Probable fishing grounds for anchovy in northern Chile using an expert system

Probable fishing grounds (PFG) of anchovy (Engraulis ringens) for the industrial purse seiner fleets in northern Chile (18/spl deg/21'-24/spl deg/S) are determined by sea surface temperature (SST) and thermal gradients (TGR) information estimated with NOAA AVHRR data and validated with in situ data. Using a Geographical Information System (GIS), relations between the catch per unit effort (CPUE) and surface environmental variables (SST and TGR) under a space-temporal approach are analyzed, with data available for the 1987-97 period. With this information and using the Bayesian theory approach and the fuzzy logic, an expert system (PFG model) is developed generating PFG charts. Chlorophyll concentration information has been collected for 1999, estimated with SeaWIFS data, which has allowed the first relations to be established between this variable and the CPUE distribution, which will be integrated into the PFG model. The results of the model are validated with information compiled during 1999.