Most current bio-security measures—including those designed to protect fisheries and aquaculture from disease and invasive species—are only educational and voluntary. For example, recreational boaters are encouraged to drain and clean and dry their boats before moving from area to another, but boat launch stewards are seldom employed.
States rarely have the resources or authority to control commercial activity. For example, in Tasmania, Australia, in October, Coles supermarkets sold imported raw salmon, despite this being illegal in the state. Tasmania has Chinook salmon farms and is eager to avoid introducing diseases through discards of foreign uncooked salmon. However, as Tasmania does not control imports (a national responsibility), it can only respond to reports by consumers.
Opposing realities—that many violations pose only marginal risk, and that perfect security can never be achieved—tend to foster a sense of futility. The word “biosecurity” may be partly to blame for this attitude, since absolute security cannot be achieved. “Bio-risk reduction measures” would be more accurate.
Are stricter controls worth the cost and effort? This is a hard question to answer, since it is impossible to prove a negative. If a bay or waterway was not infected or invaded, we can rarely say with confidence that it was because of a specific measure that was taken. But we can say that containment and preventive measures against known risks pale in comparison with the economic damage of failure.
For example, in September, Norway Royal Salmon detected infectious salmon anemia at one aquaculture site, with suspicion that another may also be affected—possibly due to introduction of infected smolt. The cost to the company for replacement of stock was estimated at USD 2.41 million (EUR 2.21 million).
Consider the national-scale costs of another salmonid disease, whirling disease, caused by a parasite affecting trout, and spread in the US partly through in importation from Europe and subsequent hatchery infections. The cost to states due to severe trout mortality was over USD 300 million (EUR 276 million).
In Japan, where I live, freshwater ecosystems here are under threat from bass and bluegill. A few years ago, I went fishing with my son at a reservoir near Kobe and got strike after strike of bass and bluegill, but not a single native fish, and this is now common across the country. Black bass initially entered Japan in 1925 via Lake Ashinoko in Kanagawa Prefecture, where they were introduced by a recreational fishing business and were spread in the post-war years to every prefecture by sportsmen. The first bluegill in Japan were given by Mayor Daley of Chicago to Emperor Akihito when he was Crown Prince in 1960. They were introduced into Japan’s largest lake—Lake Biwa—as a possible food resource, and were then spread by sportsmen. A law prohibiting such introductions, the Invasive Alien Species Act, was finally passed in 2004. However, at this late stage eradication is considered impossible.
The list of new threats to aquaculture is long: the topmouth gudgeon, a small freshwater fish from China, carries a deadly parasite that would threaten many important species in North America. Pacific Mortality Syndrome currently threatens an Australian oyster industry worth USD 83 million per year and has the risk of spreading abroad. The numbers indicate that applying a strong “precautionary principle,” at an early stage is worth the cost.
