| Title | Widespread diminishing anthropogenic effects on calcium in freshwaters |
| Abstract | Calcium (Ca) is an essential element for almost all living organisms. Here, we examined global variation and controls of freshwater Ca concentrations, using 440 599 water samples from 43 184 inland water sites in 57 countries. We found that the global median Ca concentration was 4.0 mg L with 20.7% of the water samples showing Ca concentrations <= 1.5 mg L, a threshold considered critical for the survival of many Ca-demanding organisms. Spatially, freshwater Ca concentrations were strongly and proportionally linked to carbonate alkalinity, with the highest Ca and carbonate alkalinity in waters with a pH around 8.0 and decreasing in concentrations towards lower pH. However, on a temporal scale, by analyzing decadal trends in >200 water bodies since the 1980s, we observed a frequent decoupling between carbonate alkalinity and Ca concentrations, which we attributed mainly to the influence of anthropogenic acid deposition. As acid deposition has been ameliorated, in many freshwaters carbonate alkalinity concentrations have increased or remained constant, while Ca concentrations have rapidly declined towards or even below pre-industrial conditions as a consequence of recovery from anthropogenic acidification. Thus, a paradoxical outcome of the successful remediation of acid deposition is a globally widespread freshwater Ca concentration decline towards critically low levels for many aquatic organisms. |
| Source | Scientific reports (Nature Publishing Group) 9 (1) |
| Keywords | biogeochemistryfreshwaterscalciumalkalinitytrend |
| Journal | Scientific reports (Nature Publishing Group) |
| Editor | Nature Publishing Group, London, Regno Unito |
| Year | 2019 |
| Type | Articolo in rivista |
| DOI | 10.1038/s41598-019-46838-w |
| Authors | Weyhenmeyer, Gesa A.; Hartmann, Jens; Hessen, Dag O.; Kopá?ek, Ji?í; Hejzlar, Josef; Jacquet, Stéphan; Hamilton, Stephen K.; Verburg, Piet; Leach, Taylor H.; Schmid, Martin; Flaim, Giovanna; Nõges, Tiina; Nõges, Peeter; Wentzky, Valerie C.; Rogora, Michela; Rusak, James A.; Kosten, Sarian; Paterson, Andrew M.; Teubner, Katrin; Higgins, Scott N.; Lawrence, Gregory; Kangur, Külli; Kokorite, Ilga; Cerasino, Leonardo; Funk, Clara; Harvey, Rebecca; Moatar, Florentina; de Wit, Heleen A.; Zechmeister, Thomas |
| Text | 407792 2019 10.1038/s41598 019 46838 w Scopus 2 s2.0 85069530746 ISI Web of Science WOS 000475845400054 biogeochemistry freshwaters calcium alkalinity trend Widespread diminishing anthropogenic effects on calcium in freshwaters Weyhenmeyer, Gesa A.; Hartmann, Jens; Hessen, Dag O.; Kopa ek, Ji i; Hejzlar, Josef; Jacquet, Stephan; Hamilton, Stephen K.; Verburg, Piet; Leach, Taylor H.; Schmid, Martin; Flaim, Giovanna; Nõges, Tiina; Nõges, Peeter; Wentzky, Valerie C.; Rogora, Michela; Rusak, James A.; Kosten, Sarian; Paterson, Andrew M.; Teubner, Katrin; Higgins, Scott N.; Lawrence, Gregory; Kangur, Kulli; Kokorite, Ilga; Cerasino, Leonardo; Funk, Clara; Harvey, Rebecca; Moatar, Florentina; de Wit, Heleen A.; Zechmeister, Thomas Centre Alpin de Recherche sur les Reseaux Trophiques et les Ecosystemes limniques CARRTEL ; Istituto di Ricerca sulle Acque, Italy; Istituto Agrario San Michele all Adige; University of Latvia; Institute of Hydrobiology, Biology Centre of the Academy of Sciences of the Czech Republic; Estonian University of Life Sciences; Michigan State University; Universitat Hamburg; Norsk institutt for vannforskning; Universitat Wien; Rensselaer Polytechnic Institute; National Institute of Water and Atmospheric Research, New Zealand; United States Environmental Protection Agency; Helmholtz Zentrum fur Umweltforschung; Radboud University Nijmegen; United States Geological Survey; Universitetet i Oslo; Uppsala Universitet; Swiss Federal Institute of Aquatic Science and Technology; Irstea; STATE OF VERMONT DEPARTMENT OF PUBLIC SERVICE; IISD Experimental Lakes Area Inc.; Biological Station Neusiedler See; Dorset Environmental Science Centre Calcium Ca is an essential element for almost all living organisms. Here, we examined global variation and controls of freshwater Ca concentrations, using 440 599 water samples from 43 184 inland water sites in 57 countries. We found that the global median Ca concentration was 4.0 mg L with 20.7% of the water samples showing Ca concentrations <= 1.5 mg L, a threshold considered critical for the survival of many Ca demanding organisms. Spatially, freshwater Ca concentrations were strongly and proportionally linked to carbonate alkalinity, with the highest Ca and carbonate alkalinity in waters with a pH around 8.0 and decreasing in concentrations towards lower pH. However, on a temporal scale, by analyzing decadal trends in >200 water bodies since the 1980s, we observed a frequent decoupling between carbonate alkalinity and Ca concentrations, which we attributed mainly to the influence of anthropogenic acid deposition. As acid deposition has been ameliorated, in many freshwaters carbonate alkalinity concentrations have increased or remained constant, while Ca concentrations have rapidly declined towards or even below pre industrial conditions as a consequence of recovery from anthropogenic acidification. Thus, a paradoxical outcome of the successful remediation of acid deposition is a globally widespread freshwater Ca concentration decline towards critically low levels for many aquatic organisms. 9 Published version http //www.scopus.com/record/display.url eid=2 s2.0 85069530746 origin=inward Weyhenmeyer_etal_2019_SciRep Versione pubblicata Weyhenmeyer_et_al 2019 Scientific_Reports.pdf Articolo in rivista Nature Publishing Group 2045 2322 Scientific reports Nature Publishing Group Scientific reports Nature Publishing Group Scientific reports Nature Publishing Group michela.rogora ROGORA MICHELA |
