Increasing nutrient inputs over the last 500 years in an Italian low-impacted seagrass meadow. (January 2022)

• Record Type: Journal Article
• Authors: Casella, Nicolò; Careddu, Giulio; Calizza, Edoardo; Sporta Caputi, Simona; Rossi, Loreto; Belluscio, Andrea; Ardizzone, Giandomenico; Calcagnile, Lucio; Quarta, Gianluca; D'Elia, Marisa; Costantini, Maria Letizia
• Is Part Of: Marine pollution bulletin. Volume 174(2022)
• Publication Date: 2022-01
• Subjects: Long-term studies -- Global change -- Nutrient pollution -- Seagrasses -- Stable isotopes -- Posidonia oceanica; Marine pollution -- Periodicals; Marine Biology -- Periodicals; Water Pollution -- Periodicals; Mer -- Pollution -- Périodiques; Publications périodiques; Pollution des mers; Lutte antipollution; Electronic journals; 363.7394
• DOI: 10.1016/j.marpolbul.2021.113298
• Languages: English
• ISSNs: 0025-326X

Abstract

Abstract: Posidonia oceanica is a seagrass endemic to the Mediterranean and it has been widely used as a bioindicator. We studied the layers of a 500-year-old matte using a multiproxy approach (δ 13 C, δ 15 N, 14 C and C and N concentrations in seagrass debris) in order to evaluate the potential of P. oceanica as a long-term environmental indicator of N pollution and CO2 emissions. From 1581 to 1800, accumulation rate was ca. 0.35 cm year −1, while in the last 100 years it has amounted to ca. 0.51 cm year −1 . We observed increasing δ 15 N values with height in the vertical matte profile, indicating an increase in anthropogenic organic N inputs over time. In contrast, no clear trend in the δ 13 C values was observed. This study reconstructs the long-term impact of human activities on a seagrass meadow located off the Italian coast, yielding long-term background information that can help managers to implement efficient plans. Highlights: 14 C dating of the matte revealed a chronological record dating back ca. 500 years. Matte accretion rate was 0.35 cm year −1 (0.51 cm year −1 in the last 100 years). P. oceanica δ 15 N increase over time, from ca. 0‰ to ca. 3‰ in the recent layers. The highest δ 15 N in the recent layers is indicative of anthropogenic N inputs. No clear temporal trend in the δ 13 C values of P. oceanica was observed.