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CONTENTS
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ESTIMATES
Estimating the abundance of animals that spend most of
their time below the surface is difficult. The Scientific
Committee has developed guidelines on how to best estimate
abundance of whales from ships and aeroplanes for use in the
RMP. Other methods include a combination of visual and
acoustic techniques (e.g. bowhead whales off Alaska) or
mark- recapture techniques using the natural marks found on
some species that allow individuals to be identified (e.g.
humpback whales in the North Atlantic). Because of the considerable scientific
uncertainty over the numbers of whales of different species
and in different geographical stocks, the International
Whaling Commission decided in 1989 that it would be better
not to give whale population figures except for those
species/stocks which have been assessed in some detail. This does not mean that there are not other
published estimates of some species or populations or areas.
At present, these are the best estimates (and associated confidence
intervals) for some species and areas. |
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Population |
Year(s) to which
estimate applies |
Approximate point
estimate |
Approximate 95%
confidence limits |
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MINKE WHALES |
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Southern Hemisphere
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1982/83 - 1988/89 |
761,000 |
510,000 - 1,140,000 |
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Current |
The Commission is
unable to to provide reliable estimates at
the present time. A major review is underway
by the Scientific Committee. |
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North Atlantic
(Central & Northeastern) |
1996-2001 |
174,000 |
125,000 - 245,000 |
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West Greenland |
2005 |
10,800 |
3,600 - 32,400 |
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North West Pacific and
Okhotsk Sea |
1989-90 |
25,000 |
12,800 - 48,600 |
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BLUE WHALES |
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Southern Hemisphere
(excluding pygmy blue) |
1997/98 |
2,300 |
1,150 - 4,500 |
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The estimated rate of increase is 8.2% (95% confidence
interval 3.8-12.5%) per year between 1978/79 and 2003/04 |
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FIN WHALES |
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North Atlantic
(Central & Northeastern) |
1996-2001 |
30,000 |
23,000 - 39,000 |
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West Greenland |
2005 |
3,200 |
1,400 - 7,200 |
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GRAY WHALES |
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Eastern North Pacific |
1997/98 |
26,300 |
21,900 - 32,400 |
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The population was
increasing at a rate of 3.2% (95% confidence
interval 2.4% - 4.3%) over the period
1967/68 - 1987/88 with an average annual
catch of 174 whales. |
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Western North Pacific |
2007 |
121 |
112 - 130 |
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BOWHEAD WHALES |
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Bering-Chukchi-
Beaufort Seas stock |
2001 |
10,500 |
8,200 - 13,500 |
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The net rate of increase of this population since 1978 has been estimated as
about 3.2% per year
(95% confidence interval 1.4% - 5.1%).
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Off West Greenland |
2006 |
1,230 |
490 - 2,940 |
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HUMPBACK WHALES |
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Western North Atlantic |
1992/93 |
11,600 |
10,100 - 13,200 |
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A rate of population
increase of 3.1% (SE=0.005) was obtained
from the Gulf of Maine for the period
1979-1993 |
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Southern Hemisphere
south of 60S in summer (i.e. incomplete) |
1997/98 |
42,000 |
34,000 - 52,000 |
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Rates of increase. East Australia: 1981-96 12.4% (95%CI 10.1-14.4%). West
Australia: 1977-91 10.9% (7.9-13.9%) |
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North Pacific |
2007 |
at least 10,000 |
not yet available |
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Rates of increase of about 7% have been reported for
the eastern North Pacific, 1990-2002. |
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RIGHT WHALES |
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Western North
Atlantic |
2001 |
about 300 |
not available |
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Southern Hemisphere |
1997 |
about 7,500 |
not available |
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There is evidence of increase rates of 7-8% for
populations of Argentina, Australia and South Africa |
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PILOT WHALES |
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Central & Eastern North
Atlantic |
1989 |
780,000 |
440,000 - 1,370,000 |
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THE COMPREHENSIVE
ASSESSMENT When, at its 1982 meeting,
the IWC agreed to a pause in commercial whaling
(or to use popular terminology, a 'moratorium') from
1986, the amendment to the regulations included
a clause that 'the Commission will undertake a
'comprehensive assessment' of the effects of this
decision on whale stocks and consider modification
of this provision and the establishment of other
catch limits'.
The term 'Comprehensive Assessment' had not been
defined by the Commission and eventually the
Scientific Committee defined it to be:
'an in-depth evaluation of the
status of all whale stocks in the light of
management objectives and procedures... that ...
would include the examination of current stock size,
recent population trends, carrying capacity and
productivity'.
To date the Committee has
completed or is still undertaking such in-depth
analyses of:
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Antarctic minke whales -
Southern Hemisphere;
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Common minke whales - North
Atlantic; western North Pacific
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Fin whales - North Atlantic
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Humpback whales - Southern
Hemisphere and North Atlantic
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Bryde's whales - western
North Pacific
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Bowhead whales - Bering-Chukchi-Beaufort
Seas
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