Szczegóły publikacji
Opis bibliograficzny
Biogeochemical controls on carbonate dynamics driven by methane and freshwater inputs in shallow sediments of a brackish continental shelf sea / Katarzyna Łukawska-Matuszewska, Grzegorz RZEPA, Aleksandra Brodecka-Goluch, Andrzej BORKOWSKI, Beata Gebus-Czupyt, Artur BŁACHOWSKI, Maciej MANECKI, Jarosław KANIA, Maciej DWORNIK, Magdalena Radzikowska // Biogeosciences ; ISSN 1726-4170 . — 2026 — vol. 23 iss. 14, s. 5255–5279. — Bibliogr. s. 5274–5279, Abstr. — Publikacja dostępna online od: 2026-07-31
Autorzy (10)
- Łukawska-Matuszewska Katarzyna
- AGHRzepa Grzegorz
- Brodecka-Goluch Aleksandra
- AGHBorkowski Andrzej
- Gebus-Czupyt Beata
- AGHBłachowski Artur
- AGHManecki Maciej
- AGHKania Jarosław
- AGHDwornik Maciej
- Radzikowska Magdalena
Dane bibliometryczne
| ID BaDAP | 169595 |
|---|---|
| Data dodania do BaDAP | 2026-09-23 |
| Tekst źródłowy | URL |
| DOI | 10.5194/bg-23-5255-2026 |
| Rok publikacji | 2026 |
| Typ publikacji | artykuł w czasopiśmie |
| Otwarty dostęp |  |
| Creative Commons | |
| Czasopismo/seria | Biogeosciences |
Abstract
Continental shelf seas are essential to the carbon cycle, supporting nearly one-third of global marine primary production and significantly contributing to the burial of organic and inorganic carbon. Processes such as organoclastic sulfate reduction (OSR), methane production or anaerobic oxidation of methane (AOM), occurring in coastal sediments, have a significant impact on the carbon cycling in the marine environment. That impact may be modified by an increased organic matter (OM) supply or freshwater input. In the present interdisciplinary study, we investigated carbonate dynamics in three benthic environments of a brackish continental shelf sea: (1) anoxic sediments dominated by OSR; (2) nearshore sediments with high terrigenous OM input and active methanogenesis; and (3) sediments influenced by groundwater infiltration and pore-water freshening, coupled with methanogenesis. We analyzed pore-water chemistry (DIC, total alkalinity, major ions, nutrients), sediment geochemistry (CH4, total organic carbon, total nitrogen, total sulfur), and mineralogy, including authigenic carbonates and iron sulfides. We used stable isotopes of DIC (δ13C-DIC), methane (δ13C-CH4, δ2H-CH4) and organic matter (δ13C, δ15N) to trace carbon transformations. We also determined rates of OSR and AOM experimentally. Based on these data, we have proposed conceptual models of carbon cycling in the three sedimentary environments. In the methane-free sediment, organic matter degradation was primarily governed by OSR, producing 54 mmol m−2 d−1 of DIC within the top 100 cm, accompanied by limited carbonate burial and dominant pyrite accumulation. In sediments where the flux of OM exceeded sulfate supply, a substantial portion of OM remineralization shifted to methanogenesis in the uppermost decimeters, leading to rapid sulfate depletion, a shoaled sulfate–methane transition, and elevated DIC concentrations; these processes were especially pronounced in sediments affected by freshwater seepage, where pore water freshening further limited sulfate availability. In such conditions carbonate dynamics were markedly enhanced: methane-related processes – in particular AOM, which reached up to 1077 µmol dm−3 d−1 in freshwater-influenced sediments – produced additional DIC, contributed to carbonate supersaturation and promoted pronounced authigenic carbonate (mainly dolomite) formation. Depth-integrated DIC production from AOM (331 mmol m−2 d−1 over 0–100 cm) substantially exceeded OSR-derived DIC (58 mmol m−2 d−1) in these settings, corresponding with elevated authigenic dolomite burial rates (467–994 µmol m−2 d−1). To our knowledge, this study provides the first quantitative estimate of authigenic carbonate burial rates for Baltic Sea sediments.
