Infectious salmon anaemia disease

Infectious salmon anaemia virus

This fish 'flu' is deadly. It can kill up to 90% of the Atlantic salmon it infects. Other species can be carriers of the disease.

About infectious salmon anaemia virus

The virus is part of the influenza family of viruses. It can be carried in Atlantic salmon, rainbow trout, and sea trout. Only Atlantic salmon are known to develop the disease. In severe cases, it can kill up to 90% of farmed Atlantic salmon over 3 months.

Currently the virus is in the major Atlantic salmon growing areas. It's found in Norway, Canada, USA, Chile, UK, and the Faroe Islands.

Why this is a problem for New Zealand

This disease has severely reduced Atlantic salmon aquaculture production. The main species of salmon farmed in New Zealand is Chinook salmon. Although evidence of the disease's effect on Chinook salmon is limited, we don't want to have to find out the hard way.

As with many viral diseases of fish, there is no specific treatment or cure. Once established, aquatic diseases are extremely difficult to eradicate.

How it could get here

The virus could come to New Zealand through:

  • infected live or dead finfish
  • contaminated equipment (for example, on vessels, nets, and containers)
  • contaminated water.

Biosecurity New Zealand has strict measures in place to limit the chances of the virus making it through the border.

Where will I find it?

An outbreak is most likely in farmed fish in the marine environment.

How to identify it

Diagnosing fish diseases requires laboratory testing. Signs of fish diseases are difficult to tell apart.

In a fish farm, watch for salmon or trout that are:

  • congregating and gasping near the surface
  • lethargic
  • not eating
  • progressively dying.

If you find signs of infectious salmon anaemia

  • photograph it
  • take a sample (put a fish in a plastic bag and refrigerate)
  • take note of the location and any landmarks
  • call 0800 80 99 66

Note: This information is a summary of this disease's global distribution and potential impacts on New Zealand. 

Last reviewed: