The Environment Agency has instructed the owners of six still water fisheries in the south, east and midlands of England to cease all fish movements following confirmed cases of Koi Herpesvirus (KHV).

Koi Herpesvirus (KHV) was confirmed at these fisheries after the owners reported significant fish losses.

Environment Agency fish movements advisor Paul Lidgett said: “At this stage the Environment Agency will not be releasing the name of any fishery being tested for KHV, as the last thing we want to do is deter fishery owners from coming forward if they suspect an outbreak in their waters.

“We recognise that anglers may be concerned about spreading the disease inadvertently. However, the likelihood of KHV being transferred between fisheries by anglers nets is negligible when compared to the threat via fish transfer, so stopping all fish movements at the infected sites is the best way of preventing the virus spreading further.”

Although the risk from wet fishing tackle is very low, the Environment Agency is still encouraging fishery owners to adopt basic dis-infection measures to protect themselves against KHV and any other fish diseases.

In addition to the six confirmed cases of KHV, fish mortalities at five other fisheries have symptoms consistent with the KHV. Samples have been taken and laboratory results are expected this week.

While the Environment Agency has no power to close infected fisheries, they have advised fishery owners to impose their own biosecurity measures and to temporarily cease angling.

The Environment Agency considers Koi Herpesvirus to be a very significant threat to carp fisheries in England and Wales, though it is not uncommon to get a number of KHV outbreaks each year.

In fact, 16 cases of Koi Herpesvirus infection have been reported in UK fisheries since the disease was first detected in the wild in England and Wales in 2002. The virus develops clinical symptoms in infected fish when water temperatures are between 18°C and 28°C.

The Environment Agency is working with the affected fisheries to help them recover from the impact of the disease by providing advice on restocking and dis-infection. With the right fishery management there is no reason why these waters cannot recover from the current impact.

Paul Lidgett continued: “Koi Herpesvirus is not currently a notifiable disease under the EU Fish Health regime. This means there is no legal duty to report infections to Department of Environment, Food and Rural Affairs (Defra) and the Centre for Environment, Fisheries and Agriculture Science (Cefas), on Defra’s behalf, have no powers to impose movements orders themselves. Any controls are based entirely on Section 30 administered by the Environment Agency.

“However a new EU Fish Health Directive expected in September this year should change this, making KHV a notifiable disease. We welcome this as it would give Cefas powers to investigate KHV mortalities and to trace the source of the outbreak. It would also place a legal duty on fishery owners to report suspected KHV mortalities on their sites.”