Mermaids in pools: Ex-situ conservation as a cornerstone for sirenian management worldwide

Castelblanco-Martínez D.N.; Ramos E.A.; Alvarez-Aleman A.; von Fersen L.; Amaral R.S.; Attademo F.L.N.; Borges J.C.G.; Cabrias-Contreras L.J.; Caicedo-Herrera D.; Calleson T.; Carvalho V.L.; Dávila-Peñaloza A.; Freire A.C.B.; García-Herrera J.L.; Gonzalez-Socoloske D.; Keith-Diagne L.; Landeo-Yauri S.S.; Luna F.; Llinás-Pizarro A.; Marmontel M.; Mello D.M.D.; Ortega-Argueta A.; Ross M.; Sánchez-Babilonia J.J.; Sánchez-Okrucky R.; Silva C.; Silva F.J.L.; da Silva V.M.F.; Souza D.A.; Vélez-Múnera M.; Walker P.; Mignucci-Giannoni A.A. · Journal for Nature Conservation (2026) · DOI: 10.1016/j.jnc.2025.127157

Resumen

Four extant sirenian species are currently recognized: the dugong (Dugong dugon), the African manatee (Trichechus senegalensis), the Amazonian manatee (T. inunguis), and the American manatee (T. manatus), the latter with two subspecies: the Florida manatee (T. m. latirostris) and the Greater Caribbean manatee (T. m. manatus). All the species are considered Endangered or Vulnerable globally mainly due to anthropogenic threats. For the first time, we assessed the status of the extant sirenian species living ex-situ at a global scale to estimate population structure, described facility and management types, and pinpointed challenges and opportunities for achieving effective species management. At the time of this analysis, 490 sirenians (42.2 % females, 45.7 % males and 12.0 % of unknown sex) were held at 71 facilities in 24 countries, most of them being American manatees (53.3 %), followed by Amazonian (37.9 %), and African manatees (7.7 %). This population also includes three dugongs and two wild-born hybrids T. manatus X T. inunguis. A significant number of manatees (61.2 %) are undergoing management for rehabilitation objectives, including a future release. However, an important proportion (38.7 %) have no release programs in place. Additionally, we estimated a population of 126 – 131 Greater Caribbean and Amazonian manatees currently isolated from wild populations in low-management or minimal-management settings. This study provides the most comprehensive inventory of sirenians currently living ex-situ. By defining their individual management plan, establishing minimum welfare standards, and implementing structured management practices, these individuals can play a critical role in raising awareness, advancing research, and supporting the conservation of wild populations of sirenians.