A second data set was represented by trawl survey data: two experimental trawl surveys per year have been carried out in the framework of national and international programs on the assessment of demersal resources. The mean biomass (kg/km2) indices were calculated. The time series analyses were carried out by means of Min/Max Auto-correlation Factor Analysis (MAFA) and Dynamic Factor Analysis (DFA). The two techniques provided coherent results, indicating that the two most important trends in the response variables are an increase in terms of both LPUE and survey biomass index, and a fluctuating pattern, even though characterized by a general increasing tendency. What drove these trends is less clear, even though the available evidence suggests that the reduction of fishing effort has been more important than environmental factors.