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Whale Watching

 
 
 
 

Whale Population Estimates

The International Whaling Commission's most recent information on estimated abundance

On this page

Population table The IWC's figures for estimated whale populations
Comprehensive Assessment The comprehensive assessment of current whale stocks
Status of whales A brief overview of the ‘status’ of whale populations 

Estimates

Good conservation and management requires and understanding of the status of populations. A key component of this is, of course, an estimate of present abundance (and ideally trends in abundance) against which possible threats can be evaluated.

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.

The Scientific Committee is undertaking a major compilation and review of abundance estimates that is expected to be completed by mid-2013. Meanwhile, below is a selection of  approximate ‘best’ estimates (and their associated approximate 95 % confidence intervals) for some species and areas.


MINKE WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

Southern Hemisphere

1985/86-1990/91

720,000

510,000 - 1,010,000

 

1992/93-2003/04

515,000

360,000 – 730,000

North Atlantic

 

 

 

Northeastern

1998-89

65,000

125,000 - 245,000

 

1995

112,000

 

 

1996-2001

80,000

 

 

2002-2007

81,000

 

Central

2005-2007

40,000

 

West Greenland

2007

17,000

7,500 – 39,000

North Pacific

     

North West Pacific and Okhotsk Sea

1989-90

25,000

12,800 - 48,600

 

2003

Ca 22,000+

Under review

BLUE WHALES

 

Year(s) to which estimate applies

Approximate point estimate

Approximate 95% confidence limits

Southern Hemisphere (excluding pygmy blue) 

1997/98
2,300
1,150 - 4,500

The estimated rate of increase is 8.2% (95% confidence interval 3.8-12.5%) per year between 1978/79 and 2003/04

FIN WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

North Atlantic

 

 

 

East Greenland to Faroes

1988

15,000

11,000 – 19,000

 

1995

22,000

16,000 – 30,000

 

2001

26,000

20,000 – 33,000

 

2007

22,000

16,000 – 30,000

West Greenland

2007

4,500

1,900 – 10,000

GRAY WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

North Pacific

 

 

 

Eastern

1997/98

21,000

18,000 – 24,000

 

2000/01

16,500

14,000 – 18,000

 

2001/02

16,000

14,000 – 18,000

 

2006/07

19,000

17,000 – 22,000

Western

2007

121

112 - 130

BOWHEAD WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

North Pacific

 

 

 

Bering-Chukchi- Beaufort Seas stock

2001

10,500

8,000 – 13,000

 

2004

11,800

7,000 – 21,000

West Greenland feeding area

2010

1,750

1,000 – 2,500

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%).
 

HUMPBACK WHALES

 

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

Southern Hemisphere

     

Partial coverage of Antarctic feeding grounds

1997/98

42,000

34,000 – 52,000

Eastern South America

2005

6,200

4,600 – 8,500

 

Rate of increase of around 7%

Western South America

2003-4

2,900

2,000 – 4,200

Western Australian

2008

29,000

24,000 – 40,000

 

Rate of increase of around 10% 1999-2008

Western Africa

2005

9,800

7,000 – 12,000

 

Rate of increase of around 4-5%

Eastern Africa breeding stock(s)

2006

14,000

11,000 – 19,000

North Atlantic

 

 

 

Western North Atlantic

1992-93

11,600

10,000 – 13,000

West Greenland

2007

3,000

1,000 – 8,000

 

Rate of increase of around 9% 1984-2007

North Pacific

2007

22,000

19,000 – 23,000

Arabian Sea

2007

80

60 - 110

RIGHT WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

Southern Hemisphere

2009

12,000

 

Southwest Atlantic

2009

3,300

 

 

Rate of increase around 7%

Southern Africa

2009

3,900

 

 

Rate of increase around 7%

Sub-Antarctic New Zealand

2009

2,700

 

South central and Western Australia

2009

2,000

 

 

Rate of increase around 7%

North Atlantic

2010

490

 

BRYDE’S WHALES

 

Year(s) to which estimate applies

‘Best’ estimate

Approximate

95% CI

North Pacific

 

 

 

Western

1999-2000

21,000

8,000 – 51,000

Pilot Whales

 

Year(s) to which estimate applies

Approximate point estimate

Approximate 95% confidence limits

 

Central & Eastern North Atlantic

1989

780,000

 440,000 - 1,370,000

 

 
 

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:

  • Antarctic minke whales - Southern Hemisphere;
  • Common minke whales - North Atlantic; western North Pacific
  • Fin whales - North Atlantic
  • Humpback whales - Southern Hemisphere and North Atlantic
  • Bryde's whales - western North Pacific
  • Bowhead whales - Bering-Chukchi-Beaufort Seas
  • Blue whales – Southern Hemisphere
  • Sei whales – North Pacific