SC/59/O2

Necessity of combining lethal and non-lethal methods forwhale population research and their application in JARPASEIJI OHSUMI, MUTSUO GOTO AND SEIJI OTANIThe Institute of Cetacean Research, 4-5, Toyomi-cho, Chuo-ku, Tokyo, 104-0055, Japan.

ABSTRACT
Effective combination of lethal and non-lethal methods is needed to conduct whale population research taking
into consideration the biological characteristics of the target whale species and the practicality of the researchmethods used. The merits and demerits on these two kinds of research methods were compared for sevenbiological characteristics and for four items related to their practicality.
The JARPA was conducted on the Antarctic minke whale populations by effective combination of lethal andnon-lethal methods to fulfil its research objects.

KEY WORDS
Lethal method, non-lethal method, whale population research, JARPAINTRODUCTION
Conservation and management of any living marine resources, including whales, requires a variety of biologicalinformation; growth, reproduction, recruitment, mortality, estimates of abundance, distribution of the resource,
response of the resource to fishing, environmental factors, interactions with other species, and the inter-annual
variability of these factors, etc. Furthermore, depending on the character of analysis, different degrees ofstatistical accuracy are required.
There are lethal and non-lethal methods to study wild animals. Both methods have practical merits and demerits,
so that it is ideal to combine the merits of both methods in order to conduct research effectively and efficiently
according to the characteristics of target whale species, its population level, available technology and theenvironment of the target population. However, discussions about the need for and the effectiveness of lethal
and non-lethal research method have been often conducted without regard to such complexities.
The scientific research which Japan has carried out in the Antarctic (JARPA and JARPAII) and the western
North Pacific (JARPN and JARPNII) are conducted using a combination of both methods. This document was
prepared in order to provide a road map for the consideration of the issue of application of lethal and non-lethal
research methods for JARPA.

BIOLOGICAL CHARACTERISTICS OF WHALES IN RELATION TO POPULATION RESEARCH
Among the wild animals, whales have several unique characteristics related to the applicability and effectivenessof lethal and non-lethal research methods. Research objectives and obtaining a statistically significant sample
size are also factors that need to be considered in choosing the appropriate research methods. The following are
examples of such considerations.

1. Whales are completely aquatic and are distributed over huge oceanic ranges
Whales are mammals which spend their entire life in huge oceanic environments. Stranding is rare and stranded
animals can in no way be considered as normal individuals in terms of their health and behaviour patterns.
Therefore, data from stranded animals are useful but could be heavily biased. This means that population1

research must be conducted in the open sea where random sampling of normal animals is possible, and that
research vessels are needed to fulfil the study.

2. Whales swim fast and migrate long distanceThe breeding and feeding grounds of large whales are separated by very long distances. Whales migrate
between these two grounds seasonally. They have a general characteristic to gather in the feeding ground, anddisperse in the breeding ground. Whales usually swim at high speed for long periods of time. Thus, a catcher
boat with high speed is needed to apply lethal methods. A research vessel and speed boat carried by the vessel isrequired for non-lethal research such as biopsy and biologging surveys. Research using such non-lethal methods
in rough sea conditions is accompanied by considerable danger because non-lethal research usually uses smallboats.

3. Many kinds of whales have few distinctive morphological characteristics and their population size is large
There are few distinctive individual body characteristics in many whales such as the Antarctic minke whale. In
addition, the population size of many whales such as the Antarctic minke whale is large. This makes theapplication of non-lethal methods like individual identification by biopsy and photo-ID difficult for the whales
with these two biological characteristics. Even if a whale species has distinctive body characteristics, theapplication of individual identification is not practical, when the population size of this species stock is large.

4. Whales have a relatively high age of sexual maturity, a breeding cycle over many years and a long life span
Many years of tracking the same individual are needed to obtain data on these biological parameters by use of
non-lethal methods. Further, such tracking of many individuals is needed to obtain these data with statisticalsignificance making it practically impossible and certainly not cost effective. On the contrary, lethal method ismore useful for this kind of study because a large number of more accurate data can be collected in a shortertime.

5. Whales drown by anaesthesia
As the respiration of whales is controlled by voluntary muscle, they drown when anaesthetized. It is therefore
impossible to hold a whale under anaesthetic to carry out non-lethal measurements or experiments as is the casefor terrestrial mammals.

6. It is impractical to keep large whale in aquarium
Observation over long periods of time of large whales kept alive in an aquarium is still impractical. Even if it
becomes practical, this method would be opposed by some for moral reasons.

PRACTICAL CONSIDERATIONS IN WHALE POPULATION RESEARCH
We must consider the practical matters to conduct whale research in addition to the biological characteristics ofthe target whale species.

1.

Scale of the research
For conducting research in large areas of open sea in which rough weather and sea conditions are frequent,large sized research vessels are required. Therefore, it is not practical to conduct large scale whale research byuse of non-lethal methods exclusively in the open sea, for it is very costly in such a case. On the other hand,lethal methods which could earn research cost are most desirable.

2.

Practicability of research
Even if a method is theoretically reasonable, there are often practical problems to apply the method in theactual research. For example, while feces sampling may be theoretically reasonable, feces of whales are liquidand diffuse quickly and widely. Furthermore, the excretion of a whale is seldom observed. Therefore, while it is2not impossible to collect feces by chance, it is not practical to use the feces sampling method in researchrequiring statistically meaningful samples from a large number of animals.

3.

Securing of suitable research vessels, skilful crew and researchers
The maintenance of suitable research vessels and skilled crews and researchers are needed to conduct longterm population research in the open sea. Thus, whale research is costly and it is practically difficult to keepthese vessels, crew and researchers in the case in which large scale research by means of only non-lethal researchis conducted over many years to continue long term research projects.

4.

Cost of research
Population research of whales in the open sea requires very considerable expenditures. Such expenditures
over long periods of time are almost impossible to fund without some cost recovery. The use of only non-lethal
methods does not provide the possibility for cost recovery whereas most of such costs can be recovered byselling of by-products when lethal method is used. In addition, a large whale body makes it impossible for one
person to take measurements or record significant data. Even in the case of non-lethal methods, the cooperationof many persons is needed. Whale research is costly and therefore lethal methods which could recover the costfor research is more desirable. Processing of by-products obtained from lethal research is an obligation underparagraph 2 of Article VIII of the ICRW.

COMPARISON OF THE CHARACTERISTICS OF LETHAL AND NON-LETHAL METHODS
Lethal and non-lethal methods each have their own characteristics that must be considered in relation to theresearch objectives and factors such as the target whale species, research field, research season, research period,
and research cost in addition to the biological and practical factors above. The ability to utilize the resource isalso a factor. These are shown in Table 1.

APPLICATION OF LETHAL AND NON-LETHAL METHODS FOR JARPAThe JARPA which was specifically designed to provide data for improving the management of whale resources
was conducted using a combination of lethal and non-lethal methods as shown in Table 2 . Some of the research
objectives simply could not have been achieved using only non-lethal methods because internal organs wererequired. In other cases, the need for a large number of samples collected over a large area and long time period
in order to achieve statistically meaningful results made the use of non-lethal methods impractical, costineffective and prohibitively expensive.

ACKNOWLEDGEMENTS
Our sincere thanks are due to Mr. Joji Morishita of the Fisheries Agency of the Government of Japan and Mr.
Dan Goodman of the Institute of Cetacean Research for their constructive suggestions and comments.

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identification of krill species and its application to analyzing the diet of marine vertebrate predators.
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based analysis of species diversity and identity in dietary samples. Molecular Ecology 13: 1313-1322.
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whale scats. Paper SC/58/E29 presented to the IWC Scientific Committee (May 2006).
11. Pettis, H. M., Rolland, R. M., Hamilton, P. K., Brault, S., Knowlton, A. R. and Kraus, S. D. 2004 Visual
health assessment of North Atlantic right hales (Eubalaena glacialis) using photographs. Canadian Journalof Zoology 82:8-19.
12. Murase, H., Kiwada, H., Matsuoka, K. and Nishiwaki, S. 2006 Resutls of the cetacean prey survey using
echo sounder in JARPA from 1998/99 to 2004/2005. Paper JA/J06/JRxx presented to the JARPA Review
Meeting, December 2006 (unpublished). xxpp.
13. Murase, H., Tamura, T., Nishiwaki, S., Yasuma, H., Matsuoka, K., Yabuki, T. and Naganobu, M. Biomass
estimaton of Euphausia superba and E. crystallorophias in the Ross Sea in 2004/05 using Kaiyo MaruJARPA joint survey data. Paper SC/D06/J24 presented to this meeting.
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Table 1. Biological factors research requirements – a comparison of the applicability of lethal and non-lethal
methods..

Item

Lethal method

Non-lethal method

Population size

Unsuitable for rare species

Unsuitable for large sized population

Movement of whales

Applicable for slow and fast

Generally applicable only for slow

Morphological Characteristics

applicable for species without
Effective for species with individuallyindividually distinctive characteristics distinctive characteristics

Number of samples

Can collectable of large number ofsamples

Only small number of samples can becollected

Samples from bodyCollectable from inside the bodyCollectable only from body surface

Research fieldCan be surveyed in bad conditions

Can be surveyed only in goodconditions

Time of research

Day time only

Possible in night time in some cases

Possible research time period

Possible to use over long time period
in a season

Can be used only for short time
periods of a season

Research time required

For some research objectives, results
available within relatively few years

Need to survey for long number ofyears

Data continuity

Data available only at time of capture

Can observe the same individual for
longer time

Scale of research

Need of equipment to catch andprocess of whales

Catching and processing equipment
not needed

Cost of research

Cost recovery possible by utilizationof by-products

Large amount of cost is needed

Utilization of resources

Can utilize the resources

Cannot use the resources

Table 2. JARPA objectives, research items, application of lethal and non-lethal methods and the reason for the
judgment of their effectiveness

JARPA
objectives

I. The estimationof biologicalparameters to
improve the stock
management of
whalesApplication for
JARPA
Research items

LethalmethodNon-lethal
methodReasons for judgment of effectiveness of theresearch methods for achievement of JARPA
objectives
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).

Age determination

Yes

No

It's difficult to estimate accurate age by use of nonlethal method such as telomere other than using
ear plug (3).
The long-term observation with individual
identification is not possible for A. minke whale,because of high level of abundance and absence ofdistinct body characteristics.

Natural mortality

Yes

No

5

It is difficult to collect large number of samples
from whole survey area for accomplishment ofJARPA objectives with biopsy (2).
It's difficult to estimate accurate age by use of nonlethal method such as telomere other than using
ear plug (3).
The long-term observation with individual
identification is not possible for A. minke whale,because of high level of abundance and absence ofdistinct body characteristics.
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).

Age at sexual
maturity

Yes

No

It's difficult to estimate accurate age by use of nonlethal method such as telomere other than using
ear plug (3).
The long-term observation with individual
identification is not possible for A. minke whale,because of high level of abundance and absence ofdistinct body characteristics.
Determination of sexual maturation is difficult
with feces and biopsy samples (4,5,6).
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).

Pregnancy rate

Yes

No

The long-term observation with individual
identification is not possible for A. minke whale,because of high level of abundance and absence ofdistinct body characteristics.
Gestation period is not understood with the biopsy
.

(5,6)

II. Theelucidation of therole of whales in
the Antarctic
marine ecosystem

III. Theelucidation of theeffect ofenvironmental
changes on
cetaceans

Abundance

No

Yes

Sighting survey is useful for estimation ofabundance (7).

Feeding habit

Yes

No

Prey species proportion in the stomach, feedingtime etc. are not understood by feces survey (8,9,10).

Body fatness

Yes

No

Estimation of body fatness is not accurate withphotographic method (11).

Prey species
biomassNo

Yes

Echo sounder survey as well as stomach contents
survey are useful for estimation of prey abundance(12,13).
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).

Accumulation ofheavy metal andorganochlorines

Yes

No

It's difficult to estimate accurate age by use of nonlethal method such as telomere other than using
ear plug (3).
Evaluation of effect of contaminants on whale aswell as the monitoring of the accumulation trend isconducted in JARPA survey based on biological
data such as age, body length and weight ofstomach contents (14,15,16).

6

IV. Theelucidation of therange ofdistribution andboundary ofwhale stocks

Sighting survey is useful for estimation ofabundance (17).

Change inabundance of otherwhale species

Yes

Yes

Separation ofstocksYes

No

Detection ofbreeding area

Mixing of stocks
within feeding area

The data of body condition by lethal survey
provides powerful evidence (18).
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).
Attachment of satellite tag to A. minke whale has
been attempted in JARPA (19).

Yes

Yes

Yes

No

Discovery type Mark-recapture is used for
JARPA.
It is difficult to collect large number of samples
from whole survey area for accomplishment of
JARPA objectives with biopsy (2).
Attachment of satellite tag to A. minke whale has
been attempted in JARPA (19).

V. Others

Other whale
species

No

Yes

Basic study ofartificial
insemination

Yes

No

7

Sighting survey, biopsy sampling and photoidentification are conducted.
It is impossible to collect ovum and sperm by nonlethal method.