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Marine ecosystem models for fisheries management have been used to project interspecific biodiversity under several climate change and management scenarios considering ecological dynamics only. However, fish populations may also adapt to climatic and fishing pressures via evolutionary changes leading to modifications in their life history that could either mitigate or worsen pressures’ consequences. A multispecies eco-evolutionary model, Ev-Osmose, has been developed to account for evolutionary dynamics in marine fish biodiversity projections. In this model, life-history traits are mechanistically described by a bio-energetic model. Life-history traits are allowed to evolve as their values are transmitted through cohorts by gametic inheritance of parents’ genes. Under the selection pressures generated by climate change and fishing scenarios, energy fluxes and the resulting life-history traits may thus respond through phenotypic plasticity and microevolution. The Ev-Osmose model has been used to simulate the changes in biomasses, catches and species composition of North Sea exploited fish under climate change scenario (RCP8.5) for the period 2010-2100 with scenarios with and without evolution. The ecosystem's total biomass and catch stay steady in the absence of climate change whereas a great decline is projected under scenario RCP8.5. Total biomass is unaffected by evolution, while total catch drops even more with evolution than without. In an evolutionary setting, the species mean lengths exhibit changes at horizon 2100, mainly shrinkage. The species composition becomes more uniform, with a sharp rise in warm-water species and a fast decline in cold-water species, which is amplified by evolution. The fact that the biomass remains stable while the catch declines in scenarios with evolution compared to those without evolution shows that the adaptation of fish features primarily enables the avoidance of fishing pressure. Economic yield will likely be impacted by this direct impact on fishery yield will be further reduced by the decline in length and species variety. According to this first forecast study that considers evolutionary dynamics at the ecosystem level, the fishing industry appears to be the primary loser of fish evolutionary changes in response to climate change.

The otolith, found in both inner ears of bony fish, has mainly been used to estimate fish age. Another application that has been developing significantly in recent years, however, is the use of otolith shape as a tool for stock identification. Often, studies have directly used the shape asymmetry between the right and left otoliths. We tested the magnitude of directional asymmetry between the sagittal otoliths (left vs. right) of 2991 individuals according to their catch locations, and we selected species to evaluate whether directional asymmetry may itself be a tool to evaluate stock boundaries. Elliptical Fourier descriptors were used to describe the otolith shape. We used a flatfish, the common sole (Solea solea, n = 2431), from the eastern English Channel and the southern North Sea as well as a roundfish, the bogue (Boops boops, n = 560), from the Mediterranean Sea. Both species showed significant levels of directional asymmetry between the testing locations. The bogue otoliths showed significant asymmetry for only 5 out of 11 locations, with substantial separation between two large areas: the Algerian coast and the western part of the Italian coast. The sole otoliths showed significant asymmetry in the shape analysis (3.84–6.57%), suggesting a substantial separation between two large areas: the English and French parts of the English Channel and the southern North Sea. Consequently, directional bilateral asymmetry in otolith shape is a potential new method for stock identification., Biología de recursos vivos de Canarias, PACA-BIO, SI