Maximising the long term average catch of single stock fisheries as prescribed by the globally-legislated MSY objective is unlikely to ensure ecosystem, economic, social and governance sustainability unless an effort is made to explicitly include these considerations. We investigated how objectives to be maximised can be combined with sustainability constraints aiming specifically at one or more of these four sustainability pillars. The study was conducted as a three-year interactive process involving 290 participating science, industry, NGO and management representatives from six different European regions. Economic considerations and inclusive governance were generally preferred as the key objectives to be maximised in complex fisheries, recognising that ecosystem, social and governance constraints are also key aspects of sustainability in all regions. Relative preferences differed between regions and cases but were similar across a series of workshops, different levels of information provided and the form of elicitation methods used as long as major shifts in context or stakeholder composition did not occur. Maximising inclusiveness in governance, particularly the inclusiveness of affected stakeholders, was highly preferred by participants across the project. This suggests that advice incorporating flexibility in the interpretation of objectives to leave room for meaningful inclusiveness in decision-making processes is likely to be a prerequisite for stakeholder buy-in to management decisions.Versión del edito

The landing obligation policy was one of the major innovations introduced in the last Common Fisheries Policy reform in Europe. It is foreseen that the policy will affect the use of fishing opportunities and hence the economic performance of the fleets. The problem with fishing opportunities could be solved if single-stock total allowable catches (TACs) could be achieved simultaneously for all the stocks. In this study, we evaluate the economic impact of the landing obligation policy on the Spanish demersal fleet operating in the Iberian Sea region. To generate TAC advice, we used two sets of maximum sustainable yield (MSY) reference points, the single-stock MSY reference points defined by ICES and a set of multistock reference points calculated simultaneously using a bioeconomic optimization model. We found that the impact of the landing obligation is time and fleet dependent and highly influenced by assumptions about fleet dynamics. At fishery level, multistock reference points mitigate the decrease in the net present value generated by the implementation of the landing obligation. However at fleet level, the effect depends on the fleet itself and the period. To ensure the optimum use of fishing opportunities, the landing obligation should be accompanied by a management system that guarantees consistency between single-stock TACs. In this regard, multistock reference points represent an improvement over those currently in use. However, further investigation is necessary to enhance performance both at fleet level and in the long term.

The European Union Common Fisheries Policy has established a discard ban, which states that fish below a reference size cannot be sold directly for human consumption. In a fishing effort-regulated fishery, the discard ban can result in extra handling, storing and landing costs. In an output-regulated fishery, this policy might also limit the effort levels as all the catches count against the quota. In both cases, this regulation can reduce the economic performance of the companies, even in single-species fisheries. A possible solution is to increase the mesh size, thus retaining fewer small individuals. To study this option, a bioeconomic simulation of a change in the gear selectivity from 100- to 120-mm minimum mesh size (MMS) was performed. The results show that the private perspective (profits) does not change. Furthermore, due to the lower retention of 120 mm MMS, the efficiency of a fishing day was reduced by 5% and 2.5%, from the point of view of capital and labour productivity, respectively. In contrast, gross revenues increased by 1.5% and crew compensation by 2%. Given a societal benefit of this change in the mesh size, this gain could be re-distributed to provide an incentive for selectivity improvements.

Deepwater fish are characterized by long lifespans, late maturity and low productivity. This implies slow recovery from low biomass levels and it is, therefore, important to manage these stocks correctly to avoid overfishing. However, these stocks are generally data poor, which it makes difficult to apply quantitative assessment models on which to base their management. The management strategy evaluation (MSE) approach consists in evaluating the performance of management strategies by simulation before their implementation. In the evaluation, the main sources of uncertainty in a fishery system and its management process should be taken into account in order to find robust management strategies. Thus, the MSE approach is relevant to the management of data-poor stocks. We used the FLBEIA software, an FLR library coded in the R statistical language, to conduct a bio-economic impact assessment of fisheries management strategies. We evaluated the performance of several management strategies in three different deepwater case studies using the MSE approach: beaked redfish (Sebastes mentella) in the Norwegian Sea, blackspot seabream (Pagellus bogaraveo) in the Strait of Gibraltar, and French mixed deepwater fisheries in the North East Atlantic. In conclusion, we found that the S. mentella stock is very sensitive to the stock recruitment relationship chosen. For P. bogaraveo, simulations showed that the present constant catch management is as good as more sophisticated strategies. Finally, in mixed fisheries, case study fleet dynamics were key for the success of management strategies

Maurolicus muelleri is a significant component of the marine ecosystem and has the potential to be a valuable fishery resource. However, in the Bay of Biscay, its primary biological traits remain unclear. This study presents data on the length distribution, age, growth, maturity ogive, spawning season, batch fecundity, and sex ratio for Maurolicus muelleri captured in the Bay of Biscay. The results showed that in spring, the adult spawners (ages of 1 and 2) were dominant in the catches, while in September, immature juveniles (age of 0) born in spring were mostly found. Using standard lengths as a basis, 50% of the fish were mature at 34.1 mm (both sexes combined), and the sex ratio, male to female, was 0.44:0.56. The proportion of females increased with length, and a 1:1 sex ratio was predicted at a standard length of 41.5 mm. The spawning season was allocated to at least between March and September, with a likely peak in May. The batch fecundity ranged from 114 to 919 oocytes/female, and increased with the weight and length of females. The results allowed us to interpret a life history strategy for this species, i.e., a high fecundity for females, which mostly participate in one or two reproductive seasons. Therefore, any possible exploitation of age 0 fish prior to spawning could lead to a decrease in the population from which recovery could be slow.