Lesions on the gills of an Atlantic salmon with infectious salmon anemia.
On Dec. 13, 2001, the Department of Agriculture approved emergency status for infectious salmon anemia, a foreign animal disease caused by an orthomyxovirus. This is the first time the USDA has given emergency status to an aquatic animal disease.
The Secretary of Agriculture summed up the situation, saying that the disease poses a potentially serious threat to animal health and the U.S economy, but that the virus can be controlled and contained through surveillance, vaccination, and best management practices.
As of early January, researchers had identified the disease on 15 fish farms, all located in Cobscook Bay in eastern Maine. Although these facilities are all salmon farms, scientists believe that sea run brown trout, rainbow trout, and other wild fish such as herring could also carry the virus.
The declaration of the disease as an emergency provides additional funds to establish an ISA control program. The money is being used for diagnostic support, surveillance, epidemiologic studies, depopulation and disposal, clean-up and disinfection, indemnification, and training for producers and veterinarians. The USDA hopes these measures will reduce the spread of ISA and save the federal government and the salmon industry from a more costly, widespread problem.
"The presence of the USDA is really going to mean a lot for the control of this disease. They have done an excellent job of laying the groundwork and getting everything squared away, and we are in the process of depopulating the sites up here [Cobscook Bay] already," commented Dr. Paul Waterstrat in early January. Dr. Waterstrat is a veterinarian with the Maine Department of Marine Resources.
ISA is transmitted via direct contact with parts of infected fish, contaminated equipment, people who handle infected fish, and sea lice. Mortality varies, ranging from three percent to more than 50 percent over one production cycle. All fish that have been exposed to the virus are being destroyed.
"Most of the fish that are exposed are not necessarily diseased, but the risk due to the exposure is what we are trying to eliminate," Dr. Waterstrat said. "Carrying out the logistics to make sure this is done right is a pretty daunting task, and they [the USDA] are doing an excellent job."
Some individuals in the aquaculture field are merely pleased by the fact the USDA is making funds available to control an aquatic animal disease. "For too long, aquaculture farmers have had to 'bite the bullet', de-populate, and restock with their own funds, while farmers who grow fruits, vegetables, cattle, and poultry are given federal assistance when disease or storms wipe out their crops," commented Dee Montgomery-Brock, an aquatic health specialist at Hawaii's Department of Agriculture. "Hopefully, this is a sign of better things to come, for growers of fish, crustaceans, etc."