A model-based evaluation of Marine Protected Areas: the example of eastern Baltic cod (Gadus morhua callarias L.).

The eastern Baltic cod stock collapsed as a consequence of climate-driven adverse hydrographic conditions and overfishing and has remained at historically low levels. Spatio-temporal fishing closures [Marine Protected Areas (MPAs)] have been implemented since 1995, to protect and restore the spawning stock. However, no signs of recovery have been observed yet, either suggesting that MPAs are an inappropriate management measure or pointing towards suboptimal closure design. We used the spatially explicit fishery simulation model ISIS-Fish to evaluate proposed and implemented fishery closures, combining an age-structured population module with a multifleet exploitation module and a management module in a single model environment. The model is parameterized based on (i) the large amount of biological knowledge available for cod and (ii) an analysis of existing spatially disaggregated fishery data. As the population dynamics of eastern Baltic cod depend strongly on the climate-driven hydrographic regime, we considered two production regimes of the stock. MPAs were only effective for stock recovery when they reduced overall fishing effort. The performance of MPAs needs to be evaluated relative to environmental regimes, especially for stocks facing strong environmental variability

Scientific, Technical and Economic Committee for Fisheries (STECF)-Evaluation of Fishing Effort Regimes in European Waters Part 1 (STECF-12-09)

Informe de reunió

STECF Fisheries Dependent Information – FDI (STECF-19-11)

Commission Decision of 25 February 2016 setting up a Scientific, Technical and Economic Committee for Fisheries, C(2016) 1084, OJ C 74, 26.2.2016, p. 4–10. The Commission may consult the group on any matter relating to marine and fisheries biology, fishing gear technology, fisheries economics, fisheries governance, ecosystem effects of fisheries, aquaculture or similar disciplines. The STECF reviewed the report of the EWG on Fisheries-dependent Information during its winter 2019 plenary meeting

Mixed fisheries management: protecting the weakest link

North Sea cod Gadus morhua stock is outside safe biological limits, and total allowable catch (TAC) management has proved ineffective to rebuild the stock. The European Commission is considering the imposition of a discard ban to preserve vulnerable and economically important fish stocks. We explored the potential effects of a discard ban in mixed fisheries management using the French mixed fisheries in the Eastern English Channel as a model system. We examined in particular the performance of 2 different management scenarios: (1) individual quota management with a tolerance for discarding and (2) individual quota management in combination with a discard ban, using a dynamic state variable model. The model evaluates a time series of decisions taken by fishers to maximize profits within management constraints. Compliance to management was tested by applying an in-height varying fine for exceeding the quota. We then evaluated the consequences of individual cod quota in both scenarios with respect to over-quota discarding, spatial and temporal effort allocation and switching between métiers. Individual quota management without a discard ban hardly influenced fishers' behaviour as they could fully utilise cod quota and continue fishing other species while discarding cod. In contrast, a discard ban forced fishers to reallocate effort to areas and weeks in which cod catch is low, at the expense of lower revenue. In general, a restrictive policy for individual quota for cod needs to be combined with a discard ban and a high fine (>20 times the sale price) to reduce over-quota discardi

The need for a protean fisheries science to address the degradation of exploited aquatic ecosystems

[Departement_IRSTEA]Eaux [TR1_IRSTEA]QUASAREThe symposium was organized with the financial support of Ifremer, IRD, Agrocampus Ouest and la Region Languedoc-Roussillon. We would like to thank all speakers, and especially the invited speakers (A. Bertand, V. Maris, B. Planque, F. Bonhomme, P. Freon, A. Avadi and B. Ioos), the Aquarium Mare Nostrum (Montpellier, France) staff for hosting this symposium, and all persons involved in the organization, with special thanks to Catherine Le Penven. Finally, we are very grateful to D. Caitriona Carter for her help in writing this article, and to D. Verena Trenkel and an anonymous referee for their valuable suggestions and comments when revising this paper.International audienceIn this introductory paper we highlight key questions that were discussed during the symposium on "Status, functioning and shifts in marine ecosystems" organized by the Association Française d'Halieutique) (French Association for Fisheries Sciences) (Montpellier, France, July 2015). This symposium illustrated that fisheries science is now working at multiple scales, on all dimensions of socio-ecosystems (ecological, political, sociological, economical...), with a great diversity of approaches and taking into account different levels of complexity while acknowledging diverse sources of uncertainty. We argue that we should go one step further and call for a protean fisheries science to address the deteriorated states of aquatic ecosystems caused by anthropogenic pressures. Protean science is constantly evolving to meet emerging issues, while improving its coherence and integration capacity in its complexity. This science must be nourished by multiple approaches and be capable of addressing all organizational scales, from individual fish or fishermen up to the entire ecosystem, include society, its economy and the services it derives from aquatic systems. Such a protean science is required to address the complexity of ecosystem functioning and of the impacts of anthropogenic pressures

Thirty years of fleet dynamics modelling using discrete-choice models: what have we learned?

Anticipating fisher behaviour is necessary for successful fisheries management. Ofthe different concepts that have been developed to understand individual fisherbehaviour, random utility models (RUMs) have attracted considerable attention inthe past three decades, and more particularly so since the 2000s. This study aimedat summarizing and analysing the information gathered from RUMs used duringthe last three decades around the globe. A methodology has been developed tostandardize information across different studies and compare RUM results. Thestudies selected focused on fishing effort allocation. Six types of fisher behaviourdrivers were considered: the presence of other vessels in the same fishing area, tradition,expected revenue, species targeting, costs, and risk-taking. Analyses wereperformed using three separate linear modelling approaches to assess the extent towhich these different drivers impacted fisher behaviour in three fleet types: fleetsfishing for demersal species using active gears, fleets fishing for demersal speciesusing passive gears and fleets fishing for pelagic species. Fishers are attracted byhigher expected revenue, tradition, species targeting and presence of others, butavoid choices involving large costs. Results also suggest that fishers fishing fordemersal species using active gears are generally more influenced by past seasonal(long-term) patterns than by the most recent (short-term) information. Finally, thecomparison of expected revenue with other fisher behaviour drivers highlights thatdemersal fishing vessels are risk-averse and that tradition and species targetinginfluence fisher decisions more than expected revenue