Reconciling food security, economic development and biodiversity conservation is a key challenge, especially in the face of the demographic transition characterizing many countries in the world. Fisheries and marine ecosystems constitute a difficult application of this bio‐economic challenge. Many experts and scientists advocate an ecosystem approach to manage marine socio‐ecosystems for their sustainability and resilience. However, the ways by which to operationalize ecosystem‐based fisheries management (EBFM) remain poorly specified. We propose a specific methodological framework—viability modelling—to do so. We show how viability modelling can be applied using four contrasted case‐studies: two small‐scale fisheries in South America and Pacific and two larger‐scale fisheries in Europe and Australia. The four fisheries are analysed using the same modelling framework, structured around a set of common methods, indicators and scenarios. The calibrated models are dynamic, multispecies and multifleet and account for various sources of uncertainty. A multicriteria evaluation is used to assess the scenarios’ outcomes over a long time horizon with different constraints based on ecological, social and economic reference points. Results show to what extent the bio‐economic and ecosystem risks associated with the adoption of status quo strategies are relatively high and challenge the implementation of EBFM. In contrast, strategies called ecoviability or co‐viability strategies, that aim at satisfying the viability constraints, reduce significantly these ecological and economic risks and promote EBFM. The gains associated with those ecoviability strategies, however, decrease with the intensity of regulations imposed on these fisheries.

Like many tropical small-scale fisheries, the French Guiana coastal fishery is characterized by the high fish biodiversity of its ecosystem, the weak selectivity of the fleets exploiting the resources, and the heterogeneity of the vessels in terms of size and fishing techniques. The Rapfish method is used to assess sustainability within 11 fishery systems by means of 27 attributes relating to ecological, economic, social, and technological fields. Overall results indicate an average performance in the weak sustainability range. Comparisons made among the FSs show a gradient of sustainability performance from the western portion of the coast to the eastern portion. Several recommendations are formulated to raise the current "sustainability" status, such as the reduction of discards. This study is used as a complementary tool to the bioeconomic model in order to define a sustainable management plan for the French Guiana coastal fishery. Highlights ► Sustainability of French Guiana coastal fishery is analyzed using Rapfish method. ► Sustainability is evaluated in a multidimensional framework. ► Within the fishery, production systems present different performance levels. ► A gradient of sustainability appears from the west to the east. ► Strong sustainability concept is more functional for identifying potential issues.

This paper offers a theoretical and empirical model of ecosystem-based fishery management. A multi-species and multi-fleet model integrating Lotka-Volterra trophic dynamics as well as production and profit assessments is developed and applied to the coastal fishery of French Guiana. This small-scale fishery constitutes a challenging example with high fish biodiversity, several non-selective fleets and a potentially increasing local food demand due to demographic growth. The dynamic model is calibratedThis work was carried out with the financial support of the ANR (French National Research Agency) under the ADHOC program, the ERDF (European Regional Development Fund) under the DEPECHE program, the FRB (Fondation Recherche Biodiversité) under the BIO-MER project and IFREMER. We thank all the fishermen who agreed to provide economic data as well as all the observers who collected the other fishery data sets each day. 246 A. A. Cissé et al. with 13 species and four fleets using monthly catch and effort data from 2006 to 2009. Several contrasted fishing scenarios including status quo, total closure, economic and viable strategies are then simulated. They are compared from the viewpoints of both biodiversity preservation and socioeconomic performance, assuming fixed landing prices and fixed costs. We show that fishing outputs, including food supply and fleet profitability, can be sustained on average but a loss of species cannot be avoided. IntroductionMarine fishery resources are under extreme pressure worldwide. According to recent studies (Garcia and Grainger, 2005; FAO, 2010), three-quarters of fish stocks are maximally exploited or over-exploited. Moreover, the proportion of marine fish stocks which are intensively exploited is growing. Hence, sustainability is nowadays a major concern raised by international agreements and guidelines to fisheries management. Standard approaches to the sustainable management of fisheries such as MSY (maximum sustainable yield), MEY (maximum economic yield) or ICES 1 precautionary approaches usually address each exploited species separately (Grafton et al., 2007). These management approaches have not succeeded in avoiding biodiversity loss, over-exploitation and fishing overcapacity worldwide (Hall and Mainprize, 2004). The ecosystem approach for fisheries (EAF) or ecosystem-based fisheries management (EBFM) advocate an integrated management of marine resources to promote sustainability (FAO, 2003). Such a management policy requires first to account for the complexity of ecological mechanisms that encompass community dynamics, trophic webs, geographical processes and environmental uncertainties (habitat, climate). Furthermore, by putting emphasis on sustainability, this type of approach strives to balance ecological, economic and social objectives for present and future generations and to handle a large range of goods and services provided by marine ecosystems (Jennings, 2005), including both monetary and non-monetary values.However, operationalizing the EBFM approach remains un...