A transfer function for the quantitative reconstruction of oxygen contents in marine paleo- environments

Abstract

We observed living (Rose Bengal stained) foraminifera in the Indian Ocean, Atlantic Ocean and Mediterranean Sea, and compared the distributional patterns with micro-profiled oxygen contents in the sediment column. Our data demonstrate that one group ofspecies is apparently oxyphilic and that their abundances co-vary linearly with the oxygen content at the sediment-water interface. We developed a transfer function and tested this on a historic record from the Adriatic Sea. We show that application of this transfer ti.mction to benthic foraminiferal patterns in a core from the Adriatic Sea results in an accurate quantitative reconstruction of the oxygenation history over the past r60 years. The reconstructed record shows that the marine system rapidly becanle prone to hypoxia between AD r890 and 1935. We suggest that this was due to the man-induced increased nutrient load of Po waters, related to the introduction of artificial fertiliser in the drainage area.