| Resumo: |
Whitemouth croaker (Micropogonias furnieri)has a broad distribution along the Atlantic coast of the Americas, from Mexico to the south of the Province of Buenos Aires, Argentina. At the southern end of distribution, Argentina and Uruguay catch the species with different commercial fleet types bay or creek, coastal and off-shore and modalities of bottom trawling with doors and paired trawling. Maximum catches of both countries, that reached 60,000 t, were registered between 1995 and 1997. After that period a remarkable decrease was observed, specially in Argentina where catches remained at around 6,000 t over a total of 30,000 t for both countries. The commercial fleet was divided in three categories and the total area of study in three subareas: El Salado, Uruguay and Mar del Plata. Whitemouth croaker biomass in the Rio de la Plata area and the Common Fishing Zone (period 1989-2002)was estimated using the biomass dynamics model calibrated to the Argentine fleet CPUE standardized with the General Lineal Model and applied considering the following factors: Year, Area, Trimester, Fleet Type and first order interaction Area x Trimester. Schaefer model, in which a non proportional relationship between CPUE and stock biomass was used, proved to be useful to describe biomass dynamics, to estimate management parameters and to make a diagnosis of the resource status. The results of the analysis suggest that the resource is depleted, biomass at the beginning of 2003 was below the optimal (B(actual)B(optimal)=0.5). The risk analysis indicates that, if the biomass depletion risk is to be kept below 5. , annual catches should not exceed 22,300 t. On the other hand, assuming a 10. risk level, catches should not exceed 23,900 t. Consequently, for 2003, a Biologically Acceptable Maximum Catch of 22,300 t with a maximum limit of 23,900 t is suggested.
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