Fish
have a nervous system and pain receptors like all other animals.
Twenty-five years ago the RSPCA’s Medway
Report (1981) concluded that fish are capable of suffering and feeling
pain, yet the slaughter regulations which offer some level of protection
to other farmed animals still do not apply to fish.
In a review carried out in 2004 the scientific evidence for the existence
of sentience in farmed fish was evaluated. It was concluded that pain,
fear and psychological stress are likely to be experienced by fish. This
implies,
like other vertebrates, that fish have the capacity to suffer and that
welfare consideration for farmed fish in this instance should be taken
into account(4).
The Welfare of Animals (Slaughter or Killing) Regulations 1995 legislation
states that ‘It is an absolute offence to cause or permit an animal
avoidable excitement, pain or suffering’. There are also specific
rules on handling, stunning, slaughter or killing of animals(5). The
basic act of removing a fish from water causes severe pain and distress,
even
before the killing begins. Wild caught fish, when hauled up from the
depths, undergo excruciating decompression. Frequently, the intense internal
pressure
ruptures the swim bladder, while the eyes pop out and the oesophagus
and stomach can be pushed out through the animal’s mouth.
Farmed
fish may not be endangered but they are caged in cramped and unhealthy
conditions, causing great stress and rendering them susceptible to
disease. Farmed salmon, for example, can grow up to 2.5 feet long and
yet are only given space equivalent to a bathtub of water. Sea lice
pose a huge problem to the welfare of farmed fish. They feed on their
blood and underlying tissues causing skin and scale loss. Lice damage
around the head can be so severe that the bone of the living fishes’ skulls
can be exposed, a condition referred to as the "death crown"(6).
Aquaculture relies on the artificial breeding of fish. Females have
their eggs extracted on several occasions under anaesthetic. Most of
them are then eventually killed as their recovery process from the
anaesthetic is considered to be uneconomic. Males are milked several
times for their semen before slaughter(7).
Farmed fish are normally starved for about 7 to 10 days before slaughter.
There are a number of methods used to kill farmed fish (mostly salmon
and trout). These include:
• Carbon
dioxide stunning
The fish are placed in a bath saturated with carbon dioxide. This environment
causes changes to behaviour, with fish being observed to shake their
heads and tails vigorously trying to escape(8). Movement ceases
after 30 seconds, but sensibility may not be lost for 4 to 9 minutes.
Bleeding
after CO2 stunning is essential to avoid fish recovering. If fish are
removed early from the stunning tank, they are likely to have their
gills cut when immobile but still conscious(6).
• Suffocation
on air / ice
The fish may be taken out of the water and allowed to die through suffocation
in air. Alternatively, fish are removed from water onto ice. This method
prolongs suffering as the cooling effect of the ice can lengthen the
time to unconsciousness with fish aware of what is happening to them
15 minutes after being taken out of water. The Farm Animal Welfare
Council (FAWC) recommended 10 years ago that this method should be
prohibited(6). Fish farmers have admitted that ‘letting
tens of millions of fish die of suffocation each year as unacceptable’(9).
• Gill
Cutting and Percussive Stunning
Gill cutting without prior stunning has shown that certain responses
of fish are not immediately lost and vigorous movements occurred. Percussive
stunning involves the fish being hit on the head with a rapidly moving,
manually applied club. When sufficient force is applied the concussion
can be irrecoverable, however in practice the stun is often not immediate
and fish are hit more than once(10).
(italicised
numbers in brackets indicate references) |
