Composite difference maps for (a) SST (°C), (b) sea surface height (m), (c) 0–200 m vector currents (m/s) in respect of high minus low fish catch, and (d) vector wind stress (N/m2). Composite vertical N-S sections of (e) temperature (°C), (f) salinity (g/kg) and V W currents (m/s), with vertical motion exaggerated. Vertical bar represents Antilles, South America is left-side of sections. Key vectors are given.