The Humane Slaughter Association’s (HSA) view
While animals continue to be reared and slaughtered for food it is importantthat every effort is made to protect their well-being. The HSA seeks humane
methods of slaughter. This means that all animals without exception should beproperly stunned and rendered unconscious before being bled. TheAssociation also believes that those handling and slaughtering fish must be
fully trained and competent to take responsibility for the fish in their care.
What does the HSA do?
The HSA is the only registered charity which specialises in the welfare of foodanimals throughout the marketing and slaughter processes. It is anindependent, organisation beholden to neither government, trade nor
emotional pressures and is thus able to play an unbiased role in promoting thehumane treatment of food animals. It achieves its aim by lectures and practicaldemonstrations of stunning methods; by publishing educational materialand funding research projects.
How can you help?
The HSA depends upon voluntary subscriptions, donations and legacies for
its income. Support is needed from both individuals and corporate groups sothat the Association may continue to play an effective role in the welfare offood animals.
The annual subscription for individual members is £15, for corporate groups£50 and for those in full-time education £5.
The Old School, Brewhouse Hill,
Wheathampstead, Herts AL4 8AN
t: +44 1582 831919
f: +44 1582 831414
e: info@hsa.org.uk
w: www.hsa.org.uk
Registered in England Charity No 1159690
Charitable Incorporated Organisation© HSA 2016 text amended July 2014

Humane Harvest?
Should we be worried about the way fish are killed?
Every year millions of fish are farmed around the world forhuman consumption. Recent scientific evidence shows that fishreact to perceived painful actions in a manner similar tomammals. Furthermore, under certain circumstances, fishexhibit responses much like the stress responses in otheranimals, suggesting they too can suffer. The time leading up to,and during, killing can be particularly stressful, as fish are
handled and manipulated more than they may be used to. Some
traditional killing methods cause suffering and are inhumane
and unacceptable.
Are fish protected by the law?
Under European Law, all animals, including fish, must be sparedavoidable suffering and pain during slaughter. Fish should
therefore be handled in a manner that minimises stress andshould not be subjected to unnecessary pain during this time.
How are fish killed?
The killing of fish (often referred to as ‘harvesting’) can be split into
five stages: grading, fasting, crowding, transport and killing.
Grading occurs on a number of occasions throughout the life offish, to ensure they are kept in groups of similar size. Fasting for
72 hours serves to clear food and waste materials from the fishgut. Crowding of fish reduces the area available and enables
them to be lifted out of the water more easily. The first threestages are carried out by farm staff at the growing site. The nextstage, transport, is carried out by specialised staff. The final stage,killing, is either done by farm staff or a dedicated killing team.
Killing teams will work at one dedicated site or travel around thefarms. Traditional methods of killing fish include: removal fromwater; exposure to extreme cold; exposure to carbon dioxide orbleeding. These methods take several minutes for the fish tobecome insensible and can cause suffering. Recently developed
methods involve stunning and killing the fish. This can either be
two separate procedures of stunning and killing or one action thatstuns and kills. Fish can be stunned/killed with either electricity,
anaesthetics or a percussive blow to the head.
Humane Slaughter Association

Harvesting of Farmed Fish

How does stunning benefit producers?
In addition to significant welfare improvements, correct stunning has been
demonstrated to improve flesh quality. Besides the premium for animal welfare
accreditation, stunning can benefit the industry by improving appearance (byreducing ‘soft’ flesh, bruising and scale loss) and shelf-life when compared to
traditional harvesting systems. Mechanical/electrical stunning also improves
the working conditions for staff and can reduce the chance of repetitive injuries.

Can fish be killed humanely?
Staff training, planning and utilising the fishes natural behaviour will all help
optimise the welfare of fish during killing. Good husbandry and constantmonitoring and control of the surrounding conditions (ie maintaining
oxygen and carbon dioxide levels) during crowding and transport, will also
reduce potential welfare problems during harvest.
Stunning fish prevents stress and pain at killing. Stunning is any processthat rapidly causes insensibility to pain or, if slow acting, induces
insensibility in a manner that does not cause the animal to suffer. Stunning
may not kill the fish; it is therefore important that it remains insensible until
death occurs. When a stunning method does not kill the animal, a separate
killing process should be used, so that the animal dies before recovering
consciousness.
Where are fish killed?
Fish are farmed in either onshore or offshore cages or tanks; therefore
harvesting locations vary considerably, but will either be at central killing
stations on the mainland or on the farm where the fish have grown.
Historically, fish were always harvested at the site where they were grown.
However, following transport improvements and business mergers, some of
the larger companies now have a dedicated harvest station to which all thefish are transported for slaughter.
Transport
As mentioned above, some fish (mainly salmon) are transported to a central
harvest site. This is done using large boats known as wellboats. Fish are
pumped or brailed (lifted using a large net, which should be lined to reducethe distress experienced by the fish) from their cage onto the wellboat. Onceon the boat, fish are kept in aerated tanks with strict controls on the water
quality. Levels of oxygen and carbon dioxide are constantly monitored so thequality of the water does not become unacceptable to the fish. The wells also
contain cameras to monitor the behaviour of the fish.
Crowding
In order for fish to be lifted out of the water effectively they need to be broughttogether: this is known as crowding. As crowding brings fish very close
together it can be an extremely stressful time, as they try to escape fromeach other. As this process can be so stressful and also physicallydamaging, the time in which fish are crowded should be limited and should
never exceed two hours.
Humane Slaughter Association

Humane stunning
For a method of stunning to be humane it must render the fish unconscious
without fear or pain and that condition must last until death occurs. Thiscan be done by either percussive or electrical stunning. Humane stunning
methods can also kill the animal if they are of sufficient magnitude todisrupt brain function until the fish dies (usually from lack of breathing).
During the slaughter process the time the fish are held out of water can be
minimised by applying the stun in water, in the case of electrical andchemical stunning. In the case of new percussive stunners by exploiting
the fishes natural behaviour can be exploited by encouraging them to swim
into the stunner. At present there are commercially-available electrical andpercussive stunners for salmon and trout. Further research is underway forthese and other species to improve animal welfare, productivity and quality
with these and new stunners.
Percussive stunning
Percussive stunning is achieved by applying a targeted blow to the skull of
the fish on a specific area above the brain. If sufficient force is correctlyapplied, there is immediate disruption of normal brain function making thefish insensible for some time. A killing procedure, such as bleeding is
usually required since percussive stunning can be reversible. Percussive
stunning may be done by a hand-held club (priest) for small numbers offish or by machine when large numbers are killed. This method is suited tolarge round fish such as large trout and salmon.
Electrical stunningIn electrical stunning an electrical current is passed through the brain of the
fish to disrupt normal brain function and make the fish immediatleyinsensible to pain. This may be done by hand-held electrodes for small
numbers, or by immersing the fish in an electrified water bath. It can beused for both small and large fish. When sufficient current is applied for anadequate duration, the stun is irreversible and therefore an extra killing
step may not be required.
Anaesthetics
Chemical stunning is achieved by administering a food-safe anaesthetic
such as iso- Eugenol (a similar compound to clove oil) to the fish in sufficientamounts to make them insensible to pain. Chemical anaesthesia has notbeen licensed and is not practised in the UK.
Humane Slaughter Association