Widespread diminishing anthropogenic effects on calcium in freshwaters

0509978 - BC 2020 RIV GB eng J - Journal Article
Weyhenmeyer, G. A. - Hartmann, J. - Hessen, D. O. - Kopáček, Jiří - Hejzlar, Josef - Jacquet, S. - Hamilton, S. K. - Verburg, P. - Leach, T. H. - Schmid, M. - Flaim, G. - Nõges, T. - Noges, P. - Wentzky, V. C. - Rogora, M. - Rusak, J. A. - Kosten, S. - Paterson, A. M. - Teubner, K. - Higgins, S. N. - Lawrence, G. - Kangur, K. - Kokorite, I. - Cerasino, L. - Funk, C. - Harvey, R. - Moatar, F. - de Wit, H. A. - Zechmeister, T.
Widespread diminishing anthropogenic effects on calcium in freshwaters.
Scientific Reports. Roč. 9, JUL (2019), č. článku 10450. ISSN 2045-2322. E-ISSN 2045-2322
Institutional support: RVO:60077344
Keywords : crustacean zooplankton * global carbon * chemistry * forest * lakes
OECD category: Environmental sciences (social aspects to be 5.7)
Impact factor: 3.998, year: 2019
Method of publishing: Open access
https://www.nature.com/articles/s41598-019-46838-w.pdf

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-1 with 20.7% of the water samples showing Ca concentrations <= 1.5 mg L-1, 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.
Permanent Link: http://hdl.handle.net/11104/0300677