Winners and losers of a technical change: A case study of long-term management of the Northern European Hake

Abstract

Since 2004 management of the Northern Stock of European Hake has been focused on recovering the stock level up to a level consistent with the precautionary approach. After that, in 2007 and once this objective was on the track of being fulfilled a long term management plan was proposed. This plan has to be congruent with the maximum sustainable yield policy as well as producing stable yields and population levels. Thus, in that year, a bioeconomic impact assessment of long-term management plans for this stock was carried out. However the biological and economic assessments were not integrated and not fully congruent. On the basis of this assessment additional questions relating to the combination of harvest control rules with technical measures were raised by the managers and stakeholders. Here, the model used in the biological assessment is extended in order to integrate the economic part and to shed light on the effect of technical measures at stock and fleet level. Two scenarios are presented: a `base case', where the model is parameterized from historical observations; and an `alternative case' where an increase in the mesh size of some trawlers is simulated. In both scenarios the probability of falling below limit reference points is above 0, contrary to the result obtained in 2007. However, the relative trends of the median of population indicators are similar. While the biological performance of the base and alternative scenarios is also similar the trawlers are highly penalized when their mesh size is increased and the overall economic profit is lower. Furthermore, two fleets gain and the rest remain the same with the increase in the mesh size of trawlers. (C) 2011 Elsevier B.V. All rights reserved.