In management terms, it is such fishing effort that is the best proxy for fishing mortality, the latter being the product of the former.On average, the 15 days per month limits imply a reduction in UK fishing effort on cod of 25%; the 2001-02 decommissioning schemes imply a reduction in UK fishing effort on cod of around 10%, and other measures (such as Scottish mesh size changes) might also reasonably be expected to deliver some reduction in fishing mortality.We negotiated on the basis of such assumptions and concluded that further decommissioning schemes in the UK should aim to remove an additional 15 to 20% of UK fishing effort on cod to ensure reasonable consistency with the 65% reduction in fishing mortality implied by the agreed TACs.