Comparison between the dead and living benthic foraminiferal assemblages in Aveiro Lagoon (Portugal)

• Comparison between living (LAs) and dead assemblages (DAs) of benthic foraminifera
• Advanced multivariate statistical analyses applied to a multiproxy approach.
• Factors that control the level of agreement/disagreement between the DAs and the LAs
• Hydrodynamics' influence due to very strong tidal currents
• Ecological preferences of living benthic foraminifera in a polluted lagoon system

This work provides a comparison between living (LAs) and dead (DAs) benthic foraminiferal assemblages in 53 sampled sites located in intertidal and subtidal areas of Ria de Aveiro (Portugal).The results of multivariate statistical analysis provide evidence for the main factors that control the distribution of DAs and LAs, which seems to correspond to different gradients of marine/continental influence, conditioned by differences in the hydrodynamics of tidal currents. In addition to these factors, the LAs are clearly influenced by the total organic carbon, biopolymers and pollutants. The main factor that however drives the high level of agreement or the degree of disorder between the DAs and the LAs seems to be the hydrodynamics. The highest level of agreement between the DAs and the LAs is found in sheltered inner lagoon areas, out of the tidal currents strongest influence. This study shows an interesting application of advanced statistical analysis to study the similarity between LAs and DAs aiming to identify the zones or conditions of a coastal system in which the DAs can potentially be a better record of Las. Through similar studies conducted in coastal systems it is possible to select the most suitable sites to collect cores in view of the development of paleoenvironmental studies.