The reef builder gastropod Dendropoma petreaum - A proxy of short and long term climatic events in the Eastern Mediterranean

High-resolution δ¹⁸O and δ¹³C records obtained from seven cores were drilled from ledges of the reef builder gastropod Dendropoma petreaum and used to reconstruct variations in the Levantine basin sea surface temperature, hydrology and productivity during the past 500 years. The δ¹⁸O of the aragonite shell of living D. petreaum indicate that skeletal deposition occurs under isotopic equilibrium and faithfully record the temperature and surface water δ¹⁸O during summer and autumn. The mean down core δ¹⁸O record clearly captures global and local climatic events, such as the Little Ice Age (LIA) and the recent warming of surface waters in the Eastern Mediterranean. Comparison to the Western Mediterranean vermetid δ¹⁸O record reveals changes in the freshwater/evaporation budgets of the two basins during cold and warm periods. The Eastern basin had lower surface temperatures and excess evaporation during the LIA and experienced a relatively larger warming and/or a decrease in freshwater/evaporation during the past 70 years. The D. petraeum δ¹³C is strongly related to δ¹³C of dissolved inorganic carbon and to the primary productivity of the surface water. The mean down core δ¹³C record exhibits enrichment during the LIA maximum and a strong depletion trend during the last century. The LIA δ¹³C enrichment is attributed to an increase in primary production and high nutrient levels which resulted from increased vertical mixing and upwelling. The last century δ¹³C depletion is mostly related to the increased anthropogenic emissions of ¹³C depleted carbon dioxide and to a certain decrease in primary production. The data indicate that D. petraeum isotopic signatures are unique proxies for last 500 years high-resolution reconstruction of paleo-oceanographic environments in the Mediterranean and potentially in the sub-tropical Atlantic regions.