Decline in male loggerhead turtles Caretta caretta on Maio Island, Cabo Verde: local fishers’ insights

Abstract

The reproductive success and long-term resilience of sea turtle populations crucially depends on the availability of adult males, yet studying these individuals remains challenging owing to their predominantly aquatic lifestyle. Sex determination in sea turtles is temperature dependent, with lower incubation temperatures producing males and higher temperatures producing females. Consequently, global warming could feminise hatchlings, thereby reducing male recruitment and exacerbating population vulnerability. This study provides the first systematic assessment of artisanal fishers’ perceptions regarding changes in the abundance of male loggerhead turtles Caretta caretta in the eastern Atlantic. Drawing on the extensive experience of artisanal fishers (mean ± SD = 38.6 ± 7.9 years; n = 21) as a potential source of incidental loggerhead turtle bycatch, we conducted structured interviews with long-term fishers in six fishing communities on Maio Island, Cabo Verde, in regard to sightings of male sea turtles and mating events, as well as traditional uses of sea turtle parts. Their responses revealed a widespread perception of declining male abundance, mating activity and availability of organs used in cultural practices. These findings underscore the value of combining local ecological knowledge with biological monitoring to guide conservation strategies that reflect both ecological realities and cultural contexts.