis suggests that the Vibrio strain AND4 obtained proteorhodopsin through lateral gene transfer, which could have modified the ecology of this marine bacterium. We demonstrate an increased long-term survival of AND4 when starved in seawater exposed to light rather than held in darkness. Furthermore, mutational analysis provides the first direct evidence, to our knowledge, linking the proteorhodopsin gene and its biological function in marine bacteria. Thus, proteorhodopsin phototrophy confers a fitness advantage to marine bacteria, representing a novel mechanism for bacterioplankton to endure frequent periods of resource deprivation at the ocean’s surface.

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  • 238.
    Götmark, Frank
    et al.
    University of Gothenburg, Sweden.
    Götmark, Elin
    Chalmers University of Technology, Sweden;University of Gothenburg, Sweden.
    Jensen, Anna M.
    Linnaeus University, Faculty of Technology, Department of Forestry and Wood Technology.
    Why Be a Shrub?: a Basic Model and Hypotheses for the Adaptive Values of a Common Growth Form2016In: Frontiers in Plant Science, ISSN 1664-462X, E-ISSN 1664-462X, Vol. 7, article id 1095Article in journal (Refereed)
    Abstract [en]

    Shrubs are multi-stemmed short woody plants, more widespread than trees, important in many ecosystems, neglected in ecology compared to herbs and trees, but currently in focus due to their global expansion. We present a novel model based on scaling relationships and four hypotheses to explain the adaptive significance of shrubs, including a review of the literature with a test of one hypothesis. Our model describes advantages for a small shrub compared to a small tree with the same above-ground woody volume, based on larger cross-sectional stem area, larger area of photosynthetic tissue in bark and stem, larger vascular cambium area, larger epidermis (bark) area, and larger area for sprouting, and faster production of twigs and canopy. These components form our Hypothesis 1 that predicts higher growth rate for a small shrub than a small tree. This prediction was supported by available relevant empirical studies (14 publications). Further, a shrub will produce seeds faster than a tree (Hypothesis 2), multiple stems in shrubs insure future survival and growth if one or more stems die (Hypothesis 3), and three structural traits of short shrub stems improve survival compared to tall tree stems (Hypothesis 4)—all hypotheses have some empirical support. Multi-stemmed trees may be distinguished from shrubs by more upright stems, reducing bending moment. Improved understanding of shrubs can clarify their recent expansion on savannas, grasslands, and alpine heaths. More experiments and other empirical studies, followed by more elaborate models, are needed to understand why the shrub growth form is successful in many habitats.

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  • 239.
    Haemig, Paul D.
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sjöstedt de Luna, S
    Grafström, A
    Lithner, Stefan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Lundkvist, Åke
    Waldenström, Jonas
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Kindberg, Jonas
    Stedt, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Olsen, Björn
    Forecasting risk of tick-borne encephalitis (TBE): using data from wildlife and climate to predict next year's number of human victims.2011In: Scandinavian Journal of Infectious Diseases, ISSN 0036-5548, E-ISSN 1651-1980, Vol. 43, no 5, p. 366-372Article in journal (Refereed)
    Abstract [en]

    BACKGROUND: Over the past quarter century, the incidence of tick-borne encephalitis (TBE) has increased in most European nations. However, the number of humans stricken by the disease varies from year to year. A method for predicting major increases and decreases is needed.

    METHODS: We assembled a 25-y database (1984-2008) of the number of human TBE victims and wildlife and climate data for the Stockholm region of Sweden, and used it to create easy-to-use mathematical models that predict increases and decreases in the number of humans stricken by TBE.

    RESULTS: Our best model, which uses December precipitation and mink (Neovison vison, formerly Mustela vison) bagging figures, successfully predicted every major increase or decrease in TBE during the past quarter century, with a minimum of false alarms. However, this model was not efficient in predicting small increases and decreases.

    CONCLUSIONS: Predictions from our models can be used to determine when preventive and adaptive programmes should be implemented. For example, in years when the frequency of TBE in humans is predicted to be high, vector control could be intensified where infested ticks have a higher probability of encountering humans, such as at playgrounds, bathing lakes, barbecue areas and camping facilities. Because our models use only wildlife and climate data, they can be used even when the human population is vaccinated. Another advantage is that because our models employ data from previously-established databases, no additional funding for surveillance is required.

  • 240.
    Hagström, Johannes
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Granéli, Edna
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Moreira, M O P
    Odebrecht, C
    Domoic acid production and elemental composition of two Pseudo-nitzschia multiseries strains, from the NW and SW Atlantic Ocean, growing in phosphorus- or nitrogen-limited chemostat cultures.2011In: Journal of Plankton Research, ISSN 0142-7873, E-ISSN 1464-3774, Vol. 33, no 2, p. 297-308Article in journal (Refereed)
    Abstract [en]

    Here we compare cell physiology and domoic acid (DA) production for two strains of the diatom Pseudo-nitzschia multiseries originating from two opposite latitudes: Canada (CA) and Brazil (BR). The algae were grown as chemostat cultures at 0.2, 0.3 and 0.4 day−1 under nitrogen (N)- and phosphorus (P)-deficient conditions. The level of deficiency significantly affected the atomic C:N, C:P, C:Si and N:P ratios in both strains. In both strains, P per cell was 2–4× higher in the N- than in the P-deficient cultures. The opposite was not found for N in the P-deficient cultures, as shown by the N:P ratios and C:N ratios. The C:N and C:P ratios were significantly lower in the CA strain, and this did not change due to the level of deficiency. The concentration and production of DA per cell per day were significantly higher for both strains under P deficiency as expected since the toxin is rich in N. However, DA was also produced by both strains during continuous cell division under N deficiency. High or low bacterial densities associated with P. multiseries did not increase or decrease DA production. Our data imply that more attention needs to be given to the N:P ratios and concentrations in the waters where these algae occur, as both N and P deficiencies affect DA production and cellular DA concentrations.

  • 241.
    Hagström, Johannes
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Natural Sciences.
    Sengco, Mario
    Villareal, Tracy
    Potential methods for managing Prymnesium parvum blooms and toxicity, with emphasis on clay and barley straw: A review2010In: Journal of the American Water Resources Association, ISSN 1093-474X, E-ISSN 1752-1688, Vol. 46, no 1, p. 187-198Article in journal (Refereed)
    Abstract [en]

    Harmful algal bloom (HAB) control and mitigation is a complex problem in ecosystem management. Phytoplankton play an important role in aquatic ecosystems as primary producers and food sources for many commercially important shellfish and there are limited options for targeting just a single species within the community. Chemical treatments (e.g., algaecides), rotting barley straw, nitrogen and phosphorus manipulation, and clay and/or flocculants are but a few techniques tested or used to reduce fish kills or shellfish contamination during a HAB event. Prymnesium parvum control has focused on the use of chemicals, nutrient manipulation, and clay flocculation. However, many HAB control methods have been rejected due to their effects on ecosystems, high costs, or limited effects on target organisms. For example, rotting barley straw (Hordeum vulgare) is considered to be an environmentally friendly alternative, but has been found to have very different results on the phytoplankton community depending on the dominating taxa and is ineffective against P. parvum and dinoflagellate blooms. Clay flocculation is a useful control/mitigation technique during fish kills in marine aquaculture sites in South Korea and can be effective in freshwater if the correct combination of clay and flocculent is used. Toxins produced by P. parvum and Karenia brevis also bind to phosphatic clay, thereby removing and/or neutralizing the toxins, but there is concern that the clay will have a negative effect on sessile organisms. Some shellfish suffer high mortalities and significant impacts on somatic and reproductive tissue growth at high clay loads; however, benthic communities appear to be unchanged after five years of clay treatment in South Korea. There are likely site-specific and ecosystem-specific characteristics that make generalizations about control options difficult and require careful assessment of options at each location.

  • 242.
    Hagström, Åke
    et al.
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Azam, Farooq
    Univ Calif San Diego, USA.
    Berg, Carlo
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Zweifel, Ulla Li
    University of Gothenburg.
    Isolates as models to study bacterial ecophysiology and biogeochemistry2018In: Aquatic Microbial Ecology, ISSN 0948-3055, E-ISSN 1616-1564, Vol. 80, no 1, p. 15-27Article in journal (Refereed)
    Abstract [en]

    Here, we examine the use of bacterial isolates growing in artificial media or seawater as a means to investigate bacterial activity in the upper ocean. The discovery of a major role of bacteria in the ocean's carbon cycle owes greatly to the development of culture-independent assemblage-level approaches; however, this should not detract from the recognition of model isolates as representing the environmental microbiome. A long-established tool for culturing bacteria, in medicine and general microbiology, has been agar plates. In addition, a great variety of liquid substrates including seawater have been used to successfully identify and cultivate important bacteria such as Pelagibacter ubique. Yet, the discrepancy between microscopic counts and plate counts, the great plate count anomaly, has led to a biased perception of the limited relevance of isolated bacteria. Linking isolates to whole-genome sequencing, phylogenetic analysis and computational modeling will result in culturable model bacteria from different habitats. Our main message is that bacterial ecophysiology, particularly growth rates in seawater, and functionalities inferred through the identity, abundance and expression of specific genes could be mechanistically linked if more work is done to isolate, culture and study bacteria in pure cultures. When we rally behind a strategy aimed at culturing targeted phenotypes, we are not saying that culture independent studies of bacteria in the sea are not informative. We are suggesting that culturebased studies can help integrate the ecological and genomic views.

  • 243.
    Hall, Marcus
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Reproductive timing as a driver of intrapopulation trait diversity in Perch (Perca fluviatilis)2020Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Many populations show a large degree of variation in reproductive timing among its individuals, resulting in their offspring being introduced into a variety of seasonally dependent environmental conditions. These conditions may influence adaptive gene and trait variation within and among populations, but we know very little about whether, when, and how differences in reproductive timing lead to distinct subpopulations and temporal local adaptations within a population and reproductive season. I used a combination of field observations and laboratory studies on anadromous perch (Perca fluviatilis) to examine how reproductive time and individual differences in reproductive timing is related to environmental conditions that influence offspring survival (water temperature, zooplankton abundance, and predator presence (sticklebacks)). Moreover, I evaluated whether individual differences in reproductive timing had led to seasonally dependent temperature adaptations in eggs (hatching success) and early juvenile stages (juvenile size). My results showed that the spawning season extended over 58 days (22 April – 19 June 2019), with a distinct peak in spawning activity in late May/early June. This peak coincided with a distinct increase in zooplankton abundance in the stream, and an immigration of sticklebacks into the spawning area of perch. The hatching success of perch that spawned in either the early or mid-portion of the spawning period decreased with an increase in temperature. In contrast, the hatching success of late spawning perch generally increased with increasing temperatures. These results suggest an adaptive difference in temperature optima between perch that spawn late in the reproductive season (in 18-21 ˚C) and perch that spawn in the early-mid portion of the season (in 10-18 ˚C). Furthermore, I also found a seasonal pattern in the size of juveniles, with larger juveniles hatching in the early-mid portion of the spawning season, driven by a seasonal aggregation of large perch that overall produced larger juveniles. In summary, this study highlight how seasonally dependent trait variation can emerge within populations that have an extended reproductive period. Furthermore, the aggregation of large perch in time indicate that seasonally sorted phenotypes, if consistent, could contribute to an increased trait diversity in the next generation. These findings showcase how individual variation in reproductive time can contribute to an increase in intrapopulation trait diversity, and thereby promote population persistence/viability.

  • 244. Hameed, Mahmood
    The most ecological Problems in the modern world1995 (ed. 1)Book (Refereed)
    Abstract [ar]

     

    أهم المشكلات البيئية في العالم المعاصر: يقدم هذا الكتاب شرحا مفصلا لأهم المشكلات البيئية التي يرزح تحتها عالمنا المعاصر من تلوث للهواء والتربة والماء والغذاء مع اسقاط الضوء على مشكلتي الاحتباس الحراري وثقب الأوزون: حيث يتم طرح المشكلة مع بيان أسبابها والأضرار الناجمة عنها وطرق علاجها.

  • 245.
    Hammarsten, Maria
    et al.
    Jönköping University, Sweden.
    Askerlund, Per
    Jönköping University, Sweden.
    Almers, Ellen
    Jönköping University, Sweden.
    Avery, Helen
    Jönköping University, Sweden.
    Samuelsson, Tobias
    Jönköping University, Sweden.
    Developing ecological literacy in a forest garden: children’s perspectives2019In: Journal of Adventure Education and Outdoor Learning, ISSN 1472-9679, E-ISSN 1754-0402, Vol. 19, no 3, p. 227-241Article in journal (Refereed)
    Abstract [en]

    Today, cities become more dense, green spaces disappear and children spend less time outdoors. Research suggests that these conditions create health problems and lack of ecological literacy. To reverse such trends, localities are creating urban green spaces for children to visit during school time. Drawing on ideas in ecological literacy, this study investigates school children’s perspectives on a forest garden, a type of outdoor educational setting previously only scarcely researched. Data were collected through walk-and-talk conversations and informal interviews with 28 children aged 7 to 9. Many children in the study expressed strong positive feelings about the forest garden, the organized and spontaneous activities there, and caring for the organisms living there. We observed three aspects of learning in the data, potentially beneficial for the development of children’s ecological literacy: practical competence, learning how to co-exist and care, and biological knowledge and ecological understanding.

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  • 246.
    Hansson, Lars-Anders
    et al.
    Lund University.
    Bianco, Giuseppe
    Lund University.
    Ekvall, Mikael
    Lund University.
    Heuschele, Jan
    Lund University.
    Hylander, Samuel
    Linnaeus University, Faculty of Health and Life Sciences, Department of Biology and Environmental Science.
    Yang, Xi
    Lund University.
    Instantaneous threat escape and differentiated refuge demand among zooplankton taxa2016In: Ecology, ISSN 0012-9658, E-ISSN 1939-9170, Vol. 97, no 2, p. 279-285Article in journal (Refereed)
    Abstract [en]

    Most animals, including aquatic crustacean zooplankton, perform strong avoidance movements when exposed to a threat, such as ultraviolet radiation (UVR). We here show that the genera Daphnia and Bosmina instantly adjust their vertical position in the water in accordance with the present UVR threat, i.e., seek refuge in deeper waters, whereas other taxa show less response to the threat. Moreover, Daphnia repeatedly respond to UVR pulses, suggesting that they spend more energy on movement than more stationary taxa, for example, during days with fluctuating cloud cover, illustrating nonlethal effects in avoiding UVR threat. Accordingly, we also show that the taxa with the most contrasting behavioral responses differ considerably in photoprotection, suggesting different morphological and behavioral strategies in handling the UVR threat. In a broader context, our studies on individual and taxa specific responses to UVR provide insights into observed spatial and temporal distribution in natural ecosystems.

  • 247.
    Hansson, Lars-Anders
    et al.
    Lunds universitet.
    Hylander, Samuel
    Lunds universitet.
    Effects of ultraviolet radiation on pigmentation, photoenzymatic repair, behavior, and community ecology of zooplankton2009In: Photochemical and Photobiological Sciences, ISSN 1474-905X, E-ISSN 1474-9092, Vol. 8, no 9, p. 1266-1275Article in journal (Refereed)
    Abstract [en]

    In this report, we provide a perspective on how zooplankton are able to respond to present and future levels of ultraviolet (UV) radiation, a threat that has been present throughout evolutionary time. To cope with this threat, zooplankton have evolved several adaptations including behavioral responses, repair systems, and accumulation of photoprotective compounds. Common photoprotective compounds include melanins and carotenoids, which are true pigments, but also mycosporine-like amino acids (MAAs) and several other substances, and different taxa use different blends of these compounds. It is not only the level of UV radiation, however, that determines the amount of photoprotective compounds incorporated by the zooplankton, but also other environmental factors, such as predation and supply rate of the compounds. Furthermore, compared to taxa that are less pigmented, those taxa with ample pigmentation are generally less likely to exhibit diel migration. The photoenzymatic repair of UV damages seems to be more efficient at intermediate temperature than at low and high temperatures, suggesting that it is less useful at high and low latitudes, where UV radiation is often extremely high. While predicted future increases in UV radiation are expected to substantially affect many processes, recent studies show that most zooplankton taxa are well adapted to cope with such increases, either by UV avoidance behavior or by incorporation of photoprotective compounds. Hence, we conclude that future increase in UV radiation will have only moderate direct effects on zooplankton biomass and community dynamics.

  • 248.
    Hansson, Lars-Anders
    et al.
    Lunds universitet.
    Hylander, Samuel
    Lunds universitet.
    Size-structured risk assessments govern Daphnia migration2009In: Proceedings of the Royal Society of London. Biological Sciences, ISSN 0962-8452, E-ISSN 1471-2954, Vol. 276, no 1655, p. 331-336Article in journal (Refereed)
    Abstract [en]

    One of the more fascinating phenomena in nature is animal mass migrations and in oceans and freshwaters, diel variations in depth distribution of zooplankton are a phenomenon that has intrigued scientists for more than a century. In our study, we show that zooplankton are able to assess the threat level of ultraviolet radiation and adjust their depth distribution to this level at a very fine tuned scale. Moreover, predation risk induces a size-structured depth separation, such that small individuals, which we show are less vulnerable to predation than larger, make a risk assessment and continue feeding in surface waters during day, offering a competitive release from down-migrating larger animals. Hence, we mechanistically show that such simple organisms as invertebrate zooplankton are able to make individual, size-specific decisions regarding how to compromise between threats from both predators and UV radiation, and adjust their diel migratory patterns accordingly.

  • 249. Hansson, Maria C.
    et al.
    Persson, Maria E.
    Larsson, Per
    University of Kalmar, School of Pure and Applied Natural Sciences.
    von Schantz, Torbjörn
    Polychlorinated biphenyl (PCB) load, lipid reserves and biotransformation activity in migrating Atlantic salmon from River Mörrum, Sweden2009In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 157, no 12, p. 3396-3403Article in journal (Refereed)
    Abstract [en]

    Atlantic salmon accumulate high levels of contaminants such as polychlorinated biphenyls (PCBs) in their lipids during the adult growth phase spent at sea. The lipids are later utilized during migration for swimming and biological adaptations. We hypothesize that migrating salmons' biotransformation processes are affected by the high levels of built-up PCBs compared to salmon that in a pre-migrational stage. For these analyses we sampled adult Atlantic salmon during migration in the Swedish River Morrum and measured the 21 most common PCB congeners (Sigma PCB) and lipid levels in muscle tissue, aryl hydrocarbon receptor (AHR2) and cytochrome P4501A1(CYP1A1) transcript levels as well as ethoxyresorufin-O-deethylase activity (EROD) in liver. We also determined which AHR2 genotypes the salmon carried. We show that EROD activity is correlated to CYP1A1 level but not to Sigma PCB concentration. Sigma PCB concentration does not predict levels of neither the AHR2 nor CYP1A1 genes. We find no associations between specific AHR2 transcription levels and AHR2 genotypes or a correlation between AHR2 and CYP1A1 transcription levels, which is in direct contrast to pre-migrational adult salmon from the Baltic Sea. When we compare River Morrum to salmon we have previously sampled in the Baltic Sea we show that migrating salmon have significantly lower lipid levels in their muscles; higher muscle concentrations of Sigma PCB on a lipid basis; and significantly lower CYP1A1 and EROD levels compared to salmon from the Baltic Sea. Also, transcript levels of three out of four AHR2 genes are significantly different. In conclusion, migrating Swedish Atlantic salmon carry higher concentrations of PCBs in their lipids compared to salmon in the Baltic Sea, but have lower activation of biotransformation genes and enzymes. Our results indicate that accumulated pollutants from the Baltic Sea are deactivated inside the migrating salmon's lipid tissues and increase in concentration when migration is initiated thereby limiting their impact on biotransformation processes.

  • 250. Haraldsson, C
    et al.
    Granéli, Edna
    University of Kalmar, School of Pure and Applied Natural Sciences.
    Trace metals as nutrients1996In: Manual on harmful marine microalgae / [ed] G.M- Hallegraeff, D.M. Amderson and A.D. Cembella, Paris: Unesco, 1996, 1, p. 269-275Chapter in book (Other academic)
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