Biogeochemical and mineralogical effects of Fe-P-S dynamics in sediments of continental shelf sea: Impact of salinity, oxygen conditions, and catchment area characteristics.

Autor: Łukawska-Matuszewska K; Faculty of Oceanography and Geography, Institute of Oceanography, University of Gdańsk, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland. Electronic address: katarzyna.lukawska-matuszewska@ug.edu.pl., Brocławik O; Faculty of Oceanography and Geography, Institute of Oceanography, University of Gdańsk, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland., Brodecka-Goluch A; Faculty of Oceanography and Geography, Institute of Oceanography, University of Gdańsk, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland., Rzepa G; Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland., Manecki M; Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Kraków, Poland., Bolałek J; Faculty of Oceanography and Geography, Institute of Oceanography, University of Gdańsk, Al. Marszałka Piłsudskiego 46, 81-378 Gdynia, Poland.
Jazyk: angličtina
Zdroj: The Science of the total environment [Sci Total Environ] 2022 Feb 10; Vol. 807 (Pt 3), pp. 151035. Date of Electronic Publication: 2021 Oct 16.
DOI: 10.1016/j.scitotenv.2021.151035
Abstrakt: In this study, we investigate how salinity, oxygen concentration and catchment area characteristics impact the dynamics of Fe-P-S cycling in the continental shelf sea sediments. Samples were collected from three sites representing different environmental conditions: Gdańsk Deep (southern Baltic Sea), Gotland Deep (central Baltic Sea) and Bothnian Sea (northern Baltic Sea). Sediments were analysed for their mineral composition and speciation of iron and phosphorus. The main groups of Prokaryota involved in Fe-P-S cycling in sediments were indicated. Concentrations of sulphate, hydrogen sulphide, alkalinity, chloride, calcium, phosphate and iron were measured in pore waters. We demonstrated that in the eutrophicated southern region with moderate salinity and oxygen deficit in bottom water, sediments had high potential for retaining Fe and releasing P as indicated by high concentrations of pyrite and labile forms of phosphorus, respectively. Strong salinity stratification and intermittent pelagic redoxcline in the central Baltic Sea resulted in a clearly higher rate of pyrite deposition. Sediment was enriched with Mn due to the formation of Ca-Mn carbonates driven by intensive Mn redox cycling and sulphate reduction. Because of high availability of Mn oxides connected with episodic inflows of oxic seawater from the North Sea, sulphate was present in the entire profile of the studied sediments in the Gotland Deep. Sediments in the well-oxygenated, virtually fresh and rich in land-derived iron northern Baltic Sea retained significant amounts of P in authigenic minerals. Organic matter mineralisation in the surface sediment of this area was dominated by iron reduction. The variability of environmental conditions and consequent availability of electron acceptors were the cause of regional differences in the composition of Prokaryota communities - the number of sulphate reducers in the Gdańsk and Gotland Deeps was greater than in the Bothnian Sea, where there were more Fe reducers and bacteria that oxidise Fe and S.
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 The Authors. Published by Elsevier B.V. All rights reserved.)
Databáze: MEDLINE
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