Effect of North Atlantic climate variability on hawksbill turtles in the Southern Gulf of Mexico

► Sea turtles are particularly vulnerable to climate change. ► A 7-year cycle in annual relative number of hawksbill turtles in Campeche was found. ► This signal is inversely related with a 8-year cycle in the North Atlantic SST. ► Alternation between favourable and unfavourable ecological conditions may be implied. ► Hawksbill turtles cconservation should consider global warming and natural environmental variability.