Protect our oceans

Fish health and fish welfare

For the Group, fish welfare involves protecting fish against unnecessary stress and impact.


Our fish welfare initiatives are comprehensive and cover every part of our farming value chain.

Mandatory fish welfare training for all staff comprise legislation, animal welfare, fish health biology, stress, sedation and euthanasia. Other topics covered are natural behavior, environmental requirements, water quality and physiology. Based on this knowledge, staff are also trained in internal fish handling protocols/handling policies.

Welfare indicators are used throughout the production cycle. At harvest stations, welfare  indicators are used to monitor the fish prior to, and after stunning and bleeding. All our harvest stations use either electrical or precussive stunning for anaesthesia. This precude is then followed by bleeding the fish. Bleeding is performed either manually or robotic. Indicators such as eye reflex and operculum movements are monitored and recorded daily. The effect of anaesthesia and bleeding is monitored, and in case of insufficiant effect, a reserve system is used.

In case of loss of power, an emergency power supply will help evacuationg the fish from the rig.

In case of the need to euthanize fish on the farmsite, the fish is anaesthetized with an approved medicament or by percussion. Farm personell are trained in fish welfare at least every 5 years. In addition, they are guided by fish health professionals, who visit the farm at least monthly.

During transportation of fish in well boats, there is implemented a risk based water quality monitoring and control program. This continous monitoring includes parameters such as temperature, dissolved oxygen and pH. Limits are set according to duration of transport, density in tanks and size of the fish.

What measures do we take to handle the fish as gently as possible?

The Group strive to minimize handling operations of live fish. As little handling as possible improves fish health and welfare , which is an important objective for the Group.

We use procedures as management tools for our production. The procedures help us to standardize events at each life stage, and they are updated as soon as we gain new crucial knowledge regarding fish welfare. In this way, the entire organization acquires the new knowledge quickly and efficiently.


Pumps, transportation pipes, sorting equipment and vaccination equipment are checked at regular intervals and any damage or defects are repaired before use.

During major operations such as vaccination and sorting, the fish is checked for any damage at regular intervals to detect any defects of equipment.

All components used during sea transfer are checked regularly. If situations arise where an increased incidence of mechanically inflicted damage is registered, delivery is stopped until the cause of the damage has been investigated and corrected.

Ongrowing stages:

During sea transfer, dead fish are controlled for mechanical damage that may have been inflicted in connection with the transport. If it turns out that there is presence of mechanically inflicted wounds, a review of the delivery process will be taken.

When fish are crowded during various forms of handling, we have our own handling policies describing how this is to be carried out to ensure fish welfare.

In all non-medical lice treatments, welfare screening of the fish is performed before and after it has been treated. In this way, we have documentation of the impacts for the fish, and whether measures may need to be taken to reduce the negative consequences or not.


The company produces around 10 million Lump sucker per year. This implies a high ratio of self-supply, which in turn ensures predictability for deliveries and enables us to control targeted improvement measures, aiming to ensure predictability and biological  improvements for production.

Welfare for cleaner fish has been debated for some time, and we acknowledge the challenges involved in farming  cleaner fish. At the same time, we are aware that our  measures are moving us in the right direction, biologically.

Our onshore production facilities have implemented improvement measures within operations and biosafety, providing significant improvements to biology and cleaner fish welfare.

These measures encompass a wide range and comprise of:

  • Screening and selection of parent fish
  • Value chain regionalisation
  • Providing optimal environmental conditions
  • Providing optimal nutritional values
  • Improvements within logistics and handling
  • General biosafety measures such as input water disinfection, hygiene zones in time and space
  • Production biology

After transfer to salmon production sites, when the cleaner fish perform their function by eating salmon lice, we continue to experience challenges. The causes  of terminal losses are dominated by bacterial disease.

Measures to improve welfare are: 

  • Dedicated personell that provides daily care specific for the cleanerfish
  • Facilitate natural behavior by providing a good habitat
  • Offer a fed that is adapted to the species
  • Stimulate good health condition by preventive measures (t.ex. active immunization)
  • Perform health controls

Additional, we aim to not use more cleanerfish than necessary for lice management.

We provide a (at least) monthly health assessment, performed by authorised animal health personnel. Cleaner fish in the harvest stations are anesthezised and euthanized.

MAIN GOAL:  Work for a better survival rate after transfer  to salmon production sites.

MAIN GOAL:  No disease and good fish welfare


POLICY: Fish health and fish welfare

KPI: Fish health and fish welfare


All of our on-growing sites take part in a zone - based cooperation with other farmers. In all regions where the Group has operations, fallowing, washing/disinfection and restocking are coordinated in zones every second year. This cooperation also involves coordination of operations, collaboration relating to lice, disease management and other issues where the solution to the problem requires a joint, coordinated effort.


The group participates in many different research projects in order to be at the forefront in terms of the best possible fish health and to implement new technology and expertise as soon as possible.

The various projects can be roughly divided into 3 different areas:

  • Sea lice
  • Medication
  • Survival

Most of our ongoing projects will fall into one of these groups.

Exsamples: Oxygenation in seacages, Feeding and cardiomyopathi syndrome, Wounds in smolts, Vaccine trials, Fish welfare indicators and thecnologicel measurment, Bacterial wounds in salmon ongrowing, Wounds in postsmolts, Sceletal deformities in trout, Health and growth in smolts.


Disease management is of essential importance for all animal farming. Within the Group, disease  management is based on a preventive operational practice, where the primary goal is to prevent problems before they occur.

Our work on disease management is based on  recognized principles. These are in turn based on  biological know-how and attitudes, in which training for our employees and a live internal control system lay the foundations for operations. 

Disease prevention and management are monitored by fish health professionals (authorized animal health personnel), who also play key roles related to Lerøy's continuous learning  and development of best operational practice.

We aim to farm fish under production conditions that safeguard the biological requirements of all species. Density and water quality parameters, such as temperature, salinity and oxygen shall be adapted to the requirements for fish at different life stages. We operate a specific vaccination program and vaccinate all our farmed fish before sea transfer.

The main target for fish health and welfare is to increase fish survival rates throughout the production value chain.  Salmon mortality rates due to viral diseases has decresed by 19,4% during the last two years. All employees involved in handling live fish undergo training focusing on fish welfare.

Fish welfare is developed and monitored by keeping use of  medicines to a minimum, with careful assessment of use, using only approved medicines which have documented environmental impact in accordance with the  requirements of The Norwegian Medicines Agency, monitoring and documenting tolerance, and  following up biological feed factors.

Use of medication

Medication is used only when this is deemed appropriate and necessary.

We exclusively make use of licensed products, and all medicine prescriptions are issued by authorized animal health personnel. Lerøy Seafood Group currently employes 20-30 fish health professionals (authorized animal health personnel).

Chemical used in delousing, active agents (kg) per ton gross weight

Year  Via feed (kg) Via bath (kg) Hydrogen peroxide* (kg)
2021 0.000062 0.014 8.72
2020 0.0001  0.00012 5.3
2019 0.000149  0.000030  2.5
2018 0.000023 0.000003 6.11
2017 0.000162 0.000076 1.83
2016 0.00160 0.000547 18.40
2015 0.00132 0.001361 50.45
2014 0.002474 0.003034 40.87
2013 0.00006 0.002321 4.35



Policy:  Use of medication