Influencia del tipo de enzuelo y la profundidad de pesca en la captura con palangre de tiburones y otras especies pelágicas al noroeste del Pacífico mexicano

An experiment using longlines to evaluate the effects of hook type and depth of longline on the catches of sharks and other pelagic species was carried out close to Mazatlan, Mexico. We compared the J-style hooks, tuna hook, tuna 18° offset hook, and circle hook at three depth strata: S₁ (0-55 m), S₂ (55-85 m) y S₃ (85-99 m). From the total capture, the circle hook had significantly higher catch rate than J-style hook and tuna hook. The main species caught with circle hook were blue marlin (Makaira nigricans) and striped marlin (Tetrapturus audax). The highest biomass of blue shark (Prionace glauca), blue marlin, sailfish (Istiophorus platypterus) and striped marlin was found in the shallow stratum (0-55 m) than in the deep stratum (85-99 m). By hook type, the higher capture of blue marlin was with circle hook and tuna hook at shallow depths (0-55 m).