The Brazilian sardine. Is there any room for modelling

Brazilian sardine (Sardinella brasiliensis) production has declined along the last 30 years, being today around 40 000 tons. The fleet, despite the reduction in number of boats still has an excessive fishing power when related to the stock size. It is probable that besides overfishing, climatic and oceanographic phenomena interfere with recruitment success. Several hypotheses were suggested and a few models implemented aiming at the correlation of recruitment and environmental variables. In almost all cases, in spite of environmental variation, the spawning stock biomass seemed to be a main factor for recruitment success. The state of overfishing prevailing in the international scenario has determined the proposal of more robust strategies for fisheries management, based in marine protected areas and in a sharp reduction of fishing effort. The management of the Brazilian sardine stock is set up in an inefficient system of special permissions granting and in the definition of closed seasons. The slight trend of catches recovery, in the latest years, impelled the fisheries authority to reduce the closed seasons, showing a misled policy intended to capitalize on any apparent stock increase or marginal fishing opportunity. In fact, modeling is always necessary to better understand and represent nature, but in the case of the sardine stock a sound management based on the preservation of the spawning stock size above a critical value through effective control of licensing and closed seasons deserves priority.