Evaluation of the health and welfare implications of fasting during Atlantic salmon parr and smolt production in recirculating aquaculture systems (RAS)
1 Formål
The purpose of experiment is to determine what is the effect of fasting on Atlantic salmon parr and smolt health and welfare, water quality, biofilter function and stability of system operation in RAS. In addition, the sound that salmon is producing in regard to feeding will be recorded to evaluate the use of this indicator to monitor fish appetite.
2 Skadevirkninger
Two fasting periods of five days will be included in the experiment, one at parr and one at smolt stage. The duration of starvation period is based on existing practices in the industry and based on scientific literature. At the parr stage aggression can occur that can affect fin, skin and eye injuries. Placement of equipment (hydrophones) for sound measurement can potentially cause additional damage if fish get in frequent contact with it (snout and eye damages, skin wounds).
3 Forventet nytteverdi
-Knowledge on how fasting up to five days in RAS is affecting salmon's health and welfare
- Knowledge on how fasting in RAS affects microbial community of the biofilters
- Identification of soundscapes related to salmon appetite
4 Antall dyr og art
Total of 2400 Atlantic salmon individuals of approximately 30 g (mixed sex) will be used. The number of animals is determened based on number of necessary samples that will be taken and based on statistical variation that is expected in relation to use of single RAS (4 systems per treatment used).
5 Hvordan etterleve 3R
-Replacement: The aim of this project is focused on the response of individuals to specific production practices and replacement was not possible.
-Reduction: The experiment will be done in smaller scale tanks. In this way the relevant densities for the industry will be achieved with less individuals.
-Refinement: In order to reduce potential discomfort, fish will be sampled on day 3 and if negative effects of fasting are observed, feed withdrawal period will be ended before planned (5 day starving). Hydrophones will be isolated from the direct contact with fish to prevent potential contact injuries.
The purpose of experiment is to determine what is the effect of fasting on Atlantic salmon parr and smolt health and welfare, water quality, biofilter function and stability of system operation in RAS. In addition, the sound that salmon is producing in regard to feeding will be recorded to evaluate the use of this indicator to monitor fish appetite.
2 Skadevirkninger
Two fasting periods of five days will be included in the experiment, one at parr and one at smolt stage. The duration of starvation period is based on existing practices in the industry and based on scientific literature. At the parr stage aggression can occur that can affect fin, skin and eye injuries. Placement of equipment (hydrophones) for sound measurement can potentially cause additional damage if fish get in frequent contact with it (snout and eye damages, skin wounds).
3 Forventet nytteverdi
-Knowledge on how fasting up to five days in RAS is affecting salmon's health and welfare
- Knowledge on how fasting in RAS affects microbial community of the biofilters
- Identification of soundscapes related to salmon appetite
4 Antall dyr og art
Total of 2400 Atlantic salmon individuals of approximately 30 g (mixed sex) will be used. The number of animals is determened based on number of necessary samples that will be taken and based on statistical variation that is expected in relation to use of single RAS (4 systems per treatment used).
5 Hvordan etterleve 3R
-Replacement: The aim of this project is focused on the response of individuals to specific production practices and replacement was not possible.
-Reduction: The experiment will be done in smaller scale tanks. In this way the relevant densities for the industry will be achieved with less individuals.
-Refinement: In order to reduce potential discomfort, fish will be sampled on day 3 and if negative effects of fasting are observed, feed withdrawal period will be ended before planned (5 day starving). Hydrophones will be isolated from the direct contact with fish to prevent potential contact injuries.