Effects of seasonal variations in meteorology and oceanography on the Brazilian sardine fishery

Abstract

Seasonal variations in meteorological and oceanographic processes in the South Brazil Bight were studied to assess their influence on the Brazilian sardine Sardinella brasiliensis fishery. According to its environmental characteristics, the South Brazil Bight was divided into three sectors. The northern and southern sectors were similar during the spring and summer, showing areas of coastal upwelling and low rainfall rates. The middle sector was characterized by the presence of low‐salinity coastal waters in the inner shelf and by high rainfall. During autumn and winter, the middle and southern sectors were similar, both being under the influence of sub‐Antarctic waters. Multiple regression analyses showed significant correlation between environmental data and catches, although at a lower level in the northern sector (r2 = 0.57). In the middle and southern sectors, environmental data were highly correlated with the catches (r2 = 0.90 and 0.84). The sardine landings in the middle sector are principally affected by meteorological parameters, and in the south by oceanographic ones. In the middle sector, an inverse correlation between landings and rainfall is shown, while in the south, landings are positively correlated with salinity and sea temperature. The conclusion is that the seasonal landings of the Brazilian sardine within the South Brazil Bight are influenced by the distribution of less saline waters, the coastal waters and sub‐Antarctic waters.