Coastal engineering infrastructure impacts Blue Carbon habitats distribution and ecosystem functions

Este artículo contiene 13 páginas, 6 figuras, 2 tablas.Intertidal estuarine habitats (e.g., saltmarshes and tidal fats) provide important ecosystem services to society, including coastal protection, food provision and Corg sequestration. Yet, estuaries and estuarine habitats have been subjected to intense human pressure, such as land-use change and artifcialization of the shoreline to support economic activities and uses. Construction of engineering infrastructures (e.g., piers, bridges) in these areas alters estuary-wide hydromorphological conditions and thus sedimentation patterns at the estuarine scale, which are key drivers of habitats distribution and ecosystem structure, processes and functions. Most of the research on the impact of civil engineering structures on coastal habitats has focused on the biological communities that colonize them or the bottoms where they are placed, whereas their indirect impacts on adjacent habitats has been largely unexplored. Understanding the infuence of man-made infrastructures on the distribution of estuarine habitats and functions is critical, particularly considering that shoreline armoring is expected to increase as a way to protect coastal areas from hazards derived from climate change. Shifts in habitat distribution and functions occur in several years or decades and relating them with the occurrence of past historical events is challenging when no monitoring data is available. By examining historical aerial photographs and diferent biogeochemical properties along a saltmarsh soil record, this study demonstrates that the construction of an infrastructure (i.e. bridge) caused a rapid transformation (~30 years) of a bare sandfat into a high marsh community and to signifcant changes in sediment biogeochemical properties, including the decrease in sediment accretion rate and Corg burial rates since then. This study contributes to increase the knowledge on the impact that the construction in coastal areas of civil engineering infrastructures can cause in intertidal habitats distribution and the ecological functions they provide for climate change adaption and mitigation.Tis research was carried out with the contribution of the LIFE Programme of the European Union to the Project ADAPTA BLUES (ref. LIFE18 CCA/ES/001160). Tis document refects only the author’s view and the Agency/ Commission is not responsible for any use that may be made of the information it contains. Authors acknowledges the fnancial support from the Government of Cantabria through the Fénix Programme. Te authors want to thank the support of the Generalitat de Catalunya to MERS (2017 SGR-1588) and the Spanish Government for the “Maria de Maeztu” program for Units of Excellence to ICTA (Grant No. CEX2019-000940-M).Peer reviewe