NZFFA Commentary
When most New Zealanders hear the word biosecurity, they probably think of foot-and-mouth disease or, more recently, H5N1 avian influenza. Yet some of the greatest biosecurity threats facing our freshwater fisheries receive very little public attention. While anglers focus on river conditions, spawning runs and fish numbers, there are viral diseases overseas capable of devastating trout and salmon populations if they were ever to reach New Zealand.
Fortunately, New Zealand remains free of several of the world’s most serious salmonid diseases, including Viral Haemorrhagic Septicaemia (VHS), Infectious Haematopoietic Necrosis (IHN) and Infectious Salmon Anaemia (ISA). These viruses have caused severe losses in overseas fisheries and aquaculture, sometimes resulting in the destruction of entire fish stocks and long-term movement restrictions.
The encouraging news is that these diseases are not spread by casual contact alone. Strong border controls, careful management of imported fish products, surveillance and strict hatchery biosecurity have helped keep New Zealand free of these pathogens. This is one area where prevention is unquestionably better than cure.
For anglers, the implications are significant. A major disease outbreak could affect much more than commercial salmon farming. Wild trout fisheries, hatcheries, fish transfers and spawning programmes could all be disrupted. Rivers might remain open, but stocking programmes, fish movements and even organised angling events could face restrictions while authorities attempted to contain an outbreak.
None of this should cause alarm. Rather, it serves as a reminder that protecting our fisheries involves far more than managing fish numbers or regulating harvest. Healthy fisheries depend upon healthy ecosystems, responsible anglers and effective biosecurity.
There are practical steps every angler can support. Clean and dry boats, nets and waders before moving between waterways. Never transfer live fish between catchments. Respect hatchery biosecurity requirements. Report unusual fish deaths or signs of disease to the appropriate authorities. These simple measures reduce the risk of spreading both exotic diseases and established aquatic pests.
New Zealand enjoys some of the finest trout and salmon fisheries in the world. That reputation has not occurred by accident. It has been built through careful management, healthy waterways and an enviable disease-free status. Protecting that status is in the interests of every angler.
Most of the time, the greatest success of biosecurity is invisible. We continue to enjoy healthy fisheries because many of the world’s most damaging fish diseases have never reached our shores. Keeping it that way is one of the best investments we can make in the future of recreational fishing.
