Isolate and acclimatise

Newly arrived fish need to be kept separate from existing stock for a period of time whenever possible. Quarantine in itself does nor always relate to a specific time period, for example if trying to secure against KHV then temperature paramenters would be used to assess the risk. If the new stock of fish are carrying pathogens then varying the temperature will help, along with appropriate treatments, prevent the tranfer to existing stock.

Work ‘clean to dirty’

Work routines should always start with the species and groups regarded as cleanest stock. Newly arrived fish need to be treated with caution to ensure diseases are not transferred to or from them. Fish which require disease treatment should always be delt with last, working in this order reduces the risk of pathogen transfer to ‘clean’ fish.

Seperation

Each pond on a fishery should, as far as is possible be allocated separate equipment. This seperation needs to be strictly adheared to espescially in isolation areas. If the fishery can as far as possible keep their own equipment for use on specific ponds this significantly reduces the risk of introducing pathogens into the lake or pond.

Steralising and disinfecting equipment

Nets and other equipment can carry pathogens between ponds or lakes and as such act as disease vectors. Either equipment should be allocated to specific ponds/lakes or disinfected if is to be moved around the site. This also applies to staff and hands and boots should be thoroughly washed between different locations of the site

Water management

Where possible systems within the fishery should be kept closed and water quality should be checked regularly at various points around the site. Where this is not possible or the fishery is ‘on-line’ then there needs to be a regular monitoring program of water quality at the inlet. As far as is possible fish migration should be discouraged and measures put in place to stop unknown species entering the fishery.

This can be achieved by placing fine grills over the inlet, the other option is to take the fishery off-line by diverting the channel. This is a more secure option and should be considered as the ‘best practice’ approach when safe guarding the fishery. Flood mitigation measures should be in place, this can be as simple as providing habitat to avoid fish wash out in potential flood events.

Stocking of ponds

Over stocked ponds increase the risk of disease in a number of ways. Fish stress levels rise due to competition and where fish health levels fall disease has a higher likelihood of spreading. Stocking levels should be carefully monitored to ensure the system is as balanced as possible.

Monitoring

Monitoring measures are essential to the success of any bio-security risk assessment program and as such must be fully integrated into the plan. It is recommended that monitoring of water quality and fish health should be undertaken on a weekly basis to ensure the security of the fishery.

Where fish are being introduced into the fishery the processes outlined above must be adhered to and new stocks must be monitored before they are introduced into the general fish population. The monitoring of health and safety and cleaning procedures must also be carried out stringently with records kept and where applicable further training should be carried out.