Koi Herpes Virus (KHV) - PLEASE READ

Please take the time to read the following notes on KHV and familiarise yourself with the symptoms and what to look out for. If you have any doubts at all report your suspicions to the environment agency. Please disinfect your nets, weigh-sling, matt's and sacks and then dry them out completely.

Don't take chances, this disease will decimate any lake it gets into

Incident hotline 0800 807060 (Freephone, 24 hour service)

www.environment-agency.gov.uk

The Fish Health Inspectorate can be contacted at:

FHI, Cefas, Barrack Road, The Nothe, Weymouth , Dorset DT4 8UB.

Tel: 01305 206673/4/9; Fax: 01305 206602;

Email: fish.health.inspectorate@cefas.co.uk

Guidance Notes

Koi Herpes Virus (KHV) is a highly contagious, viral disease which may cause significant fish kills in koi, ghost koi and common carp. Historically, the first outbreak of KHV was reported in 1998, since when it has been found in the United States , Europe and Asia . In England there have been more than 60 confirmed outbreaks since 2003, peaking at 23 cases during the hot summer of 2006. There is no known cure for KHV. KHV can cause partial or complete fish mortalities, and fish are most susceptible at water temperatures of 15-28°C. Outside this temperature range the disease can remain inactive and latent. KHV is believed to remain in infected fish for life, and all exposed or recovered fish should be considered as potential carriers of the virus. KHV is now a notifiable disease, and it is a legal requirement that outbreaks, or suspected outbreaks, be reported to the Fish Health Inspectorate at the Centre for Environment, Fisheries & Aqua culture Science (Cefas).

Symptoms

Clinical signs of KHV are often non-specific. Affected fish may exhibit severe gill lesions, with distinct red and white patches, bleeding gills, sunken eyes and pale patches or blisters on the skin. In some cases, secondary bacterial and parasitic infections may be the most obvious problem. Behaviorally, affected fish often remain near the surface, swim lethargically, and may exhibit respiratory distress and uncoordinated swimming.

Means of Infection

KHV is spread by direct contact between fish, with fluids from infected fish, or with water or mud from infected systems. It is also likely that the virus can live for a short period in water, fish slime and even fish faeces. There is circumstantial evidence - but no scientific proof - that anglers' nets, water birds and aquatic mammals could spread it between fisheries.

Prevention

Fish Stocking

By far the most important precaution fishery owners can take against KHV is to either not introduce additional carp or to be scrupulous about the source of any stocked fish. If stocking is essential, it is preferable to use farm-reared fish of known parentage, age, history and health status. Legally, all fish introductions must be consented by the Environment Agency. At existing fisheries sites, consideration should be given to creating, developing and managing stock-rearing ponds to provide indigenous stocks of carp suitable to transfer to the fishing lakes, if necessary.

Bio security

Good bio security is also important, with enforced prohibition on the unauthorised transfer of fish onto (and from) a fishery site. This includes pet fish which have outgrown bowls, tanks and garden ponds, as well as compassionate transfers of ornamental fish which may be 'rescued' from ponds due to be in filled or abandoned (e.g. when the owner moves house or dies).

Drying

A precautionary approach should also be taken regarding anglers' keep nets, landing nets and ancillary equipment (unhooking mats, carp sacks and weighing bags). To ensure that this kit cannot accidentally transfer KHV, equipment should be dried thoroughly in full sunlight for at least 48 hours.

Net Dips

At many recreational fisheries it will be impossible to be certain that all nets have been dried completely. Here, fishery rules should be instigated to require all anglers to immerse their nets and ancillary equipment in disinfectant dips, primarily Iodine-based preparations (iodophors) or Virkon S. Equipment should first be cleaned of all mud and debris before it is immersed in a dilute solution of the chosen disinfectant. An immersion time of at least 15 minutes is required, although this should ideally be as long as 30 minutes. The disinfectant should then be rinsed off with clean water in a separate rinse tank. Exhausted disinfectant and disinfectant washings must be disposed of in a way that does not harm the environment and not into surface drains. The manufacturer's guidelines should be followed. Suitable disinfectant products include Iosan CCT, Deosan Iodophor Udderwash, Tegudine and FAM 30. When active, iodophors are dark brown solutions which turn colourless when inactivated by prolonged exposure to light. Dilution of iodophors varies between products, and the manufacturer's guidelines should always be adhered to. Most good agricultural suppliers will have appropriate disinfectants available.

Dip tanks should be located close to the main access point for anglers - by the car park or reception building, for example. Here, prominent notices should be erected to inform anglers that they must dip their keep nets, landing nets and ancillary equipment prior to fishing, and then rinse them in the separate, clean water rinse tank. Suitable tanks include plastic, central heating header tanks, cattle watering tanks, plastic dustbins and 'Wheelybins'.

The disinfectant dip and rinse water should be replaced periodically. To prevent the risk of vandals overturning the tanks, where this is a possibility, it is suggested that they are part-buried or locked into position (to a stout post, perhaps). The dip tank should be fitted with a lid to prevent dilution by rainwater and degradation by sunlight.

Net Provision

Alternatively, some fisheries may insist that anglers only use nets supplied by the fishery itself. This measure is most successful where it is easy to dispense and recover nets, which should be clearly labelled to reduce the risk of theft or accidental retention by anglers. Some owners supply nets for matches only, dispensing them before each match and collecting them from competitors at the weigh-in, whereafter they are disinfected, dried and stored for future use.

Finally.

KHV infections can have serious implications on recreational coarse fisheries, and it is far better to take precautionary, preventative measures than to cope with the disease should an outbreak take place. Nevertheless, most fisheries have not been affected, and Government agencies and fisheries representatives are developing strategies to minimise the likelihood that that further KHV incidents will occur.

Further Information

Emergency Hotline

Suspected outbreaks of KHV should be reported immediately to the Environment Agency 24-hour emergency freephone on: 0800 807060

Cefas

The Fish Health Inspectorate can be contacted at:

FHI, Cefas, Barrack Road, The Nothe, Weymouth , Dorset DT4 8UB.

Tel: 01305 206673/4/9; Fax: 01305 206602;

Email: fish.health.inspectorate@cefas.co.uk

Cefas leaflets which provide further information on KHV and the means of preventing it include:-

•  Koi Herpesvirus Disease (KHV)

•  A Guide to the Disinfection of Angling Equipment

They are available from Cefas (above) or, electronically, at: www.efishbusiness.co.uk

Dip Chemicals

The chemicals can be obtained from larger suppliers of agricultural equipment and chemicals.