In situ heavy metals (copper, lead and cadmium) in different plankton compartments and suspended particulate matter in two coupled Mediterranean coastal ecosystems (Toulon Bay, France)

We monitored the concentrations of copper, lead and cadmium in seawater, in suspended particulate matter (SPM) and in bacteria, phyto- and zooplankton communities separated from abiogenic particles, over a one year cycle in two coupled Mediterranean coastal ecosystems (Little Bay (LiB) and Large Bay (LaB)). Metals were present in seawater in the order Cu > Pb > Cd in both bays and showed important variations within the same month than among months. In LiB, their concentrations were between 0.62 and 2.82 μg Cu l−1, 0.16 and 19 μg Pb l−1 and 0.007 and 0.14 μg Cd l−1, respectively, whereas in LaB, they were between 0.23 and 2.11 μg Cu l−1, 0.09 and 0.76 μg Pb l−1 and not detected and 0.65 μg Cd l−1. SPM play an important role on metal adsorption, especially for copper. Bioaccumulation factors showed that bacteria and phytoplankton accumulate metals whereas zooplankton tends to biodiminish them in the plankton food web.