A national survey conducted under the Coordinated Food Survey Plan with participation by food regulatory agencies in all Australian states and territories
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.
- Jurisdictions (home states) with positive samples discussed their follow up actions to ensure as consistent an approach as possible. In those states or territories where malachite green residues were detected in domestically farmed fish, further investigations have been conducted to determine the scope of malachite green use in the industry, including taking additional samples.
- Full sampling details were provided to the Australian Quarantine and Inspection Service (AQIS) who provided advice back to the Network on regulatory options at the border. As of 26 September 2005, AQIS initiated random testing for malachite green in imported aquacultured fish.
- FSANZ prepared a risk assessment incorporating a dietary exposure assessment and toxicology assessment. The risk assessment conducted by FSANZ concluded that the public health risk associated with low residues of malachite green chloride and leucomalachite green in aquacultured fish is very low.
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.