Heavy metal uptake of near-shore benthic foraminifera during 1 multi-metal culturing experiments 2

Heavy metal pollution originating from anthropogenic sources, e.g., mining, industry and extensive land 8 use, is increasing in many parts of the world and influences coastal marine environments for a long timeeven after 9 the source has ceased pollution. The elevated input of heavy metals into the marine system potentially affects the 10 biota because of their toxicity, persistence and bioaccumulation. An emerging tool for environmental applications 11 is the heavy metal incorporation into foraminiferal tests calcite tests, which facilitates monitoring of anthropogenic 12 footprints on recent and past environmental systems. The aim of this study wais to investigate whether the 13 incorporation of heavy metals in foraminifera is a direct function of their concentration in seawater. Culturing 14 experiments with a mixture of dissolved chromium (Cr), manganese (Mn), nickel (Ni), copper (Cu), zinc (Zn), 15 silver (Ag), cadmium (Cd), tin (Sn), mercury (Hg) and lead (Pb) in artificial seawater were carried out over a wide 16 concentration range to assess the uptake of heavy metals by the near-shore foraminiferal species Ammonia 17 aomoriensis, Ammonia batava and Elphidium excavatum. Seawater analyseis exhibited revealed the increasing 18 metal concentrationss for most metals between culturing phases between culturing phases and revealed high metal 19 concentrations in the beginning of the culturing phases due to the punctual metal addition. Furthermore, a loss of 20 metals during the culturing process was discovered, by an offsetwhich lead to a deviation between the expected 21 added and the actual concentrations of the metals in seawater. Laser ablation ICP-MS analysis of the newly formed 22 calcite revealed species-specific differences in the incorporation of heavy metals. The foraminiferal calcite of all 23 three species exhibited Pb and Ag concentrations reveals a strongly correlated with positive correlation with Pb 24 and Ag concentrations in the seawater culturing medium (partition coefficients and standard deviation for Ag: 25 Ammonia aomoriensis=0.50 ±0.02, Ammonia batava=0.17 ±0.01, Elphidium excavatum=0.47 ±0.04; for Pb: 26 Ammonia aomoriensis=0.39 ±0.01, Ammonia batava=0.52 ±0.01, Elphidium excavatum=0.91 ±0.01). Ammonia 27 aomoriensis further showed a correlation with Mn and Cu, A. batava with Mn and Hg and E. excavatum with Cr 28 and Ni, and partially also with Hg. However, Zn, Sn and Cd showed no clear trend for the species studied, which 29 in case of Sn was may be caused by the little lack of variation of the seawater Sn concentration se metals in 30 seawater. Our The calibrations and the calculated partition coefficients render A. aomoriensis, A. batava and E. 31 excavatum as natural archives that enable the determination of variations of some heavy metal concentrations in 32 seawater direct quantification of metals in polluted and pristine environments. This in turn allows monitoring of 33 the ecosystem status of areas that are potentially under the threat of anthropogenic pollution in order to evaluate 34 contemporary emission reduction measures. 35