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The Revised Management Procedure (RMP) is the process developed by the IWC's Scientific Committee to estimate sustainable catch limits for commercial whaling of baleen whales.

In 1986 the Commission introduced a moratorium on commercial whaling and set all catch limits to zero.  It asked the Scientific Committee to develop a new, safe and practical approach to providing scientific advice on commercial catch limits. 

This was a complex task and took eight years to complete.  It involved data evaluation and analysis, computer modelling and the development and trialling of alternative ways to calculate safe catch limits.  Each approach was subject to rigorous tests, and a set of accompanying rules and data requirements was also devised to ensure data quality and consistency of method. 

The RMP was adopted by the Commission in 1994 and is regarded as setting a precedent for provision of scientific management advice for marine and other living resources.  This is in part because the RMP was the first process to take into account the large levels of uncertainty inevitable in disciplines like cetacean science. 

The RMP has two stages.  The first is the Catch Limit Algorithm (CLA).  The same CLA is used for all whale species and all areas.  This is a mathematical formula which requires only the two most reliable pieces of information to calculate a safe catch limit.  The two pieces of information are:

  1. an estimate of the whale population (known as an 'abundance estimate')
  2. past (and, if relevant, present) catch numbers

The second stage of the RMP is known as Implementation or Implementation Review.  This is a review of all the available information on all the populations of a single species within a specific region (usually an ocean basin, for example the North Atlantic), at a particular time.  Therefore each Implementation or Implementation Review is a new, unique process. 

Many regions  include a number of separate or overlapping populations of the same  species.  Understanding this 'stock structure' is an important aspect of the Implementation process, in part because the CLA establishes a total catch limit for that region, and this total must be divided between the different populations.

For largely unseen and migratory animals like most whale species, it is extremely difficult to establish any definitive facts and figures.  Computer modelling is used to test the robustness of the CLA against many uncertainties, using the widest possible variety of plausible scenarios.  Testing different theories regarding stock structure (the numbers within each population, their boundaries and movements across those boundaries) is the most challenging test of the CLA. 

Following these tests, the total catch limit for the region, as established by the CLA, is distributed between different populations within the designated region.  Precisely how the catch limit is distributed depends on the nature of the stock structure and the number of different populations within the region.

The RMP has  many uses aside from setting catch limits.  The modelling component particularly can be used to test and understand the impact of different potential threats to individual whale populations, for example habitat degradation, ship strikes, or contagious disease.  

The Commission decided that the RMP should not be implemented and used in the context of whaling until the accompanying Revised Management Scheme (RMS) was agreed.  The RMS covers the aspects of commercial whaling regulation not related to setting catch limits, such as observer schemes and record keeping.  The Commission recognised that discussions on the RMS had reached an impasse in 2006 and the commercial whaling moratorium remains in place.

  • To read more about the RMP click here.
  • To read a chronological account of negotiations regarding the RMS click here.
  • Click here to read The Revised Management Procedure for Baleen Whales (Scientific Committee document)