8. Whaling Models for Cetacean Conservation
117
Catch cascading appears to work well for Minke Whales in the north Atlantic,
but choice of method must be evaluated by simulation for each area. Catch
capping is the safest approach when high variance exists among small areas.
Pooling offers advantages for catch cascading when sample sizes are small for
individual areas such that increased power associated with pooling samples can
increase yields over an area.
Even if commercial whaling were to follow the RMP, there may be errors in
stock identification that could lead to local extirpation. Uncertainty of distribution
and movement patterns is high and may vary considerably. For example, Alaskan
Humpback Whales normally winter off Hawaii, but individuals documented off
Hawaii have been seen in subsequent years off Baja (Evans 1987). Also, errors in
identification of species may occur by whalers; in particular, the status of the
Pygmy Right Whale (Caperea marginata) is poorly known, but it may be subject
to accidental harvest as a Minke Whale because it is difficult to distinguish the two
species (Evans 1987). Likewise, because of their similar appearance, whalers
often have not recognized Bryde’s (Balaenoptera edeni) and Sei Whales to be
distinct species (Gambell 1976).
Species-level problems of identification, however, are relatively minor compared with the difficulty of identifying small genetically isolated subpopulations
within a species. Recall my example that if whales from small coastal populations
are likely to be caught in conjunction with whaling of larger pelagic populations,
and if these coastal stocks are not recognized to be distinct, they easily could be
extirpated. Insufficient data exist on the spatial distribution and composition of
most whale populations to eliminate such a threat. Furthermore, due to problems
of population estimation, most estimates of stock size are burdened by enormous
confidence intervals.
Unfortunately, no monitoring is required that would ensure appropriateness of
small area definitions nor to evaluate the efficacy of harvest implementations
(Smith et al. 1994).
Should We Use the CLA?
The immediate issue at hand is whether to implement the CLA as a component of
the RMP to set quotas for the commercial harvest of Minke Whales. Strong
arguments can be made for either position. Many reasons exist to be concerned
about the reauthorization of whaling, even if primarily sanctioned for the abundant Minke Whale (plans also exist to continue with whaling for Fin Whales off
Iceland and Brudas Whales in the north Pacific). The primary arguments against
future whaling include the following: (1) Many people find whaling objectionable
on ethical grounds (Freeman and Kellert 1994) irrespective of the strength of the
stocks. (2) Nations proposing to reinstate commercial whaling have a poor track
record with documented violations of past IWC regulations. Rather than risking
future violations of quotas that could further threaten stocks perhaps the safest
approach is to ban all commercial whaling. (3) Because we do not understand the
117
Catch cascading appears to work well for Minke Whales in the north Atlantic,
but choice of method must be evaluated by simulation for each area. Catch
capping is the safest approach when high variance exists among small areas.
Pooling offers advantages for catch cascading when sample sizes are small for
individual areas such that increased power associated with pooling samples can
increase yields over an area.
Even if commercial whaling were to follow the RMP, there may be errors in
stock identification that could lead to local extirpation. Uncertainty of distribution
and movement patterns is high and may vary considerably. For example, Alaskan
Humpback Whales normally winter off Hawaii, but individuals documented off
Hawaii have been seen in subsequent years off Baja (Evans 1987). Also, errors in
identification of species may occur by whalers; in particular, the status of the
Pygmy Right Whale (Caperea marginata) is poorly known, but it may be subject
to accidental harvest as a Minke Whale because it is difficult to distinguish the two
species (Evans 1987). Likewise, because of their similar appearance, whalers
often have not recognized Bryde’s (Balaenoptera edeni) and Sei Whales to be
distinct species (Gambell 1976).
Species-level problems of identification, however, are relatively minor compared with the difficulty of identifying small genetically isolated subpopulations
within a species. Recall my example that if whales from small coastal populations
are likely to be caught in conjunction with whaling of larger pelagic populations,
and if these coastal stocks are not recognized to be distinct, they easily could be
extirpated. Insufficient data exist on the spatial distribution and composition of
most whale populations to eliminate such a threat. Furthermore, due to problems
of population estimation, most estimates of stock size are burdened by enormous
confidence intervals.
Unfortunately, no monitoring is required that would ensure appropriateness of
small area definitions nor to evaluate the efficacy of harvest implementations
(Smith et al. 1994).
Should We Use the CLA?
The immediate issue at hand is whether to implement the CLA as a component of
the RMP to set quotas for the commercial harvest of Minke Whales. Strong
arguments can be made for either position. Many reasons exist to be concerned
about the reauthorization of whaling, even if primarily sanctioned for the abundant Minke Whale (plans also exist to continue with whaling for Fin Whales off
Iceland and Brudas Whales in the north Pacific). The primary arguments against
future whaling include the following: (1) Many people find whaling objectionable
on ethical grounds (Freeman and Kellert 1994) irrespective of the strength of the
stocks. (2) Nations proposing to reinstate commercial whaling have a poor track
record with documented violations of past IWC regulations. Rather than risking
future violations of quotas that could further threaten stocks perhaps the safest
approach is to ban all commercial whaling. (3) Because we do not understand the