Résumé: Peru is the top exporter of fishmeal and fish oil (FMFO) worldwide and is responsible for half and a third of global production, respectively. Landings of “anchoveta” (Engraulis ringens) are used nearly exclusively for FMFO production, despite a proactive national food policy aimed at favoring the direct human consumption of this inexpensive species. It may be surprising that in a country where malnutrition and caloric deficit constitute major issues, a low-priced and highly nutritious fish such as anchovy does not have stronger domestic demand as a food fish. Here, we review and assess eight potential politico-socio-economic processes that can explain this situation. The main explanation are dietary habits, the preference for broiler and the higher profit from anchovy sold as feed fish compared to its use as a food fish due to historically high FMFO prices, boosted by an increasing demand for aquaculture in a context of finite forage and trash fish resources. In addition, the recent introduction of an individual quota system has shifted bargaining power from processors to fishers, thereby increasing competition for the raw material. This competition results in an increase in anchovy prices offered by the feed fish industry due to its onshore processing overcapacity, which is detrimental to the food fish industry. In the end, although the dominant use of anchovy for fish feed is largely explained by integrating these market mechanisms and other minor ones, this use raises other issues, such as rent redistribution through public policies, employment, equitability and utility (low social costs), and resource management (threats to ecosystems or global change). Different policy scenarios are proposed in relation to these issues.

Résumé: The marine ecosystem off British Columbia (BC), Canada, has experienced various changes in the last two decades. Understanding how stressors interactively and cumulatively affect commercially important fish species is key to moving towards ecosystem-based fisheries management. Because it is challenging to assess the cumulative effects of multiple stressors by using empirical data alone, a dynamic, individual-based spatially-explicit ecosystem modeling platform such as OSMOSE represents a valuable tool to simulate ecological processes and comprehensively evaluate how stressors cumulatively impact modelled species. In this study, we employed OSMOSE to investigate the cumulative effects of fishing, plankton biomass change, and marine mammal consumption on the dynamics of some fish species and the BC marine ecosystem as a whole. We specifically simulated ecosystem dynamics during the last 20 years under two sets of scenarios: (1) unfavorable conditions from the perspective of commercial fish species (i.e., doubling fishing rates, halving plankton biomass, and doubling marine mammal biomass, acting individually or collectively); and (2) favorable conditions with the three factors having opposite changes (i.e., halving fishing rates, doubling plankton biomass, and halving marine mammal biomass, acting individually or collectively). Our results indicate that, under unfavorable conditions, the degree to which species biomass was reduced varied among species, and that negative synergistic and negative dampened effects were dominant under historical and doubled fishing mortality rates, respectively. Under favorable conditions, species biomasses did not increase as much as expected due to the existence of complex predator-prey interactions among fish species, and positive synergistic and positive dampened effects were prevailing under historical and halved fishing mortality rates, respectively. The ecosystem total biomass and the biomass to fisheries yield ratio were found to be good ecological indicators to represent ecosystem changes and track the impacts from the multiple drivers of change. Our research provides insights on how fisheries management should adapt to prepare for potential future impacts of climate change.

Résumé: Periodically harvested closures (PHCs) are small fisheries closures with objectives such as sustaining fisheries and conserving biodiversity and have become one of the most common forms of nearshore marine management in the Western Pacific. Although PHCs can provide both short-term conservation and fisheries benefits, their potential as a long-term management strategy remains unclear. Through empirical assessment of a single harvest event in each of five PHCs, we determined whether targeted fishes that differ in their vulnerability to fishing recovered to pre-harvest conditions (the state prior to last harvest) and demonstrated post-harvest recovery benefits after 1 year of re-closure. For low and moderately vulnerable species, two PHCs provided significant pre-harvest benefits and one provided significant post-harvest recovery benefits, suggesting a contribution to longer-term sustainability. PHCs with a combination of high compliance and longer closing times are more likely to provide fisheries benefits and recover from harvest events, however, no benefits were observed across any PHCs for highly vulnerable species. We recommend PHCs have longer closure periods before being harvested and species that are highly vulnerable to fishing (e.g. large species of; grouper, wrasse and parrotfish) are avoided during harvests to avoid overexploitation and increase the sustainability of small-scale fisheries. (C) 2016 Elsevier Ltd. All rights reserved.