SURVEILLANCE of pharmaceutical use on Norwegian fish farms has shown no negative impacts on seafood safety.

The analysis by the Norwegian Institute of Public Health on farmed fish in 2009 did not reveal any residues of illegally used pharmaceuticals, or levels of legally used pharmaceuticals above the set limits.

The statistics show a small increase in the use of pharmaceuticals against bacterial infections, while the amount of agents used for fungal infections and internal parasites decreased slightly, compared to the previous year.

The statistics also revealed an increase is in the use of de-licing agents, with the amount used in 2009 coming to more than 5 tonnes (calculated as active component). Of the delousing agents, azametifos, diflubenzuron and teflubenzuron were used in the largest amounts. In addition, hydrogen peroxide is used to remove fish lice. All substances are approved for use in farming.    

The research organisation, NIFES analysed around 9000 fish samples for a variety of different substances. For de-licing agents, 725 fish were analysed and 145 fish were examined for residues of diflubenzuron and teflubenzuron. The surveillance did not reveal any use of illegal substances or residues of legally used substances above the internationally set limits.  Therefore, the use of pharmaceuticals for farmed fish did not affect seafood safety, even though the use of some pharmaceuticals was higher in 2009 than in 2008 .

Norway has a surveillance system according to international legislation, initiated in accordance with the EU-directive 96/23 for the surveillance of foods of animal origin, including farmed fish. The system includes registration of prescriptions for pharmaceuticals used for animals, establishing withdrawal periods to ensure that fish are only slaughtered after a preset time after medication and analytical examination of fish for residues of pharmaceuticals. The number of samples which should be analysed is determined by the production volume of farmed fish as well as the use of pharmaceuticals. The Norwegian Food Safety Authority is responsible for implementing the directive in Norway and NIFES performs the chemical analyses and risk assessment. The system is monitored on a regular basis by the  EFTA Surveillance Authority (ESA). The results from the surveillance programme is published in publicly available reports on www.nifes.no.