Whaling Models for Cetacean Conservation

Conclusions

The IWC’s RMP makes use of a CLA with a simple density-dependent model that only requires data on previous catch and current stock size from which to set catch quotas. Although the underlying model is simple in structure, the algorithm is designed to reduce harvests to compensate for uncertainty in a way that makes it unlikely that overexploitation will occur when following the CLA. Careful consideration for uncertainty ensures that the RMP will be a safer model for governing whale harvests than its predecessor, the New Management Procedure. The RMP’s Bayesian approach to interfacing data with the model affords a powerful way to design ecological models. Nevertheless, problems with implementation may remain due to excessive harvests under the CLA if there are unreported harvests, overestimates of stock size, and failure to identify spatially structured stocks.

To my mind, however, these problems pale in comparison to the fundamental flaw that the RMP is a single-species approach to management that fails to consider ecosystem structure and function in setting management objectives. Despite knowledge that the krill-based ecosystem of the southern ocean has been seriously disrupted by the decimation of the great whales, the IWC has recently established a sanctuary making the entire region off limits to whaling. This may not be sufficient, and recovery of the great whales may require intervention by selective removal of Minke Whales as proposed by Japan. If taken in the context of the ocean ecosystems in which it would be applied, the RMP could provide a useful baseline for adaptive management.

The moot point is, whether Leviathan can long endure so wide a chase, and so remorseless a havoc; whether he must not at last be exterminated from the waters, and the last whale, like the last man, smoke his last pipe, and then himself evaporate in the final puff. —Herman Melville, Moby Dick (1851)