Blue whiting is assessed as a single stock from the Norwegian Sea down to Portugal. However recently, the Scientific, Technical and Economic Committee of the European Commission (STEFC) was requested to report on whether there is sufficient basis to implement management measures for two identifiable, seperate stocks.
Based on a review of the evidence for stock separation in northeast Atlantic blue whiting, STECF concluded that there are ‘northern’ and ‘southern’ stocks that, if technically feasible, should be treated as separate stocks for assessment and management.
STECF concluded that the southern boundary for the ‘northern’ stock lies at 53.5° N and a northern boundary for the ‘southern’ stock at 52.0° N. The northern boundary for the ‘southern’ stock should extend from the west coast of Ireland to 15° W.
STECF also concludes that the area north of 52.0° N to 53.5° N and to the east of 15° W would be defined as the ‘mixing area’ and that, in a two stock management system, this should be managed to ensure that catches from this area do not compromise the management objectives for either the ‘northern’ or the ‘southern’ stock.
To achieve the seperation of stocks, STECF recommends that the International Council for the Exploration of the Sea (ICES) make their own assessment of the 'northern' and 'southern' stocks, to ensure that information found is consistent with STECF data.
Given some uncertainty about the extent to which adults of blue whiting that migrate from the north will produce progeny that drift north, and also the extent to which adults of blue whiting from the south produce progeny that drift to the south, the assessment should consider the evidence for one of the proposed stocks being a recruitment ‘sink’.
If it is feasible to perform separate and acceptable stock assessments for the two stocks, STECF recommended that a management plan for the blue whiting fisheries be developed that includes control rules for fixing fishing opportunities for the two stocks and addresses the management of carches from the mixing area in accordance with the management objectives for each stock.
Further Reading
 |
- | You can view the full report (chapter 8.5) by clicking here. |
