Long-term dynamics of production in western Mediterranean seagrass meadows: Trade-offs and legacies of past disturbances Carmen Leiva-Dueñas a, ⁎, Antonio Martínez Cortizas b,a , Nerea Piñeiro-Juncal b,a , Elena Díaz-Almela a , Jordi Garcia-Orellana c,d , Miguel A. Mateo a,e a Centro de Estudios Avanzados de Blanes, Consejo Superior de Investigaciones Científicas, Blanes, Spain b EcoPast (GI-1553), Facultade de Bioloxia, Universidade de Santiago de Compostela, Santiago de Compostela, Spain c Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, Barcelona, Spain d Departament de Física, Universitat Autònoma de Barcelona, Barcelona, Spain e School of Natural Sciences, Centre for Marine Ecosystems Research, Edith Cowan University, Joondalup, Australia HIGHLIGHTS • Long-term dynamics are studied in seagrass meadows of southeastern Spain. • This study pioneers in the use of FTIR spectroscopy in seagrass paleoreconstructions. • Productivity decreased since AD ~1850 along the mainland coast but not in the island. • Synergy of local and global drivers may explain the worse state of some meadows. • Paleoecology can help identify meadows where local management can be more efficient. GRAPHICAL ABSTRACT abstract article info Article history: Received 11 June 2020 Received in revised form 12 August 2020 Accepted 30 August 2020 Available online 3 September 2020 Editor: Lotfi Aleya Seagrasses are marine angiosperms that can form highly productive, and valuable underwater meadows, which are currently in regression. A reliable assessment of their status and future evolution requires studies encompassing long-term temporal scales. With the aim of understanding seagrass ecosystem dynamics over the last centuries and millennia, twelve sediment cores were studied from seagrass meadows located along the Andalusian coast and at the Cabrera Island (western Mediterranean). This study is pioneer in using Fourier Transform Infrared (FTIR) spectroscopy as a tool to study environmental change in seagrass sediments. FTIR is a form of vibrational spectroscopy that provides information about the sediment chemical composition. Principal Component Analysis (PCA) was used to summarise spatio-temporal data of the FTIR vibratory peaks in combination with climate and geochemical proxy data. Several PCA signals were identified: (1) one likely related to the relative changes of the main primary producers and the sedimentary environment (carbonate or siliciclastic sediments, with aromatic or aliphatic organic matter); (2) the marine community production (polysaccharides, total organic matter content and biogenic silica); and (3) the seagrass production (aromatics, carbohydrates, phenols, proteins and lipids). A decrease of seagrass production along the mainland coast was evident since AD ~1850, which may be due to combined negative impacts of seawater warming, local anthropogenic impacts, and extreme setting conditions. The legacy of these combined stressors might have influenced the current poor state of seagrass meadows in the Alboran Sea. Our results also revealed a significant Keywords: Marine paleoreconstructions FTIR-ATR Global change Paleoproductivity Seagrass environmental record Coastal sediments Science of the Total Environment 754 (2021) 142117 ⁎ Corresponding author. E-mail address: cleiva@ceab.csic.es (C. Leiva-Dueñas). STOTEN-142117; No of Pages 18 https://doi.org/10.1016/j.scitotenv.2020.142117 0048-9697/© 2020 Elsevier B.V. All rights reserved. Contents lists available at ScienceDirect Science of the Total Environment journal homepage: www.elsevier.com/locate/scitotenv Please cite this article as: C. Leiva-Dueñas, A. Martínez Cortizas, N. Piñeiro-Juncal, et al., Long-term dynamics of production in western Mediterranean seagrass meadows: Trade-offs and legacies ..., Science of the Total Environment, https://doi.org/10.1016/j.scitotenv.2020.142117