The STECF was tasked with an analysis of the likely effects of proposed management plans for the Southwestern (Bay of Biscay and Iberia) and Northwestern (Celtic sea) waters. Quantitative analyses were carried out to compare the likely effect of those management plans and of the direct application of the CFP on both stocks and fleets involved in these fisheries. Based on the results of simulations of the provisions of the proposed management plans, STECF concluded that, setting fishing opportunities in line with single-species FMSY ranges will provide managers with additional flexibility compared to the basic provisions of the 2013 CFP. Such flexibility is likely to help alleviate the problem of mismatches in quota availability in mixed-species fisheries thereby reducing the risk of early closure of some fisheries due to choke species. Adopting FMSY ranges will therefore increase the likelihood that desired exploitation rates will be achieved and will reduce the risk that some fishing fleets will go out of business. STECF considers that it is crucial that managers take note that persistent fishing at the upper limits of the FMSY ranges across all or most stocks simultaneously negates the flexibility introduced by the FMSY ranges and greatly increases the risk of overfishing. Such an approach will also increase the risk that the objectives of the CFP will not be achieved. STECF concludes that single species biomass safeguards for all stocks should be maintained to provide a basic level of protection. STECF notes that for the fleets affected by the SWW MAP, those providing the highest employment are generally not dependent to a great extent on the species that will be regulated through the MAP proposals. STECF notes that in the NWW there are some fleets which provide significant levels of employment and seem to be very dependent on the species that will be regulated through the MAP proposals. Nevertheless, there are a number of fleets in the NWW area that are not included in the employment analysis because of an absence of appropriate data. .Regarding the number and scope of MAPs as currently defined, STECF considers that a MAP covering a wider geographic area has advantages in terms of reducing management overheads and avoiding multiple regulations affecting the sector. A larger MAP area however, may have disadvantages associated with reducing the emphasis on local management measures and this may discourage the involvement of stakeholders, although this effect will depend on how the process of regionalization operates within the MAP. To evaluate the question of whether management of the species that drive the fisheries adequately allows for the management of by-catch species, the EWG carried out an analysis of correlations between catches of driver species identified in the plan and a variety of by-catch species. The analysis suggested only limited correlation. In view of this, the STECF notes that it is unlikely that relying on the TAC of the driver species to manage other species will be effective, in accordance with CFP requirements. STECF however notes that when analysis was performed at the fleet level, there were more obvious correlations, suggesting some scope to use fleet related management measures for the driver species as a way of managing some of the bycatch species. STECF therefore concludes that management of exploitation rates of non-driver (or bycatch) species is unlikely to occur as an automatic consequence of the management of the main (driver) stocks by TAC considered in the MAP.