This estimate is based on a new line transect survey which was carried out in 1995 using methodology previously approved by the Scientific Committee.
An additional 6000 minke whales were asigned to a survey lock north and east of the Jan Mayen island.
International observers and scientists were present on the vessels, including 4 of
the 9 scientists
who took part in the group that finally established the estimate. The IWC
Scientific Committee has
later "agreed that the estimates of abundance are adequate for use in the Revised
Management
Procedure".
(The IWC Scientific Committee, 1996 Report)
The international group of scientists furthermore made a recalculation of the
estimate from the
1988/89 survey. The new figure of 65,000 was also endorsed by the Scientific
Committee.
The
recalculations came as a result of problems in reproducing the estimate of 86,700
comfirmed by
the Scientific Committee in 1992. Errors were found in the computer sofware
used. The software
has now been subject "to an extensive and independent review". (SC Report,
1996, p 16).
The international group of scientists noted that the estimates from the 1995 survey and the 1989/90 survey are not directly comparable owing to differences in methodology.
The Scientific Committee report notes that the estimate from the 1995 survey is "a more reliable estimate" than that resulting from the 1988/89 survey. Among the reasons given for this, is that during the 1995 survey there were two observer platforms on every vessel with two independent teams of observers. This was not the case in 1988/89, but a separate independent observer experiment was performed in 1990 with two platforms on one vessel.
The Scientific Committee also gives other reasons why the 1988/89 estimate could be seriously downwards biased, but notes that "a natural rate of increase" is a very likely factor involved regarding part of the difference between the two estimates.