Fish Production

The intensification of fish production provides an ideal environment in which disease-causing organisms can flourish and cause serious damage to productivity. Disease may come from any number of sources, for example, viruses and bacteria. However it originates; it spreads through recognised vectors of infection. These include fish stocks, staff and visitors, equipment, vehicles and transportation, other aquatic life, birds and animals, the aquatic environment and even the air itself.

Medication and vaccination have traditionally played a major role in treating diseases but it is now widely accepted that they cannot, in isolation, prevent losses due to disease. Modern farming demands a holistic approach. Unless the background challenge from disease-causing organisms can be controlled, and good management practices strictly followed, medication and vaccination alone are not capable of adequately protecting fish stocks.

Fish must be given an environment in which the level of infection is controlled to the point where vaccination and medication can achieve beneficial effects. Biosecurity is the key to achieving this.

Biosecurity involves the exclusion of disease-causing organisms from the environment. This is particularly important in fish production. It is achieved by the use of external and internal biosecurity barriers:

External Barriers – blocking the spread of disease onto and off of a fish farm

Internal Barriers – blocking the spread of disease within the fish farm

The correct use and selection of disinfectants is very important and ensures that pathogen challenge is minimised, maximising the fish’s natural defence against infection.

PROVEN EFFICACY

Not all disinfectants are effective against the wide range of viral and bacterial disease-causing organisms that affect fish production. Even disinfectants with similar chemistry can have widely different spectra of activity and effective dilution rates. Selecting a disinfectant is therefore very important. The disinfectant must have independently proven efficacy against a wide range of aquaculture pathogens and be effective at low temperatures.

LANXESS biosecurity products and procedures have been developed to maximise the benefits achievable through good cleaning and disinfection biosecurity practices. The procedures have been developed to be consistent with HACCP principles, the seven point systematic approach to food safety adopted by livestock producers around the world.

HACCP (Hazard Analysis Critical Control Points) strategies identify the areas where pathogens may enter the system, ways to eliminate them, and the methods to show that the chain of production is being continuously audited to ensure that every procedure within that chain is effective.

THE PRINCIPLES

Principle 1. Hazard analysis

To identify hazards, both microbiological and physical, at each step in the process through to delivery.

Principle 2. Critical Control Points (CCPs)

At CCPs action can be taken to reduce or eliminate the hazard. For example, within the fish farm, there are control points at which pathogen reduction can take place as part of a biosecurity programme.

Principle 3. Critical limits

Establish acceptable limits for each hazard identified.  Cleaning and disinfection in accordance with LANXESS biosecurity procedures will ensure that microbiological hazards meet those limits. LANXESS technical team can advise in more detail in this important area.

Principle 4. Monitoring

Observation and measurement of cleaning and disinfecting to ensure the critical limits are met at each step.

Principle 5. Correction

Action must be taken if the critical limits are not met at each step. A review of the application procedure should be made to ensure that it is in accordance with LANXESS biosecurity guidelines.

Principle 6. Recording

A complete set of records is important for legal action and may form part of a current site Quality Scheme e.g. ISO 9001. Records must be kept to show that biosecurity procedures are in place and are being implemented correctly. Records should be kept of products used, critical limits, cleaning schedules and any corrective action taken.

Principle 7. Verification

Tests and procedures to ensure that the HACCP system is working properly. The audit is often external and may include verification of dilution rates, application rates and bacteriological tests.

Biosecurity plays an important part throughout every stage of the life cycle of a fish, from hatching through to processing. Thorough cleaning is an essential precursor to any effective disinfection process to maximise the benefits of Virkon^® AQUATIC, the complementary Biosolve^® E heavy-duty cleaner should be used. The following table indicates the specific key biosecurity tasks which will have the greatest impact on controlling the spread of disease, see below for Biosolve^® E & Virkon^® AQUATIC application rates.

Principle 3. Critical limits

BIOSOLVE^® HEAVY-DUTY CLEANER APPLICATION AND USE

VIRKON^® AQUATIC APPLICATION AND USE

The following table indicates the additional routine biosecurity tasks required for a complete biosecurity programme.

BIOSOLVE^® HEAVY-DUTY CLEANER APPLICATION AND USE

VIRKON^® AQUATIC APPLICATION AND USE