Bioerosion by microbial euendoliths in benthic foraminifera from heavy metal-polluted coastal environments of Portovesme (south-western Sardinia, Italy)

[摘要] A monitoring survey of the coastal area facing theindustrial area of Portoscuso-Portovesme (south-western Sardinia, Italy)revealed intense bioerosional processes. Benthic foraminifera collected atthe same depth (about 2 m) but at different distances from the pollutionsource show extensive microbial infestation, anomalous Mg/Ca molar ratiosand high levels of heavy metals in the shell associated with a decrease inforaminifera richness, population density and biodiversity with the presenceof morphologically abnormal specimens. We found that carbonate dissolutioninduced by euendoliths is selective, depending on the Mg content andmorpho-structural types of foraminiferal taxa. This study provides evidencesfor a connection between heavy metal dispersion, decrease in pH of thesea-water and bioerosional processes on foraminifera.

[学科分类] 地球化学与岩石