Infectious Salmon Anemia is a lethal viral infection that kills salmon. It was developed by the Norwegian fish farm companies in the early 1980s. The freshwater ISA virus, a non-lethal version, mutated with the contact of wild Atlantic salmon and farmed Atlantic salmon in Norway.
ISA has plagued in-ocean, open-containment fish farms everywhere they have spread. It has spread from Norway to Scotland, Ireland, the Faroe Islands, Canada (NB, then NS, then PEI), the USA (Maine) and Chile. Norway has never been free of ISA since the fish farms developed the lethal strain in 1984.
Read this article and note the world map of where this Norwegian disease has spread: http://www.thefishsite.com/articles/598/the-global-spread-of-infectious-salmon-anaemia.
This article was written in 2009, so it does not have the full cost of the Chilean fish farm collapse. The Norwegian derivative fish farms, for example, Cermaq/Mainstream reportedly lost $323 million, while Marine Harvest lost 1.4 billion Euros.
63 workers were killed in Chile, and 13,000 were let go when the 500 fish farms (there were 800) had to have their fish slaughtered. At the conservative estimate of 500,000 Atlantic salmon per farm, that means 250 million, or a quarter of a billion dead fish. This is only one fish farm disease.
As ISA was only an Atlantic Ocean disease, Chile is the site of the first Pacific Ocean infection. It was brought there by the Norwegian derivative fish farm companies.
Aquagen the company that vertically transmitted ISA to Chile, took the report writers to the commission in Norway that deals with fraudulent science. Their ruling was that with a few caveats, that the reserchers were not faudulent.
This is the ruling: http://www.aqua.cl/files3/918b93_ISA%20ethics%20investigation%20Apr%202011_EN.pdf.