Pathogen breach and disinfection in Atlantic salmon RAS
1. Purpose
Recirculating aquaculture systems (RAS) offer several advantages in advancing land-based production of Atlantic salmon. Enhanced biosecurity and disease control are some of the benefits from RAS compared with traditional flow-through systems. This is achieved by efficient biosecurity system that is in place to prevent pathogens from entering and proliferating in the system. Routine disinfection of the RAS loop water is part of running a RAS facility. However, we have limited information on whether these water disinfection protocols are effective following a pathogen breach. Ideally, RAS is an environment that is well-protected from the outside environment, nonetheless, pathogen entry is a potential challenge via different vectors such as intake water, infected stocks, among many other. Therefore, the experiment described in the application will explore how routine water loop disinfection affect fish health and explore its efficiency in controlling an outbreak following a biosecurity breach through intake water.
2. Distress
Fish will be exposed to two oxidants (i.e. ozone and peracetic acid) which has the potential to trigger localised and systemic oxidative stress. In addition, fish will be exposed to Infectious Pancreactic Necrosis virus. It will be expected that fish will develop pathological signs associated with the disease and susceptible fish may even die.
3. Expected benefit
The proposed trial will provide experimental evidence how routine disinfection of the RAS loop water plays a role in controlling an outbreak following a biosecurirty breach. This expected result will be crucial for developing risk assessment protocols, designing optimised disinfection strategy and improving biosecurity measures in post-smolt RAS production.
4. Number of animals and what kind
Nine hundred (900, appr. 80 g) mixed-sex Atlantic salmon (Salmo salar) post-smolt are intended to be used in the trial.
5. How to adhere to 3R
There is no other way to test the hypothesis in the study than performing a trial using live fish. However, the experiment has been designed so that the number of fish is reduced to a minimum, i.e., minimum stocking density in the tank. The ozone and PAA concentrations were based on previous trials and found to be safe for salmon. Humane endpoints are clearly defined and, the experimental systems are designed for optimal rearing conditions for post-smolts.
Recirculating aquaculture systems (RAS) offer several advantages in advancing land-based production of Atlantic salmon. Enhanced biosecurity and disease control are some of the benefits from RAS compared with traditional flow-through systems. This is achieved by efficient biosecurity system that is in place to prevent pathogens from entering and proliferating in the system. Routine disinfection of the RAS loop water is part of running a RAS facility. However, we have limited information on whether these water disinfection protocols are effective following a pathogen breach. Ideally, RAS is an environment that is well-protected from the outside environment, nonetheless, pathogen entry is a potential challenge via different vectors such as intake water, infected stocks, among many other. Therefore, the experiment described in the application will explore how routine water loop disinfection affect fish health and explore its efficiency in controlling an outbreak following a biosecurity breach through intake water.
2. Distress
Fish will be exposed to two oxidants (i.e. ozone and peracetic acid) which has the potential to trigger localised and systemic oxidative stress. In addition, fish will be exposed to Infectious Pancreactic Necrosis virus. It will be expected that fish will develop pathological signs associated with the disease and susceptible fish may even die.
3. Expected benefit
The proposed trial will provide experimental evidence how routine disinfection of the RAS loop water plays a role in controlling an outbreak following a biosecurirty breach. This expected result will be crucial for developing risk assessment protocols, designing optimised disinfection strategy and improving biosecurity measures in post-smolt RAS production.
4. Number of animals and what kind
Nine hundred (900, appr. 80 g) mixed-sex Atlantic salmon (Salmo salar) post-smolt are intended to be used in the trial.
5. How to adhere to 3R
There is no other way to test the hypothesis in the study than performing a trial using live fish. However, the experiment has been designed so that the number of fish is reduced to a minimum, i.e., minimum stocking density in the tank. The ozone and PAA concentrations were based on previous trials and found to be safe for salmon. Humane endpoints are clearly defined and, the experimental systems are designed for optimal rearing conditions for post-smolts.