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Pérez-Rodríguez, A., Koen-Alonso, M., and Saborido-Rey, F. 2012. Changes and trends in the demersal fish community of the Flemish Cap, Northwest Atlantic, in the period 1988–2008. – ICES Journal of Marine Science, 69: 902–912.The Flemish Cap fish community (NAFO Division 3M) has been fished since the 1950s, and major changes in the biomass and abundance of its most important commercial species have been reported since the late 1980s. Variations in oceanographic conditions at the Cap, with alternating periods of cold and warm weather, have also been described. This work examines the existence of common trends in the biomass levels of the main demersal species over time using dynamic factor analysis, and the occurrence of “occasional species” was explored in relation to temperature conditions. Overall, there have been significant changes in community structure involving both commercial and non-commercial species. Common trends among species were identified and overall fishing pressure, environmental conditions (represented by a moving average of the North Atlantic Oscillation, NAO), and predation pressure (represented by the abundance of piscivorous fish) emerged as important drivers of the temporal dynamics. The NAO influence in the dynamics of most species was in agreement with their temperature preference. For occasional species, their pattern of occurrence appears also to be linked to changes in temperature regimes. [ABSTRACT FROM PUBLISHER]

A histological method is used to detect the proportion of both adult and recruit females at the beginning of gonad development, in summer, a few months after spawning. At this time it is difficult to make a visual diagnosis of the sexual maturity stage. The proportion of females with postovulatory follicles is used to determine the length and age at maturity in the year of sampling, and the proportion of females in the cortical alveoli and/or vitellogenic stages is used to estimate the same parameter for the following year. Variations in age and length at maturity during the period 1992–1995 were analysed by comparing the respective maturity curves of both the “previous spawners” and the “next-year spawners” females. A drastic decrease in both the age and the length at maturity is observed in this period and it seems likely that the age at maturity of female cod became fixed at around age 3 at the end of the period analysed. The possibility that this could be a density-dependent response of the stock at the Flemish Cap is discussed. [ABSTRACT FROM PUBLISHER]

The food and feeding of Flemish Cap cod are described for 5 years based on 3921 stomachs collected in the fishing grounds off the Flemish Cap, Newfoundland in summer 1989–1993. Feeding intensity was high but the prey spectrum was narrow in all years with hyperiids and redfish (Sebastes sp.) predominating. Squid and poly-chaetes had a high inter-annual variability. Juvenile cod diet was dominated by crustaceans, mainly hyperiids, and polychaetes, while in adult cod diet the most important prey were fish, mainly redfish. The maximum size of redfish eaten increased with cod size, but prey–predator size relationships showed weak correlation. Cannibalism increased in 1991 (mainly upon 1-year-olds), coinciding with the appearance of a large year class in 1990. In the years 1992 and 1993, a change in the diet was observed involving an increase of hyperiids in the adult cod diet and a decline of redfish. [ABSTRACT FROM PUBLISHER]