El Ni？o Southern Oscillation and spatial-temporal variability of the nominal performances of swordfish (Xiphias gladius) in the southeastern Pacific

swordfish (xiphias gladius) is a highly migratory pelagic species, found in tropical, subtropical and temperate regions. in the pacific ocean, several studies have linked their wide latitudinal distribution (50on-50os) to environmental variables, since food is abundant along the frontal zones where currents or water bodies converge. in the southeastern pacific, the subtropical anticyclone positively forces ocean temperatures along the west coast of south america, decreasing pole ward from the subtropical latitudes due to the el ni？o southern oscillation. environmental data from remote sensing enabled us to study changes in the spatial position of the 18oc isotherm in relation to spatial-temporal changes in swordfish nominal fishing yields (cpue) of industrial longline fleet in the coast of chile. correlations were obtained between the latitudinal gravity center (lgc) of cpue and the latitudinal position of the 18oc isotherm, between the latitudinal position of the 18oc isotherm and the area bounded by the 17oc isotherm, as well as between el ni？o 12 index and the latitudinal position of the 18oc isotherm. at a seasonal level, the 18oc isotherm moves south of 37os at the beginning of the year, reaching 25os in august. this pattern occurs in a similar way to the area bounded by the 17o and 18oc isotherm. two phases were observed in the swordfish cpue, with 0.65 ± 0.06 kg per hook since mid-april to early june, and 0.37 ± 0.05 kg per hook from early september until late november.