Garcias-Bonet, Neus Delgado-Huertas, Antonio Carrillo-de-Albornoz, Paloma Anton, Andrea Almahasheer, Hanan Marbà, Núria Hendriks, Iris E. Krause-Jensen, Dorte Duarte, Carlos M. Data_Sheet_1_Carbon and Nitrogen Concentrations, Stocks, and Isotopic Compositions in Red Sea Seagrass and Mangrove Sediments.PDF <p>Coastal vegetated ecosystems are intense global carbon (C) sinks; however, seagrasses and mangroves in the Central Red Sea are depleted in organic C (C<sub>org</sub>). Here, we tested whether C<sub>org</sub> depletion prevails along the Red Sea, or if sediment C<sub>org</sub> and nitrogen (N) stocks reflect the latitudinal productivity gradient of the Red Sea. We assessed C<sub>org</sub> and N concentrations, stocks, isotopic compositions (δ<sup>13</sup>C and δ<sup>15</sup>N), and the potential contribution of primary producers to the organic matter accumulation in seagrass and mangrove sediments along the Eastern coast of the Red Sea. Sediment C<sub>org</sub> concentration was higher in mangroves than seagrasses, while N concentrations were similar, resulting in higher C/N ratios in mangrove than seagrass sediments. Mangrove C<sub>org</sub> stocks (integrated over the top 10 cm) were twofold higher than those of seagrasses. N concentrations and stocks decreased from south to north in seagrass sediments matching the productivity gradient while C<sub>org</sub> concentrations and stocks were uniform. The δ<sup>15</sup>N decreased from south to north in seagrass and mangrove sediments, reflecting a shift from nitrate and nitrite as N sources in the south, to N<sub>2</sub> fixation toward the north. Stable isotope mixing models showed that seagrass leaves and macroalgae blades were the major contributors to the organic matter accumulation in seagrass sediments; while mangrove leaves were the major contributors in mangrove sediments. Overall, vegetated sediments in the Red Sea tend to be carbonate-rich and depleted in C<sub>org</sub> and N, compared to coastal habitats elsewhere. Specifically, mean C<sub>org</sub> stocks in Red Sea seagrass and mangrove sediments (7.2 ± 0.4 and 14.5 ± 1.4 Mg C ha<sup>-1</sup>, respectively) are lower than previously reported mean global values. This new information of Blue Carbon resources in the Red Sea provides a background for Blue Carbon programs in the region while also helping to balance global estimates.</p> nitrogen;carbon;sediment stocks;stable isotopes;stable isotope mixing model;seagrasses;mangroves 2019-05-29
    https://frontiersin.figshare.com/articles/dataset/Data_Sheet_1_Carbon_and_Nitrogen_Concentrations_Stocks_and_Isotopic_Compositions_in_Red_Sea_Seagrass_and_Mangrove_Sediments_PDF/8197553
10.3389/fmars.2019.00267.s001