2.1 For closer identification of major issues to be discussed during the meeting a brief account of main results achieved during previous working groups was made to the participants.
2.2 The CRODT study on the fishery-climate relationship was presented. Relationship between fishery statistics (catches, CPUE and effort) and climatic data were reviewed, using time as common indicator.
This is dealt with at three different levels:
a short-term approach based on multivariate time series analysis, to study the relationship between CPUE series and surface temperatures per intervals of two weeks. Empirical models used may prove of interest for short term CPUE surveys;
a medium-term approach which analyses variations in annual CPUE values in relation to the intensity of the upwelling or of other environmental variables (Binet, 1983; Fréon, 1986; Cury and Roy, 1987). This type of global model, which introduces climate variables, should greatly increase knowledge on the impact of fishing and of environmental variations on the annual abundance level. Basically explicative in nature, this type of model is poorly predictive;
a long-term approach which concentrates on describing the demographic strategies of the two sardinella species by comparing the biological/demographical parameters for better understanding of factors responsible for the instability of Sardinella aurita stocks (Cury and Fontana, 1988). This approach highlights the need for resource management based on the biological strategy of the species involved.
