Disease and Parasite Transfer

Sea Lice on pink salmon fry

Farming systems that release untreated discharge directly into the marine ecosystem, such as ocean open net pens and coastal shrimp ponds, cannot effectively prevent the transfer of diseases and parasites to wild stocks.

Small Space + Many Fish = Potential Epidemic

Similar to a child that goes to school with a cold, within a confined space and many potential carriers (e.g. class mates), that cold can quickly spread and become a potential epidemic for the class. Similarly, crowded pens of fish are inevitably vulnerable to disease and parasite epidemics.

Lethal impacts on wild fish are well documented and this is of particular concern when the health of affected wild fish is already poor. But the concerns don’t stop there – increasingly toxic pesticides and antibiotics are being used to control diseases and parasites and are directly entering the marine environment and negatively impacting local sea life.

  • Avoid open-net farmed salmon. Choose closed containment (U.S.) farmed salmon instead.
  • Avoid pond farmed shrimp. Choose closed containment (U.S.) farmed shrimp instead.
  • Choose closed containment farmed finfish: Arctic char, rainbow trout, barramundi (U.S.), tilapia (U.S.) and salmon (Canada, U.S.).
  • Search for sustainable seafood.
A Closed Case Unlike open-net pens, closed containment farms eliminate the risk of parasites and disease transfer to wild fish. Many “Best Choice” farmed options are farmed in land-based closed containment, including Arctic char, rainbow trout and U.S. catfish. In fact, salmon can be farmed sustainably by using closed containment recirculating technology, eliminating unnecessary risks to wild salmon populations.