Cadmium flux and genotoxicity in an experimental marine food chain

Cadmium flux through a lab food chain (Phaeodactylum tricornutum Bohlin-Penaeus orientalis Kishinouye-Hexagrammos otakii Jordan et Starks) and its genotoxicity were investigated. The results are as follows:

1. High doses of cadmium (>0.003 mol/L) induced flocculation and quick precipitation ofPhaeodactylum tricornutum; lower doses of cadmium could be adsorbed on and absorbed byP. tricornutum without delaying its growth. Cadmium concentrations in algae increased with dosage, and cadmium ions removed from the medium were in proportion to dosage. In vivo chelation and organizable combination of absorbed cadmium ions by metabolites ofP. tricornutum can be considered as bio-detoxification.
2. Cadmium concentration decreased in the transfers fromP. tricornutum toP. orientalis and from the latter toH. otakii. Transfer coefficient of cadmium in the first flux was 66.6% and 29.9% in the second. Results of t tests showed that mutagenicity of ashed internal organs of experimental prawns was significantly higher than that of ashed muscles, and also significantly higher than that of ashed internal organs of the controls (P<0.01).