The concentrations of Cu, Zn, Pb and Cd in the natural marine
ecosystem (including in seawater, sediment, coral reef, phytoplankton,
macrophyte, shrimp, crab, shellfish, planktivorous and
carnivorous fish) and the mariculture ecosystem (including in
farmed fish and fish feed) of Daya Bay in South China were in the
low-middle ranges of the global values. Pb and Zn levels were
markedly higher in phytoplankton than in macrophytes. This was
probably caused by the larger specific surface area in phytoplankton.
Meanwhile, Cu and Cd levels were slightly lower in
phytoplankton than in macrophytes, indicating that metal has its
unique strategy to be bio-concentrated in algae. The highest
levels of Zn, Pb and Cd among wild organism were all found in
clam, indicating that metals were apt to bioaccumulate in shellfish.
The concentrations of targeted metals except for Pb in the
marine wild fish muscle tissue were significantly higher than
those in the marine farmed fish muscle. Heavy metals BCFs, BAFs
and TFs in organism were calculated and discussed. Obvious
positive correlation between biologically essential metals (Cu and
Zn) concentrations and lipid contents both in snapper and pompano
were observed. Farmed fish has specially high levels of Pb,
due to high transfer factor and attention should be paid to
regulate fish feed production.