8. Whaling Models for Cetacean Conservation
111
management procedure (NMP) was adopted by the IWC that based harvest quotas
on a harvest model adapted from fisheries (Young 1993). With this model, quotas
were set for each species at levels thought to be sustainable.
In some instances, the apparent mismanagement of whale stocks may partly
relate to the modeling approach used to recommend quotas for taking whales. The
underlying structure of the NMP was a model of maximum sustained yield (MSY)
(i.e., harvesting that achieves a maximum harvest that can be sustained indefinitely). Flaws in the IWC’s application of the MSY model included (1) poor or
insufficient data with which to parameterize the model, and (2) inappropriateness
of the model because it is a single-species equilibrium model (Botkin 1990).
Further problems plagued implementation of the NMP that could be attributed to
inflexible management procedures on the part of the IWC and their refusal to heed
advice of the Commission’s Scientific Committee (Frost 1979; Smith et al. 1994).
Perhaps most important, insufficient attention had been given to the role that
uncertainty should play in shaping harvest quotas.
Finally, the IWC agreed in 1982 to establish an indefinite moratorium on
commercial whaling effective in 1986. To conclude the moratorium, the IWC’s
Scientific Committee developed a revised management procedure (RMP) that
offers a more conservative and robust method for setting whaling quotas. The
RMP requires data on stock size and harvests of sufficient accuracy and precision
to ensure that populations are not overexploited before implementation can go
forward.
Japan and Norway are forcing the issue to lift the moratorium on whaling.
Indeed, Norway began whaling again, in 1993 taking 226 Minke Whales (Balaenoptera acutorostrata). Japan has asked to harvest 2,000 Minke Whales annually from Antarctic seas and has spent millions of dollars on sighting surveys to
justify future whaling.
Management Objectives
In 1989, the IWC provided its Scientific Committee with priority criteria for the
RMP. These included (1) perpetuation of stocks, (2) maximum sustained harvest,
and (3) relative constancy of catch limits. The IWC gave clear priority to conservation (i.e., the first criterion). To optimize the harvest under these seemingly
conflicting objectives, the IWC proposed to use a model, the catch-limit algorithm
(CLA), to set harvest quotas for whaling that are encumbered with numerous
cushions so that harvesting will occur only when it poses no threat to the persistence of populations of whales. Accomplishing this balance among objectives
requires careful consideration of various sources of uncertainty in data and the
model. If used according to the guidelines developed by the IWC, the CLA is
designed to accomplish all objectives by setting consistent harvests of whales,
while still protecting whale stocks from overexploitation. For the near future, this
implies that none of the severely depleted stocks will be harvested.
111
management procedure (NMP) was adopted by the IWC that based harvest quotas
on a harvest model adapted from fisheries (Young 1993). With this model, quotas
were set for each species at levels thought to be sustainable.
In some instances, the apparent mismanagement of whale stocks may partly
relate to the modeling approach used to recommend quotas for taking whales. The
underlying structure of the NMP was a model of maximum sustained yield (MSY)
(i.e., harvesting that achieves a maximum harvest that can be sustained indefinitely). Flaws in the IWC’s application of the MSY model included (1) poor or
insufficient data with which to parameterize the model, and (2) inappropriateness
of the model because it is a single-species equilibrium model (Botkin 1990).
Further problems plagued implementation of the NMP that could be attributed to
inflexible management procedures on the part of the IWC and their refusal to heed
advice of the Commission’s Scientific Committee (Frost 1979; Smith et al. 1994).
Perhaps most important, insufficient attention had been given to the role that
uncertainty should play in shaping harvest quotas.
Finally, the IWC agreed in 1982 to establish an indefinite moratorium on
commercial whaling effective in 1986. To conclude the moratorium, the IWC’s
Scientific Committee developed a revised management procedure (RMP) that
offers a more conservative and robust method for setting whaling quotas. The
RMP requires data on stock size and harvests of sufficient accuracy and precision
to ensure that populations are not overexploited before implementation can go
forward.
Japan and Norway are forcing the issue to lift the moratorium on whaling.
Indeed, Norway began whaling again, in 1993 taking 226 Minke Whales (Balaenoptera acutorostrata). Japan has asked to harvest 2,000 Minke Whales annually from Antarctic seas and has spent millions of dollars on sighting surveys to
justify future whaling.
Management Objectives
In 1989, the IWC provided its Scientific Committee with priority criteria for the
RMP. These included (1) perpetuation of stocks, (2) maximum sustained harvest,
and (3) relative constancy of catch limits. The IWC gave clear priority to conservation (i.e., the first criterion). To optimize the harvest under these seemingly
conflicting objectives, the IWC proposed to use a model, the catch-limit algorithm
(CLA), to set harvest quotas for whaling that are encumbered with numerous
cushions so that harvesting will occur only when it poses no threat to the persistence of populations of whales. Accomplishing this balance among objectives
requires careful consideration of various sources of uncertainty in data and the
model. If used according to the guidelines developed by the IWC, the CLA is
designed to accomplish all objectives by setting consistent harvests of whales,
while still protecting whale stocks from overexploitation. For the near future, this
implies that none of the severely depleted stocks will be harvested.