Zooplankton as an indicator of the status of contamination of the Mediterranean Sea and temporal trends

Zooplankton has been intensively used as bioindicators of water pollution at global level, however, only few comprehensive studies have been conducted from the Mediterranean Sea and manly dated back to the 1970s. To redress the urgent need for updated data, this study provides information on the presence and levels of contaminants in zooplankton from the Tyrrhenian Sea. Although banned, both PCBs (46.9 +/- 37.2 ng g-1) and DDT (8.9 +/- 10.7 ng g-1) are still present and widespread, but their contamination appears to be a local problem and to be declining over the past 50 years. Zooplankton accumulates high levels of certain TEs, including Zn (400 +/- 388 ppm) and Pb (35.3 +/- 45.5 ppm), but shows intermediate concentrations of other TEs, including Cd (1.6 +/- 0.9 ppm) and Hg (0.1 +/- 0.1 ppm), comparing with both strongly polluted and more pristine marine habitats, which may reflect a general improvement.

Automated summary

Zooplankton has been used as bioindicators of water pollution globally, but there are few comprehensive studies on Mediterranean Sea. This study provides updated information on the presence and levels of contaminants in zooplankton from the Tyrrhenian Sea. Although banned, PCBs and DDT are still present but their contamination appears to be declining locally. Zooplankton accumulates high levels of certain TEs such as Zn and Pb, but intermediate levels of other TEs such as Cd and Hg, indicating a general improvement.