Report on a Survey of Chemical Residues in Domestic and Imported Aquacultured Fish

A national survey conducted under the Coordinated Food Survey Plan with participation by food regulatory agencies in all Australian States and Territories

November 2005

Executive Summary

Food Standards Australia New Zealand (FSANZ) was the lead agency for a national coordinated survey of Chemical Residues in Aquacultured Fish. The survey’s aim was to determine if residues of antimicrobials and other substances are present in both local and imported aquaculture product.   Prior to the survey there had been reports from overseas regulators of unapproved antimicrobials being found in aquacultured fish.

All Australian States and Territories participated in this national survey and a total of 60 samples of local and imported aquacultured finfish were sampled from across Australia. Samples were collected from late April until early June 2005.

The analysis of samples has been completed for a range of over 50 substances and their metabolites including; nitrofurans, chloramphenicol, sulphonamides, tetracyclines, malachite green, penicillins, macrolides, trimethoprim, quinolones and PCBs.

Overall, the results were very good with no detections for 54 of the 56 chemicals tested for.   However, trace levels of malachite green and leucomalachite green were detected in 10 samples; 3 fish grown in Australia and 7 Basa fish samples imported from Vietnam. The residues were at low levels ie all less than 0.14 mg/kg. The 3 positives out of 14 (21%) in domestically farmed fish were 1 Rainbow Trout sample produced in NSW and 2 Silver Perch samples produced in NSW and WA. The 7 positives out of 46 (15%) in imported fish were all Basa from Vietnam, which equates to a 39% non-compliance rate from this country.

In accordance with the agreed protocol for national surveys, the results from the survey were discussed at the Food Surveillance Network (the Network) meeting on 2 August 2005 where a number of actions were agreed by jurisdictions.

This coordinated national survey identified a compliance issue with the presence of malachite / leucomalachite green being detected in both domestic and imported fish.   The findings do not appear to raise public health and safety concerns and are being managed in an appropriate and timely manner.