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Reitzel, Kasper
Alternative names
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diva2:1172208
Open this publication in new window or tab >>Orsaker till minskande syrehalter i Bottenhavet
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2017 (Swedish)Report (Refereed)
Abstract [sv]

Resultat från den nationella miljöövervakningen visar att syrehalterna i Bottenhavet har minskat sedan 1970-talet, en minskning som accelererat från 1990. För att ha möjlighet att på något sätt kunna åtgärda denna försämring av den marina miljön är det nödvändigt att identifiera orsakerna till denna syreminskning, eftersom olika orsaker kan kräva olika former av åtgärder. Om orsaken till exempel är ökad syreförbrukning beroende på regional övergödning, skulle detta innebära ökat behov av regionala reningsåtgärder. Målsättningen med projektet var därmed att ge en tillförlitlig förklaring till de sjunkande syrehalterna i Bottenhavet under de senaste 20 åren genom att använda data från de nationella miljöövervakningsprogrammen. De huvudhypoteser som undersöktes som orsaker till de sjunkande syrehalterna var:  • Ökad regional gödning av Bottenhavet och därmed ökad produktion.  • Tillförsel av syrefattigt och fosfatrikt från Egentliga Östersjön.  • Starkare haloklin och försämrad ventilation av Bottenhavets djupvatten.  • Ökad temperatur och ökad tillförsel av löst organiskt kol. Analys av tidsserier och modellanalyser utifrån miljöövervaknings- och forskningsdata visade att den observerade syrehaltsminskningen i Bottenhavets djupvatten främst beror på en ökning av vattentemperaturen och delvis på en ökning av löst organiskt kol i vattnet, samt tillflöde från Egentliga Östersjön. Dataanalysen visade däremot inget tydligt stöd för att ökad produktion av biomassa i Bottenhavet orsakat de minskande syrehalterna. Detta gäller indikatorer för växtplankton, sedimentation och bakterieplankton som alla förväntas öka vid ökad produktion och det finns således inga direkta indicier för att stödja hypotesen om ökad gödning av Bottenhavet.  Sammantaget visar de analyser som gjorts inom projektet att Bottenhavets framtida hälsa främst gynnas av en kombination av åtgärder för att motverka globala klimatförändringar, samt åtgärder för att förbättra vattenkvaliteten i Egentliga Östersjön. Näringstillförsel från Bottenhavets avrinningsområden bedöms främst ha haft betydelse för syresituationen i kustnära vattenförekomster. Den bedöms därför inte i betydande omfattning ha orsakat de minskande syrehalterna i Bottenhavets utsjöområden.  

Place, publisher, year, edition, pages
Göteborg: , 2017. p. 25
Series
Havsmiljöinstitutets rapport ; 2017:5
National Category
Environmental Sciences
Research subject
biology, Environmental Science
Identifiers
urn:nbn:se:umu:diva-143775 (URN)
Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2018-06-09Bibliographically approved
Ahlgren, J., Grimvall, A., Omstedt, A., Rolff, C. & Wikner, J. (2017). Temperature, DOC level and basin interactions explain the declining oxygen concentrations in the Bothnian Sea. Journal of Marine Systems, 170, 22-30
Open this publication in new window or tab >>Temperature, DOC level and basin interactions explain the declining oxygen concentrations in the Bothnian Sea
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2017 (English)In: Journal of Marine Systems, ISSN 0924-7963, E-ISSN 1879-1573, Vol. 170, p. 22-30Article in journal (Refereed) Published
Abstract [en]

Hypoxia and oxygen deficient zones are expanding worldwide. To properly manage this deterioration of the marine environment, it is important to identify the causes of oxygen declines and the influence of anthropogenic activities. Here, we provide a study aiming to explain the declining oxygen levels in the deep waters of the Bothnian Sea over the past 20 years by investigating data from environmental monitoring programmes. The observed decline in oxygen concentrations in deep waters was found to be primarily a consequence of water temperature increase and partly caused by an increase in dissolved organic carbon (DOC) in the seawater (R-Adj(2). = 0.83) as well as inflow from the adjacent sea basin. As none of the tested eutrophication-related predictors were significant according to a stepwise multiple regression, a regional increase in nutrient inputs to the area is unlikely to explain a significant portion of the oxygen decline. Based on the findings of this study, preventing the development of anoxia in the deep water of the Bothnian Sea is dependent on the large-scale measures taken to reduce climate change. In addition, the reduction of the nutrient load to the Baltic Proper is required to counteract the development of hypoxic and phosphate-rich water in the Baltic Proper, which can form deep water in the Bothnian Sea. The relative importance of these sources to oxygen consumption is difficult to determine from the available data, but the results clearly demonstrate the importance of climate related factors such as temperature, DOC and inflow from adjacent basins for the oxygen status of the sea.

Keywords
Oxygen depletion, Hypoxia, Bothnian Sea, Baltic Sea, Climatic changes, Modelling
National Category
Oceanography, Hydrology and Water Resources Environmental Sciences
Identifiers
urn:nbn:se:umu:diva-136048 (URN)10.1016/j.jmarsys.2016.12.010 (DOI)000401211400003 ()
Available from: 2017-06-20 Created: 2017-06-20 Last updated: 2018-06-09Bibliographically approved
Ahlgren, J., Djodjic, F., Borjesson, G. & Mattsson, L. (2013). Identification and quantification of organic phosphorus forms in soils from fertility experiments. Soil use and management, 29, 24-35
Open this publication in new window or tab >>Identification and quantification of organic phosphorus forms in soils from fertility experiments
2013 (English)In: Soil use and management, ISSN 0266-0032, E-ISSN 1475-2743, Vol. 29, p. 24-35Article in journal (Refereed) Published
Abstract [en]

The effects of soil type, crop rotation, fertilizer type and application rate on the composition of organic phosphorus (P) compounds in soils from four sites in a Swedish long-term fertilizer experiment were investigated with 31P-NMR. Soil textures investigated were loamy sand, sandy loam, silty clay loam and clay. Phosphorus has been added to the soils since the 1950s and 1960s at four different rates in the form of either mineral fertilizer or a combination of manure and mineral fertilizer. Results show that in soils receiving no P addition, most of the soil P was present in the form of phosphate monoesters (6070%, depending on soil type). However, a P addition equivalent to the amount of P removed annually by harvest altered this relationship so that the soils were dominated by orthophosphate instead. This trend became more obvious with increasing P addition. At the greatest P application rate, orthophosphate comprised 70% or more of the total extracted P in all the soils. These changes in the soil were due entirely to increase in orthophosphate, because the amounts of monoesters did not change with increasing P additions. This was true both for mineral fertilizer and the combination of manure and mineral fertilizer P. Soil type and crop rotation did not influence the results. The results indicate that there is no apparent build-up of organic P in the soils, but that P addition mainly affects the orthophosphate amounts in the soils regardless of form or amount of fertilizer.

Keywords
Organic phosphorus, nuclear magnetic resonance, soil, fertilizers, crop rotation
National Category
Environmental Sciences related to Agriculture and Land-use
Identifiers
urn:nbn:se:umu:diva-113608 (URN)10.1111/sum.12014 (DOI)000315827800004 ()
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Ahlgren, J., Djodjic, F. & Wallin, M. (2012). Barium as a Potential Indicator of Phosphorus in Agricultural Runoff. Journal of Environmental Quality, 41(1), 208-216
Open this publication in new window or tab >>Barium as a Potential Indicator of Phosphorus in Agricultural Runoff
2012 (English)In: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 41, no 1, p. 208-216Article in journal (Refereed) Published
Abstract [en]

In many catchments, anthropogenic input of contaminants, and in particular phosphorus (P), into surface water is a mixture of agricultural and sewage runoff. Knowledge about the relative contribution from each of these sources is vital for mitigation of major environmental problems such as eutrophication. In this study, we investigated whether the distribution of trace elements in surface waters can be used to trace the contamination source. Water from three groups of streams was investigated: streams influenced only by agricultural runoff, streams influenced mainly by sewage runoff, and reference streams. Samples were collected at different flow regimes and times of year and analyzed for 62 elements using ICP-MS. Our results show that there are significant differences between the anthropogenic sources affecting the streams in terms of total element composition and individual elements, indicating that the method has the potential to trace anthropogenic impact on surface waters. The elements that show significant differences between sources are strontium (p < 0.001), calcium (p < 0.004), potassium (p < 0.001), magnesium (p < 0.001), boron (p < 0.001), rhodium (p = 0.001), and barium (p < 0.001). According to this study, barium shows the greatest potential as a tracer for an individual source of anthropogenic input to surface waters. We observed a strong relationship between barium and total P in the investigated samples (R-2 = 0.78), which could potentially be used to apportion anthropogenic sources of P and thereby facilitate targeting of mitigation practices.

National Category
Environmental Sciences related to Agriculture and Land-use
Identifiers
urn:nbn:se:umu:diva-113610 (URN)10.2134/jeq2011.0220 (DOI)000299213900022 ()22218189 (PubMedID)
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Reitzel, K., Ahlgren, J., Rydin, E., Egemose, S., Turner, B. L. & Hupfer, M. (2012). Diagenesis of settling seston: identity and transformations of organic phosphorus. Journal of Environmental Monitoring, 14(3), 1098-1106
Open this publication in new window or tab >>Diagenesis of settling seston: identity and transformations of organic phosphorus
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2012 (English)In: Journal of Environmental Monitoring, ISSN 1464-0325, E-ISSN 1464-0333, Vol. 14, no 3, p. 1098-1106Article in journal (Refereed) Published
Abstract [en]

Solution (31)phosphorus NMR spectroscopy and sequential fractionation were used to follow diagenetic changes in phosphorus forms during decomposition of settling seston in Lake Nordborg, a shallow eutrophic lake in Denmark. In a decomposition experiment, seston released >60% of their total phosphorus during similar to 50 days incubation, although seston collected during summer contained more phosphorus and released it over a longer period compared to seston collected during spring. Seston decomposition increased concentrations of potentially bioavailable polyphosphate and phosphodiesters, but also promoted the formation of refractory phosphorus forms that might be buried permanently in the sediment. Combining these results with in situ measurements of phosphorus concentrations in lake water and sediment traps revealed that the release from settling seston plays only a minor role in the accumulation of phosphorus in the hypolimnion of Lake Nordborg.

National Category
Natural Sciences
Research subject
Limnology
Identifiers
urn:nbn:se:umu:diva-113609 (URN)10.1039/c2em10883f (DOI)000300875100040 ()22344567 (PubMedID)
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Ahlgren, J., Reitzel, K., De Brabandere, H., Gogoll, A. & Rydin, E. (2011). Release of organic P forms from lake sediments. Water Research, 45(2), 565-572
Open this publication in new window or tab >>Release of organic P forms from lake sediments
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2011 (English)In: Water Research, ISSN 0043-1354, E-ISSN 1879-2448, Vol. 45, no 2, p. 565-572Article in journal (Refereed) Published
Abstract [en]

The effects of different physical and chemical conditions on the decomposition and release of organic and inorganic P compound groups from the sediment of Lake Erken were investigated in a series of laboratory experiments. Conditions investigated were temperature, oxygen level, and the effects of additions of carbon substrate (glucose) and poison (formalin). The effects on the P compound groups were determined by measurements with (31)P NMR before and after the experiments, as well as analysis of P in effluent water throughout the experiment. Phosphate analysis of the effluent water showed that oxygen level was the most influential in terms of release rates, with the sediments under anoxic conditions generally releasing more phosphate than the other treatments. (31)P NMR showed that the various treatments did influence the P compound group composition of the sediment. In particular, the addition of glucose led to a decrease in orthophosphate and polyphosphate while the addition of formalin led to a decrease in phosphorus lipids, DNA-phosphate and polyphosphate. Oxic conditions resulted in an increase in polyphosphates, and anoxic conditions in a decrease in these. Temperature did not seem to affect the composition significantly. (c) 2010 Elsevier Ltd. All rights reserved.

Keywords
Organic phosphorus, Release, Sediments, (31)P NMR
National Category
Natural Sciences
Research subject
Limnology
Identifiers
urn:nbn:se:umu:diva-113611 (URN)10.1016/j.watres.2010.09.020 (DOI)000286790500015 ()20947118 (PubMedID)
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Taubald, H., Tonderski, K., Andersson, L., Ronnberg, R. & Ahlgren, J. (2010). Oxygen isotopes in phosphate as a tracer for sources and pathways of catchment P in stream water. Paper presented at Conference on Goldschmidt 2010 - Earth, Energy, and the Environment, JUN 13-18, 2010, Knoxville, TN. Geochimica et Cosmochimica Acta, 74(12), A1030-A1030
Open this publication in new window or tab >>Oxygen isotopes in phosphate as a tracer for sources and pathways of catchment P in stream water
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2010 (English)In: Geochimica et Cosmochimica Acta, ISSN 0016-7037, E-ISSN 1872-9533, Vol. 74, no 12, p. A1030-A1030Article in journal, Meeting abstract (Other academic) Published
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:umu:diva-113612 (URN)000283941400100 ()
Conference
Conference on Goldschmidt 2010 - Earth, Energy, and the Environment, JUN 13-18, 2010, Knoxville, TN
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
De Brabandere, H., Danielsson, R., Sjoberg, P. J. R., Ahlgren, J., Rydin, E. & Waldeback, M. (2008). Sediment extraction and clean-up for organic phosphorus analysis by electrospray ionization tandem mass spectrometry. Talanta: The International Journal of Pure and Applied Analytical Chemistry, 74(5), 1175-1183
Open this publication in new window or tab >>Sediment extraction and clean-up for organic phosphorus analysis by electrospray ionization tandem mass spectrometry
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2008 (English)In: 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) Published
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, P-31-nuclear magnetic resonance Spectroscopy (P-31 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 P-31 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. (c) 2007 Elsevier B.V. All rights reserved.

Keywords
organic phosphorus, sediment, sample preparation, ESI-MS-MS, P-31 NMR
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:umu:diva-113613 (URN)10.1016/j.talanta.2007.08.030 (DOI)000253514700013 ()18371767 (PubMedID)
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Reitzel, K., Ahlgren, J., DeBrabandere, H., Waldeback, M., Gogoll, A., Tranvik, L. & Rydin, E. (2007). Degradation rates of organic phosphorus in lake sediment. Biogeochemistry, 82(1), 15-28
Open this publication in new window or tab >>Degradation rates of organic phosphorus in lake sediment
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2007 (English)In: Biogeochemistry, ISSN 0168-2563, E-ISSN 1573-515X, Vol. 82, no 1, p. 15-28Article in journal (Refereed) Published
Abstract [en]

Phosphorus (P) binding groups were identified in phytoplankton, settling particles, and sediment profiles by P-31 NMR spectroscopy from the Swedish mesotrophic Lake Erken. The P-31 NMR analysis revealed that polyphosphates and pyrophosphates were abundant in the water column, but rapidly mineralized in the sediment. Orthophosphate monoesters and teichoic acids degraded more slowly than DNA-P, polyphosphates, and P lipids. Humic acids and organic acids from phytoplankton were precipitated from the NaOH extract by acidification and identified by P-31 NMR spectroscopy. The precipitated P was significantly more recalcitrant than the P compound groups remaining in solution, but does not constitute a major sink of P as it did not reach a stable concentration with depth, which indicates that it may eventually be degraded. Since P also precipitated from phytoplankton, the origin of humic-P can not be related solely to allochthonous P.

Place, publisher, year, edition, pages
Univ So Denmark, Inst Biol, DK-5230 Odense M, Denmark. Uppsala Univ, Dept Analyt Chem, S-75124 Uppsala, Sweden. Uppsala Univ, Dept Organ Chem, S-75124 Uppsala, Sweden. Uppsala Univ, Dept Limnol, S-75236 Uppsala, Sweden.: , 2007
Keywords
organic P, P-31 NMR, lake sediment, degradation rates
National Category
Natural Sciences
Research subject
Limnology
Identifiers
urn:nbn:se:umu:diva-113615 (URN)10.1007/s10533-006-9049-z (DOI)000244070900002 ()
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07
Ahlgren, J., De Brabandere, H., Reitzel, K., Rydin, E., Gogoll, A. & Waldeback, M. (2007). Sediment phosphorus extractants for phosphorus-31 nuclear magnetic resonance analysis: A quantitative evaluation. Journal of Environmental Quality, 36(3), 892-898
Open this publication in new window or tab >>Sediment phosphorus extractants for phosphorus-31 nuclear magnetic resonance analysis: A quantitative evaluation
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2007 (English)In: Journal of Environmental Quality, ISSN 0047-2425, E-ISSN 1537-2537, Vol. 36, no 3, p. 892-898Article in journal (Refereed) Published
Abstract [en]

The influence of pre-extractant, extractant, and post-extractant on total extracted amounts of P and organic P compound groups measured with 31 P nuclear magnetic resonance (P-31-NMR) in lacustrine sediment was examined. The main extractants investigated were sodium hydroxide (NaOH) and sodium hydroxide ethylenediaminetetraacetic acid (NaOH-EDTA) with bicarbonate buffered dithionite (BD) or EDTA as pre-extractants. Post extractions were conducted using either NaOH or NaOH-EDTA, depending on the main extractant. Results showed that the most efficient combination of extractants for total P yield was NaOH with EDTA as pre-extractant, yielding almost 50% more than the second best procedure. The P compound groups varying the most between the different extraction procedures were polyphosphates and pyrophosphates. NaOH with BD as pre-extractant was the most efficient combination for these compound groups.

Place, publisher, year, edition, pages
Uppsala Univ, Dept Phys & Analyt Chem, S-75124 Uppsala, Sweden. Univ So Denmark, Inst Biol, DK-5230 Odense M, Denmark. Uppsala Univ, Dept Biochem & Organ Chem, S-75124 Uppsala, Sweden. Uppsala Univ, Dept Ecol & Evolut, S-75123 Uppsala, Sweden.: , 2007
National Category
Analytical Chemistry
Identifiers
urn:nbn:se:umu:diva-113614 (URN)10.2134/jeq2006.0235 (DOI)000246430500028 ()17485721 (PubMedID)
Available from: 2015-12-21 Created: 2015-12-21 Last updated: 2018-06-07

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