| Summary: | 322 páginas Across the period 1988-2008, the most abundant demersal species were cod, redfish, Northern shrimp and Greenland halibut accounting, as an average, for the 83.5% of total index of biomass every year. The analyses of biomass indices showed that the demersal community experienced notable variations across the period 1988-2008, due to changes in biomass of most of the 67 demersal populations studied. The Dynamic Factor Analysis (DFA) identified common trends in the trajectories of the 31 most abundant species in the demersal community. This suggests that the dynamics of the demersal species in the Flemish Cap are interconnected, and can be summarized by a few common patterns. The explanatory variables considered in the analyses appeared to be consistently important for the population biomass dynamic of these species. Water temperature, along with predation and fishing mortality were significant drivers of the Flemish Cap demersal community. The abundance of the less common demersal species was related with water temperature, with a transition in the species composition between cold and warm periods. Changes in the demersal community were globally registered in the diversity indexes and the Abundance Biomass Comparison (ABC) method, with notable variations in the relative location of biomass and abundance kdominance curves. The size based indicators showed marked declines in the size structure of the fish demersal community. Parallel to these changes in the demersal community, since 1993 important variations in feeding habits for the most important fish species were observed. First, strong variations in feeding habits with size were found in most fish species and hence, biological species were split into trophic species. These trophic species belonged to four different trophic guilds, the bentho-pelagic invertebrate feeders, the benthic invertebrate feeders, the pelagic invertebrate feeders and the piscivorous guild. Not only intra-guild but also inter-guild common trends were found. The dominant ...
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