Quantifying organic carbon burial rates and stocks in seagrass meadow sediments influenced by sargassum-brown tides

作者：Melisa Aranza Sánchez-Rojas, Ana Carolina Ruíz-Fernández, Brigitta I. van Tussenbroek, Joan-Albert Sánchez-Cabeza, Libia Hascibe Pérez-Bernal, José Gilberto Cardoso‐Mohedano · 发表于：Marine Environmental Research · 年份：2024 · DOI：10.1016/j.marenvres.2024.106875 · 被引用次数：3 · 研究领域：Marine and coastal plant biology、Coastal wetland ecosystem dynamics、Marine Biology and Ecology Research

Seagrass meadow sediments are efficient organic carbon (C org ) sinks and can store C org for hundreds of years. The temporal variation of C org burial rates and stocks over recent decades at nearshore seagrass meadows in the Puerto Morelos Reef Lagoon, Mexico, was evaluated in 210 Pb-dated sediment cores from nearshore meadows dominated by Thalassia testudinum. The sediments were predominantly sandy (>52% sand) rich in carbonate grains (11.8–12.5% C inorg ) with minor C org (0.24–1.12%) and N org (0.02–0.13%) concentrations. The C:N ratio (9.4–13.0) indicated that marine-derived C org was prevalent. C org stocks in the upper 30 cm sediment were 15.9 ± 3.0–24.8 ± 4.6 Mg ha −1 . Sedimentary mass accumulation rates (MAR) (0.7–1.5 g cm −2 yr −1 ) were higher than those previously recorded in seagrass sediments from the reef lagoon and other parts of the world. The highest MAR values, recorded in 2015 (±0.13) and 2018 (±0.03), coincided with the peak sargassum influx years. MAR and C org burial rates (11.4–133 g m −2 yr −1 ) were correlated (r 2 = 0.76), indicating that the massive influxes of sargassum have accelerated C org burial rates in the region since 2015. This study marks the initial evaluation of the interaction between the massive influx of sargassum, MAR, and C org burial rates in seagrass sediments, potentially laying the groundwork for future extended monitoring initiatives. • Organic carbon (C org ) stock and burial rates were measured in seagrass sediment cores. •...