Shrimp Production

White Spot Syndrome virus (WSSv) is the most serious viral pathogen of farmed shrimp. It is highly virulent and can spread rapidly, resulting in up to 100% mortality within shrimp farm populations in just 3-10 days. WSSv has been reported within all stages of the shrimps life cycle, from eggs to brood stock, decimating shrimp stocks and drastically affecting the productivity and profitability of the farm.

TRANSMISSION

Vertical transmission of the disease occurs from infected brood stock with horizontal transmission usually occurring directly through contaminated water, or via cannibalism of sick or dying shrimp.

Selecting Specific Pathogen Free (SPF) brood stock can help prevent vertical transmission, but the only real way of preventing horizontal transmission of the disease is through implementing a best practice biosecurity programme, utilising a proven effective disinfectant.

PATHOGENESIS

The pathogenesis of WSSv can be divided into two distinct stages. The first stage is when a newly infected shrimp is living in a stress-free environment. Under stress-free conditions the shrimp will show no symptoms of the disease, the virus is effectively under control and its spread is contained in the affected internal organ.

Stage two occurs when the infected shrimp are subjected to stressful environmental conditions. The disease becomes virulent with the virus spreading rapidly to the shrimps other vital organs, resulting in high levels of mortality.

VIRKON^® AQUATIC – UNIQUE FORMULATED DISINFECTION POWER BACKED BY SCIENCE

Virkon^® AQUATIC’s modern, powerful broad spectrum formulation has been scientifically developed to address and meet the pathogen control needs of the intensified shrimp production industry. As with pharmaceutical products, disinfectants with similar chemistries can have widely different performance when it comes to efficacy and kill power. Selecting the correct disinfectant for shrimp production biosecurity with a solid dataset is therefore critical for the survival of the shrimp.

With proven efficacy against the WWS virus, Virkon^® AQUATIC can be applied directly and continuously into shrimp ponds to reduce the risk of cross-contamination and prevent the disease from taking hold and helping to: 

• Rapidly knock-down and control the infections
• Reduce the rate of infection spread within the shrimp population
• Reduce the risk of the infection spreading to adjacent ponds

BELOW IS AN EXAMPLE OF HOW BEST TO CONTROL WSSV WITH VIRKON^® AQUATIC

NEIGHBOURING FARMS:

To prevent the spread of WSSv from an infected farm to its neighbours during an outbreak:

• Install a plastic fence around the farm(s).
• Treat all incoming water in the reservoir with Virkon^® AQUATIC at 2ppm.
• Apply Virkon^® AQUATIC at 2ppm in culture ponds, and repeat every 7 days.
• If shrimp mortality occurs in a previously uninfected pond, please follow the Emergency Disease Control (EDC) Biosecurity procedures as above.

Intensified shrimp production provides an ideal environment in which disease-causing organisms can flourish and cause serious damage to productivity.

However the diseases originate, they can spread through recognised vectors of infection. These include; the shrimp pond liner or other surfaces (earth, concrete, wood), equipment & tools, vehicles, boats, staff & visitors, and even the water preparation itself.

Therefore, it is essential to follow a structured terminal biosecurity program, using Virkon^® AQUATIC before each production cycle begins. This will help to prevent the “carry-over” of disease-causing organisms, thus ensuring that each new crop of shrimps gets a completely clean fresh start.

VIRKON^® AQUATIC – FORMULATED DISINFECTION POWER

Virkon^® AQUATIC is a formulated, fast-acting, broad spectrum disinfectant technology which has been specifically developed to meet the biosecurity needs of intensified shrimp production. It has a wide range of independently proven efficacy against key disease-causing organisms, and provides farmers with a convenient, multipurpose terminal biosecurity system all in one pack.

KEY TERMINAL BIOSECURITY TASKS

The table provides details of the key terminal biosecurity tasks that need to be carried out, and the dilution and application rates that Virkon^® AQUATIC should be applied at.

Shrimp must be given an environment in which the disease-causing organisms are controlled to manageable levels, in order to provide them with the best chance of survival. Virkon^® AQUATIC Broad Spectrum Disinfectant, in combination with an effective shrimp production biosecurity program, are the keys to achieving this.

During its lifecycle, a shrimp will face continuous environmental and pathogenic challenges during the production process.

Pond water contains various levels of nutrients including, plankton, organic matter, feed and waste. Combine this with pond salinity factors, high humidity, bright sunlight and the surrounding environment, it can easily be determined that a pond has all the right ingredients to sustain disease-causing organisms that will affect shrimp health, growth and mortality.

It is therefore essential to provide the shrimp with the best chance of surviving the production cycle, and continuous biosecurity procedures, utilising Virkon^® AQUATIC, have a very important role to play.

SHRIMP POND WATER CARE

A program of procedures for shrimp pond water care should be put in place throughout the duration of the production cycle to help reduce instances of disease, including:

• Organic load management
• Feed & shrimp health control measures
• Wildlife prevention
• Continuous biosecurity disease prevention and control

VIRKON^® AQUATIC FOR CONTINUOUS BIOSECURITY

Virkon^® AQUATIC provides shrimp farmers with a convenient, multipurpose continuous biosecurity disinfection system all in one pack for:

• Continuous water disinfection, during the grow-out stage
• Footdips & vehicles
• Movable equipment
• Hard surfaces
• Emergency disease control outbreaks

Virkon^® Aquatic has a broad spectrum of efficacy against the key disease-causing organisms including, White spot syndrome, Vibrio harveyi, Vibrio parahaemolyticus virus, and Taura syndrome virus.

Its modern chemical formulation enables Virkon^® AQUATIC to be applied directly to the pond water at regular scheduled intervals, in the presence of both larvae and shrimp.

This ability to be continually applied helps to reduce the levels of disease-causing organisms within the pond water to manageable levels. This inhibits their ability to rapidly replicate and pose a serious disease threat.

From experience, the wide use of Virkon^® AQUATIC in the industry, together with numerous studies, has shown that shrimp disease-causing organism counts can be controlled by adding Virkon^® AQUATIC at 1.2 ppm to the pond at 7-day intervals right from the beginning, and throughout the remaining shrimp production cycle.

VIRKON^® AQUATIC DILUTION RATES AGAINST KEY DISEASE-CAUSING ORGANISMS

VIRKON^® AQUATIC IS SAFE FOR THE SHRIMP

Virkon^® AQUATIC effectively kills shrimp disease-causing organisms, then rapidly degrades leaving no residue of concern. Other disinfectant technologies take longer to eliminate the pathogen challenge, and leave harmful chemicals in the water. The table clearly demonstrates the rapid degradation of Virkon^® AQUATIC when compared to Calcium Hypochlorite (under test condition designed to simulate a shrimp pond environment), over a 7-day period from the initial introduction of the disinfectant to the shrimp pond water.

VIRKON^® AQUATIC – FORMULATED DISINFECTION POWER

Not all disinfectants are effective against the wide range of viral, bacterial and fungal disease-causing organisms that affect shrimp, especially within harsh pond environments. Even disinfectants with similar chemistry can have widely different spectra of activity and effective dilution rates. Selecting the correct disinfectant for shrimp production biosecurity is therefore critical for effective disease prevention and control.

Virkon^® AQUATIC has been independently proven to be highly effective and rapidly kills major shrimp disease-causing organisms in variable water conditions including, White spot syndrome virus (WSSV), Vibrio harveyi, Vibrio parahaemolyticus, and Taura syndrome virus.

Virkon^® AQUATIC does not negatively impact the shrimp’s food source, phytoplankton, or leave residues of concern within the shrimp itself.

DISINFECTANT DEGRADATION RATES

Some disinfectants, whilst effective against pathogens, can have a negative residual toxic effect on developing shrimp, due to their inability to degrade rapidly within water.

In simple terms, Virkon^® AQUATIC effectively kills the shrimp disease-causing organisms and then rapidly degrades leaving no residue of concern. Other disinfectant technologies take longer to eliminate the pathogens and leave harmful chemicals in the water.

The graphs below clearly demonstrate the rapid degradation of Virkon^® AQUATIC, when compared to Calcium Hypochlorite (Under test conditions designed to simulate a shrimp pond environment), over a 7-day period from the initial introduction of the disinfectant to the shrimp pond water.

VIRKON^® AQUATIC FOR CONTINUOUS POND WATER BIOSECURITY

Disinfect the newly prepared and refilled pond water with Virkon^® AQUATIC at a dilution rate of 1.2ppm – 2ppm one day before post larvae stocking.

Shrimp disease-causing organism counts can be kept below the maximum acceptable threshold of 103 (CFU/ ml) by adding Virkon^® AQUATIC at 1.2 ppm to the pond at 7-day intervals from day one, and throughout the remaining production cycle.

Use a mechanical filtration system to help remove large particular matter during the production cycle; this will help improve and maintain water quality.

Ensure standard continuous disinfection biosecurity procedures are adhered to as part of the overall pond water management process.

These include:

• Disinfectant foot & wheel dips
• Boat and vehicle disinfection
• The disinfection of movable equipment & tools
• Hard surfaces (path & roadways)

PROTECT YOUR INVESTMENT

The intensification of shrimp 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. Unless the background challenge from disease-causing organisms can be controlled, and good management practices strictly followed, shrimp stocks will be affected by poor growth and high mortality rates.

FORMULATED DISINFECTION POWER BACKED BY SCIENCE

• VIRKON^® AQUATIC – UNIQUE FORMULATED DISINFECTION POWER BACKED BY SCIENCE
  The intensification of shrimp 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. Unless the background challenge from disease-causing organisms can be controlled, and good management practices strictly followed, shrimp stocks will be affected by poor growth and high mortality rates.
  
  
• Proven Data Set
  You can have confidence in Virkon^® AQUATIC as we have carried out extensive testing and have data showing proven efficacy.
  
  
• Complex Chemistry
  A synergistic blend of ingredients which are unique to Virkon^® AQUATIC for maximum pathogen killing power.
  
  
• Not Toxic to Shrimp
  Virkon^® AQUATIC is kind to shrimp and, if used regularly, protects your investment in the pond, preventing bacteria outbreaks.
  Virkon^® AQUATIC’ modern, powerful broad spectrum formulation has been scientifically developed to address and meet the pathogen control needs of an intensified shrimp production industry.  Like with pharmaceutical products, disinfectants with similar chemistry can have widely different performance when it comes to efficacy and kill power. Selecting the correct disinfectant for shrimp production biosecurity with a solid dataset is therefore critical for the survival of the shrimp.
  Virkon^® AQUATIC is a synergistic and balanced mix of ingredients that is formulated and subsequently produced with utmost precision. This is why Virkon^® AQUATIC can achieve rapid maximum pathogen killing power while having no negative toxicological effect on the ecosystem of the pond or shrimp themselves when used according to label directions.
  Not all disinfectants are effective against the wide range of viral, bacterial and fungal disease-causing organisms that affect shrimp, especially within harsh pond environments. The independent studies prove the effectiveness of Virkon^® AQUATIC in variable water conditions and demonstrate that Virkon^® AQUATIC does not negatively impact the shrimp’s food source, phytoplankton, or leave residues of concern within the shrimp itself.

PREVENTION AND MAINTENANCE

Good biosecurity practices should focus on prevention and control of pathogen growth. It is generally accepted that the shrimp should only grow and thrive in an environment where the bacterial level in water is kept below the maximum disease threshold of 103 (CFU/ml). Virkon^® AQUATIC, as part of a biosecurity protocol, is therefore a key tool in controlling pathogen levels in the pond. From experience, the wide use of Virkon^® AQUATIC in the industry, together with numerous studies, has shown that shrimp disease-causing organism counts can be controlled by adding Virkon^® AQUATIC at 1.2 ppm to the pond at 7-day intervals right from the beginning, and throughout the remaining shrimp production cycle.
The aim of a standard shrimp disease prevention biosecurity program is first to prevent the pathogens from establishing themselves within the shrimp pond and, secondly, to prevent the spread of an infection within the farm site, from pond to pond. With this in mind, the following disease prevention and control biosecurity tasks and procedures must be implemented and adhered to at all times.

SHRIMP DISEASE MANAGEMENT

When a shrimp farmer is faced with a highly contagious disease which rapidly spreads throughout and kills shrimp farm populations, the entire investment can be lost. With increasing densities of ponds located in the same area, the risk of a disease spreading from a nearby pond to the next is increasing. And the spread can happen in a matter of days. In such cases it is essential to contain and control the spread of the disease as effectively and quickly as possible.

With proven efficacy against the most important viruses and bacteria that threaten modern shrimp production today, Virkon^® AQUATIC can be applied in ponds to reduce the risk of cross-contamination and prevent the disease from taking hold. Virkon^® AQUATIC has been tested in simulated shrimp pond production waters against the most problem-causing pathogens and has been proven to:

• Rapidly knock-down and control the infections
• Reduce the rate of infection spread within the shrimp population
• Reduce the risk of the infection spreading to adjacent ponds

Below are examples of how best to control some of the most common shrimp disease-causing organisms in 20 ppt salinity waters with a medium organic loading. Use the Virkon^® AQUATIC Dose Calculator (ADC) for exact dilution rates against specific shrimp diseases, taking into account your ponds water quality conditions (e.g. salinity, organic load and temperature).

VIRUSES

BACTERIA

VIRKON AQUATIC IS SAFE TO SHRIMP

Some disinfectants, while effective against pathogens, can have a negative residual toxic effect on developing shrimp, due to their inability to degrade rapidly within water.

Virkon^® AQUATIC’s oxygen-based chemistry contains organic salts and acids, and its active ingredient decomposes rapidly by a variety of routes within the environment, in sediment and water, breaking down to form the naturally occurring substances, potassium salts and oxygen.

In simple terms, Virkon^® AQUATIC effectively kills the shrimp disease-causing organisms at low concentrations and then rapidly degrades leaving no residue of concern. Other disinfectant technologies require higher doses and take longer to knock-down the pathogens and leave harmful chemicals in the water. The following graphs clearly demonstrate the rapid degradation of Virkon^® AQUATIC, when compared to Calcium Hypochlorite (under test conditions designed to simulate a shrimp pond environment), over a 7-day period from the initial introduction of the disinfectant to the shrimp pond water.

DISINFECTANT STOCK SOLUTION PREPARATION