BACKGROUND:

Diets used in commercial fish farming use significant proportions of crop derived commodities and it is important to understand the potential for transfer of any pesticide residues on the crop into edible tissues in fish. It is a current requirement in the EU that fish metabolism studies must be performed when a pesticide is used in crops where commodities or processed fractions are fed to farmed fish. Fish metabolism studies in both rainbow trout and common carp have been carried out, following the new working document on nature of pesticed residues in fish using 14 C labelled pesticide.

 

RESULTS:

The ingestion of the experimental diets by rainbow trout and common carp resulted in the uptake and metabolism of the test item as shown by liquid scintillation counting (LSC) analysis in combination with radio-TLC analysis. Species specific differences in the chromatographic profile of pesticide metabolites were observed regarding the proportional distribution of metabolites rather than their general pattern.

 

CONCLUSIONS:

Metabolism studies for regulatory purposes can be carried out with both fish species under laboratory conditions. The experimental design reported is suitable to quantify the transfer of residues to edible tissues and to enable characterisation of the chemical nature of residues.