"Anthropocene" imprint of shipbuilding industry , blossom, decay and reactivation

Abstract

2 pages.-- International Estuarine Biogeochemistry Symposium, Vigo (Spain), 4-5th June 2019 ; The globalization of the industrialization is being pointed out as the synchronous and global event that potentially marks the starting point of a current-proposed stratigraphic epoch: the 'Anthropocene'. Its study makes necessary high-resolution (yearly) works on recent stratigraphic records such as estuarine sediments. Concerning industrialization, the Ria of Ferrol represents a paradigmatic example in the NW of the Iberian Peninsula. This area is under the impact of military shipyards since 1730. Their maximum activity happened after 1947, consequence of the industry restructuring and the implementation of civil shipbuilding (including oil super-tankers). The present study focused on a sediment core of 50 cm long that holds record since the beginning of the 20th century, according to Pb-210 dating. Trace metal contents were evaluated to identify the human imprint. Background levels established in nearby areas with similar mineralogical characteristics were considered. Three main periods can be distinguished based on the trace-element to Al ratios: (i) from the beginning of the 20th century until about 1970, when ratios increase usually about 1.5 to 2.4 times, (ii) between around 1970 to 1990, when these ratios decrease usually about 1.4 to 2.3 times, and (iii) from 1990 to 2010, when ratios maintained. The studied sediments reflect the human-environment relationship in the area during the 20th century: the metal to Al ratios, sediment accumulation rates, total metal fluxes and enrichment factors show a first period of increasing industrialization without environmental concern, followed by an industrial collapse and a subsequent reactivation while implementing environmental friendly processes and policies ; This study from the project "Coastal contributions of trace elements during different oceanographic periods" (CTM2011-28792-C02-02), funded by MINECO ; Peer reviewed