Variability of the Environmental Conditions and Fish Communities in the Altlantic Iberian Waters and its Relationship to the NAO.

This study investigates the possible link between a large-scale atmospheric phenomenon, the North Atlantic Oscillation, and local fluctuations of some environmental variables, air and sea surface temperature, precipitation, wind, Ekman transport, and mean sea level, as well as time series (1975-1997) of catches and recruitment of some fish populations of commercial interest around Atlantic Iberian waters. The area of study (Figure 1) is located in the intergyre region between the subpolar gyre (North Atlantic current), the subtropical gyre (Azores Current), and the European shelf. The response of atmospheric signals to the different NAO phases in this area is different to that of Northern Europe, and follows the dipole form presented by Dickson (1997). Pérez et al (2000) compared conditions in river discharge in Scotland and Iberian rivers and found opposing conditions. Winter 1996 marked the minimum of the value of the NAO index, after a high value in 1995. However, although the simple index continued to increase returning to positive values, the actual pattern of the NAO over the ICES area did no