Salmonid Alphavirus is a virus that primarily affects fish, particularly species in the Salmonidae family, such as salmon and trout. It is known to cause infectious salmon anemia (ISA), a serious disease that can lead to significant mortality in affected fish populations. The virus is typically transmitted through direct contact or contaminated water. The presence of Salmonid Alphavirus can have severe economic impacts on the aquaculture industry, as outbreaks can lead to substantial losses in fish stocks. Control measures often include vaccination, biosecurity practices, and monitoring to prevent the spread of the virus in fish farms and natural water bodies.