Salmon farming - welfare at the time of killing: guidance

Welfare at the Time of Killing in Salmon Farming

A. Training and Competence

Slaughter, euthanasia or culling operations include functions such as crowding, transfer, grading, handling, stunning and killing. All personnel involved in slaughter operations and/or the killing of salmon should be suitably trained (with records maintained and available for inspection), competent and aware of their duty of care.

All slaughter or killing and related operations should be overseen by a designated trained, competent and suitable person who has overall control and responsibility for fish welfare.

Personnel involved in slaughter, euthanasia or culling operations should be able to recognise farmed fish density and stress responses, so that this can be balanced with efficiency of fish capture/treatment and duration of crowding, prior to slaughter or killing.

Personnel involved in stunning operations should be able to recognise the signs and check for ineffective electrical or percussive stunning or recovery from stunning:

i. eye movement (vestibulo-ocular reflex) when fish are rotated (see annex B)

ii. rhythmic opercular movement

iii. involuntary muscular twitches, that are not mild or short term

iv. reaction to tail pinch.

Personnel involved in stunning operations should be trained to operate equipment safely and effectively, and in accordance with manufacturer’s instructions. Records of training should be kept and be available for inspection.

The supporting management system of all companies involved in slaughter operations should maintain a knowledge base of current legislation.

B. Preparation for Slaughter or Killing

A suitable plan should be developed prior to commencement of any slaughter, euthanasia or culling operation, specifying the methods to be used.

The slaughter, euthanasia or culling plan must detail an evaluation of the appropriateness of the expected time delay between fish being removed from the production unit and stunning.

The impact of successive crowding events on the health and welfare of stock should be evaluated prior to commencement of a slaughter operation.

The feed withdrawal period before slaughter should be expressed in degree days, be compatible with hygiene and welfare requirements and should follow veterinary advice.

Where cleanerfish are present, slaughter or killing plans should specifically evaluate the risks to their welfare during periods of feed withdrawal, crowding and grading/ separation.

Removal from sea pens or other appropriate measures should be in place to protect cleanerfish before feed withdrawal to avoid the risk of predation.

Slaughter, euthanasia or culling plans should include a contingency stunning/killing method(s) which must be described and readily available for implementation in case of a breakdown or emergency.

C. Crowding and Transport

Where pumps, pipes and grading equipment are used, these should be properly designed and correctly set up and operated so that they do not injure or unnecessarily stress fish.

Operations should be planned and carried out to minimise the duration of crowding.

Records of acceptable water quality (specifically oxygen availability) should be accessible to operators throughout the period of crowding and transport of fish during slaughter operations. Personnel involved in slaughter operations should understand what suitable oxygen concentrations are required for each operation and at what point to intervene by providing supplemental oxygen or halting operations. These records should be available for examination for at least 12 months after the operation.

Intervention levels and action to be taken should be specified in a standard operating procedure or slaughter plan.

Where farmed fish are pumped to slaughter facilities, pumping pressure and flow rates should be monitored so it can be adjusted as necessary, with communications maintained between those controlling the pumping operation and the slaughter facility.

Fish should be slaughtered without unnecessary delay after delivery from the pumping system and the flow adjusted to avoid supplying more fish than the stunning system can handle. Fish may take slightly longer to reach the stunning equipment when passive, counter current “swim through” systems are used.

If fish need to be lifted by hand for any reason, they should only be lifted individually and adequate support should be given to the body - live fish should never be held by the gills or tail only.

Transport in wellboats

Wellboats should be fitted with moveable bulkheads or other arrangements to deliver efficient and timely discharge.

Wellboats should be able to monitor and record the numbers of fish loaded in each well.

There should be appropriate lighting to enable continuous inspection/monitoring of the fish throughout the well.

Where systems are reliant on automatic monitoring equipment, this equipment should be alarmed and have fully operational manual back-up systems. This includes water quality control methods, such as oxygenators/aerators and carbon dioxide strippers.

Weekly checks should be made and recorded for the calibration accuracy on automatic equipment or there should be a demonstrable way of ensuring that the equipment is working properly.

The standard maximum stocking density in the well should be based on the liveweight of the fish, as shown below.

Pumping of the fish from the well to the slaughter plant should be done in a way that:

a) does not demonstrably compromise fish welfare

b) ensures that slaughter personnel can maintain an efficient stunning and bleeding procedure.

There should be a standard operating procedure in place to ensure that all fish are removed humanely from the vessel, pumps and pipes at the end of unloading, which must not be injurious to the fish.

The maximum dwell time in the pipe should be no more than 10 minutes.

The following records should be kept for inspection, and be available on request:

a) place of loading and destination of fish

b) times of fish movements

c) number of fish loaded

d) fish size distribution

e) route covered during transport

f) timing of open and closed valve operations.

There should be evidence that vessel crew members and skippers have completed an appropriate fish welfare course.

Wellboats should be equipped with water quality monitoring and maintenance equipment, which should be calibrated so it is working and fit for purpose at all times.

Water should be chilled at a maximum of 1.5^oC per hour.

Wellboat systems should maintain the pH of the wellwater between 6.8 and 8.

Oxygen concentrations should be:

a) continuously monitored

b) maintained at a minimum of 7mg/litre.

Various parameters, such as salinity and water temperature, will affect the solubility of oxygen in water. Therefore, the minimum oxygen concentration of 7mg/l should be increased, as required, to ensure the optimum oxygen concentration for the fish is always maintained.

Carbon dioxide concentrations should not exceed 40mg/l.

D. All Killing

Farmed fish, cleaner fish cohabiting with salmon, and incidentally caught species within the farm pen, should only be killed by a humane method specified at Annex A.

Farmed fish, cleaner fish and incidentally caught species must not under any circumstances be killed by inhumane methods, including in particular:

i. bleeding (exsanguination) by gill cutting or other means without prior stunning

ii. asphyxia in air

iii. evisceration or decapitation

iv. live chilling (fast or slow)

v. ice slurry or bath

vi. carbon dioxide narcosis

E. Slaughter for Human Consumption

All farmed fish slaughtered for human consumption must be stunned before killing by a humane method specified in the table at annex A. Unless stunned and killed simultaneously, death should occur before consciousness is regained.

Stunning equipment must be checked regularly. A regular evaluation of slaughter operations should demonstrate that the key parameters of stunning equipment set out in Annex A have been properly applied and deficiencies corrected without delay.

The flow of fish into stunning systems must be of an appropriate speed so that fish are out of water for the minimum time necessary and allow operators (or automated systems) time to handle individual fish with care, or ensure only single fish are entering the slaughter systems at a time.

Fish must be presented to the stunner in a way that prevents mis-stunning or fish missing the stunner, e.g. falling from the stun table to the floor.

Automated equipment should be tested at the start of each operation to ensure it is working properly with at least the first 10 fish.

A priest or secondary stunner should be available at all times and used to immediately administer a percussive blow if a fish is not effectively stunned.

A record of the number of fish requiring re-stunning during each operation should be kept and be available for inspection.

All equipment must be operated, cleaned and maintained in accordance with the manufacturer’s recommendations or relevant internal protocols.

Maintenance/servicing records should be kept and be available for inspection.

All slaughter operations, on land or on vessels, should employ CCTV covering both the stunning and bleeding operations. Recordings should be retained and available for inspection for a rolling period of at least 90 days.

Percussive stunning

Automated, mechanical stunning devices should be used in preference to a manual percussive blow

Each fish must receive a percussive blow to the top of the head just behind the eyes, of sufficient force to kill the individual or cause immediate loss of consciousness that lasts until death via other means.

Mechanical devices must be monitored to ensure that they are working properly and adjusted so that they are delivering a stun of the correct force and at the correct location considering the size of fish being stunned.

There must be sufficient time after stunning to assess the effectiveness of the stun in all fish and ensure any fish that have not been effectively stunned are re-stunned immediately.

If fish have not been effectively stunned or bled this should be reported to the designated person in overall charge of fish welfare for the operation. Immediate action should be taken to rectify any issue and the action recorded.

All fish must be bled (exsanguinated) within 10 seconds of the stun/kill method.

Electrical stunning

Electrical in-water stunning of salmon for human consumption as described in annex A may take place before percussive stunning.

Whatever electrical process is used it must be ensured that:

a) insensibility of the fish is achieved immediately (within 1 second)

b) there are no pre-stun shocks

c) the stun is maintained until either the fish dies, or receives a subsequent percussive stun

d) fish are assessed regularly to ensure there are no signs of consciousness post-stun demonstrate signs of effective stunning.

Equipment must be fitted with a visible means of checking that the correct current is being administered throughout the process.

F. Euthanasia and Culling Not for Human Consumption

Procedures for the euthanasia or culling of fish not for human consumption should be documented in a Standard Operating Procedure or within the farm Veterinary Health and Welfare plan.

Requirements in section A above regarding personnel training and competence apply to killing of fish for any purpose.

Fish farm operators should have contingency plans in place for emergency culling in situations such as the loss or malfunction of equipment, disease outbreak or invasion by predators. Plans should include detailed standard procedures for how fish will be humanely killed when necessary, including sourcing of equipment and personnel.

Methods to be used routinely in other situations (euthanasia of individual fish, cleaner fish or incidentally caught species and grading of juvenile fish) should also be specified in standard operating procedures approved by a veterinary surgeon.

Where anaesthetic overdose is used as a killing method, dosage, exposure time, size and weight of fish, water temperature and other relevant factors to ensure a suitable transition to lasting unconsciousness and an effective kill should be evaluated within the standard operating procedure.

In-water electrical systems using suitable parameters to produce an effective stun to kill are recommended where practicable.

Cleanerfish (wrasse & lumpfish) should be killed by an anaesthetic overdose using a suitable product in accordance with veterinary advice, or a percussive blow or electrical stun-to-kill for wrasse over 50g only.

Incidentally caught fish species during harvest operations should also be humanely killed using a method in annex A, subject to any legislation relating to protected species.

The number of cleaner fish or incidentally caught species that are culled/slaughtered should be recorded.