81 results on '"Laurion I"'
Search Results
2. Greenhouse gas emission and storage in a small shallow lake
- Author
-
Bartosiewicz, M., Laurion, I., and MacIntyre, S.
- Published
- 2015
- Full Text
- View/download PDF
3. The SPLASH Action Group - Towards standardized sampling strategies in permafrost science
- Author
-
Bouchard, Frédéric, Agnan, Yannick, Bröder, Lisa, Fouché, Julien, Hirst, Catherine, Sjöberg, Ylva, Alexis M, Behmel S, Biskaborn B, Christaki U, Dean J, Desyatkin A, Farquharson L, Fishback L, Fortier D, Fritz M, Gandois G, Hugelius L, Jardillier L, Jones B, Kanevskiy M, Lantuit H, Laurion I, Lebedeva L, Opfergelt, Sophie, Palmtag J, Roy-Léveilléee P, Rudy A, Séjourné A, Siewert M.B, Tank S, Tanski G, Teisserenc R, Vonk J.E., Zolkos S, and UCL - SST/ELI/ELIE - Environmental Sciences
- Subjects
biogeochemistry ,aquatic systems ,lateral transport ,minerals ,soils ,organic matter - Published
- 2020
4. The SPLASH Action Group – Towards standardized sampling strategies in permafrost science
- Author
-
Bouchard F. , Agnan Y. , Bröder L. , Fouché J. , Hirst C. , Sjöberg Y. , Alexis M. , Behmel S. , Biskaborn B. K. , Christaki U. , Dean J. , Desyatkin A. , Farquharson L. , Fishback L. , Fortier D. , Fritz M. , Gandois L. , Hugelius G. , Jardillier L. , Jones B. M. , Kanevskiy M. , Lantuit H. , Laurion I. , Lebedeva L. , Opfergelt S. , Palmtag J. , Roy-Léveillée P. , Rudy A. , Séjourné A.
- Published
- 2020
- Full Text
- View/download PDF
5. Biomass offsets little or none of permafrost carbon release from soils, streams, and wild␣re: an expert assessment
- Author
-
Abbott, B. W., Jones, J. B., Schuur, E. A. G., Chapin, F. S., Bowden, W. B., Bret-Harte, M. S., Epstein, H. E., Flannigan, M. D., Harms, T. K., Hollingsworth, T. N., Mack, M. C., Mcguire, A. D., Natali, S. M., Rocha, A. V., Tank, S. E., Turetsky, M. R., Vonk, J. E., Wickland, K. P., Aiken, G. R., Alexander, H. D., Amon, R. M. W., Benscoter, B. W., Bergeron, Y., Bishop, K., Blarquez, O., Bond-Lamberty, B., Breen, A. L., Buffam, I., Cai, Y. H., Christopher Carcaillet, Carey, S. K., Chen, J. M., Chen, H. Y. H., Christensen, T. R., Cooper, L. W., Cornelissen, J. H. C., Groot, W. J., Deluca, T. H., Dorrepaal, E., Fetcher, N., Finlay, J. C., Forbes, B. C., French, N. H. F., Gauthier, S., Girardin, M. P., Goetz, S. J., Goldammer, J. G., Gough, L., Grogan, P., Guo, L. D., Higuera, P. E., Hinzman, L., Hu, F. S., Hugelius, G., Jafarov, E. E., Jandt, R., Johnstone, J. F., Karlsson, J., Kasischke, E. S., Kattner, G., Kelly, R., Keuper, F., Kling, G. W., Kortelainen, P., Kouki, J., Kuhry, P., Laudon, H., Laurion, I., Macdonald, R. W., Mann, P. J., Martikainen, P. J., Mcclelland, J. W., Molau, U., Oberbauer, S. F., Olefeldt, D., Pare, D., Parisien, M. A., Payette, S., Peng, C. H., Pokrovsky, O. S., Rastetter, E. B., Raymond, P. A., Raynolds, M. K., Rein, G., Reynolds, J. F., Robards, M., Rogers, B. M., Schadel, C., Schaefer, K., Schmidt, I. K., Shvidenko, A., Sky, J., Spencer, R. G. M., Starr, G., Striegl, R. G., Teisserenc, R., Tranvik, L. J., Virtanen, T., Welker, J. M., Zimov, S., Institute of Arctic Biology and Department of Biology & Wildlife, University of Alaska [Fairbanks] (UAF), Ecosystèmes, biodiversité, évolution [Rennes] (ECOBIO), Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Ecologie des Hydrosystèmes Naturels et Anthropisés (LEHNA), Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE), McMaster University [Hamilton, Ontario], 955713, National Science Foundation, OPP-0806394, Office of Polar Programs, Future Forest (Mistra), SITES (Swedish Science Foundation), TOMCAR-Permafrost #277059, Marie Curie International Reintegration, Institute of Arctic Biology, Université de Rennes (UR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR), Université de Rennes (UR)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Rennes 2 (UR2)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Centre National de la Recherche Scientifique (CNRS), Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École Nationale des Travaux Publics de l'État (ENTPE)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Rennes (OSUR)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Rennes 1 (UR1), Université de Rennes (UNIV-RENNES)-Université de Rennes (UNIV-RENNES), Earth and Climate, Systems Ecology, Amsterdam Global Change Institute, Environmental Sciences, Tarmo Virtanen / Principal Investigator, and Environmental Change Research Unit (ECRU)
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Biomass ,F800 ,SEQUESTRATION ,Permafrost ,01 natural sciences ,FIRE ,wildfire ,Klimatforskning ,Arctic ,вечная мерзлота ,Dissolved organic carbon ,ECOSYSTEMS ,SDG 13 - Climate Action ,boreal ,General Environmental Science ,Total organic carbon ,ARCTIC TUNDRA ,CLIMATE-CHANGE ,Carbon ,Climate change ,Miljövetenskap ,Permafrost carbon cycle ,Earth and Related Environmental Sciences ,STORAGE ,углеродный баланс ,particulate organic carbon ,Climate Research ,permafrost carbon ,Soil science ,010603 evolutionary biology ,BOREAL FOREST ,биомасса ,Ecosystem ,SDG 14 - Life Below Water ,1172 Environmental sciences ,0105 earth and related environmental sciences ,INTERIOR ALASKA ,coastal erosion ,Hydrology ,VULNERABILITY ,NITROGEN DEPOSITION ,Renewable Energy, Sustainability and the Environment ,coastal erosion Supplementary material for this article is available ,Public Health, Environmental and Occupational Health ,Geovetenskap och miljövetenskap ,15. Life on land ,dissolved organic carbon ,Tundra ,13. Climate action ,Soil water ,Environmental science ,[SDE.BE]Environmental Sciences/Biodiversity and Ecology ,Environmental Sciences - Abstract
CT3 ; EnjS4; International audience; As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wild␣re, and hydrologic carbon ␣ux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identi␣ed water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous ␣ndings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
- Published
- 2016
- Full Text
- View/download PDF
6. Reviews and syntheses : Effects of permafrost thaw on Arctic aquatic ecosystems
- Author
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Vonk, J. E., Tank, S. E., Bowden, W. B., Laurion, I., Vincent, W. F., Alekseychik, P., Amyot, M., Billet, M. F., Canário, J., Cory, R. M., Deshpande, B. N., Helbig, M., Jammet, M., Karlsson, J., Larouche, J., Macmillan, G., Rautio, M., Walter Anthony, K. M., Wickland, K. P., Organic geochemistry, NWO-VENI: Ancient organic matter that matters: The fate of Siberian Yedoma deposits, Organic geochemistry, and NWO-VENI: Ancient organic matter that matters: The fate of Siberian Yedoma deposits
- Subjects
0106 biological sciences ,010504 meteorology & atmospheric sciences ,Evolution ,Earth science ,lcsh:Life ,010501 environmental sciences ,Permafrost ,Freshwater ecosystem ,01 natural sciences ,Thermokarst ,Behavior and Systematics ,lcsh:QH540-549.5 ,SDG 13 - Climate Action ,Organic matter ,14. Life underwater ,Thaw depth ,Ecology, Evolution, Behavior and Systematics ,Earth-Surface Processes ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Ekologi ,geography ,geography.geographical_feature_category ,Ecology ,Aquatic ecosystem ,010604 marine biology & hydrobiology ,lcsh:QE1-996.5 ,Lake ecosystem ,15. Life on land ,lcsh:Geology ,lcsh:QH501-531 ,chemistry ,Arctic ,13. Climate action ,Environmental science ,lcsh:Ecology - Abstract
The Arctic is a water-rich region, with freshwater systems covering 16 % of the northern permafrost landscape. The thawing of this permafrost creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge regarding how permafrost thaw affects lentic and lotic systems, exploring the effects of both thermokarst (thawing and collapse of ice-rich permafrost) and deepening of the active layer (the surface soil layer that thaws and refreezes each year). Within thermokarst, we further differentiate between the effects of thermokarst in lowland areas, vs. that on hillslopes. For almost all of the processes that we explore, the effects of thaw vary regionally, and between lake and stream systems. Much of this regional variation is caused by differences in ground ice content, topography, soil type, and permafrost coverage. Together, these modifying variables determine the degree to which permafrost thaw manifests as thermokarst, whether thermokarst leads to slumping or the formation of thermokarst lakes, and the manner in which constituent delivery to freshwater systems is altered by thaw. Differences in thaw-enabled constituent delivery can be considerable, with these modifying variables determining, for example, the balance between delivery of particulate vs. dissolved constituents, and inorganic vs. organic materials. Changes in the composition of thaw-impacted waters, coupled with changes in lake morphology, can strongly affect the physical and optical properties of thermokarst lakes. The ecology of thaw-impacted systems is also likely to change, with thaw-impacted lakes and streams having unique microbiological communities, and showing differences in respiration, primary production, and food web structure that are largely driven by differences in sediment, dissolved organic matter and nutrient delivery. The degree to which thaw enables the delivery of dissolved vs. particulate organic matter, coupled with the composition of that organic matter and the morphology and stratification characteristics of recipient systems will play an important role in determining the balance between the release of organic matter as greenhouse gases (CO2 and CH4), its burial in sediments, and its loss downstream. The magnitude of thaw impacts on northern aquatic ecosystems is increasing, as is the prevalence of thaw-impacted lakes and streams. There is therefore an urgent need to address the key gaps in understanding in order to predict the full effects of permafrost thaw on aquatic ecosystems throughout the Arctic, and their consequential feedbacks to climate.
- Published
- 2015
- Full Text
- View/download PDF
7. Biomass offsets little or none of permafrost carbon release from soils, streams, and wildfire: an expert assessment
- Author
-
Abbott, B.W., Jones, J.B., Schuur, E.A.G., Chapin III, F.S., Bowden, W.B., Bret-Harte, M.S., Epstein, H.E., Flannigan, M.D., Harms, T.K., Hollingsworth, T.N., Mack, M.C., McGuire, A.D., Natali, S.M., Rocha, A.V., Tank, S.E., Turetsky, M.R., Vonk, J.E., Wickland, K.P., Aiken, G.R., Alexander, H.D., Amon, R.M.W., Benscoter, B.W., Bergeron, Y., Bishop, K., Blarquez, O., Bond-Lamberty, B., Breen, A.L., Buffam, I., Cai, Y., Carcaillet, C., Carey, S.K., Chen, J.M., Chen, H.Y.H., Christensen, T.R., Cooper, L.W., Cornelissen, J.H.C., de Groot, W.J., DeLuca, T.H., Dorrepaal, E., Fetcher, N., Finlay, J.C., Forbes, B.C., French, N.H.F., Gauthier, S., Girardin, M.P., Goetz, S.J., Goldammer, J.G., Gough, L., Grogan, P., Guo, L., Higuera, P.E., Hinzman, L., Hu, F.S., Hugelius, G., Jafarov, E.E., Jandt, R., Johnstone, J.F., Karlsson, J., Kasischke, E.S., Kattner, G., Kelly, R., Keuper, F., Kling, G.W., Kortelainen, P., Kouki, J., Kuhry, P., Laudon, H., Laurion, I., Macdonald, R.W., Mann, P.J., Martikainen, P.J., McClelland, J.W., Molau, U., Oberbauer, S.F., Olefeldt, D., Paré, D., Parisien, M., Payette, S., Peng, C., Pokrovsky, O.S., Rastetter, E.B., Raymond, P.A., Raynolds, M.K., Rein, G., Reynolds, J.F., Robards, M., Rogers, B.M., Schädel, C., Schaefer, K., Schmidt, I.K., Shvidenko, A., Sky, J., Spencer, R.G.M., Starr, G., Striegl, R.G., Teisserenc, R., Tranvik, L.J., Virtanen, T., Welker, J.M., Zimov, S., Abbott, B.W., Jones, J.B., Schuur, E.A.G., Chapin III, F.S., Bowden, W.B., Bret-Harte, M.S., Epstein, H.E., Flannigan, M.D., Harms, T.K., Hollingsworth, T.N., Mack, M.C., McGuire, A.D., Natali, S.M., Rocha, A.V., Tank, S.E., Turetsky, M.R., Vonk, J.E., Wickland, K.P., Aiken, G.R., Alexander, H.D., Amon, R.M.W., Benscoter, B.W., Bergeron, Y., Bishop, K., Blarquez, O., Bond-Lamberty, B., Breen, A.L., Buffam, I., Cai, Y., Carcaillet, C., Carey, S.K., Chen, J.M., Chen, H.Y.H., Christensen, T.R., Cooper, L.W., Cornelissen, J.H.C., de Groot, W.J., DeLuca, T.H., Dorrepaal, E., Fetcher, N., Finlay, J.C., Forbes, B.C., French, N.H.F., Gauthier, S., Girardin, M.P., Goetz, S.J., Goldammer, J.G., Gough, L., Grogan, P., Guo, L., Higuera, P.E., Hinzman, L., Hu, F.S., Hugelius, G., Jafarov, E.E., Jandt, R., Johnstone, J.F., Karlsson, J., Kasischke, E.S., Kattner, G., Kelly, R., Keuper, F., Kling, G.W., Kortelainen, P., Kouki, J., Kuhry, P., Laudon, H., Laurion, I., Macdonald, R.W., Mann, P.J., Martikainen, P.J., McClelland, J.W., Molau, U., Oberbauer, S.F., Olefeldt, D., Paré, D., Parisien, M., Payette, S., Peng, C., Pokrovsky, O.S., Rastetter, E.B., Raymond, P.A., Raynolds, M.K., Rein, G., Reynolds, J.F., Robards, M., Rogers, B.M., Schädel, C., Schaefer, K., Schmidt, I.K., Shvidenko, A., Sky, J., Spencer, R.G.M., Starr, G., Striegl, R.G., Teisserenc, R., Tranvik, L.J., Virtanen, T., Welker, J.M., and Zimov, S.
- Abstract
As the permafrost region warms, its large organic carbon pool will be increasingly vulnerable to decomposition, combustion, and hydrologic export. Models predict that some portion of this release will be offset by increased production of Arctic and boreal biomass; however, the lack of robust estimates of net carbon balance increases the risk of further overshooting international emissions targets. Precise empirical or model-based assessments of the critical factors driving carbon balance are unlikely in the near future, so to address this gap, we present estimates from 98 permafrost-region experts of the response of biomass, wildfire, and hydrologic carbon flux to climate change. Results suggest that contrary to model projections, total permafrost-region biomass could decrease due to water stress and disturbance, factors that are not adequately incorporated in current models. Assessments indicate that end-of-the-century organic carbon release from Arctic rivers and collapsing coastlines could increase by 75% while carbon loss via burning could increase four-fold. Experts identified water balance, shifts in vegetation community, and permafrost degradation as the key sources of uncertainty in predicting future system response. In combination with previous findings, results suggest the permafrost region will become a carbon source to the atmosphere by 2100 regardless of warming scenario but that 65%–85% of permafrost carbon release can still be avoided if human emissions are actively reduced.
- Published
- 2016
8. Phototrophic pigment diversity and picophytoplankton in permafrost thaw lakes
- Author
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Przytulska, A., primary, Comte, J., additional, Crevecoeur, S., additional, Lovejoy, C., additional, Laurion, I., additional, and Vincent, W. F., additional
- Published
- 2016
- Full Text
- View/download PDF
9. Effect of short-term light- and UV-stress on DMSP, DMS, and DMSP lyase activity in Emiliania huxleyi
- Author
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Darroch, L.J., Lavoie, M., Levasseur, M., Laurion, I., Sunda, W.G., Michaud, S., Scarratt, M., Gosselin, M., Caron, G., Darroch, L.J., Lavoie, M., Levasseur, M., Laurion, I., Sunda, W.G., Michaud, S., Scarratt, M., Gosselin, M., and Caron, G.
- Abstract
The ecological conditions and cellular mechanisms which affect the production of dimethylsulfoniopropionate (DMSP) and dimethylsulfide (DMS) in marine ecosystems are still enigmatic. This information is crucial for deriving accurate oceanic ecosystem models for the dynamics of these major players in the Earth’s sulfur cycle and climate. In the present study, we examined the effect of short-term increases in photosynthetically active radiation (PAR) and ultraviolet radiation (UVR) on the production of DMSP and DMS and on DMSP lyase potential activity (DLPA) in an axenic culture of the coccolithophore Emiliania huxleyi (CCMP 1742). Algal cells were subjected to a rapid shift from a low intensity of PAR (50 μE m-2 s-1; low light, LL) to a high intensity of PAR (198 μE m-2 s-1) and elevated UVR conditions (high light, HL), simulating what may occur during upward mixing in the surface mixed layer or during changes in cloud cover. During the 4.5 h exposure to HL, the intracellular DMSP normalized to cell volume increased by ca. 30%, and dissolved DMSP doubled relative to control values. However, the DLPA per unit of cell volume decreased by ~45% compared to the control value. The up-regulation of cellular DMSP concentration is consistent with an antioxidant and/or energy dissipation role for DMSP. The decrease in DLPA may indicate that the DMSP lyase enzyme plays no role in antioxidant protection in this algal species, but rather serves some other cellular function, such as grazing protection.
- Published
- 2015
10. Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems
- Author
-
Organic geochemistry, NWO-VENI: Ancient organic matter that matters: The fate of Siberian Yedoma deposits, Vonk, J. E., Tank, S. E., Bowden, W. B., Laurion, I., Vincent, W. F., Alekseychik, P., Amyot, M., Billet, M. F., Canário, J., Cory, R. M., Deshpande, B. N., Helbig, M., Jammet, M., Karlsson, J., Larouche, J., Macmillan, G., Rautio, M., Walter Anthony, K. M., Wickland, K. P., Organic geochemistry, NWO-VENI: Ancient organic matter that matters: The fate of Siberian Yedoma deposits, Vonk, J. E., Tank, S. E., Bowden, W. B., Laurion, I., Vincent, W. F., Alekseychik, P., Amyot, M., Billet, M. F., Canário, J., Cory, R. M., Deshpande, B. N., Helbig, M., Jammet, M., Karlsson, J., Larouche, J., Macmillan, G., Rautio, M., Walter Anthony, K. M., and Wickland, K. P.
- Published
- 2015
11. Modern to millennium-old greenhouse gases emitted from ponds and lakes of the Eastern Canadian Arctic (Bylot Island, Nunavut)
- Author
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Bouchard, F., primary, Laurion, I., additional, Prėskienis, V., additional, Fortier, D., additional, Xu, X., additional, and Whiticar, M. J., additional
- Published
- 2015
- Full Text
- View/download PDF
12. Carbon dynamics in highly heterotrophic subarctic thaw ponds
- Author
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Roiha, T., primary, Laurion, I., additional, and Rautio, M., additional
- Published
- 2015
- Full Text
- View/download PDF
13. Supplementary material to "Phototrophic pigment diversity and picophytoplankton abundance in permafrost thaw lakes"
- Author
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Przytulska, A., primary, Comte, J., additional, Crevecoeur, S., additional, Lovejoy, C., additional, Laurion, I., additional, and Vincent, W. F., additional
- Published
- 2015
- Full Text
- View/download PDF
14. Phototrophic pigment diversity and picophytoplankton abundance in permafrost thaw lakes
- Author
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Przytulska, A., primary, Comte, J., additional, Crevecoeur, S., additional, Lovejoy, C., additional, Laurion, I., additional, and Vincent, W. F., additional
- Published
- 2015
- Full Text
- View/download PDF
15. Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic
- Author
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Bouchard, F., primary, Laurion, I., additional, Preskienis, V., additional, Fortier, D., additional, Xu, X., additional, and Whiticar, M. J., additional
- Published
- 2015
- Full Text
- View/download PDF
16. Supplementary material to "Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic"
- Author
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Bouchard, F., primary, Laurion, I., additional, Preskienis, V., additional, Fortier, D., additional, Xu, X., additional, and Whiticar, M. J., additional
- Published
- 2015
- Full Text
- View/download PDF
17. Reviews and Syntheses: Effects of permafrost thaw on arctic aquatic ecosystems
- Author
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Vonk, J. E., primary, Tank, S. E., additional, Bowden, W. B., additional, Laurion, I., additional, Vincent, W. F., additional, Alekseychik, P., additional, Amyot, M., additional, Billet, M. F., additional, Canário, J., additional, Cory, R. M., additional, Deshpande, B. N., additional, Helbig, M., additional, Jammet, M., additional, Karlsson, J., additional, Larouche, J., additional, MacMillan, G., additional, Rautio, M., additional, Walter Anthony, K. M., additional, and Wickland, K. P., additional
- Published
- 2015
- Full Text
- View/download PDF
18. Effect of short-term light- and UV-stress on DMSP, DMS, and DMSP lyase activity in Emiliania huxleyi
- Author
-
Darroch, LJ, primary, Lavoie, M, additional, Levasseur, M, additional, Laurion, I, additional, Sunda, WG, additional, Michaud, S, additional, Scarratt, M, additional, Gosselin, M, additional, and Caron, G, additional
- Published
- 2015
- Full Text
- View/download PDF
19. Landscape Control of High Latitude Lakes in a Changing Climate
- Author
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Quesada, A., primary, Vincent, W. F., additional, Kaup, E., additional, Hobbie, J. E., additional, Laurion, I., additional, Pienitz, R., additional, LÓPez-MartÍNez, J., additional, and DuráN, J.-J., additional
- Full Text
- View/download PDF
20. Attenuation of ultraviolet radiation in mountain lakes: Factors controlling the among- and within- lake variability
- Author
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Laurion, I., Ventura, M., Catalan, J., Psenner, R., and Summaruga, R.
- Published
- 2000
21. Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes.
- Author
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Mladenov, N., Sommaruga, Rubén, Morales-Baquero, M., Laurion, I., Camarero, Lluís, Diéguez, M., Camacho, Antonio, Delgado Huertas, Antonio, Torres, O., Chen, Z., Felip, Marisol, Reche, Isabel, Mladenov, N., Sommaruga, Rubén, Morales-Baquero, M., Laurion, I., Camarero, Lluís, Diéguez, M., Camacho, Antonio, Delgado Huertas, Antonio, Torres, O., Chen, Z., Felip, Marisol, and Reche, Isabel
- Abstract
Remote lakes are usually unaffected by direct human infl uence, yet they receive inputs of atmospheric pollutants, dust, and other aerosols, both inorganic and organic. In remote, alpine lakes, these atmospheric inputs may infl uence the pool of dissolved organic matter, a critical constituent for the biogeochemical functioning of aquatic ecosystems. Here, to assess this infl uence, we evaluate factors related to aerosol deposition, climate, catchment properties, and microbial constituents in a global dataset of 86 alpine and polar lakes. We show signifi cant latitudinal trends in dissolved organic matter quantity and quality, and uncover new evidence that this geographic pattern is infl uenced by dust deposition, fl ux of incident ultraviolet radiation, and bacterial processing. Our results suggest that changes in land use and climate that result in increasing dust fl ux, ultraviolet radiation, and air temperature may act to shift the optical quality of dissolved organic matter in clear, alpine lakes.
- Published
- 2011
22. Arctic microbial ecosystems and impacts of extreme warming during the International Polar Year
- Author
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Vincent, W.F. (Warwick F.), Whyte, L.G. (Lyle G.), Lovejoy, C. (Connie), Greer, C.W. (Charles W.), Laurion, I. (Isabelle), Suttle, C.A. (Curtis A.), Corbeil, J. (Jacques), Mueller, D. (Derek), Vincent, W.F. (Warwick F.), Whyte, L.G. (Lyle G.), Lovejoy, C. (Connie), Greer, C.W. (Charles W.), Laurion, I. (Isabelle), Suttle, C.A. (Curtis A.), Corbeil, J. (Jacques), and Mueller, D. (Derek)
- Abstract
As a contribution to the International Polar Year program MERGE (Microbiological and Ecological Responses to Global Environmental change in polar regions), studies were conducted on the terrestrial a
- Published
- 2009
- Full Text
- View/download PDF
23. Lakes and reservoirs as regulators of carbon cycling and climate
- Author
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Tranvik, L.J., Downing, J.A., Cotner, J.B., Loiselle, S.A., Striegl, R.G., Ballatore, T.J., Dillon, P., Knoll, L.B., Kutser, T., Larsen, S., Laurion, I., Leech, D.M., McAllister, S.L., McKnight, D.M., Melack, J., Overholt, E., Porter, J.A., Prairie, Y.T., Renwick, W.H., Roland, F., Sherman, B.S., Schindler, D.W., Sobek, S., Tremblay, A., Vanni, M.J., Verschoor, A.M., von Wachenfeldt, E., Weyhenmeyer, G., Tranvik, L.J., Downing, J.A., Cotner, J.B., Loiselle, S.A., Striegl, R.G., Ballatore, T.J., Dillon, P., Knoll, L.B., Kutser, T., Larsen, S., Laurion, I., Leech, D.M., McAllister, S.L., McKnight, D.M., Melack, J., Overholt, E., Porter, J.A., Prairie, Y.T., Renwick, W.H., Roland, F., Sherman, B.S., Schindler, D.W., Sobek, S., Tremblay, A., Vanni, M.J., Verschoor, A.M., von Wachenfeldt, E., and Weyhenmeyer, G.
- Abstract
We explore the role of lakes in carbon cycling and global climate, examine the mechanisms influencing carbon pools and transformations in lakes, and discuss how the metabolism of carbon in the inland waters is likely to change in response to climate. Furthermore, we project changes as global climate change in the abundance and spatial distribution of lakes in the biosphere, and we revise the estimate for the global extent of carbon transformation in inland waters. This synthesis demonstrates that the global annual emissions of carbon dioxide from inland waters to the atmosphere are similar in magnitude to the carbon dioxide uptake by the oceans and that the global burial of organic carbon in inland water sediments exceeds organic carbon sequestration on the ocean floor. The role of inland waters in global carbon cycling and climate forcing may be changed by human activities, including construction of impoundments, which accumulate large amounts of carbon in sediments and emit large amounts of methane to the atmosphere. Methane emissions are also expected from lakes on melting permafrost. The synthesis presented here indicates that (1) inland waters constitute a significant component of the global carbon cycle, (2) their contribution to this cycle has significantly changed as a result of human activities, and (3) they will continue to change in response to future climate change causing decreased as well as increased abundance of lakes as well as increases in the number of aquatic impoundments., We explore the role of lakes in carbon cycling and global climate, examine the mechanisms influencing carbon pools and transformations in lakes, and discuss how the metabolism of carbon in the inland waters is likely to change in response to climate. Furthermore, we project changes as global climate change in the abundance and spatial distribution of lakes in the biosphere, and we revise the estimate for the global extent of carbon transformation in inland waters. This synthesis demonstrates that the global annual emissions of carbon dioxide from inland waters to the atmosphere are similar in magnitude to the carbon dioxide uptake by the oceans and that the global burial of organic carbon in inland water sediments exceeds organic carbon sequestration on the ocean floor. The role of inland waters in global carbon cycling and climate forcing may be changed by human activities, including construction of impoundments, which accumulate large amounts of carbon in sediments and emit large amounts of methane to the atmosphere. Methane emissions are also expected from lakes on melting permafrost. The synthesis presented here indicates that (1) inland waters constitute a significant component of the global carbon cycle, (2) their contribution to this cycle has significantly changed as a result of human activities, and (3) they will continue to change in response to future climate change causing decreased as well as increased abundance of lakes as well as increases in the number of aquatic impoundments.
- Published
- 2009
24. Distribution and identity of Bacteria in subarctic permafrost thaw ponds
- Author
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Rossi, PG, primary, Laurion, I, additional, and Lovejoy, C, additional
- Published
- 2013
- Full Text
- View/download PDF
25. Dust inputs and bacteria influence dissolved organic matter in clear alpine lakes
- Author
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Mladenov, N., primary, Sommaruga, R., additional, Morales-Baquero, R., additional, Laurion, I., additional, Camarero, L., additional, Diéguez, M.C., additional, Camacho, A., additional, Delgado, A., additional, Torres, O., additional, Chen, Z., additional, Felip, M., additional, and Reche, I., additional
- Published
- 2011
- Full Text
- View/download PDF
26. Phototrophic pigment diversity and picophytoplankton abundance in permafrost thaw lakes.
- Author
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Przytulska, A., Comte, J., Crevecoeur, S., Lovejoy, C., Laurion, I., and Vincent, W. F.
- Subjects
FROZEN ground ,LAKES ,PIGMENTS ,PERMAFROST ,GROUND ice - Abstract
Permafrost thaw lakes (thermokarst lakes) are widely distributed across the northern landscape, and are known to be biogeochemically active sites that emit large amounts of carbon to the atmosphere as CH
4 and CO2 . However, the abundance and composition of the photosynthetic communities that consume CO2 have been little explored in this ecosystem type. In order to identify the major groups of phototrophic organisms and their controlling variables, we sampled 12 permafrost thaw lakes along a permafrost degradation gradient in northern Québec, Canada. Additional samples were taken from 5 rock-basin reference lakes in the region to determine if the thaw waters differed in limnological properties and phototrophs. Phytoplankton community structure was determined by high performance liquid chromatography analysis of their photoprotective and photosynthetic pigments, and autotrophic picoplankton concentrations were assessed by flow cytometry. One of the black colored lakes located in a andscape of rapidly degrading palsas (permafrost mounds) was selected for high-throughput 18S rRNA sequencing to help interpret the pigment and cytometry data. The results showed that the limnological properties of the thaw lakes differed significantly from the reference lakes, and were more highly stratified. However, both waterbody types contained similarly diverse phytoplankton groups, with dominance of the pigment assemblages by fucoxanthin-containing taxa, as well as chlorophytes, cryptophytes and cyanobacteria. Chlorophyll a concentrations (Chl a) were correlated with total phosphorus (TP), and both were significantly higher in the thaw lakes (overall means of 3.3 μg Chl a L-1 and 34 μg TP L-1 ) relative to the reference lakes (2.0 μg Chl a L-1 and 8.2 μg TP L-1 ). Stepwise multiple regression of Chl a against the other algal pigments showed that it was largely a function of lutein, fucoxanthin and peridinin (R² = 0.78). The bottom waters of two of the thaw lakes also contained high concentrations of bacteriochlorophyll d, showing the presence of green photosynthetic sulphur bacteria. The molecular analyses indicated a relatively minor contribution of diatoms, while chrysophytes, dinoflagellates and chlorophytes were well represented; the heterotrophic eukaryote fraction was dominated by numerous ciliate taxa, and also included Heliozoa, Rhizaria, chytrids and flagellates. Autotrophic picoplankton occurred in cell concentrations up to 8.8 × 105 mL-1 (picocyanobacteria) and 4.6 × 105 mL-1 (picoeukaryotes). Both groups of picophytoplankton were positively correlated with total phytoplankton abundance, as measured by Chl a; picocyanobacteria were inversely correlated with dissolved organic carbon, while picoeukaryotes were correlated with conductivity. Despite their net heterotrophic character, subarctic thaw lakes are rich habitats for diverse phototrophic communities. [ABSTRACT FROM AUTHOR]- Published
- 2015
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- View/download PDF
27. Modern to millennium-old greenhouse gases emitted from freshwater ecosystems of the eastern Canadian Arctic.
- Author
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Bouchard, F., Laurion, I., Prėskienis, V., Fortier, D., Xu, X., and Whiticar, M. J.
- Subjects
GREENHOUSE gases ,FRESH water ,ECOSYSTEMS ,EBULLITION - Abstract
Ponds and lakes are widespread across the rapidly changing permafrost environments. Aquatic systems play an important role in global biogeochemical cycles, especially in greenhouse gas (GHG) exchanges between terrestrial systems and the atmosphere. The source, speciation and emission of carbon released from permafrost landscapes are strongly influenced by local specific conditions rather than general environmental setting. This study reports on GHG ages and emission rates from aquatic systems on Bylot Island in the eastern Canadian Arctic. Dissolved and ebullition gas samples were collected during the summer season from different types of water bodies located in a highly dynamic periglacial valley: polygonal ponds, collapsed ice-wedge trough ponds, and larger lakes overlying unfrozen soils (talik). The results showed strikingly different ages and fluxes depending on aquatic system types. Polygonal ponds were net sinks of dissolved CO
2 , but variable sources of dissolved CH4 . They presented the highest ebullition fluxes, one or two orders of magnitude higher than from other ponds and lakes. Trough ponds appeared as substantial GHG sources, especially when their edges were actively eroding. Both types of ponds produced modern to hundreds of years old (< 550 yr BP) GHG, even if trough ponds could contain much older carbon (> 2000 yr BP) derived from freshly eroded peat. Lakes had small dissolved and ebullition fluxes, however they released much older GHG, including millennium-old CH4 (up to 3500 yr BP) sampled from lake central areas. Acetoclastic methanogenesis dominated at all study sites and there was minimal, if any, methane oxidation in gas emitted through ebullition. These findings provide new insights on the variable role of permafrost aquatic systems as a positive feedback mechanism on climate. [ABSTRACT FROM AUTHOR]- Published
- 2015
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- View/download PDF
28. Packaging of mycosporine-like amino acids in dinoflagellates
- Author
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Laurion, I, primary, Blouin, F, additional, and Roy, S, additional
- Published
- 2004
- Full Text
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29. UV‐Acclimation of Cultured Phytoplankton Exposed to Natural and Enhanced UVB Radiation and Methodological Aspects of MAA Quantification
- Author
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Laurion, I., primary and Roy, S., additional
- Published
- 2002
- Full Text
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30. Landscape Control of High Latitude Lakes in a Changing Climate.
- Author
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Bergstrom, D. M., Convey, P., Huiskes, A. H. L., Quesada, A., Vincent, W. F., Kaup, E., Hobbie, J. E., Laurion, I., Pienitz, R., LÓPez-MartÍNez, J., and DuráN, J.-J.
- Published
- 2006
- Full Text
- View/download PDF
31. Distribution of mycosporine-like amino acids and photoprotective carotenoids among freshwater phytoplankton assemblages
- Author
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Laurion, I, primary, Lami, A, additional, and Sommaruga, R, additional
- Published
- 2002
- Full Text
- View/download PDF
32. UVB effects on a plankton community: results from a large-scale enclosure assay
- Author
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Laurion, I, primary, Lean, DRS, additional, and Vincent, WF, additional
- Published
- 1998
- Full Text
- View/download PDF
33. The microbial food web associated with the ice algal assemblage:biomass and bacterivory of nanoflagellate protozoans in Resolute Passage (High Canadian Arctic)
- Author
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Laurion, I, primary, Demers, S, additional, and Vézina, AF, additional
- Published
- 1995
- Full Text
- View/download PDF
34. Underwater ultraviolet radiation: Development of spectral models for northern high latitude lakes
- Author
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Laurion, I., Warwick Vincent, and Lean, D. R. S.
35. Variability in greenhouse gas emissions from permafrost thaw ponds
- Author
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Laurion, I., Warwick Vincent, Macintyre, S., Retamal, L., Dupont, C., Francus, P., and Pienitz, R.
36. Spatiotemporal insights of phytoplankton dynamics in a northern, rural-urban lake using a 3D water quality model.
- Author
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Hosseini-Sadabadi SA, Rousseau AN, Laurion I, Behmel S, Sadeghian A, Foulon E, Wauthy M, and Cantin AM
- Subjects
- Environmental Monitoring, Biomass, Seasons, Phosphorus analysis, Chlorophyll A analysis, Eutrophication, Lakes, Phytoplankton growth & development, Water Quality
- Abstract
Lake St. Charles, located north of Quebec City, Canada, is a shallow fluvial lake with two distinct basins bridging rural and urban landscapes. Mainly used as a source of drinking water for 300,000 residents, the lake has faced a steady degradation in water quality due to urbanization and the discharge of domestic wastewater. This study introduces a 3D hydrodynamics and water quality model using the Environmental Fluid Dynamics Code to enhance our understanding of algal bloom dynamics in Lake St. Charles. More specifically, we ran simulations for eight years (i.e., a three-year period for calibration, 2015 to 2017; and a five-year period for validation, 2018 to 2022) to reproduce the complex circulation patterns and dynamics of water quality within the system. The simulation results for chlorophyll-a demonstrate seasonal fluctuations in phytoplankton biomass, closely aligning with in situ observations and achieving Relative Root Mean Square Error (RRMSE) values below 50%. (i) In spring, runoff from snowmelt brought phosphorus into the lake, triggering primary production. Diatom growth was initially predominant in the shallow southern basin, then spread to the deeper northern basin due to favorable environmental conditions, including flow- and wind-induced currents, warmer water temperatures and nutrient availability. (ii) In summer, warm water temperatures stimulated biological activity, leading to the growth of cyanobacteria at the expense of diatoms, as well as a drop in phosphorus. (iii) The cyanobacteria persisted into the fall but began to decline in mid-November. (iv) Winter conditions, including the presence of an ice cover, limited the input of phosphorus and minimized phytoplankton production, but diatoms were observed in low concentrations near Des Hurons River inflow. Overall, during the open-water period, the lake-maintained chlorophyll-a concentrations indicative of mesotrophic conditions, with occasional periods when the biomass increased above the eutrophic threshold. Temperature, nutrient levels, and the fluvial dynamics of the lake are the primary factors influencing phytoplankton formation and distribution in lake St. Charles., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2024
- Full Text
- View/download PDF
37. Using a retention pond to capture agricultural contaminants from surface waters.
- Author
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Marimoutou M, Gruyer N, Maranger R, Thériault G, and Laurion I
- Abstract
To meet the demand of a constantly growing population, agriculture is intensifying, causing an increased use of fertilizers and pesticides. Excessive nutrients transfer to aquatic ecosystems can disrupt the water quality and impact the aquatic life. Pesticides can also have toxic effects on non-target organisms from aquatic systems. The purpose of this study was to evaluate the efficiency of an agricultural retention pond in reducing the supply of nutrients, pesticides and suspended solids to the Nicolet River, a tributary of Lake St. Pierre in the St. Lawrence River. Research combining the study of the fate of a wide range of contaminants in both pond water and sediments, their toxicity to microcrustaceans, microalgae and amphipods, and the effectiveness of contaminant removal, has rarely been carried out in the past. Peak contaminant concentrations occurred one to two months after pesticide and fertilizer applications, and during the months with the highest rainfall. Toxic effects were only observed on microalgae, with suspended solids apparently responsible for this effect through light inhibition on growth rates. However, the pond was not effective in removing this toxicity even if suspended solids were largely removed. Pesticides removal varied widely among sampling dates and pesticide types, with an efficiency reaching 95 % for thiamethoxam, but generally remaining low and often negative (higher concentrations in outflowing water) for other pesticides. On the other hand, the mean fractional removal of suspended solids, phosphorus, and nitrogen based on concentrations was 71 %, 44 % and 22 %, respectively. These are conservative estimations since the removal rates based on loads were above 94 %. The use of retention ponds thus seems an efficient approach to reduce the quantity of fertilizers in rivers draining agriculture areas, but the studied pond was not systematically effective in removing pesticides., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)
- Published
- 2023
- Full Text
- View/download PDF
38. Integrated approach towards quantifying carbon dioxide and methane release from waste stabilization ponds.
- Author
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Bartosiewicz M, Coggins LX, Glaz P, Cortés A, Bourget S, Reichwaldt ES, MacIntyre S, Ghadouani A, and Laurion I
- Subjects
- Carbon Dioxide analysis, Greenhouse Effect, Nitrous Oxide analysis, Ponds, Greenhouse Gases, Methane analysis
- Abstract
Accurate estimations of gaseous emissions and carbon sequestration in wastewater processing are essential for the design, operation and planning of treatment infrastructure, particularly considering greenhouse gas reduction targets. In this study, we look at the interplay between biological productivity, hydrodynamics and evasion of carbon-based greenhouse gases (GHG) through diffusion and ebullition in order to provide direction for more accurate assessments of their emissions from waste stabilization ponds (WSPs). The ponds stratified in the day and mixed at night. Buoyancy flux contributed between 40 and 75% to turbulence in the water column during nocturnal cooling events, and the associated mixing lead to increasing carbon dioxide (CO
2 ) and methane (CH4 ) concentrations by up to an order of magnitude in the surface. The onset of stratification and phytoplankton surface blooms, associated with high pH as well as low and variable CO2 partial pressure resulted in an overall reduction of CO2 efflux. Ebullition represented between 40 and 99% of the total CH4 efflux, and up to 95% of the integrated GHG release during wastewater treatment (in CO2 equivalents). Hydrodynamic conditions, diurnal variability and ebullition need to be accounted for reliable assessments of GHG emissions from WSPs. Our study is an important step towards gaining a deeper understanding in the functioning of these hot spots of carbon processing. The contribution of WSPs to atmospheric GHG budget is likely to increase with population growth unless their performance is improved in this regard., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
39. Effects of phytoplankton blooms on fluxes and emissions of greenhouse gases in a eutrophic lake.
- Author
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Bartosiewicz M, Maranger R, Przytulska A, and Laurion I
- Subjects
- Carbon Dioxide analysis, China, Methane analysis, Phytoplankton, Greenhouse Gases, Lakes analysis
- Abstract
Lakes are important sources of greenhouse gases (GHGs) to the atmosphere. Factors controlling CO
2 , CH4 and N2 O fluxes include eutrophication and warming, but the integrated influence of climate-warming-driven stratification, oxygen loss and resultant changes in bloom characteristics on GHGs are not well understood. Here we assessed the influence of contrasting meteorological conditions on stratification and phytoplankton bloom composition in a eutrophic lake, and tested for associated changes in GHGs inventories in both the shallow and deep waters, over three seasons (2010-2012). Atmospheric heatwaves had one of the most dramatic effects on GHGs. Indeed, cyanobacterial blooms that developed in response to heatwave events in 2012 enhanced both sedimentary CH4 concentrations (reaching up to 1mM) and emissions to the atmosphere (up to 8 mmol m-2 d-1 ). That summer, CH4 contributed 52% of the integrated warming potential of GHGs produced in the lake (in CO2 equivalents) as compared to between 34 and 39% in years without cyanobacterial blooms. High CH4 accumulation and subsequent emission in 2012 were preceded by CO2 and N2 O consumption and under-saturation at the lake surface (uptakes at -30 mmol m-2 d-1 and -1.6 µmol m-2 d-1 , respectively). Fall overturn presented a large efflux of N2 O and CH4 , particularly from the littoral zone after the cyanobacterial bloom. We provide evidence that, despite cooling observed at depth during hot summers, CH4 emissions increased via stronger stratification and surface warming, resulting in enhanced cyanobacterial biomass deposition and intensified bottom water anoxia. Our results, supported by recent literature reports, suggests a novel interplay between climate change effects on lake hydrodynamics that impacts both bloom characteristics and GHGs production in shallow eutrophic lakes. Given global trends of warming and enrichment, these interactive effects should be considered to more accurately predict the future global role of lakes in GHG emissions., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier Ltd. All rights reserved.)- Published
- 2021
- Full Text
- View/download PDF
40. Water column gradients beneath the summer ice of a High Arctic freshwater lake as indicators of sensitivity to climate change.
- Author
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Bégin PN, Tanabe Y, Rautio M, Wauthy M, Laurion I, Uchida M, Culley AI, and Vincent WF
- Abstract
Ice cover persists throughout summer over many lakes at extreme polar latitudes but is likely to become increasingly rare with ongoing climate change. Here we addressed the question of how summer ice-cover affects the underlying water column of Ward Hunt Lake, a freshwater lake in the Canadian High Arctic, with attention to its vertical gradients in limnological properties that would be disrupted by ice loss. Profiling in the deepest part of the lake under thick mid-summer ice revealed a high degree of vertical structure, with gradients in temperature, conductivity and dissolved gases. Dissolved oxygen, nitrous oxide, carbon dioxide and methane rose with depth to concentrations well above air-equilibrium, with oxygen values at > 150% saturation in a mid-water column layer of potential convective mixing. Fatty acid signatures of the seston also varied with depth. Benthic microbial mats were the dominant phototrophs, growing under a dim green light regime controlled by the ice cover, water itself and weakly colored dissolved organic matter that was mostly autochthonous in origin. In this and other polar lakes, future loss of mid-summer ice will completely change many water column properties and benthic light conditions, resulting in a markedly different ecosystem regime.
- Published
- 2021
- Full Text
- View/download PDF
41. Control and Surveillance Operations to Prevent Chronic Wasting Disease Establishment in Free-Ranging White-Tailed Deer in Québec, Canada.
- Author
-
Gagnier M, Laurion I, and DeNicola AJ
- Abstract
Chronic wasting disease (CWD), a degenerative and fatal prion disease affecting cervids, was detected for the first time in the province of Québec, Canada, in a red deer ( Cervus elaphus ) farm in the Laurentides region on 10 September 2018. To assess CWD prevalence and control the disease in the free-ranging white-tailed deer (Odocoileus virginianus) population, a response plan including enhanced surveillance, population control, regulatory measures, and public outreach was deployed by the Ministry of Forests, Wildlife, and Parks (MFFP). In the 401 km
2 white-tailed deer control area, a total of 750 free-ranging white-tailed deer were culled over 70 days, from 22 September to 15 December 2018. Of the culled deer, 534 were tested for CWD. We also tested for CWD a total of 447 white-tailed deer hunted from the enhanced surveillance zone and 2584 free-ranging white-tailed deer harvested outside this zone. Regulations were applied to prevent the spread of the disease through movements of infected animals harvested by hunters. Although no case of CWD was detected in free-ranging cervids in Québec in 2018, this does not confirm the absence of the disease in these populations. However, the results suggest that if CWD is present, few free-ranging cervids are infected, making it possible to prevent its establishment in the province of Québec., Competing Interests: The authors declare no conflict of interest.- Published
- 2020
- Full Text
- View/download PDF
42. The NSERC Canadian Lake Pulse Network: A national assessment of lake health providing science for water management in a changing climate.
- Author
-
Huot Y, Brown CA, Potvin G, Antoniades D, Baulch HM, Beisner BE, Bélanger S, Brazeau S, Cabana H, Cardille JA, Del Giorgio PA, Gregory-Eaves I, Fortin MJ, Lang AS, Laurion I, Maranger R, Prairie YT, Rusak JA, Segura PA, Siron R, Smol JP, Vinebrooke RD, and Walsh DA
- Abstract
The distribution and quality of water resources vary dramatically across Canada, and human impacts such as land-use and climate changes are exacerbating uncertainties in water supply and security. At the national level, Canada has no enforceable standards for safe drinking water and no comprehensive water-monitoring program to provide detailed, timely reporting on the state of water resources. To provide Canada's first national assessment of lake health, the NSERC Canadian Lake Pulse Network was launched in 2016 as an academic-government research partnership. LakePulse uses traditional approaches for limnological monitoring as well as state-of-the-art methods in the fields of genomics, emerging contaminants, greenhouse gases, invasive pathogens, paleolimnology, spatial modelling, statistical analysis, and remote sensing. A coordinated sampling program of about 680 lakes together with historical archives and a geomatics analysis of over 80,000 lake watersheds are used to examine the extent to which lakes are being altered now and in the future, and how this impacts aquatic ecosystem services of societal importance. Herein we review the network context, objectives and methods., (Copyright © 2019 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2019
- Full Text
- View/download PDF
43. Effects of climate change and episodic heat events on cyanobacteria in a eutrophic polymictic lake.
- Author
-
Bartosiewicz M, Przytulska A, Deshpande BN, Antoniades D, Cortes A, MacIntyre S, Lehmann MF, and Laurion I
- Subjects
- Carbon Dioxide analysis, Geologic Sediments chemistry, Lakes chemistry, Lakes microbiology, Phosphorus analysis, Quebec, Seasons, Climate Change, Cyanobacteria physiology, Hot Temperature adverse effects, Lakes analysis, Phytoplankton physiology
- Abstract
Mixing regime and CO
2 availability may control cyanobacterial blooms in polymictic lakes, but the underlying mechanisms still remain unclear. We integrated detailed results from a natural experiment comprising an average-wet year (2011) and one with heat waves (2012), a long-term meteorological dataset (1960-2010), historical phosphorus concentrations and sedimentary pigment records, to determine the mechanistic controls of cyanobacterial blooms in a eutrophic polymictic lake. Intense warming in 2012 was associated with: 1) increased stability of the water column with buoyancy frequencies exceeding 40 cph at the surface, 2) high phytoplankton biomass in spring (up to 125 mg WW L-1 ), 3) reduced downward transport of heat and 4) depleted epilimnetic CO2 concentrations. CO2 depletion was maintained by intense uptake by phytoplankton (influx up to 30 mmol m-2 d-1 ) in combination with reduced, internal and external, carbon inputs during dry, stratified periods. These synergistic effects triggered bloom of buoyant cyanobacteria (up to 300 mg WW L-1 ) in the hot year. Complementary evidence from polynomial regression modelling using historical data and pigment record revealed that warming explains 78% of the observed trends in cyanobacterial biomass, whereas historical phosphorus concentration only 10% thereof. Together the results from the natural experiment and the long-term record indicate that effects of hotter and drier climate are likely to increase water column stratification and decrease CO2 availability in eutrophic polymictic lakes. This combination will catalyze blooms of buoyant cyanobacteria., (Copyright © 2019 Elsevier B.V. All rights reserved.)- Published
- 2019
- Full Text
- View/download PDF
44. Corrigendum to "Greenhouse gas emissions from waste stabilisation ponds in Western Australia and Quebec (Canada)" [Water Res. 101 (2015) 64-74].
- Author
-
Glaz P, Bartosiewicz M, Laurion I, Reichwaldt ES, Maranger R, and Ghadouani A
- Published
- 2017
- Full Text
- View/download PDF
45. Temperature effects on net greenhouse gas production and bacterial communities in arctic thaw ponds.
- Author
-
Negandhi K, Laurion I, and Lovejoy C
- Published
- 2017
- Full Text
- View/download PDF
46. Greenhouse gas emissions from waste stabilisation ponds in Western Australia and Quebec (Canada).
- Author
-
Glaz P, Bartosiewicz M, Laurion I, Reichwaldt ES, Maranger R, and Ghadouani A
- Subjects
- Methane, Quebec, Western Australia, Greenhouse Effect, Ponds
- Abstract
Waste stabilisation ponds (WSPs) are highly enriched environments that may emit large quantities of greenhouse gases (GHG), including CO2, CH4 and N2O. However, few studies provide detailed reports on these emissions. In the present study, we investigated GHG emissions from WSPs in Western Australia and Quebec, Canada, and compared emissions to WSPs from other climatic regions and to other types of aquatic ecosystems. Surface water GHG concentrations were related to phytoplankton biomass and nutrients. The CO2 was either emitted or absorbed by WSPs, largely as a function of phytoplankton dynamics and strong stratification in these shallow systems, whereas efflux of CH4 and N2O to the atmosphere was always observed albeit with highly variable emission rates, dependent on treatment phase and time of the day. The total global warming potential index (GWP index, calculated as CO2 equivalent) of emitted GHG from WSPs in Western Australia averaged 12.8 mmol m(-2) d(-1) (median), with CO2, CH4 and N2O respectively contributing 0%, 96.7% and 3.3% of the total emissions, while in Quebec WSPs this index was 194 mmol m(-2) d(-1), with a relative contribution of 93.8, 3.0 and 3.2% respectively. The CO2 fluxes from WSPs were of the same order of magnitude as those reported in hydroelectric reservoirs and constructed wetlands in tropical climates, whereas CH4 fluxes were considerably higher compared to other aquatic ecosystems. N2O fluxes were in the same range of values reported for WSPs in subtropical climate., (Copyright © 2016 Elsevier Ltd. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
47. Temperature effects on net greenhouse gas production and bacterial communities in arctic thaw ponds.
- Author
-
Negandhi K, Laurion I, and Lovejoy C
- Subjects
- Arctic Regions, Bacteria genetics, Bacteria isolation & purification, Carbon metabolism, Carbon Dioxide analysis, High-Throughput Nucleotide Sequencing, Ponds chemistry, RNA, Ribosomal, 16S genetics, Soil Microbiology, Temperature, Bacteria classification, Climate Change, Geologic Sediments microbiology, Greenhouse Effect, Methane biosynthesis, Permafrost microbiology, Ponds microbiology
- Abstract
One consequence of High Arctic permafrost thawing is the formation of small ponds, which release greenhouse gases (GHG) from stored carbon through microbial activity. Under a climate with higher summer air temperatures and longer ice-free seasons, sediments of shallow ponds are likely to become warmer, which could influence enzyme kinetics or select for less cryophilic microbes. There is little data on the direct temperature effects on GHG production and consumption or on microbial communities' composition in Arctic ponds. We investigated GHG production over 16 days at 4°C and 9°C in sediments collected from four thaw ponds. Consistent with an enzymatic response, production rates of CO2 and CH4 were significantly greater at higher temperatures, with Q10 varying from 1.2 to 2.5. The bacterial community composition from one pond was followed through the incubation by targeting the V6-V8 variable regions of the 16S rRNA gene and 16S rRNA. Several rare taxa detected from rRNA accounted for significant community compositional changes. At the higher temperature, the relative community contribution from Bacteroidetes decreased by 15% with compensating increases in Betaproteobacteria, Alphaproteobacteria, Firmicutes, Acidobacteria, Verrucomicrobia and Actinobacteria. The increase in experimental GHG production accompanied by changes in community indicates an additional factor to consider in sediment environments when evaluating future climate scenarios., (© FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2016
- Full Text
- View/download PDF
48. Heat-Wave Effects on Oxygen, Nutrients, and Phytoplankton Can Alter Global Warming Potential of Gases Emitted from a Small Shallow Lake.
- Author
-
Bartosiewicz M, Laurion I, Clayer F, and Maranger R
- Subjects
- Gases, Global Warming, Greenhouse Effect, Hot Temperature, Methane, Phytoplankton, Lakes, Oxygen
- Abstract
Increasing air temperatures may result in stronger lake stratification, potentially altering nutrient and biogenic gas cycling. We assessed the impact of climate forcing by comparing the influence of stratification on oxygen, nutrients, and global-warming potential (GWP) of greenhouse gases (the sum of CH4, CO2, and N2O in CO2 equivalents) emitted from a shallow productive lake during an average versus a heat-wave year. Strong stratification during the heat wave was accompanied by an algal bloom and chemically enhanced carbon uptake. Solar energy trapped at the surface created a colder, isolated hypolimnion, resulting in lower ebullition and overall lower GWP during the hotter-than-average year. Furthermore, the dominant CH4 emission pathway shifted from ebullition to diffusion, with CH4 being produced at surprisingly high rates from sediments (1.2-4.1 mmol m(-2) d(-1)). Accumulated gases trapped in the hypolimnion during the heat wave resulted in a peak efflux to the atmosphere during fall overturn when 70% of total emissions were released, with littoral zones acting as a hot spot. The impact of climate warming on the GWP of shallow lakes is a more complex interplay of phytoplankton dynamics, emission pathways, thermal structure, and chemical conditions, as well as seasonal and spatial variability, than previously reported.
- Published
- 2016
- Full Text
- View/download PDF
49. High Methylmercury in Arctic and Subarctic Ponds is Related to Nutrient Levels in the Warming Eastern Canadian Arctic.
- Author
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MacMillan GA, Girard C, Chételat J, Laurion I, and Amyot M
- Subjects
- Arctic Regions, Canada, Carbon Dioxide analysis, Ecosystem, Environmental Monitoring, Global Warming, Lakes analysis, Mercury analysis, Methane analysis, Nitrogen analysis, Nunavut, Phosphorus analysis, Ponds chemistry, Methylmercury Compounds analysis, Ponds analysis, Water Pollutants, Chemical analysis
- Abstract
Permafrost thaw ponds are ubiquitous in the eastern Canadian Arctic, yet little information exists on their potential as sources of methylmercury (MeHg) to freshwaters. They are microbially active and conducive to methylation of inorganic mercury, and are also affected by Arctic warming. This multiyear study investigated thaw ponds in a discontinuous permafrost region in the Subarctic taiga (Kuujjuarapik-Whapmagoostui, QC) and a continuous permafrost region in the Arctic tundra (Bylot Island, NU). MeHg concentrations in thaw ponds were well above levels measured in most freshwater ecosystems in the Canadian Arctic (>0.1 ng L(-1)). On Bylot, ice-wedge trough ponds showed significantly higher MeHg (0.3-2.2 ng L(-1)) than polygonal ponds (0.1-0.3 ng L(-1)) or lakes (<0.1 ng L(-1)). High MeHg was measured in the bottom waters of Subarctic thaw ponds near Kuujjuarapik (0.1-3.1 ng L(-1)). High water MeHg concentrations in thaw ponds were strongly correlated with variables associated with high inputs of organic matter (DOC, a320, Fe), nutrients (TP, TN), and microbial activity (dissolved CO2 and CH4). Thawing permafrost due to Arctic warming will continue to release nutrients and organic carbon into these systems and increase ponding in some regions, likely stimulating higher water concentrations of MeHg. Greater hydrological connectivity from permafrost thawing may potentially increase transport of MeHg from thaw ponds to neighboring aquatic ecosystems.
- Published
- 2015
- Full Text
- View/download PDF
50. Small thaw ponds: an unaccounted source of methane in the Canadian high Arctic.
- Author
-
Negandhi K, Laurion I, Whiticar MJ, Galand PE, Xu X, and Lovejoy C
- Subjects
- Arctic Regions, Canada, Carbon Dioxide analysis, Genes, Archaeal, Global Warming, Methanobacterium genetics, Molecular Typing, Phylogeny, Ponds, RNA, Ribosomal, 16S genetics, Water Microbiology, Methane analysis
- Abstract
Thawing permafrost in the Canadian Arctic tundra leads to peat erosion and slumping in narrow and shallow runnel ponds that surround more commonly studied polygonal ponds. Here we compared the methane production between runnel and polygonal ponds using stable isotope ratios, ¹⁴C signatures, and investigated potential methanogenic communities through high-throughput sequencing archaeal 16S rRNA genes. We found that runnel ponds had significantly higher methane and carbon dioxide emissions, produced from a slightly larger fraction of old carbon, compared to polygonal ponds. The methane stable isotopic signature indicated production through acetoclastic methanogenesis, but gene signatures from acetoclastic and hydrogenotrophic methanogenic Archaea were detected in both polygonal and runnel ponds. We conclude that runnel ponds represent a source of methane from potentially older C, and that they contain methanogenic communities able to use diverse sources of carbon, increasing the risk of augmented methane release under a warmer climate.
- Published
- 2013
- Full Text
- View/download PDF
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