The science of animal welfare and its relevance to whales
Donald M. Broom, Centre for Animal Welfare and Anthrozoology, Department of
Veterinary Medicine, University of Cambridge, Madingley Road, Cambridge CB3
0ES U.K. firstname.lastname@example.org
The welfare of animals is a major factor affecting the acceptability of human
activities, and hence their sustainability, and whales are the subject of much concern
because they are considered to be sentient animals. The scientific study of animal
welfare has developed rapidly and now allows evaluation of the effects on whale
welfare of disturbance by boats, harpoon entry, pulling whales to a boat, capture
procedures, the point of unconsciousness and consequences for animals that escape.
Useful data are now being collected on some aspects but recent evidence shows that,
on average, during the capture and killing of whales, there is a high magnitude of poor
welfare and the procedure is not humane.
Welfare, pain, whale, whaling, humane, sustainability.
It is a widely held view in most countries that we have obligations to all animals that
we use, or with which we interact, and that these obligations include avoiding or
minimising poor welfare in the animals (Broom 2003, 2006, Fraser 2008). A central
question, when decisions are made about whether a system for exploiting resources
should be used, is whether or not the system is sustainable (Aland and Madec 2009).
The fact that something is profitable and there is a demand for the product is not now
sufficient reason for the continuation of production. A system or procedure is
sustainable if it is acceptable now and if its effects will be acceptable in future, in
particular in relation to resource availability, consequences of functioning and
morality of action (Broom 2001, 2010). Animal welfare is one of the key reasons why
an activity or a system of production may not be acceptable. There are many
examples of the actions of consumers and the general public in boycotting the
products of companies or countries whose actions are thought to be morally wrong
(Bennett et al 2002).
Several species of whales and dolphins are demonstrated by experimental studies to
have the characteristics of sentient animals and their pain and adrenal systems
function in the same way as those of other mammals (Reiss and Moreno 2001,
Desportes et al 2007, Broom 2007, 2010b). Hence it would seem reasonable to
assume that all cetaceans are sentient.
The development of animal welfare science
Animal welfare science has developed rapidly in recent years. Welfare refers to a
characteristic of the individual animal rather than something given to the animal by
people (Duncan 1981). Broom (1986) defined the welfare of an individual as its state
as regards its attempts to cope with its environment. It has been emphasised (Duncan
1981, Broom 1988, 1991a,b, Broom and Johnson 2000, Fraser 2008) that welfare can
be measured scientifically, independently of any moral considerations. Once the
welfare has been objectively assessed, ethical decisions can be taken about what is to
be done about it. The definition refers to a characteristic of the individual at the time,
i.e. how well it is faring (Broom and Fraser 2007, Broom 2008). This state of the
individual will vary on a scale from very good to very poor. Welfare will be poor if
there is difficulty in coping or failure to cope so that the individual is harmed. One or
more coping strategies may be used to attempt to cope with a particular challenge so a
wide range of measures of welfare may be needed to assess welfare.
Feelings, such as pain, fear and pleasure, are often a part of a coping strategy and they
are a key part of welfare (Duncan and Petherick 1991, Broom 1991b, 1998). They are
adaptive aspects of an individual's biology which must have evolved to help in
survival just as aspects of anatomy, physiology and behaviour have evolved. Fear and
pain can play an important role in the most urgent coping responses, such as
avoidance of predator attack or risk of immediate injury. Coping with pathology is
necessary if welfare is to be good so health is an important part of the broader concept
of welfare, not something separate (Dawkins 1980, Webster 1994, Broom 2006,
Broom and Fraser 2007). When considering how to assess the welfare of animals it is
necessary to start with knowledge of the biology of the animal and of all of its needs.
It is more useful to consider the needs of animals of a given species, using scientific
information about them, than to use the more vague concept of freedoms.
Welfare can be assessed using an array of measures including those of strength of
avoidance and extent of other behavioural responses, physiological responses and
pathologies (Broom and Johnson 2000, Broom and Fraser 2007, Fraser 2008). There
are differences between welfare indicators for short-term and long-term problems.
Short-term measures like heart-rate and plasma cortisol concentration are appropriate
for assessing welfare during handling or transport but not during long-term living
conditions. Some measures of behaviour, immune system function and disease state
are more appropriate for long-term problems. Welfare over longer periods is
sometimes referred to as quality of life (Broom 2007b). Measures of good and poor
welfare include a wide range of other physiological indicators and behavioural
indicators of pleasure, aversion and the extent of problems encountered. In addition,
measures of immunosuppression, disease prevalence, body damage, brain function,
ability to grow or breed and life expectancy are used.
We can find out from animals what they need by measuring how hard an individual
will work for a resource or to avoid an adverse impact. Animals will learn to travel
distances, lift weights, operate levers, or undergo unpleasant experiences in order to
achieve objectives so their actions can be used as measures of motivational strength.
Terminology used in motivational strength estimation is similar to that used in micro-
economics. Reference is made to: resources, demand, price, income, price elasticity
of demand and the consumer surplus (Kirkden et al. 2003).
The magnitude of good or poor welfare is a function of the intensity of effect and the
duration (Broom 2001). The extensive literature on the effects of handling, transport,
stunning and killing of animals (Broom and Fraser 2007, Broom 2008) is relevant to
whales. In addition to evaluation of whale welfare during whaling, the impact of
whale watching on whale welfare also requires study (Higham and Lusseau 2007).
Measurable welfare during whaling
The assessment of whale welfare can be carried out using many of the measures
mentioned above to assess the effects of disturbance by humans, fear engendered by
pursuit or perceived imminent capture, pain resulting from tissue damage or other
tissue modifying conditions, and procedures that lead to unconsciousness and death.
These topics are described briefly here whilst the substantial literature on hunting and
killing methods is reviewed by Mitchell et al 1986 and by Kestin 2001 and Bass and
Brakes (in press), who also describe some of the impact on whales.
1. Disturbance and chasing by boats can lead to fear, exhaustion, social disruption,
and perhaps to immunosuppression and increased disease. Measures of welfare during
transport and in pre-slaughter handling can be used to evaluate these components of
poor welfare (Broom and Fraser 2007, Broom 2008). There are publications showing
that whales sometimes ignore ship noise but they do respond to stimuli that may be
associated with being chased (Nowacek et al 2004). There is little direct evidence in
relation to whaling but the sonic output from whaling boats is likely to disturb whales
and whales are known to change behaviour in response to boat noise (Nowacek et al
2007). Many other studies of whale responses to noise have been carried out,
including for example ways of minimising the risk of whale entanglement in nets
(Goodson et al 1994).
2. Harpoon entry into tissues may involve a point with a barb or an explosive that
detonates, usually after the harpoon has entered the body (Oen 1995, Blix et al 2000).
Both will result in tissue damage and severe pain but the duration will vary greatly
and can be measured (Knudsen and Oen 2003, Gales et al 2007). The large literature
on the assessment of pain and other poor welfare as a result of injury is relevant here.
There is some evidence concerning the duration of the period from impact until
unconsciousness or death (Oen et al 1995). Recent collection of data in Norway on
this interval, presented as International Whaling Commission papers (see Bass and
Brakes in press), indicates that some whales die or become unconscious within one
minute of impact but there is doubt about how many short and long intervals there
are. A grenade harpoon has to strike in a small area in order that the animal will be
immobilised (Knowles and Butterworth 2006, Ishikawa and Shigemune 2008). If it is
not immobilised, the magnitude of poor welfare will be very high because the
extensive injury means a high intensity and the duration is long as it can be many
minutes or hours or longer.
3. The effects of the period of pull on the line attached to harpoon will be fear when
the whale is not able to control its movements, the extra pain when pulled and the fear
and distress associated with the perceived probability of capture. The duration of the
period when the line is being pulled can be measured. The pain and fear could be
measured using monitoring devices but this is not necessary as it is known that it will
be considerable. However, the cognitive ability of whales is certainly sufficient for:
(a) awareness of increasing proximity to the ship and (b) awareness of greater risk of
capture when close to the ship.
4. The procedures at capture will have adverse effects that will be very substantial
(Swarbrick 2001). The delay after any hoisting, or gaffing with large hooks inserted
into the flesh, or electric lancing, or shooting but before unconsciousness can be
measured. There is much information about the effects of procedures at slaughter in
farmed animals. There is some information about such effects in animals trapped and
shot on land. However, little is known about the effects of capture on whales. It is at
this time that scientific data on welfare could be readily collected. Even without good
data, extreme poor welfare can be logically assumed because of the pain and stress
5. There are some difficulties to identify exactly when a captured whale is
unconscious and when it is dead. However, the methodology for this is available in
the scientific literature. Jolly 1986, Butterworth et al (2004), Butterworth (2005) and
Knudsen (2005) review the possibilities for evaluating insensibility and death in
6. It is also relevant to measure the severity of effect and recovery time if a whale is
wounded by a harpoon but escapes. Giménez et al (2011) showed that healing of
small wounds took 3-140 days.
The term humane
The term humane in relation to animals means their treatment in such a way that their
welfare is good to a certain high degree. The welfare is either above the threshold, in
which case the treatment is humane, or it is not. Humane killing implies either that
the treatment of the animals in the course of the killing procedure does not cause poor
welfare, or that the procedure itself results in insensibility to pain and distress within
a few seconds (Broom 1999). With present methodologies for catching whales during
whaling, the extent of poor welfare during catching and killing always appears to be
substantial. Indeed, the magnitude of poor welfare is much greater than that of any
legally permitted method of killing a domestic or wild animal. The whale killing
procedure would be humane for very few whales.
I thank Arnoldus Blix and Sabrina Brando for helpful discussions.
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