Abstract
The East Pacific (EP) leatherback population is listed by the IUCN Red List of Threatened species as Critically Endangered. Despite conservation efforts, mainly focused around nesting areas, its population has declined by over 90% since the 1980s. The major current threat is fisheries bycatch, but its impact has been primary documented within South American migration and foraging habitats, with scarce information from nesting or interesting areas. To assess the impact of small-scale fisheries on EP leatherbacks inhabiting waters north of the equator we conducted rapid bycatch assessments (surveys) in 5 countries (México, Nicaragua, Costa Rica, Panamá and Colombia), some of which host the main EP leatherback nesting areas. A total of 1,778 surveys were conducted across 79 fishing ports (México = 37, Nicaragua = 6, Costa Rica = 5, Panamá = 17 and Colombia = 14). Leatherback bycatch was reported in all countries, and in 54% of ports surveyed by 7% (n = 125) of fishers interviewed. Surveys enabled identification of areas near nesting beaches (e.g. inter-nesting habitats) where leatherback bycatch was higher and periods during which fisheries interactions events were more frequent. Bycatch events were most frequently reported in gillnets and longlines using “J” hook. Data were scaled up across fishing fleets to estimate that 345 (± 210) individual leatherbacks are caught annually in the ports surveyed. Our study provides a first evaluation of leatherback bycatch by small-scale fisheries in countries of the eastern Pacific Ocean where leatherbacks nest, and it highlights areas close to index nesting beaches where conservation efforts targeting bycatch reduction and bycatch mortality may be focused.
Highlights
The East Pacific (EP) leatherback (Dermochelys coriacea) population nests from northern Mexico to Ecuador, with most nesting concentrated in the states of Michoacán, Guerrero and Oaxaca in Mexico, in Nicaragua, and in northwestern Costa Rica (Shillinger et al, 2010; Seminoff et al, 2012)
Our results show that leatherback bycatch, while present in all countries and in half the ports evaluated from Mexico to Colombia, is less frequent than bycatch of other sea turtle species
Leatherback interactions were most frequently reported occurring within gillnets, which was the most common fishing gear used in all countries except Costa Rica
Summary
The East Pacific (EP) leatherback (Dermochelys coriacea) population nests from northern Mexico to Ecuador, with most nesting concentrated in the states of Michoacán, Guerrero and Oaxaca in Mexico, in Nicaragua, and in northwestern Costa Rica (Shillinger et al, 2010; Seminoff et al, 2012). In contrast to the growing body of information about leatherback bycatch in feeding areas off South America, information about leatherback bycatch around inter-nesting and nesting areas is extremely sparse (Eckert and Sarti-Martinez, 1997; Ortega del Valle et al, 2009) This is a critical information gap because adult leatherbacks concentrate predictably in areas off nesting beaches for a well-established period each year for purposes of reproduction (Santidrián Tomillo et al, 2007; SartiMartinez et al, 2007; Eckert et al, 2012), and coastal areas around the world generally have high densities of fishing activity (Stewart et al, 2010). These types of information are critical for holistic population assessments as well as targeted conservation efforts in areas where interactions between leatherbacks and small-scale fisheries occur
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
