Global Disease

West Coast of Canada

Sea lice are a big issue for salmon farmers on the West Coast. When a wild salmon enters fresh water to spawn, the lice typically fall off and die. Because farmed salmon are cooped up in cages for the spawning stage of their lives, the lice often stay with the fish. Also, Pacific species have lived with consistent background levels of sea lice for centuries, so they have developed a natural tolerance to the parasite. Atlantic salmon, however, are more susceptible to sea lice in the Pacific, so farmers with Atlantic salmon have to be very diligent in their monitoring of and response to sea lice in their farms. In general, farmed salmon carry lower levels of sea lice than wild adult salmon, since lice levels are carefully controlled by farmers. However, scientists believe that farmed salmon can or do spread their sea lice to Pacific salmon.

Uzbekistan

Fish farming in Uzbekistan is very different from farming in BC or Norway, because Uzbekistan is a landlocked country. This means that all aquaculture must be inland. Since the Aral Sea is drying up, there are major problems with salt levels and toxins. As a result some fish stocks have been annihilated. Of the 20 known fish species there, all are now virtually extinct. The upside to this is that there's no worry of fish farms harming wild stocks, since the wild stocks are rapidly vanishing.

China

China has some fish farming problems because of poor regulations and policies. Because the industry is not regulated well many farms suffers health issues from viral, bacterial, fungal and parasitic infections. Attempts to increase fish production from ponds is struggling because of a lack of fish feed and pond maintenance.

Norway

A parasite known as Gyrodactylus Salaris Monogenea is having a catastrophic effect on young salmon. It was introduced through Swedish salmon breeders. The parasite has almost emptied some rivers of young salmonids. Atlantic salmon imported to this area lose their freshwater parasites, but just acquire new ones from the sea. Sea lice are a problem here as well: where there are Atlantic salmon farms, lice infection amongst wild fish has found to be ten times greater than areas free of farms.