Temporal trends of PCBs in feed and dietary influence in farmed rainbow trout (Oncorhynchus mykiss)

As a rainbow trout producer, Italy is accounted as fifth in the world and second in continental Europe. In this study, the levels of the eighteen PCBs in feed and in trout, showed a statistical significant difference (p < 0.01) throughout the years, with a declining trend from 2005 to 2010. This trend shows effectively that quality and safety of trout feeds has greatly improved during the last years and, as a consequence, also the PCBs values in muscle trout, showed a decreasing trend. Moreover, feed Sigma 18PCBs showed a statistical significant difference (p < 0.01) among the analysed brands and was positively correlated (p < 0.01 and r = 0.451) with the rainbow trout muscle Sigma 18PCBs. These results showed that the presence of PCBs in trout muscle is directly linked to the chemical quality of aquaculture feed. The most commonly detected PCBs congeners were congeners PCB 153 and PCB 138 in all the three compared brands. (C) 2013 Elsevier Ltd. All rights reserved.